Japan's Hayabusa2 spacecraft returned spectacular images of a near-Earth asteroid following a super-close flyby on July 5, but heated debate was needed before teams signed off on the daring attempt.

When images of the asteroid Torifune arrived on the morning of July 6 Japan time, Makoto Yoshikawa and his team at the Japan Aerospace Exploration Agency (JAXA) got two surprises at once. Torifune turned out to be a contact binary, in which two chunks of rock have come together under gravity, and the returned images were also larger than hoped.

"We did not imagine such a contact binary," Yoshikawa, former mission manager of Hayabusa2, told scientists gathered at the Asteroids, Comets and Meteors conference in Poznan, Poland, on July 10. "Originally, we didn't think we could have such a very big image. Maybe we will take a very small one, but the image was much larger than we expected."

The double surprise was the payoff of months of debate between science and engineering teams, and a last-minute proposal that alarmed some of the scientists it was meant to serve. In the end, the flyby was so close as to be at the very edge of what the aging spacecraft was designed to conduct.

Hayabusa2 launched in December 2014 and rendezvoused with the asteroid Ryugu four years later. The spacecraft collected samples and delivered them to Earth in 2020, completing its primary objectives. JAXA then made plans for an asteroid flyby and a rendezvous with the tiny asteroid 1998 KY26 in 2031.

Usually for flybys, the closest distance is 100 kilometers (62 miles), Yoshikawa said, but in Hayabusa2's case this would not be close enough to gather good images. Hayabusa2 was designed for rendezvous and proximity operations, including hovering, correcting and landing — not for a high-speed pass at 5.3 kilometers per second (3.3 miles per second). Its cameras were also not designed for high-speed slewing.

According to Yoshikawa, science team members pushed back. At a distance of 100 kilometers, Hayabusa2's cameras would barely resolve the asteroid's global shape. Engineering responded with a proposal of 10 kilometers (6.2 miles). Science said that was acceptable, but the team kept pushing. Eventually, engineers confirmed they could get to within 1 kilometer (0.6 miles) of the asteroid's center. "Science people were very happy, because they could have a nice photo," Yoshikawa said.

Then, just one month before the flyby, extended mission team leader Yuya Mimasu proposed going even closer. "Yuya Mimasu said the closest distance should be 800 meters," Yoshikawa recounted. "Some science people said 'No, it's too dangerous,' and a very heated discussion started."

One major issue was the unknown size and dimensions of Torifune and the safety of the spacecraft. The team had assumed a worst-case asteroid size of 1,400 meters by 400 meters (4,600 by 1,300 feet) based on ground-based observations. A pass 800 meters (2,625 feet) from the center of the target would sit just outside that exclusion zone. The spacecraft's optics had also been affected by dust from sampling Ryugu. The final navigation analysis put the targeting error ellipse at around 200 meters (656 feet). "The distance fixed is 800 meters," Yoshikawa said, "but this is quite a big challenge for us."

Hayabusa2 detected Torifune on June 19. The spacecraft used ground-based guidance up to three hours before the flyby, before switching to onboard guidance. "This is quite new," Yoshikawa said. "We developed software for this, and we sent it to the spacecraft."

The result was the stunning, up-close imagery of the dual-lobed Torifune, captured by the probe's Optical Navigation Camera Telescope (ONC-T). But all four of Hayabusa2's science instruments returned data. The Thermal Infrared Imager (TIR) captured nine seconds of thermal imaging between 09:29:50 and 09:29:59 GMT on July 5, just a second before closest approach, independently confirming the contact binary structure in heat emission.

The Near Infrared Spectrometer (NIRS3) and laser altimeter (LIDAR) also got data, with the latter delivering what Yoshikawa described as possibly the first successful LIDAR ranging measurement during an asteroid flyby. But while the most urgent 25 MB of data was downlinked, teams will need to wait months for the rest of the 300 MB of total science data. Hayabusa2's ion engine system restarted on July 9 to begin the cruise toward two Earth flybys in 2027 and 2028 and will fire for around four months. Only after this can the rest of the data be sent to Earth.

Yoshikawa explained that the Torifune flyby was more than just a bonus milestone and photo and science op. The successful super-close flyby means that "JAXA has acquired the technology to collide spacecraft with a small celestial body," he said in his closing remarks at ACM, drawing a parallel to NASA's DART mission. "This flyby mission can be said to serve as a demonstration of the fast reconnaissance concept in planetary defense," verifying the ability to characterize an unknown asteroid rapidly — a capability that could provide crucial information ahead of an impactor mission.

This is not the end for Hayabusa2. The ultimate destination for the spacecraft's extended mission is the tiny asteroid 1998 KY26, a roughly 36-foot-wide (11 m), rapidly rotating rock with which it is scheduled to rendezvous in 2031.

China has announced that it wants to develop a "space-ground" asteroid early-warning network, while providing few details on what it could look like. But recent papers and presentations to the United Nations provide clues as to what the country has in mind for planetary defense.

The China National Space Administration (CNSA) made the announcement on June 30 — International Asteroid Day — stating plans to construct a coordinated ground-and-space monitoring system for near-Earth asteroids. Li Mingtao, chief scientist at CNSA's Asteroid Monitoring and Early Warning Research Center, told state media that China is studying the feasibility of an asteroid defense system, with the ground-space monitoring network as its core.

"No asteroid has so far been identified that will definitely collide with Earth in the foreseeable future, but concerns over impact risks are not unfounded. Many near-Earth asteroids remain undetected," the state-run media outlet Xinhua quoted Li as saying in a report by Science and Technology Daily.

Li added that China will deploy multiple large-aperture optical telescopes at carefully chosen sites in order to be able to survey the sky, while adding a space-based monitoring constellation, free from atmospheric disruption and day-night constraints, with a particular focus on threats from the sunward direction, which are, from the ground, lost in the glare of the sun. The meteor that exploded over Chelyabinsk, Russia, in 2013, approached roughly from a sunward direction and was only detected once it entered the atmosphere.

Li told Science and Technology Daily that more than 40,000 near-Earth asteroids have been discovered so far, including over 95% of asteroids at least 1 kilometer (0.6 miles) wide, which are capable of causing a globally catastrophic impact. However, only around 45% of asteroids in the 140-meter (460-foot) class have been detected, which are large enough to devastate a small country.

The June 30 reports and CNSA statements were vague on what China's actual plans for its monitoring network may be. However, recent journal papers and a 2025 presentation to the U.N.'s Committee on the Peaceful Uses of Outer Space (COPUOS) give more detail on the country's thinking.

For example, a paper published in the Journal of Deep Space Exploration in June 2026, co-authored by Wu Weiren, chief designer of China's lunar exploration program and a leading voice on the country's asteroid defense plans, lays out the options under study.

For the space-based component, the paper names four candidate orbital positions for a monitoring network: the Sun-Earth L1 Lagrange point, an Earth-leading or trailing orbit, a Venus-like heliocentric orbit, and an Earth-companion distant retrograde orbit (DRO). The paper also describes ongoing research into each option's monitoring effectiveness.

A similar outline was found in a 2025 technical presentation to COPUOS by Chinese researcher Chen Yongcai. A "basic model" would consist of a single satellite at Sun-Earth L1, an orbit about 1.5 million kilometers (930,000 miles) inside that of Earth, paired with northern and southern ground stations. An "extended model" includes spacecraft in the three additional orbits stated in the Wu Weiren paper. The Venus-like option in particular closely tracks an earlier proposal known as CROWN, a constellation of small satellites in Venus-like orbits designed to survey the sunward sky and use its favorable geometry to track other populations of near-Earth asteroids.

The status and timelines of these plans are unclear, but they do indicate a clear interest in and commitment to planetary defense by China. The country's 15th Five-Year Plan, approved in March, states that an asteroid defense engineering project is under study, while China is developing a kinetic-impact and observation demonstration mission, similar to NASA's DART mission and the European Space Agency's (ESA) follow-on Hera project, which is scheduled to launch in 2027.

While China's apparent plans are not unique, they could augment global efforts. Anne Virkki, an asteroid researcher at the University of Helsinki who's familiar with international monitoring efforts, noted that NASA and ESA have plans to send missions to Sun-Earth L1 to search for asteroids in infrared light — NEO Surveyor and NEOMIR respectively.

"If China launches a similar mission, hopefully it has some capability that the other two do not, and that it shares the data internationally and not only for Chinese scientists," Virkki said.

Virkki noted that asteroids approaching from the sun's direction aren't physically unusual, but they are simply harder to track, which statistically makes them more likely to produce a surprise. She also pointed to the persistent, less-discussed gap in radar tracking capacity. That capacity took a serious hit with the 2020 collapse of the Arecibo Observatory in Puerto Rico, with no U.S. successor in the works.

China has discussed building its own radar capability, which Virkki said would be a welcome addition, provided the data is shared openly. China has built the "China Compound Eye" or Fuyan project near Chongqing in the country's southwest, which can be used for near-Earth asteroid monitoring. Wu's paper also notes ground-based radar in the proposal for asteroid monitoring.

"Hopefully, as China's planetary defense plans become more specific, we'll see telescopes and space telescopes that complement the existing or planned capabilities of other countries, rather than repeat redundantly, and contribute data openly and collaboratively," Virkki said. She noted that there are likely about 100,000 near-Earth asteroids that could cause significant local damage if they hit Earth, and we know the orbits of less than half of all such space rocks.

2029 will mark the International Year of Planetary Defense, when the infamous asteroid Apophis will fly past the Earth just within the orbit of geostationary satellites. "There is a lot of work left to do, and international collaboration is crucial," said Virkki.

China's first-ever asteroid sampling mission has sent home a picture of its first target, the "quasi-moon" Kamo'oalewa.

The Tianwen-2 probe launched in 2025 and traveled 620 million miles (1 billion kilometers) to reach a safe distance about 12 miles (20 km) away from Kamo'oalewa, more formally known as asteroid 2016HO3. The spacecraft will spend nearly a year studying the asteroid with a suite of 11 different scientific instruments before attempting to collect a sample from its surface, which will be sent back to Earth.

The new photo was taken on July 2, according to China's Xinhua news outlet, and reveals the asteroid to be a small, asymmetrical rock measuring around 50–65 feet (16–20 meters) in diameter. While its origin isn't known, some scientists believe this quasi-moon could have been created when a massive impact knocked a chunk of our own moon into space between 1 million and 10 million years ago.

So-called quasi-moons (or quasi-satellites) are small bodies like Kamo'oalewa that circle the sun on orbits that keep them close to our planet. Earth has at least seven known quasi-satellites, and our planet's gravity will occasionally capture others temporarily before they are flung back out into orbit around the sun. In general, the orbits of these quasi-moons are less stable than the orbits of true moons.

Unlike most near-Earth asteroids that are thought to originate from the main asteroid belt between Mars and Jupiter, Kamo'oalewa could have come from much closer to home. A 2024 study published in Nature Astronomy proposes Kamo'oalewa could be material ejected from the moon by the impact that formed Giordano Bruno crater.

Sample of the asteroid collected by Tianwen-2 could help prove that hypothesis, if the mission is successful.

Tianwen-2 launched on May 28, 2025 atop a Long March 3B rocket from Xichang spaceport in southwestern China. The appearance of the spacecraft wasn't revealed until China's space agency released an image beamed home by Tianwen-2 when it was 1.8 million miles (3 million km) away from Earth. This occurred just over a week past launch.

While Tianwen-2 marks China's first asteroid sample attempt, Japan and the United States have already performed successful space-rock-sample missions of their own. Japan's Hayabusa spacecraft executed the world's first asteroid sample return mission when it sent material from asteroid 25143 Itokawa back to Earth in 2010.

The United States accomplished the feat in 2023 with the OSIRIS-REx mission that snagged material from asteroid Bennu. Those samples have already produced surprising scientific data, including the fact they contain the amino acids we consider vital for life here on Earth.

Tianwen-2 is China's first-ever mission to an asteroid and its second planetary exploration mission overall. Its first interplanetary endeavor, Tianwen-1, saw an orbiter and a rover reach Mars in 2020.

More Tianwen missions are in the works. China plans to launch the Tianwen-3 Mars sample-return mission in 2028 and Tianwen 4 two years later to study Jupiter and Uranus.

How do you stop a large, threatening asteroid on its way to Earth? A new Chinese paper, investigating the issue, suggests a "pre-excavation detonation" could be the solution if there's enough warning time.

There may be millions of asteroids in our solar system, with a tiny percentage of them posing a possible, very tiny threat to our planet. NASA and many other entities keep an eye on the skies, and continue discovering new asteroids, but have found no imminent threats yet; Apophis, previously believed to be a small threat during its 2068 flyby of Earth, has now been ruled out as a problem for the foreseeable future.

But Earth has been smacked by space rocks in the past, with even the moderate-sized Chelyabinsk incident of 2013 causing reported property damage near its blast site in Russia. And as the researchers of a new paper point out, asteroids tens of meters in size and larger have been tracked flying safely, but closely, by Earth.

Assuming a theoretical space rock is on an imminent collision course and exceeds about 330 feet (100 meters) in size, simply blasting it (or even guiding it away) may not be a viable option, the researchers said in a peer-reviewed study in the journal Space: Science and Technology.

"Traditional kinetic impact, or long‑term force deflection methods, offer limited energy and cannot achieve effective deflection within short timeframes," the researchers said in a press release, adding they found few comprehensive analyses of how to do so. (NASA did successfully deflect an asteroid moonlet's orbit with the DART spacecraft in 2022, for example, but that was a unique test case in space.)

So the team, led by Xiaowei Wang from the China Academy of Launch Vehicle Technology, instead proposed using one of two "defense modes" for large incoming asteroids.

The first mode is a more simple impact detonation — simply put, smacking the asteroid's surface to create a shallow crater, in which a nuclear device is exploded. The other mode is a "pre-excavation detonation", or using a penetration device to create a deeper crater before exploding a nuclear warhead to "achieve deep detonation" in the interior of the asteroid.

The researchers' modeling included the energy of a launch vehicle, the velocity of the impact spacecraft, and changes to the velocity of the asteroid, in each of these two modes. The two modes were also tested against a "virtual threat asteroid database" assuming warning times of anywhere between one year and 20 years.

All in all, assuming enough time is available, it seems the deep-crater method wins out. "The flyby pre-excavation detonation mode, due to its ability to autonomously select the cratering location and achieve deep detonation, offers stronger energy coupling," the researchers wrote in the press release.

Such an impact could "destroy" asteroids that are roughly 330 feet (100 meters) or of that range, and push away asteroids of a size reaching about 0.6 miles (1 km) by imparting a velocity change of roughly 1 m/s in about 60 days.

While a shallow-crater mission could be launched more quickly, the researchers added, "the impact location is random, energy coupling is weak, and requirements for the nuclear device's impact resistance and detonation timing are extremely stringent."

Real-world missions would also have to take into account the composition of an asteroid (as a pile of rubble would likely require a different approach than a solid rock), whether the pathways of any pieces generated by an impact pose a threat, and how to safely get the nuclear warhead into space in the first place, among many other technical issues. The researchers did not raise these considerations in the press release.

They did, however, provide "recommended solutions" for when to use each of the two options. The shallow impact might be preferable "for emergency defense" on a huge asteroid if there is an extremely short warning time, because that mission is less complex. Otherwise, the "deep impact" would be the way to go.

A Japanese spacecraft has gotten up close and personal with yet another asteroid, beaming home stunning new imagery of the distant space rock.

On Sunday (July 5), the Japan Aerospace Exploration Agency (JAXA)'s Hayabusa2 probe performed a close flyby of asteroid Torifune, a 1,475-foot (450-meter) space rock currently traveling through space some 62 million miles (100 million kilometers) from Earth. It was expected to be one of the closest-ever high-speed passes a spacecraft has had with an asteroid.

During the flyby, Hayabusa2 captured this breathtaking new image of Torifune using its optical camera, and was able to transmit it back to JAXA controllers. The probe captured additional scientific data about the asteroid, but will beam those results home at a later date, according to JAXA.

Hayabusa2 also imaged asteroid Torifune using its Mid-Infrared Camera (TIR), which allows scientists to measure asteroids' surface temperatures, thermal inertia and surface roughness, according to JAXA. This mid-infrared image reveals Torifune to be much cooler in what appear to be shadowed regions seen in the optical image, and much warmer where the surface faces the sun.

Torifune orbits the sun every 383 days and rotates every 5 hours. It belongs to the Apollo group, a classification of near-Earth asteroids whose orbits cross Earth's as they make their way around the sun.

Hayabusa2's flyby of Torifune was not part of its original mission, and one of the members of the probe's scientific team previously told Space.com the flyby was a "risky operation" due to the unknowns surrounding the asteroid.

These new images add to the growing list of incredible accomplishments the Hayabusa2 probe has notched on its now nearly 12-year mission.

Hayabusa2 launched in December 2014 on an ambitious mission to collect asteroid samples and return them back to Earth. The probe did just that in December 2020 when JAXA successfully landed samples of asteroid Ryugu in the Australian desert.

Since then, scientists have used the samples to peer back in cosmic time at the history of our solar system and have even discovered that Ryugu contains all five nucleobases found within DNA and RNA.

After collecting its precious samples, Hayabusa2 left Ryugu in 2019. It's ultimate goal is now to flyby asteroid 1998 KY26, which could become the smallest asteroid ever visited by a spacecraft. 1998 KY26 is just 36 feet (11 meters) across, close to the size of the asteroid that exploded above Chelyabinsk, Russia in 2013.

Hayabusa2 is expected to reach 1998 KY26 in the year 2031. Once there, the probe will orbit the space rock before attempting to touch down on its surface. JAXA hopes the mission will help scientists more about the structure and composition of small asteroids.

A new approach that riffs on the classic Traveling Salesperson problem could enable more efficient space missions to multiple objects that are in motion — like asteroids.

The researchers behind the fascinating solution to the problem are Isaac Rudich of the Department of Mathematical and Industrial Engineering at Polytechnique Montréal in Canada and Michael Römer, who is a decision analyst from the Faculty of Business Administration and Economics at Universität Bielefeld in Germany. "Our research is foundational, in the sense that it develops mathematical machinery that can be used by space agencies to plan missions," the duo told Space.com.

The Traveling Salesperson problem is a mathematical approach to determining the shortest route for visiting multiple destinations before returning to the point of origin. That's fine when you're a double glazing salesperson visiting a dozen stationary towns and cities, but how do you calculate the optimal route when your destinations are perpetually in motion?

This is the problem faced by spacecraft that are on a mission to visit multiple celestial objects. Sometimes the decision is obvious, necessitated by the availability of gravitational slingshots from planets, as illustrated by the Voyager 1 and Voyager 2 missions.

However, a mission that skips from one asteroid to the next, relying on fuel stored on board rather than gravitational slingshots, is more problematic. The asteroids are constantly moving in their orbits and the distances between the asteroids, and therefore the travel time, are not static.

This seemingly intransigent problem now has a solution, thanks to a team led by Rudich and Römer.

They reframed the puzzle as the "Asteroid Routing Problem," or ARP, which asks the question: In what order should a spacecraft visit multiple asteroids if both travel time and fuel consumption are to be minimized? To do so, the optimal departure time and trajectory between each pair of objects has to be calculated.

"The ARP is particularly challenging because determining the exact cost and travel time requires solving another challenging optimization problem, which is Lambert’s problem," said Römer and Rudich.

Lambert's problem was first posed all the way back in the 1700s by the Swiss polymath Johann Heinrich Lambert, who pondered how to find the optimal trajectory between two moving objects. The problem was solved mathematically later that century by Joseph-Louis Lagrange — yes, of Lagrange point fame.

Solving Lambert's problem for two objects is one thing, but when many more objects — or in this case, asteroids — are involved, it very quickly becomes computational complex because the calculation must be conducted for every possible route between every possible pair of objects.

To get around this, Rudich and Römer's team employed something called Decision Diagrams. These are a variation on Decision Trees, which map a decision problem to a graph by listing each possible set of decisions as a path on that graph, all starting from the same root, or origin. In a Decision Diagram, all the various choices that lead to the same destination in time and space are represented as a single node on the graph, making things simpler and reducing the amount of times Lambert's problem has to be solved.

"Our approach typically achieves solutions that are about 20% better than those using standard approaches, and solutions up to 20% better for larger problems," said Rudich and Römer. That percentage is a combination of total travel time and fuel consumption.

There aren't many missions that visit multiple asteroids. NASA's Dawn mission visited both Ceres and Vesta, while the Lucy mission is currently on its way to Jupiter, via the Asteroid Belt, to explore the Jovian Trojan asteroids. Lucy has flown relatively near several asteroids in the asteroid belt and will pay visits to five Trojan asteroids.

Employing their mathematical approach to see how optimal Lucy’s mission plan is “would certainly be interesting,” said Rudich and Römer, but they emphasize that the ARP is a very stylized, almost synthetic, problem that considers some, but not all, aspects of astrodynamics.

"To precisely model a real-world mission would probably require the consideration of a lot of additional aspects," they said.

However, even if it could just bring about a 1% improvement, it would still represent a substantial saving of time, money and fuel. Their research could also be applied to terrestrial problems, such as bus routes, supply chains and shipping routes, where variable weather and traffic congestion provide the dynamic properties rather than moving destinations.

The research was published on April 2 in the INFORMS Journal on Computing.

NASA's Psyche spacecraft flew by Mars on Friday (May 15), diving closer to the Red Planet than either of its tiny moons. But the precisely timed maneuver was not designed to study Mars,

Instead, the Psyche spacecraft zipped by Mars to use the planet as a celestial slingshot on its journey to its namesake, the metal-rich asteroid Psyche.The spacecraft passed within about 2,800 miles (4,500 kilometers) of Mars, which had appeared steadily larger and brighter in Psyche's view since early May.

On Friday, Psyche hurtled past the planet at roughly 12,333 mph (19,848 kph), according to NASA. The flyby boosted Psyche's speed and, more importantly, shifted its trajectory toward its destination, the asteroid 16 Psyche, which orbits the sun between Mars and Jupiter.

Scientists believe the 173-mile-wide (280 km) space rock may be the exposed metallic core of a shattered protoplanet — a primordial building block of the rocky worlds whose outer crust and mantle were likely stripped away in catastrophic collisions billions of years ago. If so, the mission could offer humanity its first direct glimpse of material normally buried deep inside planets like Earth.

A Mars assist

Friday's flyby marked one of the mission's most important milestones, conserving precious fuel while placing the spacecraft on course to reach the asteroid in 2029.

The maneuver was an example of one of the most important techniques in modern spaceflight known as the gravity assist. By carefully flying past a moving planet, spacecraft can gain speed, alter direction and conserve propellant, allowing missions to travel farther and faster than rockets alone would permit.

The concept can seem almost counterintuitive, as though spacecraft are somehow getting energy for free. A spacecraft accelerates as it falls toward a planet, then slows again while climbing back out of the planet's gravity well. Intuitively, those gains and losses should cancel each other out.

What makes the maneuver possible, however, is not simply the planet's gravity, but the planet's own motion around the sun.

Mars is hurtling through space carrying enormous momentum as it orbits the sun. By approaching the planet at a carefully calculated angle and departing in another, Psyche effectively stole a tiny fraction of that orbital energy.

The exchange follows Newton's Third Law — every action has an equal and opposite reaction — as the spacecraft gains momentum by borrowing an infinitesimally small amount from Mars, a transfer imperceptible to the planet but transformative for the mission.

"It's smart, it's cheap, and it's phenomenally clever … it's a bit like interplanetary billiards," Shadan Ardalan, a NASA scientist who was involved with the agency's Juno mission to Jupiter, previously told Space.com.

Gravity assists have long been used to explore humanity's cosmic backyard. The technique dates back to the dawn of the Space Age in 1959, when the Soviet spacecraft Luna 3 used the moon's gravity to swing behind it and photograph the lunar far side for the first time.

Many of humanity's most ambitious robotic missions would also have been impossible without such maneuvers. NASA's Voyager probes famously used a once-every-176-years alignment of the outer planets in the late 1970s to slingshot from Jupiter to Saturn, with Voyager 2 continuing onward to Uranus and Neptune in a historic grand tour of the outer solar system. Cassini relied on gravity assists with Earth, Venus and Jupiter to build up the speed needed to reach Saturn, while New Horizons swung past Jupiter to shave a few years off its journey to Pluto.

Most recently, NASA's historic Artemis 2 mission adopted a similar principle, following a “free-return” trajectory that used the moon's gravity to arc the crew of four back toward Earth without requiring major engine burns after looping around the lunar far side.

On to the asteroid belt

On Friday, the Mars encounter gave Psyche the equivalent of roughly a 2-kilometer-per-second change in velocity relative to the sun, according to a paper published in October detailing the maneuver.

Psyche uses solar-electric propulsion, relying on its solar panels to convert sunlight into electricity and slowly push the spacecraft forward by releasing charged xenon gas. The system is highly efficient, but it generates only a small amount of thrust over long periods of time.

Achieving the same boost in speed and shift in trajectory using propulsion alone would have been extraordinarily expensive and likely impractical, requiring enormous amounts of propellant — more than the spacecraft could realistically carry — while also adding weight and dramatically increasing launch costs.

The Mars flyby allowed the spacecraft to use the planet's gravity to do much of the work instead, saving fuel for the rest of the journey.

Like a baseball launched off a bat, Psyche now leaves Mars carrying new momentum and a reshaped trajectory, bound for a metallic world that may reveal what lies hidden inside planets themselves. It should arrive at asteroid 16 Psyche in July 2029.

NASA's asteroid-bound Psyche mission is headed for an encounter with Mars today (May 15). The spacecraft, which is on its way to an asteroid also called Psyche, will come within around 2,800 miles (4,500 kilometers) of the Red Planet during the flyby.

This flyby aims to utilize the gravity of Mars to give Psyche a boost to its already impressive speed of 12,333 miles per hour (19,848 kph). This will enable the spacecraft to adjust its trajectory towards the 173-mile-wide (280 km) metal-rich asteroid 16 Psyche (or just Psyche), which sits in the main asteroid belt between Mars and Jupiter.

The Psyche spacecraft, which launched in October 2023, is expected to reach its target namesake asteroid in 2029, offering scientists an opportunity to study a very unique object. 16 Psyche is thought to be an early solar system planetesimal, a body from which planets formed, that has had its outer layers stripped away by billions of years of collisions. Thus, its exposed nickel-iron core represents a rare chance to study the usually hidden cores of rocky planets.

But the Psyche spacecraft won't just use the gravity of Mars to get a boost that will help it save its xenon gas propellant; the Red Planet flyby will also offer Psyche a chance to test and calibrate the instruments it will be using when it gets to the main asteroid belt.

In order to do that, Psyche's multispectral imager will be used to capture thousands of observations of Mars. This process began earlier this month.

Psyche's operators first began prepping the spacecraft's Mars encounter by performing a trajectory correction maneuver on Feb. 23. This involved firing the spacecraft’s thrusters for 12 hours, increasing Psyche's speed, and refining its approach to the Red Planet.

"We are now exactly on target for the flyby, and we’ve programmed the flight computer with everything that the spacecraft will do throughout May," Sarah Bairstow, Psyche's mission planning lead at NASA's Jet Propulsion Laboratory in Southern California, said in a NASA statement. "This is our first opportunity in flight to calibrate Psyche's imager with something bigger than a few pixels, and we'll also make observations with the mission's other science instruments."

The team thinks that the Psyche probe may observe a faint dusty ring, or torus, around Mars, which is thought to exist as a result of tiny space rocks, or "micrometeorites," striking the surfaces of the planet's two moons, Phobos and Deimos, and ejecting dust particles into space.

The alignment between the sun, Psyche, and Mars could result in this dusty material scattering sunlight, making it visible to the spacecraft's instruments.

The team will also use Psyche to search for tiny satellites around Mars, a practice that will benefit the mission when the spacecraft hunts for "moonlets" around Psyche when it arrives at the asteroid in three years or so.

"If all our instruments are powered up, and we can do important testing and calibration of the science instruments, that would be the icing on the cake," said Lindy Elkins-Tanton, principal investigator for Psyche at the University of California, Berkeley.

COLORADO SPRINGS, Colorado — Asteroid Apophis is set to whisk by Earth in 2029 and serve as a wake-up call for getting our planetary defense act together.

Astronomers have shown that the huge chunk of extraterrestrial real estate will not hit Earth in 2029, but will come closer to Earth than our geostationary communications satellites. Radar measurements estimate Apophis is roughly 1,500 feet (450 meters) wide and some 550 feet (170 meters) tall. The April 13, 2029 (conveniently Friday the 13th) Apophis passage will be visible to the naked eye and is stirring up considerable multi-nation action plans to spy on the asteroid at various stages as it careens toward Earth, helping scientists plan for possible planetary defense scenarios.

Now, Southern California-based startup Exploration Labs' (ExLabs) has proposed what it bills as the first commercial deep space ride share mission, known as Apophis EX. At the Space Foundation's 41st Space Symposium this year, held April 13-16, ExLabs says the mission aims to rendezvous with asteroid Apophis before and after its 2029 Earth flyby and deliver unparalleled scientific data for planetary defense, resource prospecting and future deep-space exploration.

Commercially driven

Today, reaching beyond Earth orbit requires billion-dollar budgets, not to mention decade-long timelines. ExLabs, they say, wants to change that. "We're building the systems that turn bespoke missions into persistent, repeatable infrastructure — open for science, exploration, and commerce," the group's website declares.

James Orsulak is co-founder of ExLabs and is chairman of the Planetary Defense Trust. The company's objective is to study near-Earth asteroid dynamics, refine impact risk models, and appraise deflection strategies to guard Earth from incoming threats.

Orsulak said that Apophis EX is the first mission of its kind, kick-starting the beginning of a new era, one that heralds deep space exploration that is "consistent, collaborative, and commercially driven," while elevating planetary defense "from a niche discipline to a global priority" and underscores the importance of coordinated planetary defense strategies.

"NASA's planetary defense budget is less than one percent of the total space agency," Orsulak told Space.com. "That's not enough to ever do anything."

Prime-time

Orsulak and ExLabs is keen on branding the Apophis flyby by engaging IMAX and others to tell the story in a live, prime-time and captivating way. "We could get a higher viewership than the Super Bowl," he said.

So far, the story behind planetary defense leaves much to be desired, Orsulak said. Movies like Armageddon and Deep Impact have wetted the public's appetite for the ins and outs of planetary defense.

"It's time to tell the truth of science fiction becoming science fact," said Orsulak.

Orsulak chaired a blue-ribbon panel of experts during the symposium to tackle the "State of Planetary Defense, Protecting Earth and Building Repeatable Deep Space Mission Capability."

What's working, what's missing?

The focus of the panel: today's planetary defense readiness, what's working, what's missing, and how industry will coordinate to close the gap?

Moreover, the panel addressed a shift to the next era consisting of new partnerships and mission models that enable repeatable asteroid missions and sustained deep-space science programs.

"You want the government to be one customer of many customers for a very robust commercial marketplace," said Jim Bridenstine, former NASA Administrator and now managing director of the Artemis Group.

"Driving down the cost and increasing the access. You want those providers competing against each other on cost and innovation, so we get the best results for the taxpayer," Bridenstine told the invited guests. "That model has been very successful in a whole lot of ways from a NASA perspective. These are new models that can apply to planetary defense."

Bring down the risk

David Bearden, manager of the Office of Strategic Planning at the Jet Propulsion Laboratory, said in his personal view, there's a need to bring down the risk and maximize the opportunity.

On the planetary defense table are a wide variety of asteroid deflection methods, from gravity tractors, ion beams, kinetic and nuclear detonations and other concepts. "We need to learn about these techniques. Do they work …when do they work?" Bearden asked.

Edward Lu, former NASA astronaut and now head of the Asteroid Institute and co-founder of the B612 Foundation, said there's not just one best asteroid deflection technology.

"You've got to get that out of your mind," Lu said. It's a multiple step process, he noted, a need to fine-tune and verify what matches the situation.

Pace of change

Lu said that with a high flight rate "you get safety, reliability…because you know what works, what doesn't work and you get cost reduction. Those are the things we need," he advised. "This is going to be what makes the Earth secure, the industrial capacity to call up a launch, tomorrow or the next week."

Lu told Space.com that things are happening on the private side and they are happening fast.

"The pace of change is mind-boggling, the capacity of building things quickly. We are getting to the point where we can build a spacecraft in a year. That's quite doable," Lu concluded.

We are now in the home stretch in the nearly four-month saga of Comet C/2026 A1 (MAPS). This is the make-or-break week for this object as it heads for its long-awaited rendezvous with the sun this weekend.

The comet was discovered on Jan. 13, 2026, by a team of four amateur astronomers. "MAPS" is an acronym using the first letters of the surnames of the discoverers: Alain Maury, Georges Attard, Daniel Parrott, and Florian Signoret. They found the comet using a remotely operated 11-inch telescope at the AMACS1 observatory in Chile's Atacama Desert. What makes this discovery special is that Comet MAPS belongs to a special class of comets known as Kreutz sungrazers.

All Kreutz sungrazers are named after the 19th-century German astronomer Heinrich Kreutz, who first showed that such comets are related. The progenitor of this family is thought to be the fragmentation of a large sungrazing comet described by the ancient Greek philosopher Aristotle in 371 BC. This has spawned subsequent breakups, most notably in 1106 AD. A recent paper suggests that Comet MAPS is a fragment of a bright comet that was described by the historian Ammianus Marcellinus in 363 AD. But that comet may itself have been an original remnant that broke off from Aristotle's Comet.

A date with destiny

Saturday, April 4, is the day of Comet MAPS perihelion — when it will make its closest approach to the sun. Based on updated orbital elements published on the Central Bureau for Astronomical Telegrams (CBAT) Circular#5675, Comet MAPS will pass within 101,100 miles (162,700 km) above the sun's surface (the photosphere) at 10:24 a.m. EDT (1424 GMT, 7:24 a.m. PDT). The comet will then be in the midst of completing a hairpin-curved path around the sun, racing at a speed of 322 miles (518 km) per second.

Will it be visible?

It is also possible that the comet may become extremely bright around this time, possibly even bright enough to glimpse in the daytime, though the very close proximity to the sun in the sky makes this an extremely dangerous proposition. Indeed, the sun's infrared rays can burn the retina of the eye and cause irreparable damage, all without causing any pain and neither sunglasses, telescopes, nor binoculars will protect against the type of eye damage that could ultimately result in blindness, when a person — however briefly — accidentally looks directly into the sun's rays.

To get a good (and safe) view of Comet MAPS as it approaches and then sweeps rapidly around the sun, reserve a seat next to your computer and stay tuned to SOHO's LASCO (Large Angle and Spectrometric Coronagraph Experiment) C3 camera, by accessing either its near-live images or videos that span the past 24 hours.

Comet MAPS will be within range of the LASCO C3 imagery from April 2 at 8:00 a.m. EDT (1200 GMT) through April 6 at 1:00 a.m. EDT (0500 GMT). During a roughly four-hour timespan centered on the time of perihelion on April 4, the comet will appear to pass behind the sun as seen from our earthly perspective, then rapidly swing around and cross in front of the sun.

Sizzler or fizzler?

There has been much talk on social media of late, concerning whether Comet MAPS will put on a spectacular visual show for naked-eye observers after it sweeps around the sun. Since some of the brightest comets in history have belonged to the Kreutz sungrazing family, hopes have been running high that a celestial showpiece will soon adorn our western evening sky. Some have already christened Comet MAPS as "The Great Easter Comet of 2026."

But will all this actually come to pass?

As it stands now, there appear to be three possible options for Comet MAPS:

Option 1: It disintegrates at or just prior to perihelion

In this situation, as the comet is reaching its closest point to the sun, its nucleus, being subjected to intense solar heating and tidal stresses caused by the sun's gravity, completely disintegrates. Upon swinging around the sun, nothing is left to be seen.

Just such a scenario took place in November 2013 with Comet ISON. Although not a member of the Kreutz sun grazing family, Comet ISON still passed to within 724,000 miles (1.16 million km) of the sun's surface. It was highly touted to become a brilliant naked-eye object, but instead, suffered a significant disruption about a week prior to perihelion and almost completely broke up when it made its closest pass to the sun, save for a single small fragment, which had somehow survived and itself disintegrated several days later.

Option 2: It disintegrates after perihelion

Following along this script, the comet arrives at perihelion, then rapidly swings around the sun and back out into space seemingly intact. But shortly thereafter, its nucleus fragments and quickly disintegrates.

An excellent example of this was the so-called Great Southern Comet of 1887; a member of the Kreutz family. It apparently passed to within just 17,000 miles (27,000 km) of the sun's surface. In the days immediately following its mid-January perihelion, its head was described as a diffused nebulous mass, but far more noteworthy was its tail, described as a pale narrow ribbon of light. In comet annals, the 1887 comet became known as "The Headless Wonder." Another Kreutz comet was Comet Lovejoy in December 2011, which swept to within 87,000 miles (140,000 km) of the sun's surface. It seemingly emerged intact and put on a fine showing in the pre-Christmas southern morning skies, but several days after perihelion, its nucleus subsequently underwent a cataclysmic fragmentation, and it faded very rapidly thereafter. One Australian observer commented that the most striking feature of Comet Lovejoy was the extreme straightness of its 30-degree tail, but the head was "virtually nonexistent." Another headless wonder!

Option 3. It survives perihelion

In this possible eventuality, the comet sweeps around the sun and puts on a spectacular show as it moves back out into space.

For this case, we can cite "The Great Comet of 1965," Ikeya-Seki, which was the most brilliant comet of the 20th century. It attained a magnitude of at least -10 (as bright as a half-moon) and was readily visible next to the sun during the daytime. This comet was another member of the Kreutz sungrazers, passing within 280,000 miles (450,000 km) of the solar surface, with its nucleus seen breaking into three separate pieces. Nonetheless, in late October, it spawned a bright and slender curved tail, about the length of the handle of the Big Dipper, appearing above the southeast horizon a couple of hours before the sun.

Breaking up is not so hard to do

The important factor to note is that the one thing that ties all three options together is that in every case, the comet nucleus ended up breaking up, the obvious result of being exposed to the sun's intense heat as well as its massive gravitational force, pulling on the nucleus and ripping it apart.

Ultimately, this will likely be the fate of Comet MAPS.

Size matters

But which of the three options will Comet MAPS fall into? A major component to consider is the size of the nucleus. In the case of Comet Ikeya-Seki, it is believed that its mean diameter was about 5.4 miles (8.7 km).

The other comets we spoke of, however, were likely much smaller.

The diameter of the Great Southern Comet of 1887's shattered nucleus is believed to have been 1.5 miles (2.4 km). Comet ISON was estimated to be only 0.9 miles (1.4 km) wide, while Comet Lovejoy's nucleus may have been no more than a mere 0.3 miles (0.5 km) across. In a recent technical paper published in March by the American Astronomical Society (AAS), an analysis of images taken with the James Webb Space Telescope suggests that the nucleus of Comet MAPS appears to be — relatively speaking — quite puny, on the order of no more than 0.2 miles (0.4 km) in diameter.

The AAS paper thus concludes that, like Comet ISON, from thirteen years ago, the nucleus of Comet MAPS could be spun apart by outgassing torques (twisting forces that tends to cause rotation), causing it to disrupt before perihelion, ". . . in which case," note the authors, "its scattered debris would likely be thoroughly destroyed by the sungrazing encounter, leaving no observable remnant afterward."

That certainly does not bode well for a bright sky show.

Tail wags the comet?

So right now, assuming that the nucleus of Comet MAPS totally disintegrates prior to, or shortly after its closest approach to the sun, suggests that either we will see nothing emerge into the western evening sky during the second week of April, or . . . as was the case with the Great Southern Comet of 1887 and Comet Lovejoy in 2011, only the dusty residual appendage of a tail protruding up from the western horizon will be seen, with no noticeable head or coma.

Indeed, in the end, the tail might be all that is left to be seen of Comet MAPS.

Prospective comet watchers should keep watch of that part of the sky near the western horizon between 45 minutes and one hour after sunset during the April 8 to April 14 time frame. Sweeping the sky with binoculars could be beneficial in picking up the tail of Comet MAPS against the bright twilit sky glow. Of course, there is also a chance — albeit small — for a pleasant surprise, for comets tend to fickle and it seems that the only thing that is predictable about them is their unpredictability.

Or as renowned Canadian astronomer David Levy, himself a discoverer of 23 comets, has famously noted: "Comets are like cats: they have tails, and they do precisely what they want!"

We here at Space.com will continue to keep you posted on all the late-breaking developments regarding Comet MAPS, so stay tuned!

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for Natural History magazine, Sky and Telescope, The Old Farmer's Almanac and other publications.

Scientists analyzing images from NASA's Double Asteroid Redirection Test (DART) mission have found the first visual evidence that small asteroids exchange rocks and dust in a slow process that reshapes their surfaces over millions of years.

Images captured in late 2022 by the DART spacecraft — an experiment that tested asteroid-deflection technology — moments before it deliberately struck the asteroid moon Dimorphos revealed faint, fan-shaped streaks across its rocky surface, according to a new study.

Researchers say the streaks were likely formed by debris spun off from Dimorphos' binary companion, Didymos, that drifted between the two bodies and landed in slow-motion impacts.

"At first, we thought something was wrong with the camera, and then we thought it could've been something wrong with our image processing," study lead author Jessica Sunshine, of the University of Maryland, said in a statement.

However, further analysis showed the streaks were consistent with gentle, low-speed impacts from material drifting through space, "like throwing 'cosmic snowballs,'" Sunshine said.

"We had the first direct proof for recent material transport in a binary asteroid system."

The findings, described in a paper published March 6 in The Planetary Science Journal, come as another team of scientists confirmed DART not only altered Dimorphos' orbit around its companion asteroid but also slightly changed the entire binary system's orbit around the sun.

The shift in the system's orbital speed was about 11.7 microns per second, or roughly 1.7 inches per hour, researchers reported in a different paper published March 6 in the journal Science Advances.

"Over time, such a small change in an asteroid's motion can make the difference between a hazardous object hitting or missing our planet," Rahil Makadia, a planetary defense researcher at the University of Illinois Urbana-Champaign, who led the Science Advances paper, said in a separate statement.

About 15% of near-Earth asteroids are estimated to be binary systems, in which a smaller asteroid orbits a larger companion. These systems can host surprisingly complex processes, in part because sunlight can gradually speed up the rotation of small asteroids until loose material breaks free from their surfaces.

This phenomenon, known as the YORP effect, occurs when an asteroid absorbs sunlight and re-emits that energy as thermal radiation, creating a tiny but continuous thrust that can slowly spin the space rock faster.

Evidence of this process has been seen elsewhere in the solar system. Observations by NASA's Lucy spacecraft, for example, revealed ridges around the equators of the asteroid Dinkinesh and its moon Selam — features scientists believe formed as material migrated and accumulated during such spin-ups. Similar ridges appear along the equators of Dimorphos and Didymos, likely formed by material shed from the spinning asteroids that later settled back onto their surfaces.

In the new study, Sunshine and her team identified the fan-shaped streaks by developing sophisticated image-processing techniques to remove shadows cast by boulders and correct for uneven lighting across the surface, the statement said.

"As we refined our 3D model of the moon, the fan-shaped streaks became clearer, not fainter," study co-author Tony Farnham, a research scientist at the University of Maryland, said in the statement. "It confirmed to us that we were working with something real."

The team found that debris left Didymos at about 30.7 centimeters (12.1 inches) per second — so slowly that the impacts would create deposits rather than craters. The streaks are also clustered around the moon's equator, matching models predicting where the material spun off from Didymos would most likely land, scientists say.

Scientists are eager to see what the transformed Dimorphos now looks like up close. That opportunity may come as soon as this December, when the European Space Agency's Hera spacecraft arrives at the Dimorphos-Didymos system.

The $398 million Hera mission will conduct a detailed post-impact survey of Dimorphos and could reveal whether the fan-shaped streaks survived the collision, researchers say. It may also detect new ray-like patterns created by boulders that were knocked loose during the impact, offering new clues about how asteroids evolve and which ones could pose a threat to Earth.

"These new details emerging from this research are crucial to our understanding of near-Earth asteroids and how they evolve," Sunshine said in the statement. "We now know that they're far more dynamic than previously believed, which will help us improve our models and our planetary defense measures."

In 2022, NASA's Double Asteroid Redirection Test (DART) mission deliberately slammed into the asteroid Dimorphos, which orbits a larger asteroid named Didymos. Now, scientists have confirmed that not only did DART alter Dimorphos' orbit around its binary companion, but it also altered the whole binary system's orbit around the sun.

"The change in the binary system's orbital speed was about 11.7 microns per second, or 1.7 inches per hour," said Rahil Makadia of the University of Illinois Urbana-Champaign in a statement. "Over time, such a small change in an asteroid's motion can make the difference between a hazardous object hitting or missing our planet."

The objective of DART was to see whether a kinetic impactor — in this case, the DART spacecraft — could deflect an asteroid and prove that if a similarly sized asteroid were on a collision course with Earth, we could knock it out of the way.

The Didymos–Dimorphos double asteroid system was a safe place to practice this. Didymos is the larger asteroid, about 2,788 feet (850 meters) across, and the smaller 560-foot (170-meter) asteroid Dimorphos orbits around Didymos. Because astronomers had previously measured Dimorphos' orbital period and radius precisely, any deflection caused by the impact would be clear to measure as well. Plus, because Dimorphos is gravitationally bound to Didymos, the DART impact could not inadvertently knock it towards Earth.

The DART impact took place on September 26, 2022, with the spacecraft impacting at 4 miles (6.6 kilometers) per second. It knocked Dimorphos enough that its orbital period around Didymos shortened from 11 hours and 55 minutes to 11 hours and 23 minutes. Prior to impact, the aim had been to shove Dimorphos such that its orbital period reduced by a minimum of just 73 seconds, meaning the mission was a tremendous success.

New analysis of the data, led by Makadia and Steve Chesley of NASA's Jet Propulsion Laboratory (JPL), has shown that DART's effort to push Dimorphos received a helping hand from the cloud of debris, called ejecta, that it sprayed into space as it excavated a fresh new crater.

As this ejecta cloud raced away from Dimorphos, it also carried away momentum. And, as momentum is always conserved, this gave Dimorphos an added push. Scientists call this extra push the "momentum enhancement factor," and in the case of Dimorphos and the DART impact, the momentum enhancement factor had a value of two. This means that the loss of the ejecta doubled the thrust imparted on Dimorphos by the initial DART impact.

Because Dimorphos and Didymos are connected by the invisible ties of gravity, this extra push pulled both Dimorphos and Didymos off course in their orbit around the sun, changing their orbital period by 0.15 seconds.

This may not sound much, but as Makadia alludes to, it would be sufficient to push a hazardous asteroid away from Earth (so long as the asteroid is discovered in time).

To this end, NASA intends to launch a new space telescope called the Near-Earth Object (NEO) Surveyor sometime after September 2027. NEO Surveyor's mission will be to find as many of the remaining undiscovered asteroids close to Earth's orbital path as it can.

Determining the change in Didymos and Dimorphos' orbit around the sun was a labor of love, particularly for the 49 amateur astronomers who traveled to the ends of the Earth looking for stellar occultations.

A stellar occultation is when an object passes in front of a star from our point of view. When an asteroid occults a star, we can learn about the asteroid's shape, size, position and trajectory.

Stellar occultations are, alas, difficult to observe — they can only be seen from random narrow tracks across the surface of the Earth. However, thanks to the amateur astronomers who made journeys across the globe between October 2022 and March 2025 to witness 22 stellar occultations by the Didymos–Dimorphos system, Makadia and Chesley's team were able to calculate the change in the binary system's orbit around the sun.

"When combined with years of existing ground-based observations, these stellar occultation observations became key in helping us calculate how DART had changed Didymos' orbit," said Chesley. "This work is highly weather dependent and often requires travel to remote regions with no guarantee of success. This result would not have been possible without the dedication of dozens of volunteer occultation observers around the world."

Based on the orbital changes, it was also possible to calculate the densities of the two asteroids. Didymos has a density of 2,600 kilograms per cubic meter, while Dimorphos is less dense than thought, at 1,540 kg per cubic meter/, which makes it something of a loosely held together rubble pile. This supports the hypothesis that Dimorphos formed from material that was once upon a time spun-off from Didymos.

These latest findings from the DART mission were published on March 6 in the journal Science Advances.

NASA's Psyche spacecraft, which is headed toward a big and bizarre metal asteroid, has delivered a stunning perspective of our home planet from deep space.

Psyche launched atop a SpaceX Falcon Heavy rocket in October 2023 with the objective of visiting the metallic asteroid 16 Psyche, which is believed to be the exposed core of a demolished planetesimal, or tiny planet.

This past July, as part of periodic testing and calibration of Psyche's science instruments during its cruise phase, the probe's team had it look back at Earth, which was then around 180 million miles (290 kilometers) away.

The result of long-exposure shots taken on July 20 and July 23 is a thought-provoking image of Earth and the moon amid a stellar backdrop, providing a rare perspective of the Earth's place in space. The brightness of Earth and moon comes from reflected sunlight, set among stars belonging to the constellation Aries.

The image demonstrates the performance of the spacecraft's twin cameras. Its multispectral imager is designed to detect different wavelengths of light, as the spectral signatures from light that reflects off 16 Psyche can be used to learn about the asteroid's composition. For last month's imaging test, Earth and the moon, shining with reflected sunlight, provided a useful target, but the team may choose more distant objects in the future.

"After this, we may look at Saturn or [the huge asteroid] Vesta to help us continue to test the imagers," Jim Bell, the Psyche imager instrument lead at Arizona State University in Tempe, said in a statement. The imager has previously also been trained on Jupiter and Mars.

"We're sort of collecting solar system 'trading cards' from these different bodies and running them through our calibration pipeline to make sure we're getting the right answers," Bell said.

Psyche is currently on its way to Mars, and will use the Red Planet for a gravitational slingshot maneuver in spring 2026 to send it toward 16 Psyche. If all goes well, the probe will arrive at the metallic asteroid in 2029.

Once feared as a threat to Earth, the asteroid Apophis is now considered to pose a rare exploration opportunity — if space agencies can act in time.

The 1,100-foot-wide (340 meters) Apophis, also known as asteroid 99942, is set to make a very close, but safe, flyby of Earth on April 13, 2029. The European Space Agency (ESA) is preparing its Ramses (Rapid Apophis Mission for Space Safety) mission for a 2028 launch in order to accompany the rocky body during its close approach.

Ramses aims to conduct a before-and-after-flyby analysis of the asteroid and features such as its surface characteristics, composition, orbit and more. Apophis' gravitational interaction with Earth is expected to trigger tidal forces in the asteroid, potentially altering its surface and interior. Understanding how Apophis is affected will bring valuable insights for international planetary defense efforts.

And now, ESA plans to add a second cubesat to the mission, to attempt a landing on Apophis. It has selected the Spanish company Emxys to lead the development of what is a demanding task.

"Landing on an asteroid is very challenging," Paolo Martino, Ramses project manager, said in an ESA statement. "The irregular shape and surface properties make it difficult to identify a stable landing site, while the very weak gravity makes it hard to stay on the surface without bouncing off and drifting away."

The main Ramses spacecraft will be a modified version of ESA's Hera probe, which is on its way to the binary asteroid system Didymos to assess the effects of NASA's 2022 DART (Double Asteroid Redirect Test) impact.

Ramses' status is not secure, however, despite apparent momentum behind the mission, as it requires ESA member states to officially commit to financially backing the mission at the agency's Ministerial Council meeting in November this year.

Another agency looking at launching a dedicated mission to track and study Apophis is NASA. Scientists at the Apophis T-4 Years Workshop held in Tokyo in April urged NASA to repurpose the shelved Janus spacecraft to make a pre-Earth-encounter investigation of Apophis.

The agency, however, currently lacks the budget to carry out such a mission, according to reports.

A May 19 SpaceNews story reported that Nicky Fox, NASA associate administrator for science, said that the agency is looking into possibilities for using Janus for an Apophis mission, but stated that these depend on budgets for fiscal year 2026 and beyond. The context for this is not favorable, however. The Trump administration's 2026 budget request, issued earlier this month, calls for very deep cuts to the NASA budget, hitting science particularly hard.

A study into collaborating with non-traditional partners for the mission, meanwhile, was found to be not viable, also due to funding issues, SpaceNews reported.

NASA will have at least one spacecraft visiting Apophis, however. The OSIRIS-REx spacecraft, which collected samples from the asteroid Bennu and delivered them to Earth, is on an extended mission — named OSIRIS-APEX — and will arrive at Apophis roughly one month after the asteroid's Earth flyby.

Another visit will be made to Apophis due to a delay to the launch of a Japanese mission. DESTINY+ was scheduled to launch this year to study the asteroid 3200 Phaethon, the parent of the Geminid meteor shower. However, issues with the development of Japan's Epsilon S rocket have seen a change of plans, pushing back launch to 2028, but also affording the opportunity to make a flyby of Apophis on its way.

Scientists are calling for thorough Aphophis investigations beyond a mere flyby. "We recognize that the entire world will be watching how we collectively respond to the knowledge opportunity for planetary defense presented by the safe but very close Earth passage by the asteroid Apophis in April 2029," an Apophis T-4 workshop summary communique stated.

It backed OSIRIS-APEX, DESTINY+ and Ramses, calling these the highest-priority missions for Apophis, which should be "fully funded and supported to ensure successful achievement of their science objectives."

"We find that international collaborations and coordination are imperative for achieving Apophis 2029 science," the communique read, adding that time is of the essence for moving forward and funding missions.

On Tuesday (April 29), NASA announced that its Psyche probe has suffered a setback concerning its propulsion system while nearly 150 million miles (238 million kilometers) from our planet. The boxy, solar-winged craft is headed to the peculiar object for which it is named: 16 Psyche, an asteroid that appears to have an unusually high metal content.

The complication surrounds a "decrease in fuel pressure" within Psyche's solar electric propulsion setup, NASA says, which led the team to power off the thrusters until a solution arises. However, the agency also affirms that these thrusters can remain off until at least mid-June before worries arise about Psyche's trajectory toward its asteroid target. "The mission team has chosen to defer thrusting while engineers work to understand the pressure decrease," NASA said in a statement. "The electric propulsion system has two identical fuel lines, and the team may decide to switch to the backup fuel line to resume thrusting."

Like the probe itself, Psyche's propulsion system is blazing new trails. This is the first time, the mission team says, that this specific mechanism of zipping through space has been used on a probe beyond lunar orbit.

In essence, sunlight collected with Psyche's large solar arrays gets converted into electricity, which then powers up the spacecraft's four thrusters. Once powered up with enough sunlight-derived energy, the thrusters — called "Hall thrusters" — use electromagnetic fields to expel charged atoms of xenon gas that are stored in tanks aboard the spacecraft.

In addition to giving Psyche's thrusters a pretty cool neon blue glow, this xenon expulsion creates a gentle thrust to move the spacecraft — gentle enough to exert "the same amount of pressure you’d feel holding three quarters in your hand," NASA has said. However, the point is for that subtle thrust to build up momentum over time, which is especially easy to do in the vacuum of space. All the while, barely any fuel will be used, meaning Psyche is highly efficient and light.

"With no atmospheric drag to hold it back, the spacecraft eventually will accelerate to speeds of up to 124,000 miles per hour (200,000 kilometers per hour) relative to Earth," NASA explains.

By contrast, NASA says traditional chemical propulsion would have required Psyche to be packed with 15 times more fuel before it was launched to space on Oct. 13, 2023.

In terms of the issue that Psyche is currently experiencing, it has to do with the way the xenon gas is being fed into the thrusters for expulsion.

"On April 1, the spacecraft detected a pressure drop in the line that feeds the xenon gas to the thrusters, going from 36 pounds per square inch (psi) to about 26 psi," NASA said in the recent statement about the glitch.

We'll likely know more about whether the backup line will be used, or if the original line improves its condition, in the coming weeks. Hopefully, Psyche bounces back to full health so it can investigate the many mysteries of 16 Psyche. One of the biggest is whether the asteroid truly is filled with extremely valuable metals (metals we can mine?), is a bare planetary core, or is just a sneaky pile of random rubble.

The next major milestone for the mission's route falls in the spring of 2026, when Psyche will fly by Mars and use the Red Planet's gravitational tides to catapult itself toward the main asteroid belt. If all goes to plan, we'll get a peek at 16 Psyche in 2029.

Ten years ago, astronomers from various institutions, including NASA and SETI (Search for ExtraTerrestrial Intelligence), set out to map the asteroid belt by tracking meteorites as they blazed through Earth’s atmosphere.

To do this, they built a network of all-sky cameras across the globe, which they named the Global Fireball Observatory.

"This has been a decade-long detective story, with each recorded meteorite fall providing a new clue," one of the project’s founders, Peter Jenniskens of the SETI Institute and NASA Ames Research Center, said in a statement. "We now have the first outlines of a geologic map of the asteroid belt."

Jennisken’s colleague, Hadrien Devillepoix of Curtin University, added: "Others built similar networks spread around the globe, which together form the Global Fireball Observatory. Over the years, we have tracked the path of 17 recovered meteorite falls."

The team's research was published on Monday (March 17) in the journal Meteoritics & Planetary Science.

From the main asteroid belt to Earth's atmosphere

Meteorites are rocks from space that survive their fiery descent through Earth's atmosphere and reach the ground. More than just dazzling streaks of light as meteors, these ancient fragments are among the oldest materials in our solar system, originating from planets, asteroids, and comets.

Most meteorites, however, originate from the solar system's main asteroid belt—a vast region between the orbits of Mars and Jupiter where more than a million asteroids circle the sun. Its formation remains a subject of debate, but astronomers believe it dates back around 4.5 billion years to the formation of the solar system's planets. These asteroids are thought to consist of leftover planetesimals, the building blocks of planets that never fully coalesced into a larger body.

The asteroid belt contains debris fields known as clusters, which form when larger asteroids break apart due to random collisions. These smaller fragments remain grouped together and are called asteroid families.

By measuring the radioactive elements present in a meteorite, astronomers can determine their age and match it to the "dynamical age" of asteroid debris fields. The dynamical age is the amount of time that has passed since an asteroid or group of asteroids was disrupted or scattered, determined by studying how the objects have spread out over time due to their movements and interactions, like gravitational forces or collisions.

The more spread out the asteroids are, the older the debris field is likely to be. Essentially, it gives an estimate of how long it has been since the original disruption that caused the objects to scatter.

By analyzing data gathered from watching the night sky and by using a combination of video footage and photographic observations of meteors, Devillepoix, Jenniskens, and their teams have tracked the origins of 75 meteorites in the asteroid belt.

"Six years ago, there were just hints that different meteorite types arrived on different orbits, but now, the number of orbits (N) is high enough for distinct patterns to emerge," they wrote in their paper.

One particularly interesting finding centers around iron-rich ordinary chondrite meteorites or "H chondrites," one of the most common types of meteorites that land on Earth. Their chemistry is considered primitive because they have never undergone melting and have experienced very few chemical interactions since their formation—making them valuable time capsules for understanding the early solar system.

"We now see that 12 of the iron-rich ordinary chondrite meteorites (H chondrites) originated from a debris field called 'Koronis,' which is located low in the pristine main belt," said Jenniskens. "These meteorites arrived from low-inclined orbits with orbital periods consistent with this debris field.

"By measuring the cosmic ray exposure age of meteorites, we can determine that three of these twelve meteorites originated from the Karin cluster in Koronis, which has a dynamical age of 5.8 million years, and two came from the Koronis2 cluster, with a dynamical age of 10-15 million years," he continued. “One other meteorite may well measure the age of the Koronis3 cluster: about 83 million years.”

The team also discovered that several groups of meteorites, including H-chondrites, originated from different regions in the asteroid belt. Some H-chondrites, with an age of about 6 million years, come from the Nele asteroid family, while others, with an exposure age of 35 million years, come from the inner main belt, likely from the Massalia asteroid family.

They also found that the second most common group of meteorites, stony L chondrites, and the least abundant stony meteorites, LL chondrites, which are primarily from the inner main belt, trace back to the Flora and Hertha asteroid families. The L chondrites, in particular, experienced a violent origin 468 million years ago and are linked to a massive collision.

While this provides one of the most comprehensive maps of the asteroid belt to date, not all meteorites in the database were assigned, and some assignments still carried uncertainty.

But for Devillepoix and Jenniskens, this is just the beginning.

"We are proud about how far we have come, but there is a long way to go," said Jenniskens. "Like the first cartographers who traced the outline of Australia, our map reveals a continent of discoveries still ahead when more meteorite falls are recorded.

NASA's Lucy spacecraft, on its way to Jupiter's Trojan asteroids, has its next target in its sights: the main belt asteroid 52246 Donaldjohanson.

Currently 45 million miles (70 million kilometers) from the two-mile-wide (3.2-kilometer-wide) Donaldjohanson, Lucy's high-resolution camera L'LORRI (Lucy Long Range Reconnaissance Imager) spotted the asteroid moving against a background of stars. Lucy will continue to track Donaldjohanson, adjusting its trajectory to ensure an accurate flyby on April 20, when the spacecraft will come within 596 miles (960 kilometers) of the asteroid, which orbits in the asteroid belt between Mars and Jupiter.

The encounter with Donaldjohanson won't be Lucy's first visit to an asteroid. Having launched on Oct. 16, 2021, Lucy encountered the asteroid Dinkinesh and its moon, Selam, in November of 2023. Like Donaldjohanson, Dinkinesh and Selam are also inhabitants of the asteroid belt between Mars and Jupiter. Selam in particular was very interesting because it turned out to be a contact binary — two separate objects touching each other and held together by their mutual gravity. Selam's origin is still a puzzle, but scientists think it might be made from material flung off Dinkinesh as Dinkinesh's rotation was spun up by solar heating, exerting a torque over the course of millions of years.

Although relatively few minor planets have been explored by spacecraft, a high fraction of them have proved to be anything but boring, some having accompanying moons, others adopting unusual shapes and some spraying jets of debris.

For now, however, Donaldjohanson appears only as a point of light to Lucy, and the spacecraft won't be able to detect any details about its structure until the day of the close encounter, when Donaldjohanson will appear large enough in Lucy's sky to begin to resolve its features.

Who knows what Lucy will find?

Then, after the Donaldjohanson fly-by, Lucy will still have a packed schedule ahead of it. In August of 2027, Lucy will have its first encounter with one of Jupiter's Trojan asteroids. The Trojans are two huge swarms of asteroids that have settled into the Lagrange L4 and L5 points, 60 degrees ahead and 60 degrees behind Jupiter in its orbit around the sun. The Trojan asteroids are all named after heroes of the Trojan War in Greek mythology — the first Trojan that Lucy will meet is the 620-mile-wide (1,000-kilometer-wide) 3548 Eurybates, in the "Greek camp" located at L4. After visiting three more Trojan asteroids in the Greek camp, Lucy will actually head back to Earth in 2030 to receive a gravitational slingshot towards the "Trojan camp" at Jupiter's L5 point in 2033.

And, if you’re wondering, Donaldjohanson has a direct link to the Lucy spacecraft's name. Donald Johanson is a paleoanthropologist who discovered parts of a fossilized skeleton of an ancestor of homo sapiens', an australopithecine that lived 3.2 million years ago in what is now Ethiopia. That skeleton was named "Lucy." The spacecraft named after that ancient hominid is also exploring fossils, in the sense that asteroids are leftovers from the dawn of the solar system and can tell us much about Earth's origin, just as Lucy the fossil can tell us about human evolution.

NASA's Wide-field Infrared Survey Explorer (WISE) spacecraft launched to Earth orbit in 2009 and was placed in hibernation in 2011. Then, in 2013, the probe was reactivated for a new mission called NEOWISE that centered on hunting for asteroids and comets.

NEOWISE closed its eyes for good this past summer and fell back to Earth on Nov. 1. During its long and productive life, the probe spent nearly 15 years in space, conducting 21 infrared surveys of the entire night sky and capturing all manner of cosmic phenomena.

For most of its operational life, the telescope focused on identifying and observing small objects in our solar system, such as asteroids, comets, and other near-Earth objects (NEOs). Thanks to NEOWISE observing the same parts of the night sky at different intervals, researchers have been able to track the movements and behavior of a number of nearby celestial objects.

The final NEOWISE data release was made available to the astronomy community on Nov. 14. To help celebrate that milestone and the mission's success overall, NEOWISE team members have unveiled six new images dug out of the telescope's archives.

Related: NASA's 15-year-old NEOWISE asteroid hunter meets fiery doom by burning up in Earth's atmosphere

"Being able to watch the changing sky for nearly 15 years has opened a new avenue for time-domain science, for everything from the closest asteroids to the most distant quasars," NEOWISE Deputy Principal Investigator Joe Masiero, a research scientist at IPAC, said in a Nov. 26 press release.

IPAC, which is on the campus of the California Institute of Technology in Pasadena, originally stood for "Infrared Processing & Analysis Center." But the facility "has since grown beyond its inaugural name — and is now known simply as 'IPAC' — by building upon its experience in infrared data processing and analysis to provide a range of support for more than 20 missions and projects with observatories both in space and on the ground," according to the IPAC website.

One of the newly released images captures the California Nebula in all of its glory. The infrared shot shows green and red dust clouds underlying the nebula shimmering against a backdrop of stars.

The California Nebula, which is about 100 light-years wide, sits about 1,000 light-years away from Earth, in the Perseus constellation. It was named after its resemblance to the California coastline, so the newly released image is particularly meaningful to the NEOWISE data-processing team at IPAC, according to Masiero.

"I'm really grateful for all of the people at IPAC who have put so much effort into making this the best dataset possible, for today and for future generations," he said.

Another featured image depicts the Gecko Nebula, so named because part of the cloud looks like a lizard's snout.

"Near the 'snout' of the gecko you can see a blazing star with a strong red tint, due to its brightness at longer wavelengths of infrared light," IPAC team members wrote in an image description. "This baby star is in its final stages of formation, and while it gobbles up the last of its fuel, some is ejected away in jets of gas that are carving cavities through the surrounding dust clouds."

A third newly released image shows the nebula CG12, which looks like a tadpole. "It is an example of a 'cometary globule,' where a denser region of dust trails off into thread-like strands," the IPAC image description reads. "While challenging to see in visible light images, WISE easily shows the full extent of the globule’s tail as it lights up at longer wavelengths of infrared light."

You can see, and learn more about, all six images in the Nov. 26 IPAC statement. And they represent just a tiny fraction of the gems hidden away in the WISE/NEOWISE archives, mission team members said.

"We know there are more things to discover in the NEOWISE data that we just haven't noticed yet," Masiero said. "As astronomers develop new tools and techniques and as new surveys are conducted, we can be sure the NEOWISE archive will be one of the first places we look for the data needed to better understand our universe."

Earth's "second moon" won't be sticking around for Thanksgiving, but just as many of us will on Thursday (Nov. 28), it seems the asteroid was paying a visit to its relatives.

Analysis of the asteroid 2024 PT5, which will leave Earth on Monday (Nov. 25), conducted during its stay around our planet, shows it may have been born from material ejected from our true moon after one of the old collisions that left the lunar surface pitted and scarred with craters. 

The leading theory of moon formation, the aptly named "giant impact hypothesis," suggests that Earth's loyal lunar companion was born when a titanic collision around 4 billion years ago sprayed out molten material from Earth that eventually cooled and condensed. This means Earth is likely the grandparent of this "second moon," or "mini-moon."

"There are multiple lines of evidence suggesting that this asteroid may have a lunar origin," Carlos de la Fuente Marcos, discovery lead author and a professor at the Universidad Complutense de Madrid, told Space.com. "Current research favors its rapid rotation with a rotational period under one hour, to be expected if 2024 PT5 is either a large boulder from the surface of the moon or a fragment from a larger object."

The mini-moon's lunar origin is further hinted at by its spectra, which suggest its chemical composition matches well with lunar material brought to Earth by the Russian Luna missions and NASA's Apollo moon missions.

How Earth captured a mini-moon

The "mini-moon" asteroid originates from the Arjuna asteroid belt, a secondary asteroid belt made of space rocks that follow an orbit around the sun that's very similar to Earth's orbit, dwelling at an average distance of about 93 million miles (150 million kilometers) to the sun.

"Some Arjuna asteroid belt objects can approach Earth at a close range of around 2.8 million miles (4.5 million kilometers) and at a relatively low velocity of less than 2,200 miles per hour (3,540 km per hour)," Marcos explained. "Asteroid 2024 PT5 will not describe a full orbit around Earth. You may say that if a true satellite is like a customer buying goods inside a store, objects like 2024 PT5 are window shoppers."

Mini-moon events are divided into two categories: those with long episode stays, during which the asteroid completes one or more full orbits of our planet over the course of one or more years, and short engagements in which the small body does not complete one full revolution. These later, more temporary captures last just days, weeks, or even a few months.

Marcos said that, to become a mini-moon, an incoming asteroid has to approach Earth within a range of around 2.8 million miles (4.5 million km) and at about 2,200 mph (3,540 km per hour), a relatively slow speed.

These conditions were met by 2024 PT5 at 3:54 EDT (1954 UTC) on Sept. 29, 2024, marking the beginning of its short capture. The occupation will end at 11:43 EDT (1543 UTC) on (Nov. 25), when perturbations caused by the sun's gravity will disrupt its orbit. 

When it leaves Earth, the asteroid will return to its adoptive family of the Arjuna asteroid belt.

Marcos added that, thanks to the extensive astrometry obtained from the Teide Observatory, the determination of the orbit of 2024 PT5 has been greatly improved. That means it is now well known enough for NASA to study this object using radar  when it makes another close approach to Earth on Jan. 9, 2025.

But that isn't all scientists have learned about this mini-moon so far. As discussed, several papers have suggest that, before its adoption by the Arjuna asteroid belt, 2024 PT5 was a child of the moon, created when an asteroid struck the moon and caused material to be ejected. These findings could also suggest that other bodies in the Arjuna asteroid belt owe their origins to the moon.

"In the lunar ejecta formation scenario, 2024 PT5 could be a large boulder from the surface of the moon that was ejected into cislunar space after a cratering event, subsequently evolving dynamically towards an orbit within the Arjuna asteroid belt," Marcos said. "This object has helped the community to realize that lunar ejecta is probably a main source for the material that constitutes the Arjuna asteroid belt."

"I won't really be sad to see 2024 PT5 go; mini-moons come and go as they wish. I am just waiting for the next one," Marcos concluded. "That wait will not be long; the next capture will probably happen within the next few months. The ongoing Near Earth Object surveys are now sensitive enough to pick up these objects on a regular basis."

Marcos is one of the authors of a new paper on 2024 PT5 and its characteristics accepted for publication in the journal Astronomy & Astrophysics and is available on the preprint repository arXiv. 

Goodnight room, goodnight moon.

The Hera spacecraft, speeding on to an asteroid, took a look back at Earth's moon — and in a new animation, you can see our neighbor shrinking as Hera flies away.

Hera's images of the Earth (visible as a small dot) and the moon were taken between Oct. 10 and 15, according to the European Space Agency (ESA), which runs the mission.

Related: Earth sure looks spooky in these 'hyperspectral' images from Europe's Hera asteroid probe

"The images were acquired during the initial checkout of Hera’s Thermal Infrared Imager (TIRI) instrument, provided to the mission by the Japan Aerospace Exploration Agency," ESA officials added in a statement released Tuesday (Nov. 5).

The Hera spacecraft launched Oct. 7 to study a binary asteroid system up close. By 2026, it should arrive at the crash site of NASA's Double Asteroid Redirect Mission, or DART.

The NASA spacecraft slammed into an asteroid moonlet, called Dimorphos, in 2022. The orbit of Dimorphos around the larger asteroid in the system, Didymos, was permanently altered after the collision.

DART's goal was to examine how well a planetary defense strategy in moving a threatening space rock away from Earth. Hera will examine the collision from a nearby vantage point, providing a different point of view than the telescopes that examined DART's aftermath before.

Additionally, Hera will examine the mineral composition of Dimorphos to provide more information about the asteroid's origins.

NASA's venerable asteroid-hunting spacecraft is no more.

The NEOWISE spacecraft from NASA, which surveyed 3,000 near-Earth objects such as asteroids in its lifetime, burned up in the atmosphere as expected on Friday (Nov. 1), the agency announced.

NASA confirmed the spacecraft's demise on X, formerly Twitter, on Saturday (Nov. 2). While it's the end for NEOWISE, NASA continues to look for stray asteroids with a network of partner telescopes on Earth. A successor asteroid hunter may also launch soon.

NEOWISE was originally launched as WISE (the Wide-field Infrared Survey Explorer) in December 2009, aboard a United Launch Alliance Delta II rocket.

Related: After 14 years in space, NASA's prolific NEOWISE asteroid-hunter is about to shut down

WISE's job was to scrutinize the universe in infrared (or thermal) wavelengths, and it did that for more than a year. It found "the most luminous galaxies in the cosmos, finding millions of hidden black holes, and discovering the coolest class of star," NASA officials wrote in a mission summary.

The spacecraft needed coolant to function properly, and when that depleted as expected, engineers put the spacecraft in hibernation in February 2011. With funding came a "second act," as NASA termed it, of the mission: now called NEOWISE, or Near-Earth Objects Wide-field Infrared Survey Explorer, it began looking for bodies much closer to our planet instead.

The repurposed mission was due in large part to luck, then-NEOWISE principal investigator Amy Mainzer, of NASA's Jet Propulsion Laboratory in California, noted in 2019: "It turned out to be pretty good at picking up asteroids," she said during a media briefing at the Lunar and Planetary Science Conference in The Woodlands, Texas.

The spacecraft proved adept at its new task, concluding its mission after having "surpassed all expectations and provided vast amounts of data that the science community will use for decades to come," Joseph Hunt, NEOWISE's last project manager at JPL, said when the mission's end was announced in June.

NEOWISE's demise was due to the solar maximum, or the height of the sun's 11-year cycle of activity. At solar maximum, there are more frequent and powerful solar flares and coronal mass ejections, which heat up and expand Earth's atmosphere. NEOWISE had no propulsion system on board and, being in low Earth orbit, had no way of boosting itself, so it was slowly dragged down to its death.

The successor mission, NASA's NEO Surveyor (Near Earth Object Surveyor), will be the first space telescope that will be specifically designed to hunt near-Earth objects in infrared wavelengths. It is expected to launch in late 2027 for planetary defense, according to a statement issued by NASA earlier this year.

MILAN — The European Space Agency (ESA) has taken the first big steps toward rendezvousing with an asteroid due to make a close approach to Earth in 2029.

ESA signed a contract worth €63 million (about $68 million US at current exchange rates) with OHB Italia at the International Astronautical Congress (IAC) here on Thursday (Oct. 17), allowing teams to proceed with phase 1 of mission development. 

The Rapid Apophis Mission for Space Safety mission, or Ramses for short, faces a race against time. It needs to launch in early 2028 in order to get up close with the infamous asteroid Apophis as it passes Earth on April 13, 2029. The planetary defense mission would study Apophis' composition, structure and how the tidal forces of Earth affect the asteroid and its cohesion.

The mission is not completely approved and funded: ESA member states will need to dish up the full requirement of money for Ramses at the agency's next crucial Ministerial Council meeting in 2025. But Thursday's signing means that the mission can hit the ground running in case of a potential positive decision, by already getting to work on time-critical activities, including finalizing the overall design.

Related: Apophis: The infamous asteroid we thought might hit us

Ramses has the recently launched Hera mission to thank for its chance to race to meet Apophis. The spacecraft will be an adapted version of Hera, carrying a suite of instruments. And the phase 1 development is being paid for by money saved by Hera being completed under budget. 

"To be there on time is very challenging. We could not wait for the Ministerial; therefore, with exceptional circumstances, we asked our member states to make use of available resources," said Paolo Martino, ESA Ramses project manager.

The mission, however, presents an opportunity to study a unique and timely event, as the 1,230-foot-wide (375 meters) Apophis is due to make an exceptionally close pass to Earth in 2029. The asteroid will move inside geostationary orbit and be visible to the naked eye.

"This is not only a fascinating mission for us; it's also a major milestone of our planet and defense activities," said Holger Krag, ESA's Space Safety Program head. "Our goal in the space safety program is to provide warnings of three weeks' time to notice for all objects of 30-meter [100 feet] size and larger, and to deflect asteroids up to 500-meter [1,650 feet] size, and Apophis is exactly in this size."

Roberto Aceti, managing director at OHB Italia, says the mission will require a different approach, emphasizing the need for fast and efficient project management to meet the tight timeline.

"There will be a different way to deal with mission risks, because, at the end of the day, the ability to steer the mission development is directly connected to the way you manage risks. And the risk here is delays. If we miss by one week, the asteroid is gone," Aceti said.

ESA Director General Josef Aschbacher and others praised the rapid decision-making and support from member states, which allowed the pragmatic actions and the potential fast development of the Ramses mission.

ESA astronaut Samantha Cristoforetti also voiced support for the mission. "Ramses is an incredible step in progressing in our ability as humanity to take care of ourselves and protect our homeworld," Cristoforetti said.

Ramses won't be the only mission potentially visiting Apophis. NASA's OSIRIS-REx spacecraft, which collected samples from the asteroid Bennu and delivered them to Earth, is on an extended mission — named OSIRIS-APEX — and will arrive at Apophis roughly one month after the asteroid's Earth flyby.

OSIRIS-REx and Ramses, like Hera and NASA's Double Asteroid Redirection Test (DART), could be another example of space agencies coming together to develop planetary defense capabilities. 

Europe's highly anticipated Hera mission to catalog the wreckage of the asteroid Dimorphos has arrived at its Florida launch site for final checks ahead of its planned liftoff early next month.

The main Hera spacecraft and its two partner cubesats, named Milani and Juventas, are set to launch atop a SpaceX Falcon 9 rocket on Oct. 7 at 10:52 a.m. EDT (1452 GMT) from Cape Canaveral Space Force Station in Florida. They'll arrive at Dimorphos in late 2026, on a mission to study the aftermath of NASA's planetary defense test, which intentionally smashed a spacecraft into the asteroid in September 2022, shortening its orbit by 33 minutes and permanently altering its shape.

"We're very excited to go back and see what it looks like," Patrick Michel, Hera's principal investigator, said at the Europlanet Science Congress on Friday (Sept. 13) in Berlin.

Hera will assess the size and depth of the crater on Dimorphos created by NASA's DART (Double Asteroid Redirection Test) spacecraft, and determine whether the impact did indeed reshape the rubble-pile asteroid, as early simulations indicate. Once deployed, the two cubesats will for the first time assess Dimorphos' internal structure, surface minerals as well as gravity, data that will help scientists correctly reproduce the asteroid's final structure in their computer models, Michel said at the conference. Such models will then inform future planetary defense missions that similarly aim to deflect asteroids headed toward Earth.

Related: DART's epic asteroid crash: What NASA has learned

Hera and its two cubesats arrived at their launch site in Florida in early September following a transatlantic flight from Germany, with a stop in Ireland. The mission's launch window opens on Oct. 7 and closes on Oct. 27, according to the European Space Agency (ESA).

Hera has a date with Mars in March next year; it will receive a gravity boost from the Red Planet to put it on course toward Dimorphos. During the maneuver, Hera will swing past the Mars moon Deimos and test onboard science instruments and its main camera. 

"It gives us another chance to calibrate our instruments and potentially to make some scientific discoveries," Michael Kuppers, who is Hera's project scientist at ESA, said of the Mars flyby in a previous statement.

If all goes to plan, the spacecraft will arrive at Dimorphos in late 2026 and inch closer to the asteroid's surface through repeated flybys until it ends up less than 0.6 miles (1 kilometer) away, Kuppers said at the conference. 

The mission is expected to gather at least six months of close-up observations of the asteroid, which at 525 feet (160 meters) wide is about the size of the Great Pyramid of Giza in Egypt. Dimorphos' surface will be more visible at that point than it was in the immediate aftermath of the DART collision; the rocks and dust blasted into space by the smashup have since floated away, likely on their way to spark meteor showers on Mars and possibly Earth.

Hera's images of Dimorphos will also help determine whether DART's crash indeed knocked the asteroid out of alignment such that it now wobbles back and forth, as scientists have suggested.

"Dimorphos might also be 'tumbling,' meaning that we may have caused it to rotate chaotically and unpredictably," Derek Richardson, a professor of astronomy at the University of Maryland and a DART investigation working group lead, said last month in a university statement. "One of our biggest questions now is if Dimorphos is stable enough for spacecraft to land and install more research equipment on it."

That answer might arrive at the end of Hera's mission, when its two cubesats Milani and Juventas will attempt to land on Dimorphos. Hera itself might land on Didymos, Dimorphos' larger companion — both spacecraft orbit a common center of mass — although the specifics of end-of-mission scenarios are still under discussion, Kuppers said on Friday.

This article was originally published at The Conversation. The publication contributed the article to Space.com's Expert Voices: Op-Ed & Insights.

Martin D. Suttle is a Lecturer in Planetary Science at The Open University.

What's the difference between an asteroid and a comet? A comet is basically a dirty iceball composed of rock and ice. The classic image is of a bright "star" in the night sky with a long curved tail extending into space. This is what happens when they approach the sun and start emitting gases and releasing dust. It normally continues until there's nothing left but rock or until they fragment into dust.

Asteroids, on the other hand, are primarily just rocks. They might conjure up notions of Hans Solo steering the Millennium Falcon through an implausibly dense "asteroid field" to escape a swarm of TIE Fighters, but mostly they just quietly orbit the sun, minding their own business.

Yet these two space objects are not always as mutually exclusive as this would suggest. Let me introduce Phaethon, a "rock comet" that blurs the definitions between asteroid and comet, and let me tell you why it will be worth paying attention to this fascinating object in the coming years.

Phaethon was discovered by chance in 1983 by two astronomers at the University of Leicester, Simon Green and John Davies. They came across it orbiting the Sun while analyzing images collected by a space telescope called the Infrared Astronomical Satellite (Iras). Soon after, other astronomers recognized that Phaethon is the source of the annual Geminid meteor shower – one of the brightest meteor displays in Earth's calendar.

Every December, as our planet crosses the dusty trail left behind by Phaethon, we are treated to a brilliant spectacle as its dust grains burn up in our atmosphere. Yet Phaetho'’s behavior is unlike that of any other objects responsible for a meteor shower. 

Unlike typical comets that shed substantial amounts of dust when they heat up near the sun, Phaethon doesn’t seem to be releasing enough dust today to account for the Geminids. This absence of significant dust emissions generates an interesting problem.

Phaethon’s orbit brings it extremely close to the sun, much closer than Mercury, our innermost planet. At its closest approach (termed perihelion), its surface temperature reaches extremes of around 730°C.

You would expect such intense heat to strip away any volatile materials that exist on Phaethon's surface. This should either expose fresh, unheated layers and shed huge volumes of dust and gas each time it passes close to the sun, or form a barren crust that protects the volatile-rich interior from further heating, leading to an absence of gas or dust release.

Neither of these processes seem to be occurring, however. Instead, Phaethon continues to exhibit comet-like activity, emitting gas but not an accompanying dust cloud. It’s therefore not shedding layers, so the mystery is why the same crust can still emit volatile gases each time it is heated by the sun.

Our experiment 

I led newly published research aimed at addressing this puzzle by simulating the intense solar heating that Phaethon experiences during its perihelion.

We used chips from a rare group of meteorites called the CM chondrites, which contain clays that are believed to be similar to Phaethon's composition. These were heated in an oxygen-free environment multiple times, simulating the hot-cold/day-night cycles that occur on Phaethon when it is close to the sun.

The results were surprising. Unlike other volatile substances that would typically be lost after a few heating cycles, the small quantities of sulphurous gases contained in the meteorites were released slowly, over many cycles.

This suggests that even after numerous close passes by the Sun, Phaethon still has enough gas to generate comet-like activity during each perihelion.

But how might this work? Our theory is that when Phaethon's surface heats up, iron sulphide minerals held in its subsurface break down into gases, such as sulphur dioxide. However, because the surface layers of Phaethon are relatively impermeable, these gases cannot escape quickly. Instead, they accumulate beneath the surface, for example in pore spaces and cracks.

As Phaethon rotates, which takes just under four hours, day turns to night and the subsurface cools. Some of the trapped gases are able to "back-react" to form a new generation of compounds. When night turns to day again and heating restarts, these decompose and the cycle repeats.

Why this matters

These findings are not just academic but have implications for the Japanese Space Agency (Jaxa)‘s Destiny+ mission, set to launch later this decade. This space probe will fly past Phaethon and study it using two multispectral cameras and a dust analyser. It will hopefully gather particles that will provide further clues about the composition of this enigmatic object.

Either way, our research team’s theory of Phaethon’s gas-emission processes will be crucial for interpreting the data. If we are proven right, it will redefine how scientists think about solar heating as a geological process by making it relevant not only to comets but also to asteroids.

Crucially, Phaethon is not alone. There are about 95 asteroids that pass within 0.20 astronomical units (nearly 19 million miles) of the Sun. Whatever we learn from Phaethon could offer insights into their behaviour and long-term stability, too.

Finally, you may be wondering how all this relates to the Geminid meteor shower. Most likely, Phaethon was emitting dust many years ago. This would have produced the debris band that creates the Geminid shower each time the particles come into contact with Earth’s atmosphere. When we talk about gifts that keep on giving, it’s hard to think of a better example.

BOULDER, Colorado — The United Arab Emirates (UAE) Space Agency is moving forward on a one-after-another mission to the main asteroid belt. 

The UAE Space Agency-led mission will send a probe to conduct high-speed flybys of six asteroids, completing the spectacular sojourn with a rendezvous and orbiting of a seventh mini-world — and then deploy a small lander onto that final space rock destination.

The UAE and its partners have made significant progress on the bold effort, as outlined below.

Key piece of the puzzle

The Emirates Mission to the Asteroid Belt (EMA) is projected to launch in March 2028, ending its interplanetary tour by arriving at the asteroid 269 Justitia in 2034. That rocky chunk of history may have migrated from a region where giant planets formed — or from even farther out.

Related: UAE's ambitious asteroid mission will tour 7 space rocks

Five of the seven asteroid targets are carbonaceous "C-complex" rocks. That means that EMA can characterize a diverse set of carbonaceous bodies, some potentially rich in phyllosilicates, which form a key piece of the puzzle regarding early solar system formation.

The UAE's enterprising mission builds on the success of the ongoing Emirates Mars Mission, the first interplanetary exploration undertaken by an Arab nation. 

The EMM's Hope orbiter launched back in July 2020, arrived at Mars in February 2021 and continues to monitor the Red Planet's weather from above.

Collaboration 

The UAE Space Agency in Abu Dhabi is leading the upcoming EMA mission in collaboration with the Laboratory for Atmospheric and Space Physics (LASP), here at the University of Colorado Boulder. 

This new space trek will span 13 years, with a six-year spacecraft development phase followed by a seven-year voyage to the main asteroid belt beyond Mars. 

"As one of only a few asteroid missions ever planned, and the first multi-asteroid tour and landing mission to the main belt, it's very ambitious, and LASP is very excited to be involved," Pete Withnell, LASP's program manager for the mission, told SPACE.com. 

EMA involves a consortium of academic and hardware development partners within the UAE, Withnell said. The project also includes a number of international "knowledge partners," including LASP, the Italian Space Agency, the Italian National Institute for Astrophysics, Leonardo SpA, Arizona State University, Northern Arizona University and Malin Space Science Systems in San Diego.

"As the primary knowledge transfer partner, LASP is working in partnership with the UAE Space Agency on all aspects of the mission," Withnell said. This includes mission design, spacecraft development, system testing and engineering and science team development and apprenticeship. LASP also supports the UAE Space Academy program, he said.

Related: UAE's Hope Mars orbiter: The Arab world's first interplanetary mission

Fully equipped

The EMA probe will be outfitted with four instruments: a visible narrow-angle camera, a mid-wave infrared spectrometer, a thermal infrared spectrometer and a thermal infrared camera.

The spacecraft will use this scientific gear for a variety of tasks, including:

• Determine the geologic history and volatile content of multiple main belt asteroids, and investigate the interior structure of the rendezvous target;
• Determine temperatures and thermophysical properties on multiple asteroids to assess their surface evolution and volatile histories;
• Collect remote-sensing data on a representative suite of asteroids to better characterize their potential for in-situ resource utilization for future deep space exploration.

Here's the selected score card of asteroids that EMA will reconnoiter: 10253 Westerwald, 623 Chimera, 13294 Rockox, 88055 (2000 VA28), 23871 (1998 RC76), 59980 (1999 SG6) and 269 Justitia.

Asteroid resources

Heyam Alblooshi, a design engineer with the UAE Space Agency, spoke at this year's Space Resources Roundtable, which was held at the Colorado School of Mines in June. She was involved in UAE's Mars Hope mission. 

Alblooshi highlighted the EMA mission and its ability to identify and characterize resources, including volatiles, silicates and metals on multiple types of asteroids, as well as determine resource mass estimates and distributions based on the interior structure of an asteroid.

EMA can help prepare the way for future asteroid resource use, demonstrating proximity operation maneuvers to simulate landing and orbital rendezvous, Alblooshi said. She noted that the EMA lander to be deployed at the asteroid Justitia is under development by 971 and Sadeem — two private companies in the UAE. That lander design will be finalized this year.

Flight dynamics

Also engaged in EMA and a veteran of the UAE's Mars Hope mission is Fatema Hameli, a space projects development engineer for the UAE Space Agency. Her work is in navigation systems for the multi-asteroid visiting asteroid adventure.

"I'll tell you, Mars is easy to reach from a flight dynamics perspective. But getting to seven asteroids in the main belt is not easy. It's very challenging," Hameli told Space.com after her talk on Aug. 13 at the 2024 Astrodynamics Specialist Conference. 

That high-tech specialist meeting was hosted by the American Astronautical Society and co-hosted by American Institute of Aeronautics and Astronautics and held in neighboring Broomfield, Colorado. 

As a solar electric propulsion mission, Hameli reported, there are many models and assumptions that go into designing EMA's interplanetary trajectory. Recent work has gone into understanding the sensitivity of the trajectory and the overall mission objectives. 

The still-to-be-built EMA spacecraft has two separate propulsion systems: chemical hydrazine thrusters and solar electric propulsion xenon Hall effect thrusters, Hameli explained. The mission will utilize xenon for its primary propulsion needs due to its high specific impulse, translating to efficient fuel usage for long-duration interplanetary travel, she said.

Selecting the precise arrival date at a rendezvous target with asteroid 269 Justitia is critical for a successful mission and is an important factor in mission design, Hameli pointed out.

"The lander is a huge step as one of our main objectives," said Hameli. UAE Space agency teams are developing the navigation software, she said — all the tools that will allow EMA to spend a couple of months at asteroid Justitia to find a site for the spot landing.

"We keep learning as we go," Hameli said. "For me, this is a childhood dream." 

NASA is considering pulling a pair of shelved spacecraft out of storage to facilitate a non-agency mission to spy on notorious asteroid Apophis.

Apophis, also known as asteroid 99942, is a 1,100-foot (340-meter) asteroid set to fly by Earth in 2029. Named after the Egyptian god of chaos and destruction, the massive space rock was once predicted to have close to a 3% chance of hitting Earth. More recent calculations have downgraded the chances of that potential 2029 collision, but planetary defense scientists are still studying the asteroid closely to determine any future risk of an Earth impact.

NASA has already sent its OSIRIS-APEX spacecraft (formerly called OSIRIS-REx) on a "bonus mission" to study Apophis, and the European Space Agency is developing its own relevant mission known as Ramses. Still, it appears NASA wants more intel on Apophis ahead of the object's 2029 approach. In a notice posted to federal government contracting site SAM.gov, the space agency has requested information on how to develop a non-NASA-led "reconnaissance mission" to Apophis using its shelved Janus spacecraft.

The Janus spacecraft are two asteroid probes originally designed to launch with NASA's Psyche probe that lifted off atop a SpaceX Falcon Heavy rocket on Oct. 13, 2023. 

Delays to that mission meant the Janus probes would miss their targets — a pair of near-Earth asteroid binaries — so NASA decided to "stand down further work on the Janus mission," the agency wrote in July 2023. Now, it seems the Janus spacecraft could have second lives — fitting for a mission named after the Roman god of duality who is usually depicted as having two faces.

NASA's Request for Information (RFI) asks industry, academia and other researchers to propose new approaches for using the Janus spacecraft to "demonstrate a rapid-response flyby of Apophis" and further our scientific understanding of the asteroid ahead of its April 2029 near-Earth encounter. 

In particular, NASA wants proposals for how to "demonstrate and test capabilities to fly by and characterize a hazardous NEO," or near-Earth object, using a low-cost, rapid turnaround mission. 

Earlier this year, the director of NASA's planetary science division Lori Glaze said that while the 2029 Apophis approach "presents a unique opportunity," getting a mission together to study the space rock is difficult given NASA's ongoing budgetary issues. "Our budget situation is really, really challenging, and that is a reality that we have to live within." Glaze said, according to SpaceNews. "You can have the will, but without the funding it makes it really challenging," 

NASA's RFI notes that proposals for using the Janus spacecraft to fly by Apophis should include information on how interested parties will approach obtaining funding.

Asteroid-mining startup AstroForge plans to make history next year.

The California company announced Tuesday (Aug. 20) that it aims to launch its third mission in 2025, as a ridealong on Houston company Intuitive Machines' IM-3 moon mission. That launch will send AstroForge's 440-pound (200 kilograms) Vestri probe to dock with a metallic near-Earth asteroid — an unprecedented leap for a commercial spacecraft.

"If successful, this mission will be the first private mission to land on another body outside of our Earth-moon system and will move us closer to realizing our mission of making off-world resources accessible to all humankind," AstroForge wrote in an update Tuesday.

That same update revealed that AstroForge has raised $40 million more from investors, bringing its total funding haul to date to $55 million.

AstroForge was founded in January 2022 and came out of stealth mode four months later. The company plans to extract resources from asteroids, "to unlock a cost-effective and sustainable mining solution that replenishes resources and safeguards our planet's future," as it wrote in Tuesday's update.

AstroForge plans to focus on metals — a different tack than that taken by some previous off-Earth mining startups, which aimed to go after asteroid water. Water can be split into its constituent hydrogen and oxygen, the chief components of rocket fuel. Mining it in space could therefore potentially help establish "gas stations" for spacecraft, fueling their voyages deep into the final frontier cheaply and efficiently. 

That may still happen, but new players will likely have to emerge to make it so; the high-profile companies that were eyeing asteroid water are no longer actively pursuing it.

AstroForge already has one mission under its belt, sending its toaster-sized Brokkr-1 probe to orbit atop a SpaceX Falcon 9 rocket in April 2023. The chief goal was to demonstrate the company's refinery technology in space, but that didn't happen; mission team members were unable to activate Brokkr-1's refinery payload as planned.

AstroForge's second mission, called Odin, is scheduled to launch later this year, as a secondary payload on Intuitive Machines' IM-2 moon mission. Odin will pave the way for Vestri, collecting imagery of the asteroid that Vestri will land on. (AstroForge has not yet announced the identity of the target space rock.)

Odin's road to the pad has been a bit bumpy, however. This past March, the vehicle originally slated to fly on the mission failed vibration testing, which is designed to ensure that a spacecraft can survive the rigors of launch. In April, AstroForge decided to use the planned Vestri vehicle for Odin, which required "accelerated development," as the company wrote in an update last month.

The new Odin vehicle, which weighs about 220 pounds (100 kg), was built completely in-house, whereas the one that failed vibration testing consisted of parts supplied by third parties, apart from its science payload, according to AstroForge. 

That shift wasn't just a one-time thing; Vestri "will be developed completely in-house from the start," AstroForge wrote in Tuesday's update. Vestri's "insights and characterization of our target asteroid's composition will allow us to obtain the quality and quantity of valuable elements located on the asteroid." 

Actual mining activity will presumably follow, on a series of missions to come.

Earth is constantly bombarded by fragments of rock and ice, also known as meteoroids, from outer space. Most of the meteoroids are as tiny as grains of sand and small pebbles, and they completely burn up high in the atmosphere. You can see meteoroids larger than about a golf ball when they light up as meteors or shooting stars on a dark, clear night.

While very small meteoroids are common, larger ones – bigger than a dishwasher – are not.

Meteoroids are difficult objects for aerospace and geophysics researchers like us to study, because we can’t usually predict when and where they will hit the atmosphere. But on very rare occasions, we can study artificial objects that enter the atmosphere much like a meteoroid would. 

These objects come from space missions designed to transport physical extraterrestrial samples from outer space to Earth. Because of this similarity to meteoroids in entry, we often refer to these sample return capsules, or SRCs, as “artificial meteors.”

Over 80 researchers from more than a dozen institutions recently worked together to study such an “artificial meteor” – NASA’s OSIRIS-REx sample return capsule – as it reentered Earth’s atmosphere.

Related: 1st look at asteroid Bennu samples suggests space rock may even be 'a fragment of an ancient ocean world'

These institutions included Sandia National Laboratories, NASA’s Jet Propulsion Laboratory, Los Alamos National Laboratory, the Defense Threat Reduction Agency, TDA Research Inc., the University of Hawaii, the Air Force Research Laboratory, the Atomic Weapons Establishment Blacknest, Boise State University, Idaho National Laboratory, Johns Hopkins University, Kochi University of Technology, Nevada National Security Site, Southern Methodist University, the University of Memphis and Oklahoma State University.

This sample return provided our teams with a unique opportunity to measure the sound waves and other phenomena that objects from space produce as they speed through the Earth’s atmosphere.

To capture signals, we installed many sensitive microphones and other instruments in key locations close to the SRC’s flight path.

While space agencies and private companies launch objects into space all the time, the OSIRIS-REx SRC is one of only a handful of objects to return to Earth from interplanetary space since the end of the Apollo missions. Only these objects can achieve the speed of natural meteoroids, making their reentry valuable for studying the properties of natural objects. 

Sampling an asteroid 

NASA launched the Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer, or OSIRIS-REx, mission on Sept. 8, 2016. It traveled to Bennu, a near-Earth asteroid, and collected a sample from its surface in October of 2020. 

The sample returned to Earth in the early morning of Sept. 24, 2023, in a sample return capsule. The SRC reentered Earth’s atmosphere over the Pacific Ocean at a speed of over 27,000 mph (43,500 kph) and landed in Utah only a few minutes later. 

SRCs produce a shock wave as they plunge deep into the atmosphere, akin to the sonic boom generated by a supersonic jet breaking the sound barrier. The shock wave then loses strength until all that remains is low frequency sound, called infrasound.

While humans can’t hear infrasound, sensitive scientific instruments can detect it, even at great distances. Some of these instruments sit on the ground, while others are suspended in the air from balloons.

Observing the SRC 

Our teams of scientists jumped on the SRC reentry as an opportunity to learn more about meteors. One of the teams, led by Siddharth Krishnamoorthy at NASA’s Jet Propulsion Laboratory, used the SRC reentry to test infrasound-detecting balloons that could later be used on the planet Venus.

Another team, led by one of us – Elizabeth Silber – and Danny Bowman at Sandia National Labs used the SRC to better understand how we can use sound to [gather information about meteoroids].

Researchers from many institutions across the country participated in these observational campaigns.

Our teams strategically positioned instruments in locations across a 300-mile (482 km) distance spanning from Eureka, Nevada, to close to the landing site in Utah. The instruments ranged from high-tech custom sensors to smartphones on the ground around the SRC’s flight path and landing site. They monitored the low frequency sound waves from the SRC’s reentry.

In addition to the ground-based sensors, our researchers attached instruments to balloons that floated at twice the altitude of commercial planes during the SRC reentry. The sensors attached to these balloons recorded the sound waves produced by the SRC’s shock wave. These sound waves carried information about the SRC, its movement and the environment it passed through.

The balloon teams had to time the balloons carefully to make sure they would be at the right position when the SRC passed. Team members from NASA’s Jet Propulsion Laboratory, Oklahoma State University and Sandia National Laboratories launched a few different kinds of balloons before dawn from Eureka, Nevada.

Researchers from OSU, Sandia and the University of Hawaii also deployed ground infrasound sensors closer to the SRC’s landing location, along the Utah-Nevada border and at Wendover Airport. While the SRC was already slowing down and Wendover Airport was about three times farther from the flight path than the Eureka deployment, we detected a clear infrasound signal at this site as well.

Researchers on these teams are now analyzing the data to identify the points along the trajectory where instruments recorded the SRC reentry signals. Because the SRC’s flight path spanned approximately 300 miles (482 km), the researchers need to figure out the origin points of the signals as the different sensors detected them.

This was the most-instrumented hypersonic reentry in history.

This research will help our teams figure out what patterns the low-frequency sound waves propagated through the atmosphere and where the shock wave was at its peak intensity.

While our teams are still analyzing the data, the preliminary results show our instruments captured lots of signals that will help future research use low-frequency sound waves to study meteors.

And gaining insights into intricacies about how low-frequency sound waves travel through the atmosphere can help researchers use infrasound to detect hazards on Earth, such as tornadoes and avalanches.

Move over, moon rocks: Space Center Houston has a new type of space stone in its showcase.

The official visitor center for NASA's Johnson Space Center on Friday (March 1) became only the second place in the world where the public can see a sample of the asteroid Bennu as collected and brought back to Earth by the space agency's OSIRIS-REx mission.

"Having a piece of an asteroid is is very rare," said Paul Spana, Space Center Houston's director of collections and curator, in an interview with collectSPACE.com. "There were only two asteroid sample missions prior to this, which the Japanese did several years ago, and they were only able to return a very small amount."

"Other than that, there are no other samples on display in the world except at the Smithsonian and soon the University of Arizona. So in that case, it's rarer than the moon rocks," said Spana.

Related: OSIRIS-REx: A complete guide to NASA's asteroid-sampling mission

The 0.005-ounce (0.15 grams) pebble represents just 0.1% of the total material that OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer) collected from asteroid Bennu in October 2020 and returned to Earth in September 2023. Held within a small stainless steel bottle in a pure-nitrogen environment, the black rock with white speckles is displayed under a magnifying glass, given its diminutive size.

"I also spent a lot of time trying to figure out the right height, where it was both good for kids and not too low where adults had to bend way over," Spana said. "I made marks on my office wall trying to find that height. We tested it out with the real sample last night, and it worked well."

Located just within the main entrance to Space Center Houston, along the path that visitors take to access the Starship Gallery, Lunar Samples Vault and the outdoor display of NASA's 747 Shuttle Carrier Aircraft in Independence Plaza, the new OSIRIS-REx exhibit also includes a video presentation that briefly explains the history of the mission and provides a 360-degree close-up look at the sample on display, as well as a computer tomography scan exposing the rock's interior.

"It has a high carbon content with oxygen, hydrogen and nitrogen. And what's really cool about that from the scientists' point of view is the fact that — speaking of hydrogen and oxygen — the clay is saturated with water. So those are all the building blocks of what you need for life, and that is one of the most exciting discoveries they have made studying the samples at Johnson Space Center," said Spana.

Guests wanting to know more about the sample can catch brief presentations by Space Center Houston crew members once every hour in front of the exhibit.

The sample is on loan from NASA for two years, though Spana is optimistic that the agreement will be renewed.

To celebrate the sample's debut, the first 200 visitors to see the exhibit on Friday were each gifted a 3D-printed model of Bennu as a commemorative keepsake. For those who were unable to attend or who came later, Space Center Houston has provided the file for the model on its website for anyone to download and print for themselves.

The Smithsonian's National Museum of Natural History in Washington, D.C. was the first to receive a sample and unveiled its piece of Bennu in November.

The University of Arizona Alfie Norville Gem and Mineral Museum in Tucson is set to reveal the third and last fragment of the asteroid to go on public display on Wednesday (March 6). The evening event will include a presentation by OSIRIS-REx principal investigator Dante Lauretta, who is also a regents professor and the director of the Arizona Astrobiology Center at the University of Arizona.

Space Center Houston will also feature members of the OSIRIS-REx team, who are working to analyze and catalog the samples at Johnson Space Center. 

Salvador Martinez, lead astromaterial curation engineer for OSIRIS-REx, Nicole Lunning, lead OSIRIS-REx sample curator, and Justin Filiberto, branch chief of the research office and acting branch chief of curation within the Astromaterials Research and Exploration Science (ARES) division at Johnson Space Center, are scheduled to take part in a Thought Leaders Series presentation in late March.

Follow collectSPACE.com on Facebook and on Twitter at @collectSPACE. Copyright 2024 collectSPACE.com. All rights reserved.

The forthcoming Vera C. Rubin Observatory will never leave Earth itself, but the highly detailed, "big picture" view of the cosmos it will offer scientists may very well kick-start a new era of space exploration. 

The solar system is filled with billions of small rocky bodies and icy objects, many of which formed around 4.5 billion years ago when planets like the Earth were forming around the sun. Space missions like NASA's OSIRIS-REx, Lucy, and Psyche have been making strides in visiting these primordial solar system bodies. They've been collecting images, and OSIRIS-REx even snagged a few samples, for investigation here on Earth — all informed by data collected by observatories across the globe. 

Rubin, which will see its "first light" in 2025, will be capable of detecting millions of new asteroids, comets and potentially even bodies passing through our planetary backyard from other systems. Take Oumuamua, for instance, which was first spotted in 2017. After detecting these bodies, Rubin will then quickly track them as they move around the solar system and tread close to Earth — or even if they remain in the main asteroid belt between Mars and Jupiter. 

Related: Dark energy is forcing the universe to expand. This new observatory may show us how

"Nothing will come close to the depth of Rubin's survey and the level of characterization we will get for solar system objects," Siegfried Eggl, Assistant Professor at the University of Illinois Urbana-Champaign and Lead of the Inner Solar System Working Group within the Rubin's Solar System Science Collaboration, said in a statement. "It is fascinating that we have the capability to visit interesting objects and look at them close-up. But to do that, we need to know they exist and where they are. 

"This is what Rubin will tell us."

Picking out asteroid muses

Rubin will monitor solar system bodies and cosmic objects that quite far out, beyond even the limits of the solar system and the Milky Way galaxy, as it conducts its 10-year Legacy Survey of Space and Time (LSST).

Scanning the entire southern hemisphere sky every few nights with an 8.4-meter, fast-moving telescope and the largest digital camera in the world, Rubin is expected to vastly increase our catalog of known solar system objects that has been built over 200 years — by at least 5 times, scientists project.

Not only will Rubin, presently under construction on the mountain Cerro Pachón in northern Chile, spot a multitude of new solar system objects, but scientists also expect it to gather more information about the broader "spacescape" of the solar system. 

This could reveal whole regions that contain unique objects to consider as future space mission targets.

"If you think of Rubin as looking at a beach, you see millions and millions of individual sand grains that together constitute the entire beach. There might be an area of yellow sand, or volcanic black sand," Eggl said. "A space mission to an object in that region could investigate what makes it different. Often, we don’t know what’s weird or interesting unless we know the context it’s in."

The observatory will be further able to alert operators to changes in the night sky within 60 seconds of spotting them, which could help space agencies quickly plan and deploy a mission toward rapidly moving objects of interest.

This could also give scientists an early warning of an interstellar object like Oumuamua as it passes through the solar system, for instance, allowing teams to study the intruder in situ before it slips out of reach and back into deep space. 

"Rubin is capable of giving us the prep time we need to launch a mission to intercept an interstellar object," Eggl added. "That's a synergy that's very unique to Rubin and unique to the time we’re living in."

One project that is already gearing up to take advantage of Rubin data is the JAXA/European Space Agency Comet Interceptor mission that will launch in 2029. The Interceptor will await sighting of a visitable, long-period solar system comet or interstellar object as it passes in front of the sun. Then, it will be deployed for investigtaion.

Rubin could also assist with missions concerning interesting objects located close to the passage of a spacecraft as it conducts its primary mission. 

One active mission that could benefit from Rubin's eye on the solar system is NASA's asteroid-hopping spacecraft, Lucy. The 12-year mission is set to perform the first in situ study of the Trojan asteroids, two families of space rocks that share Jupiter's orbit around the sun.

Rubin could spot smaller, fainter asteroids that lie near Lucy's path to Jupiter, offering the NASA mission some new and unexpected fly-by opportunities. 

"With our current telescopes, we’ve essentially been looking at the big boulders on the beach," Eggl concluded. "But Rubin will zoom in on the finer grains of sand."

It's finally open. After months of anticipation, NASA's OSIRIS-REx mission has achieved a significant milestone by successfully accessing the treasure trove of asteroid material that the probe collected during its billion-mile journey. 

On January 10, a group of NASA technicians finally removed two stubborn fasteners that had locked away the precious cargo, allowing scientists unprecedented access to the asteroid material, according to a NASA statement.

The OSIRIS-REx spacecraft made history in September 2023 when it became the first U.S. mission to return an asteroid sample to Earth. The sample was stored securely within a return capsule, tantalizingly close but out of reach due to two stuck fasteners that the team's limited number of approved tools were unable to pry open. 

Related: NASA's 1st asteroid sample is rich in carbon and water, OSIRIS-REx team finds

While 70.3 grams (2.48 ounces) of material had already been accessed from the outside of the sampler head, known as the Touch-and-Go Sample Acquisition Mechanism (TAGSAM), the bulk of the asteroid sample material remained trapped within the capsule.

According to NASA's statement, the bulk of the asteroid material is now accessible after two of the 35 fasteners on TAGSAM that could not be removed using the existing tools approved for use inside the OSIRIS-REx sample container were finally freed.

With the fasteners finally removed, the astromaterials curation team at NASA's Johnson Space Center in Houston will proceed with disassembling the TAGSAM head to access the remaining asteroid material. This material includes dust and rocks of up to about 0.4 inches (one cm) in size. The final mass of the sample will be determined in the coming weeks.

NASA plans to release a catalog of all the Bennu samples later this year, which will enable scientists and institutions worldwide to submit requests for research or display, opening up new avenues of scientific exploration.

Asteroid Bennu, believed to be a primitive space rock dating back to the early days of our solar system, has the potential to provide invaluable insights into the formation and evolution of celestial bodies. Studying samples collected from its surface could unlock essential clues about our cosmic neighborhood, furthering our understanding of the universe's mysteries.

The OSIRIS-REx spacecraft that collected the samples, meanwhile, has changed names and missions. Now called OSIRIS-APEX, the probe is on a five-year journey to study the asteroid Apophis— named after the ancient Egyptian god of chaos— as it approaches our planet.

For months, bits of an asteroid collected by a U.S. probe during a billion-mile trek were out of reach to scientists, locked inside a return capsule in a NASA facility with two stuck fasteners preventing access to the rocky space treasure. This week, NASA won its battle against those fasteners.

On Wednesday (Jan. 10), NASA technicians finally removed the stuck fasteners from the sample return capsule of its OSIRIS-REx spacecraft — which completed the first asteroid sample return mission in U.S. history when it landed in Utah in September 2023. Tucked in its capsule were rocks and dust collected from the asteroid Bennu. Initially, the team at NASA's Johnson Space Center in Houston, Texas was able to access 70.3 grams (2.48 ounces) of material — 10 grams more than the mission’s goal — from the outside of the sampler head, called the Touch-and-Go Sample Acquisition Mechanism (TAGSAM). 

However, the bulk of the asteroid sample material remained trapped inside the capsule when two of the 35 fasteners on TAGSAM could not be removed with existing tools approved for use inside the OSIRIS-REx glovebox, which ensures the asteroid samples are not contaminated during processing. Thankfully, researchers were able to develop new tools that could tackle the stubborn fasteners, according to a statement from NASA. 

Related: NASA's 1st asteroid sample is rich in carbon and water, OSIRIS-REx finds

"Our engineers and scientists have worked tirelessly behind the scenes for months to not only process the more than 70 grams of material we were able to access previously, but also design, develop, and test new tools that allowed us to move past this hurdle,"  Eileen Stansbery, division chief for ARES (Astromaterials Research and Exploration Science) at NASA, said in the statement. "The innovation and dedication of this team has been remarkable. We are all excited to see the remaining treasure OSIRIS-REx holds."

The team created two new multi-part tools, including custom-fabricated bits made from a specific grade of surgical, non-magnetic stainless steel, which is the hardest metal approved for use in the curation gloveboxes. The tools were tested during removal procedures in a rehearsal lab to ensure they would be able to achieve the torque needed without damaging the TAGSAM head or contaminating the samples, according to the statement. 

"In addition to the design challenge of being limited to curation-approved materials to protect the scientific value of the asteroid sample, these new tools also needed to function within the tightly-confined space of the glovebox, limiting their height, weight and potential arc movement," Nicole Lunning, OSIRIS-REx curator at NASA, said in the statement. "The curation team showed impressive resilience and did incredible work to get these stubborn fasteners off the TAGSAM head so we can continue disassembly. We are overjoyed with the success."

Once the team completes the disassembly, they'll be able to weigh the full sample to determine the total mass collected from Bennu. Image specialists will also take ultra-high-resolution pictures of the samples before removing them. NASA plans to distribute a portion of the asteroid samples to the scientific community for further research later this spring.  

Asteroid Bennu is believed to be a primitive space rock that has been roaming space since the early days of our solar system. Therefore, studying samples collected from the surface of the asteroid could reveal new clues about our cosmic neighborhood. 

NASA's asteroid sampling spacecraft OSRIS-APEX will have an exciting new mission in 2029, when it will watch an exciting asteroid encounter like no other in recorded human history.

The craft, formerly known as OSIRIS-REx, will bear witness as the asteroid Apophis— named after the ancient Egyptian god of chaos— comes so close to our planet that it could be visible with the naked eye in some parts of the world. 

After bringing a sample back from asteroid Bennu, the craft was recently rebranded the Origins, Spectral Interpretation, Resource Identification, and Security – Apophis Explorer (OSRIS-APEX) in recognition of this "bonus mission."

The close approach of Apophis, which is thought to be 1,115 feet (340 meters) across almost as wide as the Empire State Building is tall, on April 13, 2029, will see the space rock come as close to Earth as 20,000 miles (32,000 kilometres), closer than some satellites.

"OSIRIS-APEX will study Apophis immediately after such a pass, allowing us to see how its surface changes by interacting with Earth’s gravity," OSIRIS-APEX project scientist Amy Simon said in a statement.

Related: Asteroid Apophis will visit Earth in 2029. Why do scientists want NASA to send a probe there first?

Apophis became notorious in 2004 as an asteroid that could potentially impact Earth with a size great enough to pose a threat to our planet. However, in March 2021, observations of the orbit of the space rock, also known as Asteroid 99942, led astronomers to conclude that it poses no threat to Earth for at least 100 years. 

NASA scientists still want to know how the brush with Earth in 2029 will affect the 324-day orbit of Apophis around the sun. Additionally, coming close to Earth, which Apophis only does around once every 7,500 Earth years, may shake up the surface of the asteroid by triggering quakes and landslides.

Though this sounds catastrophic, it could reveal what lies beneath the surface of Apophis, and OSIRIS-APEX will be on hand after the encounter to investigate any secrets that are revealed.

"The close approach is a great natural experiment," OSIRIS-APEX principal investigator and University of Arizona scientist Dani Mendoza DellaGiustina said. "We know that tidal forces and the accumulation of rubble pile material are foundational processes that could play a role in planet formation. They could inform how we got from debris in the early solar system to full-blown planets."

Because asteroids are composed of material left over from the formation of planets around the infant sun around 4.5 billion years ago, this investigation could reveal what the building blocks of Earth and its fellow rocky planets were. 

Apophis is made of silicate materials and nickel-iron, making it considerably different from the carbon-rich asteroid Bennu, which OSRIS-APEX visited under its prior moniker in Oct. 2020 to collect a sample that it dropped off at Earth in September 2023 before continuing on its mission.

OSIRIS-APEX will reach Apophis shortly after the asteroid makes its closest approach of Earth on April 13, 2029, and will operate around the asteroid for approximately six months. During this time, the spacecraft will perform some of the same investigations that it did during its time at Bennu — analyzing the surface and chemical makeup of Apophis.

And just as it did at Bennu, OSIRIS-APEX will cap this investigation off by dropping to within around 16 feet (5 meters) of the surface of Apophis and blasting it with its thrusters, further displacing surface material to get closer to the heart of the Empire State Building sized space rock.

"We learned a lot at Bennu, but now we’re armed with even more questions for our next target," Simon concluded. 

Update 1/3: NASA has clarified that, though Apophis makes its closest approach of Earth on April 13, 2029, OSIRIS-APEX will only arrive at its target shortly thereafter. This article has been updated to reflect this.

Tasked with finding clues about origins of life on Earth, NASA's OSIRIS-REx spacecraft scooped up pieces of a rugged, rubble-pile asteroid named Bennu in late 2020 and delivered them to Earth about two months ago. On Monday (Dec. 11), scientists got their first detailed description of some of that extraterrestrial collection.

"We definitely have hydrated, organic-rich remnants from the early solar system, which is exactly what we were hoping when we first conceived this mission almost 20 years ago," Dante Lauretta, the mission's principal investigator, said at the American Geophysical Union (AGU) conference being held this week in California and online. "I fully expect the cosmochemistry community is going to go to town on this."

Lauretta, a professor of planetary science and cosmochemistry at the University of Arizona, said the bits of the ancient asteroid that have been retrieved so far are from the outer lid of the sample capsule and are rich in carbon and organic molecules. All the particles are very dark in color and consist of centimeter- and millimeter-sized "hummocky boulders" that have a rough "cauliflower-like texture," said Lauretta. "They cling to everything we touch them with."

Related: OSIRIS-REx: A complete guide to the asteroid-sampling mission

The OSIRIS-Rex spacecraft was designed to be in contact with Bennu for six seconds, but it ended up plunging 1.6 feet (0.5 meters) into the asteroid's surface for 17 seconds instead. A victim of its own success, the probe dug out so much material that particles began leaking out of the sample collector's head — but they were still protected inside its outer lid. On Monday, Lauretta blamed a 1.3-inch (3.5 cm) Bennu stone that appeared to have jammed open a small flap on the head and let the material escape into the lid.

Two faulty fasteners continue to prevent technicians from removing the lid to access and catalog the bulk of the collected sample that's still trapped within the head. While they wait for new tools to be approved for use on the precious rocks, they are using tweezers to pick tiny rocks through the partially open flap, totaling the collected material to 70.3 grams (0.07 kg) — higher than the mission's mandated minimum of 60 grams (0.06 kg).

Some of that material was shipped for spectral analysis at the NASA-supported Reflectance Experiment Laboratory (RELAB) facility in Rhode Island, while another batch was sent to the Natural History Museum in London. Initial findings using spectroscopy, a scientific technique that reveals a material's makeup by studying how it reflects different wavelengths of light, show a dominant spectral signature in blue. This azure hue is currently unexplained but may mean the space rocks contain even more water than scientists initially predicted, Lauretta said, adding that more results will be shared at a scientific meeting next spring.

The material also hosts high amounts of magnesium, sodium and phosphorus, a combination that so far puzzles the team.

"I've been looking at meteorites for a long time, and I've never come across anything like that," said Lauretta. "It's a head-scratcher right now. What is this material?"

NASA thinks it knows why the OSIRIS-REx asteroid probe's return capsule failed to deploy its drogue parachute as planned while descending through Earth's atmosphere on Sept. 24.

The problem, which did not prevent the capsule from landing safely and softly that day, was likely caused by crossed wires.

"After a thorough review of the descent video and the capsule's extensive documentation, NASA found that inconsistent wiring label definitions in the design plans likely caused engineers to wire the parachutes' release triggers such that signals meant to deploy the drogue chute fired out of order," agency officials wrote in a blog post on Tuesday (Dec. 5).

"In the design plans for the system, the word 'main' was used inconsistently between the device that sends the electric signals and the device that receives the signals," they added. "On the signal side, 'main' meant the main parachute. In contrast, on the receiver side, 'main' was used as a reference to a pyrotechnic that fires to release the parachute canister cover and deploy the drogue. Engineers connected the two mains, causing the parachute deployment actions to occur out of order."

Related: NASA's OSIRIS-REx lands samples of asteroid Bennu to Earth after historic 4-billion-mile journey

The drogue chute was supposed to deploy at an altitude of 100,000 feet (30,000 meters), helping to slow and stabilize the return capsule's descent ahead of main-chute deployment at around 10,000 feet (3,000 m).

As a result of the wiring problem, however, the drogue's retention cord was cut at deployment time, leaving the chute still in the capsule. The drogue stayed there until the capsule hit 9,000 feet (2,740 m), when the main chute opened. At that point, the drogue popped free into the air and fell away, with nothing holding it to the capsule.

But the main chute overcame the problem. Its "design was robust enough to stabilize and slow the capsule, resulting in a safe landing more than a minute earlier than expected," NASA officials wrote in the statement. "There was no negative impact to OSIRIS-REx’s Bennu sample as a result of the unexpected drogue deployment."

Bennu is the near-Earth asteroid that OSIRIS-REx visited, studied and sampled. The material that the probe snagged from Bennu's surface in October 2020 is now being processed at NASA's Johnson Space Center (JSC) in Houston. 

Once that's done, researchers around the world will study the sample, searching for clues about the solar system's early days and the role that carbon-rich asteroids like Bennu may have played in bringing life's building blocks to Earth long ago.

The return capsule's parachute-release system is inside a protective glove box alongside the Bennu sample at JSC, NASA officials said. "Once the curation team there completes processing the sample material — the mission's top priority at present — NASA engineers will be able to access the parachute hardware and verify the cause," they wrote.

NASA defines near-Earth objects (NEO) as asteroids or comets with orbits that bring them within 120 million miles (195 million kilometers) of the sun, meaning they are close to Earth's orbit. The vast majority of these NEOs are asteroids, or near-Earth asteroids (NEAs).

There are over 600,000 known asteroids in the solar system, and over 20,000 of these are NEAs, according to the European Space Agency (ESA). Most of the rest are located in the main asteroid belt between Mars and Jupiter. NEAs are thought to make their way out of the asteroid belt and toward Earth's orbit as they are nudged by the gravity of other solar system bodies. The majority of NEOs range from about 10 feet to 25 miles (3 meters to 40 km) wide, according to NASA. 

Related: Planetary defense: Protecting Earth from space-based threats 

Types of near-Earth asteroids

NEAs are divided into four significant families based on their orbital parameters: Atiras, Atens, Apollos and Amors.

Atiras are NEAs with orbits that are contained entirely within Earth's orbit. They are named after the asteroid 163693 Atira. 

Atens are NEAs that cross Earth's path and whose orbits have semimajor axes smaller than that of Earth's orbit around the sun. They take their name from the asteroid 2062 Aten.

Apollos are NEAs that cross Earth's orbit with a semimajor axis larger than that of our planet. They get their name from the asteroid 1862 Apollo.

Amors are Earth-approaching NEAs with orbits that bring them within the orbit of Mars but do not bring them within the orbit of Earth. Their name comes from the asteroid 1221 Amor.

One concerning category of NEAs are so-called potentially hazardous asteroids  (PHAs),  which the NASA Jet Propulsion Laboratory's Center for Near-Earth Object Studies (CNEOS) defines based on an asteroid's potential to make a threatening close approach to Earth. Specifically, this concerns the object's "minimum orbit intersection distance (MOID)"  —  the distance an asteroid is from Earth when its orbit crosses or touches the orbit of our planet  —  and the brightness of the object if it were located at the same distance from Earth as Earth is from the sun   (1 astronomical unit, or AU),  known as absolute magnitude. 

PHAs must have a MOID of around 4.65 million miles (7.48 million km), or 0.05 AU, and an absolute magnitude of 22 or brighter. Because MOID is used to calculate the diameters of asteroids, bodies smaller than 460 feet (140 m) wide are not classified as PHAs, no matter how close they come to Earth, per CNEOS. 

Only a small fraction of NEAs are considered potentially hazardous, but their potential threat to our planet means that space agencies across the globe are working hard to identify and track these dangerous space rocks.

Near-Earth asteroids FAQs

How do we track near-Earth asteroids?

A great deal of asteroid tracking data is collected by NASA-funded observatories, such as the University of Hawaii's Panoramic Survey Telescope and Rapid Response System (Pan-STARRS), the Catalina Sky Survey, and the University of Hawaii's Asteroid Terrestrial-impact Last Alert System (ATLAS).

Data regarding the positions of NEAs around Earth are gathered by the International Astronomical Union's Minor Planet Center (MPC). The MPC handles the identification, designation and orbit computation for these objects and then announces discoveries to space agencies such as NASA. 

Once a potential NEA is discovered, the object is followed up on by projects such as NASA's space-based Near-Earth-Object Wide-Field Infrared Survey Explorer (NEOWISE) telescope, along with planetary radar projects, like JPL's Goldstone Solar System Radar Group. 

The science of NEAs falls to several bodies within NASA. For instance, CNEOS characterizes the orbits of all currently known NEOs and then predicts their close approaches to Earth. With this information, CNEOS can make comprehensive impact hazard assessments, which are supplied to NASA's Planetary Defense Coordination Office in Washington, D.C.

Performing long-term assessments and predicting PHAs' orbits with the Sentry impact monitoring system, CNEOS also maintains the Scout system, which monitors potential NEAs to assess possible impacts. After an NEA is detected but before it is confirmed, it is placed on the Minor Planet Center's NEO Confirmation Page (NEOCP). The Scout system then monitors these candidate NEAs over the coming days and weeks to assess their trajectory and possible impacts. 

Once the NEA is confirmed, it is removed from the NEOCP. Then, all of the data are compiled in the Sentry risk table ,  which lists the NEAs with the greatest probability of impacting Earth over the next 100 years. This is probability-based, because it takes many years of observations to constrain the orbit of an NEA, and even then, there are measurement uncertainties. 

What are the dangers of near-Earth asteroids?

Earth is under constant bombardment from space rocks. NASA estimates that around 48.5 tons (44 metric tons) of material falls to Earth every day, most of which burns up in the atmosphere and occasionally creates "shooting stars." According to NASA, space rocks smaller than about 82 feet (25 m) will most likely burn up as they enter Earth's atmosphere and thus cause little or no damage.

Earth's geological history is a stark reminder, however, that larger asteroids can make it through the atmosphere and that impacts by large space debris can have disastrous consequences. This is particularly evident in the case of the asteroid that caused the Cretaceous-Tertiary extinction event 66 million years ago, which eliminated 80% of plant and animal species on Earth, including the nonavian dinosaurs. 

Because of the destructive capacity of asteroids, CNEOS has a role in addition to monitoring real asteroids around Earth: It conducts hypothetical asteroid impact exercises, which have given us an idea of the kind of devastation that would result from a collision within an NEA. 

Fortunately, NASA suggests that the larger an asteroid is, the less likely it is to impact Earth. While around 100 tons (90 metric tons) of dust- and sand-size particles reach Earth every day, a roughly car-size asteroid strikes Earth's atmosphere around once a year, burning up and resulting in a fireball over Earth. 

Around every 2,000 years, Earth encounters an asteroid around the size of a football field — about 330 feet (100 m) wide. The significant destruction caused by such an impact would be localized, with the asteroid likely vaporizing just over Earth's surface and destroying buildings within a radius of 9 miles (14 km) and shattering windows within a radius of around 60 miles (100 km). More widespread damage could be caused by seismic tremors and rock hurled into the atmosphere by such an impact. 

During a CNEOS asteroid impact exercise in April 2023, NASA researchers revealed the damage that would result from impacts of larger asteroids. 

For example, a 1,000-foot-wide (300 m) asteroid could represent destruction on a continental scale, releasing as much energy as the detonation of 2,000 megatons of TNT — equivalent to 133,000 times the estimated energy released by the bomb that destroyed Hiroshima at the end of World War II. Earth experiences an impact from such a body around every 70,000 years. 

The devastation would grow significantly for a 2,000-foot-wide (600 m) asteroid. An impact with an asteroid this size would border on global catastrophe, releasing as much as 20,000 megatons of energy. This means a doubling in asteroid size has resulted in an increase in devastation power by a factor of 10. Fortunately, asteroids of this size are predicted to hit Earth just once every 200,000 years or so.

For a 3,330-foot-wide asteroid (about three times as tall as the Eiffel Tower), an impact scenario as calculated by CNEOS would become dire. Indeed, asteroids of this size are considered potential "planet killers." A planet-killer impact would release around 100,000 megatons of energy — equivalent to 6.6 million detonations of the Hiroshima nuclear blast. These impacts are estimated to occur around once every 700,000 years. 

The dinosaur-killing asteroid, known as the Chicxulub impactor, had an estimated width of 6.2 miles (10 km) and released around the same amount of energy — 720 megatons of TNT — when it hit what is now the Yucatán Peninsula in Mexico at around 45,000 mph (72,000 km/h). Asteroids above 3 miles (5 km) in width, like the Chicxulub impactor, are predicted to strike Earth once every 30 million years.

According to the University of California, Berkeley, size isn't the only characteristic that affects how much damage an NEA would cause if it hit Earth. Other factors include the asteroid's composition (for example, is it a loose rubble pile or a whole lump of iron?) as well as the angle and speed of the impact and whether the asteroid hits Earth on land or in the ocean. 

Additional resources

If you're worried about potential NEA encounters, you can keep an eye on NASA's Sentry risk table. If you'd like to estimate the damage that could result from an asteroid of a specific size and density, the Earth Impact Program, from Imperial College London and Purdue University, is a great resource. It also allows you to input hypothetical impacts on land or water and even vary the depth of water in which the space rock lands. On YouTube, math professor Nils Berglund simulates what would happen if an asteroid struck Earth in the North Pacific Ocean. 

Bibliography

NEO Basics, NASA, [Accessed 06/10/23], [https://cneos.jpl.nasa.gov/about/basics.html]

Asteroid Watch: Keeping an Eye on Near-Earth Objects, NASA Jet Propulsion Laboratory, Caltech, [Accessed 06/10/23], [https://www.jpl.nasa.gov/asteroid-watch]

NEO Observations Program,  [Accessed 06/10/23], [https://www.nasa.gov/planetary-defense-neoo/]

NEO Earth Close Approaches, [Accessed 06/10/23], [https://cneos.jpl.nasa.gov/ca/]

Space Safety: ESA's Planetary Defence Office, ESA,  [Accessed 06/10/23], [https://www.esa.int/Space_Safety/Space_Safety_ESA_s_Planetary_Defence_Office]

Something serendipitous happened in early November. It had to do with NASA's Lucy spacecraft, a solar-winged probe currently on its way to investigate a trove of ancient asteroids locked in Jupiter's orbit around the sun. They're called the Trojans, and they're believed to be leftover blocks from the box that built our solar system. 

But we're not talking about the mighty Trojans right now. We're talking about a little space object named Selam. 

Here is Selam's story.

On Nov. 1, Lucy flew by one of its non-Trojan targets; you can think of these like stepping stones (stepping asteroids, rather) on the mission's grander path. Asteroid number one's name is Dinkinesh, or as scientists adorably call it, "Dinky." Soon after, however, on Nov. 2, the Lucy team announced a surprise. Dinkinesh isn't just one, but rather a binary system of two asteroids! In other words, Dinky had its very own moon. The scientists were thrilled. Little did they know, Dinky was about to surprise us once more. 

Related: Strange moon of asteroid Dinkinesh is weirder than thought after NASA probe finds 'contact binary'

On Nov. 7, to everyone's shock, the team revealed that Dinky's newfound satellite itself had a newfound satellite. In particular, the team said, the original satellite was a "contact-binary," meaning it was two objects, a moon and a meta-moon, that were touching. This marked the first discovery of a contact-binary orbiting an asteroid. 

"It is puzzling, to say the least," the Southwest Research Institute's Hal Levison, principal investigator for Lucy, said in a statement at the time. "I would have never expected a system that looks like this. In particular, I don't understand why the two components of the satellite have similar sizes. This is going to be fun for the scientific community to figure out."

All that was left? A name. 

So, on Nov. 29, the Lucy team confirmed that we finally have a name for Dinky's little contact-binary friend: Selam. 

"Dinkinesh is the Ethiopian name for the fossil nicknamed 'Lucy,'" Raphael Marshall of the Observatoire de la Côte d’Azur in France, who originally identified Dinkinesh as a potential target of the Lucy mission, said in a statement. "It seemed appropriate to name its satellite in honor of another fossil that is sometimes called Lucy's baby." 

The fossil Selam, NASA explains, was discovered by Zeresenay Alemseged in 2000 in Dikika, Ethiopia. It's believed to have belonged to a 3-year-old girl of the same species as Lucy, one of the first hominin fossils to become a household name as the Natural History Museum says. Selam, however, is thought to have lived more than 100,000 years before Lucy. Wonderfully, Selam translates from Ethiopian language Amharic to "peace," while Dinkinesh translates to "you are marvelous."

"Dinkinesh really did live up to its name; this is marvelous," Levison had said at the time of its moon's discovery.

Now, the team intends to study both Dinkinesh and Selam in greater detail to understand precisely how this asteroid-ception arose in the first place. Thanks to Lucy's onboard instruments such as the high-resolution L'LORRI camera and Terminal Tracking Cameras, there's probably a solid amount of information to go on.

"To assemble the final images, we must carefully account for the motion of the spacecraft, but Lucy’s accurate pointing information makes this possible," said Amy Simon of NASA’s Goddard Space Flight Center, Greenbelt, Maryland. “These images will help scientists understand the composition of the asteroids, allowing the team to compare the makeup of the Dinkinesh and Selam and to understand how these bodies may be compositionally linked to other asteroids."

It's incredible that space rock stop number one on Lucy's journey since launching in 2021 has yielded such interesting results — one can only imagine what's in store for the rest of its 12-year excursion.

For quite a while, an asteroid named Phaethon has presented astronomers with something of a conundrum. 

When it passes closest to the sun during its orbit, a long tail of material can be seen leaving the three-mile-wide (five-kilometer-wide) rock. However, if Phaethon's tail is the stuff of usual comets — ice and carbon dioxide — then it should be visible when the comet is as far away as Jupiter, too. But it's not.

Scientists have therefore had some theories about what Phaethon might be composed of, which could explain what trails behind when the asteroid passes by the Sun. And in new research, astronomers have compared the infrared emissions of Phaethon analyzed by NASA's Spitzer space telescope to emissions of meteorites in laboratories, ultimately finding that Phaethon likely belongs to a rare class of meteorite, of which only six specimens are known. 

Related: The strange mystery of asteroid Phaethon's comet-like tail 

Namely, Phaethon's emission spectrum corresponds to a type of meteorite called the "CY carbonaceous chondrite." Conversely, other well known asteroids such as Ryugu and Bennu, targets of the recent JAXA and NASA sample-return missions, are CI and CM meteorites respectively.

All three classes of meteorites are believed to have originated during the birth of the solar system, as they all show signs of the chemical process in which water combines with other molecules to form phyllosilicate and carbonate materials. However, only the CY group seemed to show signs of drying and decomposition due to heating; it also exhibits a high iron sulfide content, which suggests a unique origin. 

Analyses of Phaethon's emission spectrum revealed olivine, carbonates, iron sulfides and oxide minerals — all of which supported the space rock's  connection to the CY class of asteroid. Carbonates in the asteroid indicate changes in water content (the drying), for instance, and the olivine is consistent with thermal decomposition of phyllosilicates at high temperatures. 

Researchers were able to show with thermal modeling how temperatures, such as those encountered when passing by the sun, might affect minerals in the asteroid that release gases. As the asteroid gets nearer the searing ball of plasma at our solar system's center, its surface temperatures can rise to 800°C, which the team says is easily hot enough for the object's carbonates to produce carbon dioxide, phyllosilicates to release water vapor and sulfides sulfur gas. 

Data from other studies on asteroids, combined with the new thermal models of Phaethon, led the researchers to believe that pressure from the gas released by the asteroid heating up could cause the rock to break down, producing small dust particles that are lifted  from its surface — a likely explanation for Phaethon's tail as it passes by the sun. 

"It was great to see how each one of the discovered minerals seemed to fall into place and also explain the behavior of the asteroid," said co-author Mikael Granvik from the University of Helsinki, in a press release. 

The research was published in November in the journal Nature Astronomy. 

A Japanese mission that will study the parent body of a famous meteor shower will have to wait a bit longer to get off the ground.

DESTINY+, an acronym constructed from "Demonstration and Experiment of Space Technology for Interplanetary Voyage, Phaethon Flyby and Dust Science," will study the asteroid 3200 Phaethon — the parent of the Geminid meteor shower — and interplanetary dust.

The Japan Aerospace Exploration Agency (JAXA) mission was due to launch next year, but the agency has now confirmed that it will be delayed into 2025 due to issues with the development of the Epsilon S rocket, Kyodo News reported on Oct. 27.

Related: Geminid meteor shower 2023: When, where & how to see it

Epsilon S is a planned successor to the Japanese Epsilon solid-fuel rocket. A rocket engine related to the new launch vehicle exploded during testing in July, forcing the delay.

3200 Phaethon is a curious near-Earth object, exhibiting characteristics similar to both asteroids and comets. This makes it both an unusual source of a meteor shower and also a target of significant scientific interest. The irregular, 3-mile-wide (5 kilometers) chunk of rock made a relatively close approach to Earth in 2017. It is the source of the Geminids, which rain down upon Earth's atmosphere every December.

The DESTINY+ spacecraft will launch from Uchinoura Space Center (USC). The 1,060-pound (480 kilograms) spacecraft will enter an initial elliptical Earth orbit. It will carry four ion engines to power its journey through space once it separates from the launch vehicle, using a lunar swing-by to accelerate it into deep space. It will also use thin-film lightweight solar array panels.

DESTINY+ will make a flyby of Phaethon, using telescopic and multiband cameras to survey the surface of the asteroid. The flyby, at a distance of 310 miles (500 km) and a relative speed of around 74,000 mph (119,000 kph), was expected in 2029, but JAXA has not provided a new date for the close approach.

The spacecraft will also conduct in-situ analysis of interplanetary and interstellar dust using the dust analyzer, developed under the leadership of the University of Stuttgart and supported by the Germany space agency DLR ("Deutsches Zentrum für Luft- und Raumfahrt"), JAXA says. The aim is to assess whether extraterrestrial dust particles and associated organic compounds arriving on Earth played a role in the creation of life on the planet.

JAXA says the mission will also demonstrate technologies such as its solar arrays and electric ion propulsion that will enable future low-cost and high-frequency deep space exploration.

Legendary guitarist Brian May, arguably the most famous citizen scientist in the world, has spoken about his involvement with NASA’s historic asteroid sample collection mission, OSIRIS-REx.

The sample from an asteroid named 101955 Bennu was returned to Earth on Sept. 24,; May and fellow citizen scientist Claudia Manzoni were invited to examine visual data collected by mission principal investigator and University of Arizona researcher, Dante Lauretta.

May and collaborators searched through images taken of Bennu’s surface by the OSIRIS-REx spacecraft to find opportunities to apply a technique called stereoscopy — which can basically add a 3D dimensional effect and illusion of depth to a 2D image.

"We looked for pairs of images of Bennu’s surface taken from viewpoints some distance apart," May wrote in a NASA blog post. "This separation of viewpoints, known as the 'baseline,' has to be just right to give us the experience of depth and reality when the images are viewed stereoscopically."

Related: NASA's 1st asteroid sample is rich in carbon and water, OSIRIS-REx team finds 

Pairs of 2D images are required for stereoscopic imaging so a parallax effect can develop from subtle differences in both images taken with slightly different viewpoints. 

"Such viewing requires the left and right images to be delivered separately to our left and right eyes, which is how we see in 'real life.' When this is done, the small differences between the components of the stereo pair  —  known as parallax differences  —  give our brains the opportunity to instantaneously perceive depth and solidity in the image," May explained. 

Images of the Bennu sample taken after its return to Earth in the Utah Desert were prime for such a stereoscopic approach.

"In the moments when the Touch-and-Go Sample Acquisition Mechanism (TAGSAM) head was flipped over after removing it from the avionics deck at NASA's Johnson Space Center in Houston, photographs from many angles were captured, enabling us to find just one (nearly!) perfect pair, showing the intimate structure of just a few grains of the dark, coal-black sample," May said. "The curation team made it easy for us."

Though the best stereoscopic view of the sample and its roughly 1-centimeter-wide (0.4-inch-wide) grains of asteroid material requires the use of an actual stereoscope, it is possible to mimic that false 3D view by relaxing the eyes and effectively "staring through" the screen. 

Scientists and citizen scientists like May are keen to get a look at the material that makes up asteroids like Bennu because these rocky bodies are thought to be composed of matter that was present during the solar system's formation around 4.6 billion years ago. That means these untouched asteroids could reveal the nature of the material that collected together long ago, gathering into overly dense patches of gas and dust that surrounded our infant sun to form what astronomers call a protoplanetary disk.

The OSIRIS-REx spacecraft, launched in 2016 from Cape Canaveral Space Force Station in Florida, took two years to journey the 1,720-foot-wide (524-meter-wide)  asteroid Bennu. After arriving at Bennu in August of 2018, the craft studied the asteroid from a distance for two years before dipping to the space rock’s surface and grabbing a sample. OSIRIS-REx started its 1.2 billion-mile (1.9 billion-kilometer) trip back home in 2021 and dropped the Bennu sample, safely inside a sample canister, into Earth's orbit just last month. Then, the canister descended to the ground.

But after dropping its important cargo off in orbit and changing its name to OSIRIS-APEX, the spacecraft left Earth’s vicinity once again, beginning a journey to the near-Earth asteroid Apophis. OSIRIS-APEX will reach an orbit around the 1200-foot (370-meter) wide space rock by 2029, enabling scientists to investigate yet another space rock in stunning detail. 

SpaceX's first Falcon Heavy mission for NASA did not disappoint.

The Falcon Heavy — the second-most powerful rocket currently in operation, after NASA's Space Launch System — launched the agency's Psyche asteroid mission from Kennedy Space Center in Florida this morning (Oct. 13).

It was the eighth liftoff overall for the Heavy and its fourth already in 2023. But the sight of the triple-core rocket climbing into the sky — and coming back down to Earth — was still a dazzling one, as the photos below make clear.

Related: NASA's Psyche asteroid probe on track for October launch after 1-year delay

Psyche now has a long road ahead of it. The spacecraft is scheduled to arrive at its namesake, a 173-mile-wide (280 kilometers) metallic object in the main asteroid belt between Mars and Jupiter, in 2029.

The probe will then study the asteroid Psyche up close for about two years. Scientists think the space rock may be the exposed core of an ancient planetary building block, so the mission's observations could shed considerable light on our solar system's early days, the formation of planets and the characteristics of Earth's core.

Update for 10:30 am ET: NASA's Psyche asteroid mission successfully launched into space atop a SpaceX Falcon Heavy rocket at 10:19 a.m. EDT on Oct. 13, lifting off from the Kennedy Space Center in Florida. Read our wrap story here.

SpaceX's powerful Falcon Heavy rocket will send NASA's Psyche asteroid mission skyward today (Oct. 13), weather permitting, and you can watch the action live.

The Falcon Heavy is scheduled to launch the Psyche spacecraft today at 10:19 a.m. EDT (1419 GMT) from Pad 39A at NASA's Kennedy Space Center (KSC) in Florida. That assumes Mother Nature cooperates, which is certainly no guarantee on the stormy Space Coast; current forecasts predict just a 40% chance of weather good enough for launch. 

You can watch the action live here at Space.com, courtesy of NASA TV, beginning about 45 minutes before liftoff. 

Related: NASA's Psyche asteroid probe on track for October launch after 1-year delay

If all goes according to plan, Falcon Heavy's two side boosters will come back to Earth for a landing at Cape Canaveral Space Force Station, which is next door to KSC, about 8.25 minutes after liftoff. It will be the fourth launch and landing for each booster, according to a SpaceX mission description. 

The Falcon Heavy's central core booster is flying for the first and only time today. It will splash into the Atlantic Ocean when its launch work is done.

The Heavy's upper stage, which sits atop the central booster, will finish carrying Psyche to space and deploy it there about 62.5 minutes after launch. 

The probe will then begin its long deep-space journey to Psyche, a bizarre metallic asteroid that lies in the main asteroid belt between Mars and Jupiter. 

Scientists think the space rock Psyche, which is about 173 miles (280 kilometers) wide, may be the exposed core of an ancient protoplanet — a type of object they've never seen up close before. Psyche will reach its space rock target in 2029, then study it from orbit for about two years thereafter. 

If bad weather or a technical issue scuttles today's launch attempt, SpaceX and NASA can try again soon: The mission has daily liftoff opportunities through Oct. 25.

The Falcon Heavy, the second-most powerful rocket in operation today, has flown seven times to date. The Psyche mission will be the rocket's first for NASA.

Update: Psyche launched at 10:19 a.m. EDT on Oct. 13. Read our wrap story here.

SpaceX's powerful Falcon Heavy rocket is ready to launch its first-ever NASA mission tomorrow (Oct. 13).

The Falcon Heavy rolled out to Pad 39A at NASA's Kennedy Space Center in Florida on Tuesday (Oct. 10) ahead of an originally planned Thursday (Oct. 12) liftoff of NASA's Psyche asteroid mission. But NASA and SpaceX delayed the launch by a day to wait out some bad weather brewing on the Space Coast.

If all goes according to plan, Psyche will now launch tomorrow at 10:19 a.m. EDT (1419 GMT). You can watch the action live here at Space.com, courtesy of NASA and SpaceX. 

Related: NASA's Psyche asteroid probe on track for October launch after 1-year delay

The Falcon Heavy consists of three strapped-together first stages of SpaceX's workhorse Falcon 9 rocket. The central booster is topped with an upper stage and the payload.

The Heavy — the second-most powerful rocket flying today, after NASA's Space Launch System — has flown seven times to date, most recently in July of this year. None of those missions were for NASA, however.

The two side boosters that will help launch Psyche tomorrow are spaceflight veterans, as their sooty appearance suggests: They have participated in three of seven Falcon Heavy launches to date, according to a SpaceX mission description. Both side boosters are expected come back once again if all goes smoothly, touching down in Florida shortly after liftoff.

The central booster, on the other hand, will be making its first and only flight tomorrow. It's slated to fall into the Atlantic Ocean after it finishes powering Psyche skyward.

The Psyche mission will study the bizarre metallic asteroid of the same name up close, providing key insights about the solar system's early days and the planet-formation process. (Astronomers think Psyche may be the exposed core of an ancient protoplanet.)

The 173-mile-wide (280 kilometers) Psyche lies in the main asteroid belt between Mars and Jupiter. The Psyche probe is scheduled to reach the space rock in 2029, then scrutinize it from orbit for at least 26 months.

Current forecasts call for a 50% chance of good enough weather to allow a launch tomorrow. The Psyche mission has daily launch opportunities through Oct. 25.

CAPE CANAVERAL, Florida — The launch of NASA's Psyche asteroid mission has been delayed until 10:19 a.m. EDT (1419 GMT) on Friday (Oct. 13), to account for inclement weather that's barreling in from the Gulf of Mexico. 

Psyche, NASA's probe to explore a metal asteroid of the same name, was scheduled to launch on Thursday morning (Oct. 12) on a SpaceX Falcon Heavy rocket from Pad 39A here at NASA’s Kennedy Space Center. However, during a prelaunch press briefing on Wednesday (Oct. 11) , bleak predictions for the next morning’s forecast left only a 20% chance of favorable weather conditions. 

As Wednesday night’s storms blew in, the decision was made to forgo Thursday’s launch attempt to capitalize on the better weather predicted for launch windows on Friday and Saturday (Oct. 14).

Related: NASA's Psyche metal asteroid mission will have a big impact on astronomy. Here's how

Arlena Moses, launch weather officer with the U.S. Space Force, was at Wednesday’s press briefing and explained the growing concerns. 

"One of the main watch items now has kind of shifted from just the storms in the area to our liftoff winds," Moses said. "Behind this warm front and especially with that area of low pressure coming towards us, we expect winds to pick up very quickly out of the south and southwest. We could see 20 to 25 miles an hour [32 to 40 kph], likely some stronger gusts with that as well."

Those conditions were expected to persist through Thursday’s launch window, prompting mission teams Wednesday evening to make the decision to delay until Friday. 

"For our first backup window, Friday morning, 50% chance for go conditions, with our concerns still being associated with storms in the area, where we have anvil clouds, some thick clouds, which are layered clouds, as well as cumulus clouds we get associated with storms," Moses explained during the briefing. 

"Looking at Saturday morning, a third backup window, there is still about the same probability, about 50% chance of go, and fairly similar conditions here, where there may be some storms around, but we expect most of any storms to be after our morning launch window," she added.

The decision to forgo Thursday's window may also have to do with characteristics of Psyche's launch vehicle. SpaceX's Falcon Heavy has limited launch recycle attempts, meaning the rocket can be fully fueled for launch up to two times before needing maintenance enough to delay launch more than a couple days. 

Tim Dunn, NASA's senior launch director for the Launch Services Program, touched on some of the resource constraints during Wednesday's briefing. "The limitations for recycled attempts is due to the vast quantity of densified LOX (liquid oxygen) that we use with the Falcon Heavy configuration," he explained. After a second fueling attempt, "we would be down about five days to replenish the LOX in the ground sphere and get it into a dissipated state," Dunn said. 

So NASA is now aiming for Friday's 50% "go" window, with Saturday's similar coin toss chance of favorable launch conditions as a backup. The new plan allows a higher probability of success should the first launch attempt scrub closer to T-0 in the countdown.

Psyche's launch window runs through Oct. 25. After it gets off the ground, the probe will head toward the asteroid Psyche, which lies in the main asteroid belt between Mars and Jupiter. Astronomers think the bizarre metallic body may be the exposed core of a protoplanet; the Psyche mission will help them take its measure.

It looks like Bennu was indeed the right target for NASA's first-ever asteroid sample-return mission.

That mission, OSIRIS-REx, delivered pieces of the 1,650-foot-wide (500 meters) Bennu to Earth late last month. NASA gave the world its first look at the sample today (Oct. 11) during a live webcast event, which also provided a rundown of the first analyses performed on the off-Earth material.

Those very early scientific returns are promising, showing that Bennu is rich in both water and carbon-containing compounds, mission team members said.

"The OSIRIS-REx sample is the biggest carbon-rich asteroid sample ever delivered to Earth and will help scientists investigate the origins of life on our own planet for generations to come," NASA Administrator Bill Nelson said in a statement today. 

"Almost everything we do at NASA seeks to answer questions about who we are and where we come from," Nelson added. "NASA missions like OSIRIS-REx will improve our understanding of asteroids that could threaten Earth while giving us a glimpse into what lies beyond. The sample has made it back to Earth, but there is still so much science to come — science like we've never seen before." 

Related: NASA's OSIRIS-REx lands samples of asteroid Bennu on Earth after historic 4-billion-mile journey

OSIRIS-REx launched in September 2016 and arrived at Bennu in December 2018. The probe spent the next 22 months studying the space rock from orbit and searching for the right place to swoop down and grab a sample.

That sampling run took place in October 2020, and it provided a fair bit of drama: Bennu's surface turned out to be surprisingly porous, and OSIRIS-REx sank deeply into it. 

But the probe emerged with a bounty — so much material that its collection mechanism got clogged, allowing some asteroid dirt and pebbles to escape into space. OSIRIS-REx still managed to secure most of the Bennu bits in its sample container, and the probe headed toward Earth in May 2021.

The journey home wrapped up on Sept. 24, when OSIRIS-REx's return capsule landed in the desert of northern Utah. A day later, the sample arrived at NASA's Johnson Space Center (JSC) in Houston, where it's being processed, curated and stored.

That work has only just begun. For example, mission team members still don't know exactly how much material OSIRIS-REx hauled home. They think it's about 8.8 ounces (250 grams) — far higher than the mission requirement of 2.1 ounces (60 g) — but that's just an estimate, calculated while the return capsule was still in space.

JSC will distribute parts of the Bennu sample over the coming months and years to researchers around the world, who will study it in great detail. 

Their work will determine, among other things, the identity of the carbon compounds, which could shed light on how life got started here on Earth. (Many researchers think carbon-rich asteroids like Bennu seeded our planet with life's building blocks long ago, via impacts.)

And Bennu is a relic of our solar system's planet-building era, so taking the rock's measure will help us understand the formation and evolution of our cosmic backyard on a larger scale, mission team members said.

"As we peer into the ancient secrets preserved within the dust and rocks of asteroid Bennu, we are unlocking a time capsule that offers us profound insights into the origins of our solar system," Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, said in the same statement. 

"The bounty of carbon-rich material and the abundant presence of water-bearing clay minerals are just the tip of the cosmic iceberg," he said. "These discoveries, made possible through years of dedicated collaboration and cutting-edge science, propel us on a journey to understand not only our celestial neighborhood but also the potential for life's beginnings. With each revelation from Bennu, we draw closer to unraveling the mysteries of our cosmic heritage."

The journey isn't over for the OSIRIS-REx spacecraft, by the way. Though its return capsule is now back on Earth, the probe keeps on flying, toward another asteroid called Apophis. OSIRIS-REx is scheduled to arrive at that space rock in 2029 and study it up close, on an extended mission called OSIRIS-APEX.

SpaceX's powerful Falcon Heavy rocket has made it to the pad ahead of its planned launch this week.

SpaceX rolled the Falcon Heavy out to Launch Complex 39A at NASA's Kennedy Space Center on Tuesday (Oct. 10). If all goes according to plan, the rocket will launch NASA's Psyche spacecraft toward a bizarre metal asteroid, also called Psyche, on Thursday morning (Oct. 12).

But Mother Nature may not cooperate with that plan: Current forecasts predict just a 20% chance of weather good enough for a launch on Thursday, NASA officials said in an update on Tuesday. The Psyche mission has backup launch opportunities through Oct. 25.

Related: NASA's Psyche asteroid probe on track for October launch after 1-year delay

The Falcon Heavy will send Psyche toward its namesake, a roughly 173-mile-wide (280 kilometers) object in the main asteroid belt between Mars and Jupiter. 

The spacecraft will reach its target in 2029, then study the metallic asteroid up close for at least the next 26 months. Astronomers think Psyche may be the exposed core of an ancient protoplanet, so the mission's observations could reveal a great deal about these planetary building blocks and the solar system's early days more generally.

The Falcon Heavy consists of three strapped-together first stages of SpaceX's workhorse Falcon 9 rocket, the central core of which is topped by an upper stage and the payload.

The Heavy — the second-most powerful rocket currently in operation, after NASA's Space Launch System — debuted in February 2018, on a test flight that sent Elon Musk's red Tesla Roadster into orbit around the sun. 

The rocket has flown seven times to date, most recently in July of this year. Psyche will be its first mission for NASA.

Update for 1 p.m. ET: NASA has revealed the samples of asteroid Bennu, announcing they have already discovered them to be rich in water and carbon.

NASA will unveil to the world today (Oct. 10) the fruits of its first asteroid sample-return mission.

The agency will host a webcast today at 11 a.m. EDT (1500 GMT) to reveal the asteroid dirt and gravel that its OSIRIS-REx mission delivered to Earth last month. 

You can watch the event live here at Space.com, courtesy of NASA, or directly via the agency.

Related: NASA's OSIRIS-REx lands samples of asteroid Bennu on Earth after historic 4-billion-mile journey

The $1.2 billion OSIRIS-REx mission launched in September 2016 toward the near-Earth asteroid Bennu, a carbon-rich space rock about 1,650 feet (500 meters) wide.

The probe reached its target in December 2018, setting a record for the smallest cosmic object ever orbited by a spacecraft. In October 2020, OSIRIS-REx swooped down and grabbed a sample from Bennu, sinking surprisingly deeply into the asteroid's surface in the process. 

The following May, OSIRIS-REx began the long journey back to Earth. That trek culminated with the parachute-aided touchdown of the probe's return capsule in the desert of northern Utah on Sept. 24.

The precious cargo hauled home by that capsule is now at NASA's Johnson Space Center in Houston. JSC personnel are processing, curating and storing the Bennu material, which researchers around the world will study for years to come, looking for clues about the solar system's early days and how life got its start on Earth. (Some scientists think Bennu-like asteroids seeded our planet with organic molecules — the carbon-containing building blocks of life — via impacts long ago.)

Mission team members have already begun analyzing some of the asteroid material. They'll reveal some of their early results during today's webcast, NASA officials said.

We'll also get a good look at the sample and, in all likelihood, learn just how much of it there is. The mission team said that OSIRIS-REx snagged about 8.8 ounces (250 grams) of Bennu grit during its sampling dive, but that was just a prelanding estimate. (OSIRIS-REx was supposed to return at least 2.1 ounces, or 60 g, of material, a target that it almost certainly met.)

Only the OSIRIS-REx return capsule landed in Utah last month. The larger spacecraft flew past Earth, on its way to another asteroid — the notorious Apophis. The probe is scheduled to reach Apophis in 2029 and study it in depth, on an extended mission called OSIRIS-APEX.

Five scientists gathered at NASA's Kennedy Space Center on Tuesday (Oct. 10) to lay out the blueprints of an exhilarating space mission set to launch in just a couple of days. It's called Psyche. 

Named for its target, this endeavor will send a spacecraft on an impressive 2.2-billion-mile (3.5-billion-km) journey toward an asteroid dubbed 16 Psyche — but what's key here is that this asteroid is far more than a simple space rock. It may very well be the surviving metal core of a planet that had its outer layers stripped away long, long ago. 

If the agency is right about that hypothesis, 16 Psyche has the potential to offer us a uniquely serendipitous way to study the core of planet Earth. This is because both are expected to have similar metallic compositions, possessing some combination of iron and nickel. But even if the team is wrong, and Psyche is actually some other type of cosmic object unlike the seed at our planet's center, there will still be cause for celebration. 

As Lindy Elkins-Tanton, Psyche's principal investigator says, the second leading idea for what Psyche could be is equally as intriguing as the first — and one may actually argue it's even more tantalizing. 

Related: NASA's Psyche probe will launch to a metal asteroid on Oct. 12 — and scientists are sneaking a peek at the target

Possibly, 16 Psyche is made of material that formed really close to the sun at some point in time, then got "reduced" such that the material's oxygen atoms were disconnected from its iron atoms. In turn, the iron atoms would have become their metal form. "This is a kind of material that's been hypothesized by planetary scientists for a long time, but we haven't actually found any before," Elkins-Tanton said during the press briefing on Tuesday (Oct. 10). "So think about what this means when there's only one object like Psyche in the whole solar system."

"The other idea is that Psyche is a kind of primordial unmelted body, basically formed of the very first materials in the solar system that came together under gravity," Ben Weiss, deputy principal investigator of the Psyche mission, said during the briefing, "preserved in this primordial state ever since." In that case, we'd be looking at a stunning fossil of the ancient solar system. 

Either way, this ambitious feat (presently scheduled to launch atop a SpaceX Falcon Heavy rocket on Oct. 12) is bound to end with us adding a few footnotes to our astronomy books. Already, in fact, Psyche has marked quite a few milestones.

Sci-fi propulsion is now a reality

David Oh, chief engineer for operations at NASA's Jet Propulsion Laboratory says this will be the first-ever mission to use Hall Effect thrusters in interplanetary space. What does that mean? Well basically, Hall Effect thrusters use electricity to ionize xenon gas — ionization refers to removing or adding one or two electrons from the atoms that make up a substance. In this case, the substance is a gas. 

Upon ionization, those atoms gain a charge. (Regular old atoms have neutral charges because their positive proton count and negative electron count are equal. Remove some electrons, for instance, and you lose some negativity.) The result? Ions. Then, those charged ions form an electric field which can, through a series of complicated steps, propel an object. In this case, that's the Psyche spacecraft. 

"They come out of the thruster going at 15 kilometers per second, or nine miles per second," Oh said. "That's five times faster than the speed of the fuel coming out of a regular chemical rocket."

"30 years ago when I was a graduate student, I worked on Hall Effect thrusters," he continued. "At the time, it was considered an esoteric and experimental technology of the future; it was the kind of thing that you heard about in Star Wars and Star Trek."

Now, here we are.

Tapping into this technology, the Psyche spacecraft is slated to reach its metallic target in 2029 after launching on Thursday. This does sound like a long while, but the road to getting there is so utterly complex that NASA doesn't doubt time is going to fly. "Launch is just the start," Oh said.

The route

After lifting off from our planet and separating from its Falcon Heavy rocket chariot, Psyche will begin moving toward its subject situated between Mars and Jupiter. Then, the Hall Effect thrusters come in. 

"These thrusters can operate over long periods of time; days; weeks; months," Oh said. "and this small force on the spacecraft accumulated over all that time accelerates it to the high speeds we need to be able to navigate to Mars."

Once the spacecraft reaches the vicinity of Mars, it will dip into the Red Planet's gravitational influence in order to be propelled like a slingshot toward Psyche itself. This is called a gravity assist, or as Oh puts it, a bit of "cosmic trickery."

"Then we'll restart our ion propulsion system," he said, "and use that to make the rest of our journey to Psyche."

Having reached its destination, the spacecraft will start getting into its optical navigation systems, taking pictures to help it make its way to the highest of four planned orbits around the asteroid. At this stage, lots of data will be collected about the space rock such as what its gravity field looks like by way of the team's "gravity science experiment." 

Slowly but surely, Psyche will then descend into closer orbits and ultimately approach its namesake. 

The arrival

The Psyche craft is armed with a bunch of measurement tools such as a gamma-ray neutron spectrometer that can investigate what kind of elements make up the asteroid and two magnetometers to understand the object's magnetic field.

"Psyche today is long frozen, but if it formed as a metallic core in the early solar system, it was once a molten body and has been cooling really quickly and potentially generating a magnetic field." Weiss said. "That magnetic field could be imprinted in the outer layers of Psyche's cold exterior as a kind of echo or fossil that we could then detect today." 

There's also a multispectral imager that can capture light wavelengths across the spectrum — and the gravity science experiment's scope actually also reaches into this stage. It can help scientists understand features of the asteroid such as its precise density. And as Weiss explains, this experiment quite interestingly harnesses the spacecraft's antenna, which is typically used for communication.

"It turns out you can also use this to determine the gravity field," he said, invoking the example of a train zipping by. "When it comes towards you, it's got a higher pitch. When it passes you, it's got a lower pitch. We can look at the pitch or frequency of the radio waves coming from the antenna, and figure out how fast the spacecraft is moving. We can track its disk speed as a function of its position around the asteroid — and from that we can see how lumpy the gravity field is."

In other words, if the spacecraft seems to be moving faster, it's probably going to be above a dense region. If it's moving slower, it's probably going to be above a less dense region. And so on.

Finally, on the note of communication, Abi Biswas, a technologist at NASA's Jet Propulsion Laboratory, explained that the spacecraft will be transmitting all that awesome data back to our planet through a state-of-the-art Deep Space Optical Communications project. 

DSOC, in a nutshell, uses lasers to exhibit a 10 times higher data transmission rate from Mars distances when compared to regular radio frequency transmitters. "Future NASA missions, in particular those involving human exploration of Mars," Biswas said during the briefing, "demand much higher data return rates — and that's the motivation for this technology demonstration." 

On Earth, there's a 1-meter (3 foot) telescope at Table Mountain Observatory in California that transmits a laser beam up to the spacecraft. Then, the spacecraft is able to detect the beam and track it. Once it can start tracking that laser beam, it knows where to point its own laser beam. Then, it sends a downlink beam to a receiver at the 200-inch (5 meter) Hale telescope at Palomar Observatory (which is also in California.) 

"Both these laser beams are modulated which means they're flashing on and off," Biswas continued, "those flashes are timed, and the timing of those flashes is what encodes the information that's carried over these laser beams."

The open questions 

"There aren't that many completely unexplored types of worlds in our solar system for us to go see," Elkins-Tanton said. "We visited, either in person or robotically, worlds made of rock and worlds made of ice and worlds made of gas … but this will be our first time visiting a world that has a metal surface."

Some questions that arise in this regard are: What would a crater on a metal asteroid look like? Perhaps, the team says, an impact on Psyche would spur the existence of tiny little spikes on the object rather than create a plume of debris like an impact on a rocky surface would. Another question is: Might there be huge cliffs or evidence of lava flows on an object like this one? 

Per Elkins-Tanton, experts believe that there were likely sulfur-rich eruptions from volcanoes on the asteroid when it was very young. What might that have led to? Weiss suggests the multispectral imager will be key in decoding the aftermath of such eruptions. 

"One of the things that we on the team, and in fact the whole scientific community, have been asking ourselves now for a long time," Elkins-Tanton also pointed out, "is what do we think it's going to look like?"

We do know some things about Psyche already, such as the fact its surface area is about the same as the area of California and it's sort of lumpy-shaped, for instance, but we won't actually have an idea about its true visage until the space explorer gets there. "We're going to find out that our basic scientific understanding is going to be updated, and that's why we need to go," she said.

"I just want to give my thanks to the entire team. They've come through some tough times and really have done an amazing job on this mission," Lori Glaze, director of NASA's Planetary Science Division said. 

"We know we're ready and cannot wait to get launched later this week."

NASA is preparing to launch its Psyche spacecraft on the first mission designed to study a metal-rich asteroid up close. The Psyche mission is set to blast off on Thursday (Oct. 12) from NASA's Kennedy Space Center in Florida at 10:16 a.m. EDT (1416 GMT) atop a SpaceX Falcon Heavy rocket.

After traveling an estimated 2.2 billion miles (3.5 billion kilometers), the spacecraft will arrive at the asteroid 16 Psyche, which is located at the far edge of the main asteroid belt between Mars and Jupiter, in 2029. 

Once the spacecraft is in place, mission scientists will study the metal asteroid, which is different from the rock- and ice-dominated bodies studied in situ in the past, to learn more about how the rocky planets of the solar system (Mercury, Venus, Earth and Mars) formed. 

Related: NASA's Psyche probe will launch to a metal asteroid on Oct. 12 — and scientists are sneaking a peek at the target

What's so special about metal asteroid Psyche?  

Discovered in 1852, Psyche is considered one of the most fascinating objects in the main asteroid belt, and scientists have only been able to study it at a distance. Scientists think the asteroid is composed of the exposed core of a planetesimal, a small body that formed during planet formation as gas and dust around a star collapsed in dense patches. 

A planetesimal could eventually go on to gather more mass and thus become a planet. But Psyche is thought to have failed to reach planet status because it collided with other larger bodies as the solar system was forming around 4.5 billion years ago, possibly stripping the metal-rich asteroid of its outer rocky shell and exposing its iron-rich core.

That means that studying this 173-mile-wide (279 km), potato-shaped asteroid could not only help reveal more about the collisions that took place in the early solar system but also provide scientists with a proxy for the inaccessible iron core of our own planet.

Psyche seems to diverge from the solar system planets born from planetesimals. Whereas the rocks of the inner solar system planets are replete with iron oxides  —  chemical compounds of iron and oxygen atoms  —  Psyche lacks these compounds. If Psyche is indeed composed of material left over from the birth of the rocky planets, its existence could point to a different type of planetary formation that diverges from the mechanism that created Earth. 

But even if Psyche turns out not to be an exposed planetesimal core, the asteroid is still very interesting to scientists because it could mean it belongs toa population of never-before-seen primordial solar system bodies.

What's so special about NASA's Psyche mission? 

One of the most vital parts of the Psyche mission will be getting the spacecraft to this distant asteroid and then keeping it in place so its scientific instruments can do their jobs. 

To do this, the spacecraft, which measures 16.1 by 7.1 by 7.8 feet (4.9 by 2.2 by 2.4 meters), will depend on a solar electric propulsion system that captures sunlight with its large solar arrays and then converts it to electric and magnetic fields. These fields accelerate charged atoms of the propellant xenon ,  which is commonly found in plasma televisions on Earth. These atoms, in the form of blue-glowing ionized gas, are then blasted out into space by the Psyche spacecraft's four thrusters, providing the craft with propulsion that looks like something straight out of science fiction. 

According to NASA, each of these four thrusters operates one at a time, providing a force equivalent to the weight of three quarters in your hand here on Earth — which, in the microgravity and frictionless environment of space, is enough to propel the spacecraft. 

Even with these revolutionary "Hall-effect thrusters" — which, so far, have been used to get only as far as the moon — the spacecraft's journey to the vicinity of Jupiter won't be a 'straight shot." Instead, it will require a gravity-assisted slingshot maneuver around Mars in 2026, and Psyche will arrive at its metal-rich asteroid target in August 2029.

The spacecraft will then make orbits of the asteroid at a distance of around 430 miles (700 km), which will decrease as the mission proceeds. The spacecraft will use progressively closer orbital periods ,  or "regimes ,"  to investigate different characteristics of the asteroid.

During its first orbital regime (A), lasting 56 days, the spacecraft will use its magnetometer to search Psyche for an ancient magnetic field, which would provide evidence that the asteroid was once a planetary body. As the spacecraft does this, its multispectral imager will assess the topography of Psyche's surface. This will continue as the NASA orbiter draws closer to the asteroid, hopefully revealing more details of these characteristics, particularly during the next two orbital regimes (B1 and B2), which will last 192 days. 

Moving even closer to the asteroid, during the 100-day orbital regime C, Psyche's telecommunications system, which sends data to Earth and receives commands from ground control via radio waves, will be used to investigate the gravitational influence of the metal-rich asteroid. This could help better constrain its mass and density and thus the asteroid's interior composition and structure. 

During its 100-day orbital regime D, Psyche will employ its gamma-ray neutron spectrometer to get a better picture of the asteroid's surface topology and investigate the chemical elements that are abundant on the asteroid's surface. 

The Psyche mission is the result of a collaboration among several institutions, including Arizona State University, which provided the spacecraft's multispectral imager; NASA's Jet Propulsion Laboratory, which is responsible for mission management, operations and navigation; Maxar Technologies, which provided the chassis for the solar electric propulsion system and other hardware; and NASA's Launch Services Program at Kennedy Space Center, which acquired the SpaceX Falcon Heavy rocket for launch and will handle launch services.

You can watch the launch Thursday beginning at 9:30 a.m. EDT (1330 GMT) on NASA TV and directly on Space.com courtesy of NASA.

NASA's OSIRIS-REx asteroid probe captured photos during the release of its return capsule last month, preserving the historic moment for posterity.

Those images, which the space agency released on Tuesday (Oct. 3), show the return capsule deploying from OSIRIS-REx on the morning of Sept. 24 and heading toward Earth.

"The sun is visible at the top of the frame, and a thin 'crescent Earth' can be seen at the left edge of the image," NASA officials wrote of the photos, which mission team members combined into a GIF. 

Related: NASA's OSIRIS-REx lands samples of asteroid Bennu on Earth after historic 4-billion-mile journey

The 110-pound (50 kilograms) capsule's time as a free flyer was brief: It touched down as planned under parachutes in the northern Utah desert on Sept. 24, about four hours after being jettisoned. 

The soft landing capped NASA's first-ever asteroid sample-return effort. The capsule's precious contents — dirt and gravel that OSIRIS-REx snagged from the near-Earth asteroid Bennu in October 2020 — quickly made their way to Johnson Space Center (JSC) in Houston, where the off-Earth material is getting processed, curated and stored.

Mission team members think OSIRIS-REx returned about 8.8 ounces (250 grams) of Bennu material. That's just a pre-landing estimate, however; the exact amount is being worked out now, and will likely be announced during a webcast event on Oct. 11.

The OSIRIS-REx sample is expected to be a treasure trove for scientists to study for decades to come, NASA officials have said. Scientists around the world will scrutinize the asteroid bits for clues about the solar system's early days and the role carbon-rich space rocks like Bennu may have played in delivering life's building blocks to Earth long ago, among other lines of inquiry.