On the morning of Jan. 8, 2025, a red dot popped up on NASA's Fire Information for Resource Management System. It was the first sign of what would become one of California's worst wildfires in history, going on to claim a dozen lives and burn down thousands of homes in the Palisades. All the while, the Aqua satellite was orbiting above, scanning the planet and beaming data down to ground stations in Alaska and Svalbard.

This satellite carries infrared sensors that capture changes on Earth impossible to see with the human eye, making it vital for coordinating emergency responders during natural disasters. Upon detection, NASA converts Aqua's infrared wave data into GPS coordinates, allowing officials to plot the spread of fire as points on a map. These coordinates make up what's known as the Moderate Resolution Imaging Spectroradiometer (MODIS), an instrument that spots fires on the Earth’s surface. This process often alerts emergency services faster than 911 calls from the ground.

But now, scientists are starting to find surprising gaps in that data. Logs maintained by NASA show multiple occasions where fire-tracking datasets reported errors. Why? Incoming space debris.

Missing data is a problem for scientists trying to explain the Earth's climate to politicians and business leaders who make decisions on what to do about climate change. While the data loss is currently small, scientists say the problem will only get worse over time as space debris increases.

But Aqua isn't alone. It's one of three main satellites that make up the core of the Earth Observing System (EOS), a constellation that coordinates orbit to measure the land, ocean and atmosphere simultaneously.

The EOS fleet has allowed us to understand how aerosols affect cloud formation, map the deforestation of the Amazon, and discover how the Earth's oceans have darkened thanks to phytoplankton blooms. And indeed, all three satellites — Aqua, Terra and Aura — are at risk from space junk. Starting in 2005, the EOS fleet swerved to avoid space debris on at least 32 occasions. The maneuvers may have left corrupted climate data in several of those instances, according to data logged by the Land Data Products Evaluations Assessment. Even beyond data, there is also the loss of precious fuel.

"Even without collisions, space debris has an economic cost," Andrew Bonwick, vice president at Relm Insurance, which offers satellite insurance and has to price in the risk of collision, told Space.com. "Each time a satellite has to maneuver to avoid a potential collision, it uses fuel which is a finite and precious resource."

"Things will get worse before they get better," said the NASA scientists in the 2018 report that assessed debris maneuvers. The report found that the risk of a collision between an EOS satellite and a piece of orbital debris is increasing.

In its heyday, Aqua flew around 438 miles (705 kilometers) above the surface of the Earth, moving from the North Pole to the South Pole in an ellipse 14 times a day, scanning the entire planet. The satellite sits in sun-synchronous orbit, capturing the light waves emitted from the Earth's surface.

Along that journey, Aqua has survived a battery short-circuiting, a solar panel thermistor failure, and lost 23 of its solar cell strings. But thanks to careful fuel management, the satellite has lasted 18 years longer than originally designed.

"If we knew we were going to have a spacecraft and instruments that would last 20 years, we might have put more fuel in it so that it would last even longer," said Aqua Project scientist Claire Parkinson in 2022.

Climate satellites like Aqua are more at risk from debris because they have to fly close to the planet to capture their data. Low Earth Orbit (LEO) has the highest amount of space junk, trapped there by the Earth's gravity and travelling at faster speeds than the upper atmosphere.

In 2005, the European Space Agency (ESA) was tracking about 16,000 pieces of debris. By 2026, that number had increased to more than 44,000, an increase of about 180%.

The vast majority of space debris is too small to be tracked, with ESA estimating that more than a million small pieces are unaccounted for. Even a speck of paint can be enough to wreck a satellite.

Space junk is created when satellites break up in orbit, either because of collisions or anti-satellite tests such as those carried out by China and Russia. On April 28, two Russian spacecraft passed within 10 feet (3 meters) of each other.

But space junk avoidance isn't the main reason satellites use fuel. If left alone, Aqua would eventually drift off course. Gravity from passing mountains and ocean bulges slowly pulls the satellite out of orbit, while solar radiation changes its spin, corrupting its data.

For that reason, scientists constantly have to correct satellite trajectories to avoid spacecraft crashing into other spacecraft or even just random bits of space junk. While it's true that spending fuel shortens the life of a satellite, avoiding space debris is usually worth it. Most of Aqua's fuel was used on orbital-course corrections.

"For applications where satellites are tasked to provide detailed imagery of particular areas, the job may just not get done, especially where the imagery is time critical or depends on frequent revisits," says Bonwick.

Now, Aqua is reaching the end of its life span. It's set to be switched off this year after traversing the skies for almost a quarter-century, leaving behind a legacy for future climate scientists. Less than 66 pounds (30 kilograms) of fuel remains, held in reserve for the time Aqua is lowered into the atmosphere and safely burned up. Until then, the satellite continues its orbit, like a car in neutral rolling down a hill.

After it's switched off in the fall, Aqua will no longer have enough fuel to dodge incoming space junk. The risk of collision for U.S. government satellites is supposed to be 1 in 1,000, but the risk increases once fuel runs out.

In 2007, when China destroyed one of its own satellites, multiple satellites had to maneuver to avoid space debris, raising concerns about the possibility of Kessler Syndrome, where satellite collisions begin to cascade, like dominoes.

There have been four confirmed space collisions, according to the ESA, but only one involving a climate satellite: An incident in 2021 when a piece of debris from a Russian Zenit-2 rocket hit China's Yunhai-1 02 meteorological satellite.

The danger is increasing, with ESA estimating a 20% rise in collision risk since 2024. Because of the increased risk, satellites have become almost uninsurable, meaning NGOs and government agencies are increasingly bearing the cost of threats to climate satellites.

MethaneSAT, a satellite designed to capture methane emissions to help better understand the greenhouse gas, stopped transmitting data in 2025 only fifteen months into its life cycle. After high solar activity, the satellite suddenly shut down. Investigators couldn't agree why.

Two years before that, the first satellite from London-based SatVu, HOTSAT-1, went into orbit for Earth observation. But only months after releasing its first images, the satellite’s infrared camera went dead. "If that satellite had not been insured, that would have killed the whole company," says Bonwick. "It's not just balance sheet protection, it's survival."

The MODIS fire-tracking dataset is set to continue until Aqua and its partner satellite Terra are turned off. NASA, which responded to an initial email from Space.com but has yet to answer specific questions concerning the issue, is continuing its fire detection capabilities through the Visible Infrared Imaging Radiometer Suite (VIIRS), a database that survives on multiple NASA satellites.

But with the space agency suffering from government cuts, private firms are now filling the gap. Google has published plans to launch a constellation of satellites specifically for fire detection, which promises to capture even smaller fires at greater resolution than before.

On May 4, Aqua celebrated its 24th birthday. It will probably be its last. It completed more than 126,000 orbits of the Earth, and enabled at least 30,000 scientific publications.

The satellite leaves behind one of the longest single-satellite climate data records ever compiled. Its contributions to climate science will be hard to replace.

Update 5/21: Bonwick's comment regarding satellite insurance possibly killing a company was in reference to the HOTSAT-1 satellite from London-based SatVu.

A colossal Antarctic iceberg that first broke free in the 1980s is now soaking up the summer warmth, and from orbit seems to be turning a shade of aquamarine. In this recent image from NASA's Earth Observatory, iceberg A-23A is streaked with blue meltwater ponds and surrounded by a halo of fractured ice, signs that the long-lived "megaberg" is perhaps in its final days.

What is it?

Iceberg A-23A is considered a tabular iceberg, essentially a giant floating slab that calved Antarctica's Filchner Ice Shelf in 1986, the same year as the Chernobyl explosion and the Space Shuttle Challenger disaster. Scientists have been tracking the iceberg for decades, making it one of the largest and longest-observed icebergs on record.

The "blue stripes" cutting across the iceberg are meltwater ponds: pools of liquid water that collect in low spots on the ice surface when air temperatures rise and sunlight intensifies during the austral summer. NASA's Terra satellite captured this image on Dec. 26, 2025 and the next day an astronaut aboard the International Space Station snapped an even closer view of the meltwater ponds using a Nikon Z9 camera to do so.

Where is it?

This image was taken from low Earth Orbit by NASA's Terra satellite. As of early January 2026, iceberg A-23A is drifting in the South Atlantic Ocean, between the eastern tip of South America and South Georgia Island.

Why is it amazing?

Given how large and how long Iceberg A-23A has been around, there's no guarantee it will exist much longer. Satellites like Terra help scientists capture in real time the mechanics of how big ice slabs break apart. When water gathers inside the meltwater ponds and fractures in an iceberg, its weight can pry the slab apart, causing a rapid breakup of events on ice shelves and icebergs, like A-23A. Seeing these features can help scientists test and refine models of how floating ice fails.

When an iceberg as large as A-23A melts, it injects significant cold freshwater into the ocean, which can affect mixing and local circulation. This can lead to upwelling of deeper nutrient rich waters that can help fuel phytoplankton growth, which is a key foundation in the marine food web.

While icebergs are a natural part of how ice shelves and glaciers shed mass, the effects of climate change and global warming are speeding up these processes, making it a key time for researchers to watch from space and track these icy giants.

Want to learn more?

You can learn more about icebergs and Earth-observing satellites.

A satellite that's watched Earth for 20 years is retiring to a so-called graveyard orbit high above the Earth that puts out-of-commission satellites out of harm's way. Although the satellite, Meteosat-7, was only designed for about five years of use, it's sent meteorological data back to Earth for nearly two decades.

Satellites in low-Earth orbit save enough fuel to redirect downward and eventually burn up in the atmosphere, to reduce crowding in active orbits. But some satellites like this retiring one, called Meteosat-7, are too high to make it to that final burn-up stage without carrying way too much extra fuel. Instead, Meteosat-7 will begin a complicated series of maneuvers to come to rest in a region at least 125 miles (200 km) above the highest active satellites, according to a statement from the European satellite-monitoring agency EUMETSAT.

Meteosat-7 orbits high in geostationary orbit, 22,000 miles (36,000 km) above Earth's surface, always staying above the Indian Ocean. Geostationary orbits are the highest Earth orbits satellites use — more than 21,000 miles (35,000 km) higher than the International Space Station, which is in low Earth orbit — and they stay put over one particular part of the surface as Earth rotates. [How to Spot the International Space Station & Satellites]

From its current perch, Meteosat-7 monitors Africa, Europe and part of South America, and when it departs in the spring, a recently-relocated satellite, Meteosat-8, will take over. 

Under requirements set by the International Organization for Standardization, satellites that can't reach Earth's atmosphere for burn-up must be equipped to reach a geostationary orbit of a certain altitude, EUMETSAT officials said in the statement. So it's really more of a graveyard region than graveyard orbit.

"You must target, with 90 percent probability, that you will clear this 200 km-plus region," Milan Klinc, a flight dynamics engineer at EUMETSAT, said in the statement. "We will most probably reach 500 km to 600 km [310 to 370 miles] above the geostationary protected region with Meteosat-7." 

Then, the satellite will get rid of as much leftover propellant as possible; discharge and disconnect its batteries; fire any remaining explosives (used on one-time tasks such as releasing payloads); and switch off its equipment, officials said in the statement.

Meteosat-7's path to the graveyard is a long one: It will increase its altitude every half orbit over a series of several burn maneuvers. 

"We have designed it so that after burn number three, we will have cleared the protected region," Klinc said in the statement. "We have allowed a margin for uncertainties and will keep maneuvering higher up, with up to nine burn maneuvers."

At the same time, the satellite will use specific thrusters during its maneuvers that will slow down its rapid spin over time, so any equipment that eventually broke away over time will not be flung out of its new resting orbit — during its time in action, the satellite rotated about 100 times per minute. Klinc pioneered this technique on Meteosat-5 and Meteosat-6, both of which slowed their spins significantly without using extra fuel, according to the statement, and both of which now reside high above the active orbits around Earth.

As Klinc said, the graveyard orbit isn't a single orbit, but rather a region. And the term is possibly inaccurate in another way, too, Klinc added: it might not be the satellites' ultimate resting place. Someday, the region may need to be cleared out as space fills with debris, spacecraft and satellites.

"Space debris is a major problem," Klinc said. "We recognize that the graveyard orbit can only be a temporary solution. We are only in the early, theoretical stages at the moment, but we need to look at a permanent solution involving removing or collecting the old satellites."

Email Sarah Lewin at slewin@space.com or follow her @SarahExplains. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com. 

Ten years after Hurricane Katrina ravaged the city of New Orleans and surrounding areas, NASA is building an innovative storm-monitoring system that could make significant improvements in storm monitoring and warnings.

Eight "microsatellites," each slightly larger than a carry-on suitcase, make up NASA's Cyclone Global Navigation Satellite System (CYGNSS) mission. The satellites will orbit the Earth and, together, provide scientists with updates every few hours about developing storms. A single satellite can send updates only every few days, according to a statement from NASA.

NASSA just gave the CYGNSS team the go-ahead to start building the microsatellites. Chris Ruf, principle investigator for CYGNSS, said this new phase marks "the beginning of a new era in hurricane observations." [Photos of Hurricane Katrina From Space]

The eight CYGNSS satellites will provide scientists with measurements of wind speed near the surface of the ocean, at the core of various tropical cyclones, typhoons and hurricanes.

"These measurements will advance forecasting methods by providing data that can lead to better predictions of hurricane tracks, intensities and storm surges," the NASA website for CYGNSS said. "The ability to better monitor and predict the rapid changes in hurricane intensity, such as those observed with Hurricane Katrina, is critical to hurricane forecasters and U.S. coastal communities."

Interestingly, the microsatellites won't actually take measurements of wind speed themselves; they'll collect that data from GPS satellites. This, the mission website said, is what makes the program innovative and cost-effective.

Satellites that measure wind speeds on the surface of the earth use a technique called scatterometry, in which a radar instrument shoots a signal at the ground, the signal bounces back and the instrument looks at how the signal has changed. GPS satellites already in orbit around the Earth are already generating those radar signals, so CYGNSS will only receive the GPS signals. According to NASA, building instruments that both send and receive the signals is much more expensive than instruments that do just one of those things.

With this approach, the CYGNESS team will create a "new image of wind speed over the entire tropics every few hours, compared to every few days for a single satellite," the mission home page said. The eight satellites will be spread out around the planet, each successive satellite passing over the same location at 12 minutes apart. They will collect signals from multiple GPS satellite constellations.

The CYGNSS microsatellites will each weigh about 64 lbs. (29 kilograms) and have a wingspan of about 5.5 feet (1.7 meters) with their solar panels deployed. Assembly of the first satellite is underway, with the other seven to be constructed in the next few weeks, NASA said. The satellites are scheduled to be stacked for testing in early 2016, with a scheduled launch date in late 2016, and science operations set to begin during the 2017 Atlantic hurricane season.

Follow Calla Cofield @callacofield.Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.

Remote sensing of ocean color is a currently well-established science that provides information about water composition and the depth of light penetration based on the ocean color, as seen from space. Ocean color satellites are part of an Earth observing system and, due to the importance of this system in understanding the state of the ocean and its evolution, the international scientific community has agreed to joint efforts to keep a constant constellation of ocean color satellites orbiting our planet.

The first of those ocean color sensors was the CZCS (Coastal Zone Color Scanner) Experiment, launched by NASA in 1978 onboard the Nimbus-7 satellite as part of a proof-of-concept of the capability to measure suspended and dissolved particles in ocean waters from space. Photosynthetic pigments were the main focus of this pioneering mission. Quantifying and monitoring those pigments is essential to understand the systemic functioning of our planet, since photosynthesis is the process responsible for turning carbon dioxide (CO₂) into our breathable oxygen (O₂) and for the planet's primary production that sustains the trophic web (the food web). In this way, plants and microalgae provide food and air for most of Earth's life forms, especially the macroscopic forms such as animals, obviously including humans.

Although the CZCS mission was successful, when this sensor stopped working in 1986, there was a ten year wait until a new ocean color mission was sent into space to continue those studies. These new ocean color sensors – named MOS, OCTS and POLDER – were launched in 1996. [Photos: Amazing Images of Earth from Space] 

Maintaining ocean color space-borne platforms in orbit is a goal, since scientists want to observe the ocean over long periods of time. Recently, Brazil and Argentina joined this international constellation to provide valuable data and help to prevent another ocean color data gap. The mission is called SABIA-Mar, an acronym which means Argentinean-Brazilian Satellite of Environmental Information of the Sea (the name works both in Spanish and Portuguese, the official languages of the respective countries). The name "Sabiá" means "truethrush", a group of birds form the genus Turdusthat are common in the region of Argentina and Brazil.

The SABIA-Mar mission is an initiative of Agência Espacial Brasileira– AEB (Brazilian Space Agency), Instituto Nacional de Pesquisas Espaciais- INPE (National Institute for Space Research), both from Brazil and CONAE Comisión Nacional de Actividades Espaciales (National Commission of Space Activities) from Argentina. Its technical characteristics are still a matter of discussion, so these institutions put together a workshop in Buenos Aires (March 14-15^th of 2013) and Brasília (May 13-14^th of 2013) the capitals of Argentina and Brazil, respectively. The workshop community was composed of government and private institutions from both countries, and now the greater international community of potential users of the satellites is also being asked to contribute and provide their critiques and demands. 

"The satellite must supply the highest number of demands as possible." says Petrônio de Souza, Director of Space Policy and Strategic Investments from AEB.

"It is necessary to know what the future SABIA-Mar users need," reaffirmed the Brazilian Manager of the mission, Marco Antônio Chamon, during the workshop in Brasília. As is usual for most of the other ocean color missions, the data will be available for free to interested users worldwide.

The main decision from these meetings was the agreement on splitting the SABIA-Mar mission into two satellites: one focused on imaging the global oceans, expected to launch in 2018, and another for regional studies, planned for 2019.

Imaging specific regions requires a higher spatial resolution and represents a technological jump for both countries involved. But the regional data also represents a scientific challenge for the whole ocean color research community. The open ocean is well known for its deep blue color, caused by water molecules interacting with sunlight. But coastal zones and interior water bodies such as lakes and rivers have much more complex color patterns, because they are highly influenced by suspended sediments, dissolved organic matter and phytoplankton (microalgae). It is currently hard to precisely partition the contribution of each one of these substances, so these water bodies will be the focus of the regional camera to be placed onboard the regional SABIA-Mar satellite. [Oceans & Us: A Gallery of Human Uses]   

The actual objective of this space mission is to better understand the Earth's carbon cycle, as well as to help fisheries and aquiculture, detect and monitor pollution and harmful algal blooms, follow species at risk, evaluate water quality and water visibility, and study climate and environmental changes. The mission will also aid coastal management efforts and national sovereignty and defense measures.

But while we can observe the ocean in the present, we also need to envision the ocean in the future. Ocean color remote sensing naturally is a space-borne vocation, and the discoveries of Earth possibly could be extrapolated to other planets and moons inside and outside the Solar System. Perhaps remote sensing of Earth will inspire future missions to observe the frozen ocean of Jupiter's moon Europa and the hydrocarbon lakes of Saturn's moon Titan in the coming decades.

The knowledge gained from the ocean color science may also help astrobiologists to hunt for extraterrestrial life. Ocean color is presently the only way to monitor phytoplankton from local to global scales, and its variation in density and composition through several time scales. Scientists are currently identifying the range of sunlight absorption by each photosynthetic pigment known to exist on Earth's plants and algae. Future optical sensors onboard deep space satellites or probes may look for those pigments in the nearer exoplanets. While still a matter of speculation, if such sensors turn out to be possible, the big distances involved will demand a much higher precision and accuracy than what the present ocean color science state-of-the-art technology has.

Photosynthetic pigments are the result of an evolutionary adaption of Earth's life to the available light, and depend on the Sun's distance, age and magnitude. Astrobiologists are now considering other possible photosynthetic pigments adapted to different types of stars and distances from them. For example, the forest and algae colors of other worlds may be very different than our green patterns. We can assume there could be extraterrestrial habitats verging into red and yellow colors, for instance.

By better comprehending terrestrial life and considering the biochemical possibilities, we should be able to explore whether some of our closest neighbors may harbor extraterrestrial life "as we know it," or at least, what we can assume alien life may possibly be like.  

This story was provided by Astrobiology Magazine, a web-based publication sponsored by the NASA astrobiology program.

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