Scientists have measured temperatures beneath the surface of Jupiter's volcanic moon Io, offering the first-ever glimpse of the hidden heat driving the most volcanically active world in the solar system.

During close flybys of Io in late 2023 and early 2024, NASA's Juno spacecraft turned its Microwave Radiometer (MWR) instrument toward the moon, probing roughly six to 20 feet (two to six meters) beneath its surface. Originally designed to peer through Jupiter's thick clouds, the instrument instead revealed a powerful new way to study how heat moves through planetary crusts, according to a statement from the space agency.

"The surprising discovery that we could see below a rocky moon's surface has important implications for studying Earth's volcanoes," Scott Bolton, coauthor of the study and Juno's principal investigator, said in the statement. "Juno has taught us that if we look with an MWR-type instrument near a volcano on Earth, we might see a similar signature in the subsurface temperature gradient, providing new information on how terrestrial volcanoes work."

Until now, researchers had relied almost entirely on infrared observations, which detect only the temperature of Io's surface. By probing several feet underground, Juno has revealed how heat moves through the moon's crust for the first time.

The measurements showed temperatures rising by more than 40 degrees Fahrenheit (22 degrees Celsius) just a few feet below the surface — far more than sunlight alone could explain. Juno's subsurface heat map also revealed localized regions of elevated heat, with temperatures measuring between 18 and 36 degrees F (10 to 20 degrees C) warmer than the surrounding terrain, according to the statement.

Juno's observations uncovered another surprise, too. Despite being known for its towering mountains and active volcanoes, much of Io's surface appears remarkably smooth and composed of unusually low-density material. Researchers think the moon is blanketed by porous layers of volcanic ash, sulfur frost and other eruptive debris that continually resurface Io, burying older terrain beneath fresh deposits.

Scientists think the heat detected beneath Io's surface could be rising steadily from the moon's molten interior through a conductive crust or coming from pockets of cooling lava flows trapped just below the surface. Either way, the data provide the clearest picture yet of how Io transports heat from its interior.

Unlike Earth, where volcanism is driven largely by heat from radioactive decay, Io is continuously stretched and squeezed by Jupiter's immense gravity as it orbits the giant planet. This constant tidal flexing generates enormous amounts of internal heat, fueling hundreds of active volcanoes and making Io the most volcanically active object in the solar system. By improving scientists' understanding of how heat and magma move beneath a planet's surface before eruptions, the same microwave techniques used by Juno could one day help researchers better monitor Earth's volcanoes and improve eruption forecasting.

"Io provides a unique window into learning how tidal heating works throughout the cosmos, a fundamental process that provides energy and heat to worlds that are far from their parent star," Bolton said in the statement. "This process can not only create the most volcanic body in the solar system, in the case of Io, but also fuels the subsurface oceans on the moons of giant planets, such as Europa and Ganymede. Up until this point we could only observe the heat escaping at the surface or through eruptions. Now we can characterize how the heat is moving from the interior toward the surface."

Because Io is an extreme example of volcanic activity, it serves as a natural laboratory for studying how heat moves through planetary crusts. Those insights could help scientists better understand ancient volcanism on Mars, Venus, and Earth's moon, whose landscapes were shaped by massive eruptions billions of years ago.

The technique could also aid the search for life elsewhere. While Io itself is far too hostile to support life, microwave instruments can also probe beneath icy surfaces. Juno has already used the same instrument to study Jupiter's moons Europa and Ganymede, where scientists believe vast oceans lie hidden beneath thick shells of ice. Understanding how heat moves through those crusts is key to determining whether they could harbor environments suitable for life as we know it.

Their findings were published July 22 in the Journal of Geophysical Research: Planets.

Last year, NASA's Lucy spacecraft encountered a bi-lobed asteroid that is a chunk of an even larger rocky body that was smashed apart in an almighty collision 155 million years ago. This little pitstop happened on Lucy's way to a rendezvous with the Trojan asteroids that shadow Jupiter around the sun.

The asteroid 52246 Donaldjohanson, better known as "DJ" to Lucy's mission scientists and named after the paleoanthropologist who discovered the Lucy hominin fossil in Ethiopia in 1974, orbits the sun in the inner part of the main asteroid belt between Mars and Jupiter.

The true Lucy fossil dates back in time 3.2 million years and is an important link in the evolutionary chain that led to homo sapiens. Likewise, primitive asteroidal bodies are somewhat like fossilized remnants of the building blocks of the solar system's planets, including Earth. Understanding the make-up of these asteroids and where they formed versus where they are now can provide crucial insights into how Earth was assembled and where its organic materials and water may have come from.

Lucy flew past DJ in April of 2025. It is a pretty primitive asteroid, meaning that it has, or once upon a time had, certain volatile materials such as water-ice, as well as plenty of carbon — all things that can be removed thermally over time. Most objects that contain volatiles originate in the outer solar system, where it is cold enough that the volatiles do not sublimate away.

Within DJ's composition, Lucy detected iron-bearing phyllosilicates, which are a mineral formed in the presence of liquid water.

"Phyllosilicates are an indication that water was present and there was some degree of aqueous alteration," Simone Marchi, a planetary scientist from the South-west Research Institute and lead of the study into DJ, told Space.com.

However, for DJ to have had water, it must have formed further out from the sun, possibly in the outer asteroid belt.

"But DJ belongs to the inner asteroid belt so that's already intriguing," said Marchi.

The spectral evidence also indicates DJ was only partially altered by water, which Marchi says tells us something about its history.

"The aqueous alteration terminated early, and though we don't know why, we can speculate. In order to have aqueous alteration there needs to be some internal heating [usually via radioactive elements] and if something forms later than everything else then there will be less heat [since many of the radioactive elements will have already decayed]. Or perhaps there was just less water to start with where it formed."

What we do know is that DJ was once part of a much larger asteroid that suffered a giant impact 155 million years ago, causing the parent body to break apart into a number of chunks, the largest being the 45-mile-wide (73-kilometer-wide) asteroid 163 Erigone. Consequently, the remains of this parent asteroid, including DJ, are collectively referred to as the Erigone family.

DJ's violent origin may also explain its shape, which features two lobes joined together by a narrower and relatively smooth neck.

"We have now seen many small bodies in the solar system that appear to have this bi-lobed shape, and that's across a wide range of sizes," said Marchi.

For example the near-Earth asteroids 25142 Itokawa, which was visited by the first Japanese Hayabusa mission in 2005, and 4149 Toutatis that was encountered by China's Chang'e 2 in 2012, are both bi-lobed. So too is the tiny asteroid Selam, which is a satellite of the asteroid 152830 Dinkinesh visited by Lucy in 2023. Then there are cometary bodies including 67P Churyumov–Gerasimenko visited by the Rosetta mission and comet 19P/Borrelly, imaged by NASA's Deep Space 1 spacecraft in 1999.

These objects are all different sizes, different types and in different locations, but they all share the same structure. However, Marchi cautions that they might not all form the same way. For example, the neck between the lobes of comets such as 67P might form through erosion via sublimation and outgassing as the comet gets closer to the Sun, whereas for asteroids it might indicate a history of being involved in a giant impact, the resulting fragments coming together to be bound by gravity – a so-called contact binary.

Lucy now continues onwards, scheduled to encounter its first trojan asteroid, known as 3548 Eurybates, in August 2027. Trojans are asteroids that have been captured by Jupiter's gravity at the L3 and L4 Lagrange points, 60 degrees in front and 60 degrees behind Jupiter itself.

"We think that the Trojans, based on our understanding of the solar system, formed further out and then were captured where they are today following the early shuffling of the planets," said Marchi. "This shuffling could also have been the origin of DJ, so there could be a connection there between DJ and the Trojans."

Compositionally, the majority of trojans are expected to be even more primitive than DJ, containing more carbon, water and other volatile materials that would sublimate if they got too close to the sun.

That is all except one: Eurybates.

"It is the only one of our targets that from spectroscopy appears to be relatively similar to DJ. It's not identical, but it is closer in composition to DJ than the other Trojans, so it will be intriguing to compare them," said Marchi.

Indeed, any similarities will help tell us how asteroids were herded around during the first few hundred million years of solar system history following the formation of the planets. Jupiter and Saturn, especially, began migrating inwards and then out again. In doing so, their gravity pushed and pulled minor bodies all over the place, as did the gravity of Uranus and particularly Neptune as they edged outwards. These migrations led to the formation of the asteroid belt and the Kuiper belt, and ejected trillions of bodies into the wide orbits of the Oort Cloud.

"The key question is, if DJ has been relocated in the inner asteroid belt, then how many other asteroids came along with it and ended up being closer to the Earth, where they could have delivered some water, some organics and other things to our planet?" asked Marchi.

Lucy will visit six of Jupiter's trojans, which in total number over 15,300 discovered so far. Far from lumps of rock, the trojans, along with DJ and Dinkinesh (which is the Ethiopian name for the Lucy fossil), are windows into the past, and the storytellers of the Earth's most ancient history.

Lucy's findings from Donaldjohanson were published on Thursday (June 18) in the journal Science.

Earth got some of the key ingredients for life from asteroids in the inner solar system – with a little help from the solar system's largest planet, Jupiter, according to a recent study.

To figure out why we’re all here, and whether anyone else might be out there in the universe, scientists have to start with a more basic question: how did Earth get its supply of the chemicals that make up living cells?

According to Rice University planetary scientist Rajdeep Dasgupta and his colleagues, Earth’s stockpile of phosphorus and nitrogen, two chemical elements essential to life, came mostly from chunks of rock that formed in the inner solar system. And that process might not have happened without Jupiter looming just outside the asteroid belt.

"For our own solar system, Jupiter's presence and growth history indeed seem to have played a critical role in determining the distribution of the basic chemical ingredients necessary for habitable worlds," said Dasgupta in a NASA press release. "It remains an open question whether a life-essential elements budget similar to Earth's can be estimated without a Jupiter-like planet in the population."

Jupiter scores an assist

Dasgupta and his colleagues combined lab experiments and computer simulations to map the proportions of nitrogen and phosphorus, two chemical elements essential to life, in the early solar system. Life as we know it is literally built on these two elements; you can't build amino acids without nitrogen, and you can’t build DNA or RNA without phosphorus.

Other elements are also essential: carbon, hydrogen, oxygen, and sulfur, but how Earth got its phosphorus, in particular, has gotten less attention from researchers so far.

When scientists are investigating how Earth might have received the ingredients for life, one big clue is the ratio of each element to the others. Those proportions can form sort of a chemical fingerprint pointing back to the elements’ original source. In this case, looking at the ratio of phosphorus to nitrogen in present-day Earth’s rocky bulk could shed some light on where Earth’s phosphorus came from.

In the lab, the researchers simulated how different elements sort into layers as a newly formed asteroid cools, causing molten rock to crystallize. They also used computer simulations to model how different groups of planetesimals, clumps of metal and rock that coalesced out of the swirling disk of dust around the newborn sun, became the seeds of potential planets, formed and moved around the early solar system – moving phosphorus and nitrogen with them.

It turns out that present-day Earth contains phosphorus and nitrogen in about the same proportions as rocky planetesimals that formed in the inner solar system, the area between Jupiter and the Sun, around 4.3 to 4.2 million years ago.

Dasgupta and his colleagues’ models suggest that these chunks of rock, part of our solar system’s second generation of planetesimals, probably brought their shares of phosphorus and nitrogen to Earth as our planet was still forming. In a lot of cases, Earth’s gravity probably captured these objects and pulled them in, adding them to its growing bulk. Others got flung toward the accreting planet by collisions or close encounters with other objects, and Jupiter played a key role in that process.

Jupiter formed before Earth, and its tremendous gravitational influence shaped how material flowed through the disk of gas and dust that orbited the young sun.

Before Jupiter loomed onto the scene, material in the disk tended to flow outward, carrying its stores of phosphorus and nitrogen with them. However, Jupiter's hulking presence blocked most of that flow, keeping more of that rock, dust, and gas trapped in the inner solar system.

As the second generation of planetesimals was forged in the inner solar system around 4.3 to 4.2 million years ago, with Jupiter presiding, they formed with a higher ratio of phosphorus to nitrogen than their older siblings out beyond Jupiter's orbit.

Thus, the solar system's most massive world played a key role in distributing elements throughout the solar system, including those vital to life that were later delivered to Earth by asteroids that impacted our planet in its infancy.

Dasgupta and his colleagues published their work in the journal Science Advances.

Look west sky after sunset on June 17 to witness a slender crescent moon gleaming alongside the stars of the Beehive Cluster at the head of a dazzling planetary parade.

Mercury's steady light will shine low on the western horizon in the glow of the setting sun, as while Jupiter glistens close to its upper left, with Venus and the moon lining up beyond to create a spectacular planetary display.

You may notice the soft glow of earthshine infusing the night side of the moon on June 17, as light bounces off our planet to illuminate the lunar crescent while it glides silently through the 1,000-strong stellar population of the Beehive cluster.

A pair of 10x50 binoculars will reveal dozens of the brilliant, young stars surrounding the three-day-old moon, while a 4-inch telescope will provide the magnification needed to highlight the cloud bands of Jupiter and its four large Galilean moons.

Mercury will be the first of the parade members to slip from view, less than two hours after sunset, while the moon will remain visible for another hour after that for stargazers in the U.S., before it dips below the western horizon.

The following night sees the waxing moon leave Venus and the Beehive Cluster behind, as it sweeps towards the blue-white light of Regulus — a multi-star system that glistens at the heart of the constellation Leo.

Mercury, meanwhile, will sink closer to the horizon with each passing night in the weeks that follow, as Venus rises away from Jupiter to chart a course through the constellation Cancer, before passing just 1 degree from Regulus on July 9.

Interested in snapping your own photos of the night sky? Then be sure to read our roundups of the best cameras and lenses for astrophotography, along with our beginner's guide to imaging the post sunset realm.

Editor's Note: Want to share your planetary photos with Space.com's readers? Then please send your image(s) and comments, along with your name and location to spacephotos@space.com.

Mercury reaches greatest elongation on June 15, placing the elusive planet at its farthest apparent distance from the sun in the evening sky. That makes this one of the best opportunities of the year to spot Mercury after sunset, shining below Venus and Jupiter in the western sky.

As an "inner" planet, Mercury never strays particularly far from the horizon compared to the outer planets like Mars and Jupiter, which shine brightly overhead from dusk to dawn at opposition, when they sit opposite the sun in Earth's sky.

Mercury's tight orbit around the sun sees it yo-yo back and forth between the evening and morning sky throughout the year. As such is it often lost from view in the glare of our parent star. The rocky world will reach its point of greatest elongation on June 15, when it will appear about 17 degrees away from our parent star — marking one of the best times to see it in its current evening apparition.

How to find Mercury on June 15

Look to the western sky at sunset to find Mercury shining less than 20 degrees above the horizon, with Jupiter and Venus forming a line to its upper left. The razor-thin crescent of the waxing moon will also be present to the lower right of Mercury, all but impossible to spot in the glow of the setting sun.

The weeks that follow will see Mercury's steady light move inexorably closer to the horizon with each passing night, leading up to its inferior solar conjunction on July 12, when it passes between the sun and Earth before transitioning to a morning object.

Want to catch striking images of the night sky? Then be sure to read our picks of the best cameras and lenses for astrophotography, along with our beginner's guide to imaging the night sky.

Editor's Note: If you would like to share your astrophotography with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

Astrophotographer Soumyadeep Mukherjee has shared a spectacular 30-day collage of the western night sky titled "Closer, Everyday", which captures the subtle motion of Jupiter and Venus as they danced through the skies above Kolkata, India, ahead of a dramatic planetary conjunction.

The photos used to create the collage were taken with a Nikon Z6II camera paired with a Sigma 50 mm lens in the hours following sunset from May 11 through to June 9, as Jupiter and Venus shone close to one another in the constellation Gemini.

"On most of the days, the images were captured during civil twilight in order to showcase the varying colours of the twilight sky along with the planets," Mukherjee told Space.com in an email. "However, on some occasions, due to the presence of clouds, images were captured during nautical and astronomical twilight."

Mukherjee remained consistent with his technique throughout, varying only the shutter speed to account for changing light conditions, creating a gorgeous glimpse of the planetary procession. "During capturing the images, the camera was kept level to the horizon, and the planets were placed right at the middle of the frame, as much as possible," explained Mukherjee. "The images were captured with the same camera, the same lens, at the same focal length."

Each successive shot tracked the relentless movement of Jupiter and Venus as they circled the sun, while appearing to draw closer to one another in Earth's sky. The slow dance came to a climax on June 9 — which is depicted in the far right panel — when skywatchers worldwide were treated to a dramatic planetary conjunction as Jupiter and Venus shone less than 2 degrees away from one another above the western horizon.

In reality, the close pass of Jupiter and Venus was nothing more than a misleading matter of perspective. Venus has actually been growing more distant from Jupiter throughout the 30-day photoshoot, during which time it added another 27 million miles (43 million kilometers) between itself and the gas giant as it raced toward Earth.

Want to create your own incredible photos of the night sky? Then be sure to read our roundups of the best cameras and lenses for astrophotography, along with our beginner's guide to photographing the post-sunset realm.

Editor's Note: If you would like to share your astrophotography with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

Mercury, Venus, and Jupiter align low over the western horizon after sunset tonight, creating a satisfying mini planetary parade and a perfect astrophoto opportunity using a wide-angle lens or even just a smartphone.

Even though Venus and Jupiter have drifted apart slightly since their tight embrace on June 9, Mercury has climbed up beautifully from the sun's glare to join the party. Together, they form a striking slanted line along the ecliptic in the west-northwestern sky right after sunset.

This is a high-speed game. The optimal viewing window starts exactly 30 minutes after your local sunset and lasts for only about 30 to 45 minutes before Jupiter and Mercury follow the sun below the horizon.

Look for blazing Venus first — it will pop out while the sky is still bright. Drop your eyes down and slightly to the right to easily spot Mercury and Jupiter.

For observers using telescopes or imaging equipment, June 12 also offers an interesting opportunity to compare the appearance of the three worlds. Venus will show a small, intensely bright, 80%-illuminated gibbous disk, while Mercury will present a stark contrast with its 50%-illuminated "half-moon" phase. Resolving a clean, tiny half-Mercury in twilight is an elite visual feather in any amateur's cap. Jupiter will appear as a much larger disk, although its low position above the horizon means atmospheric turbulence may blur some detail. Under steady conditions, advanced imagers may be able to capture hints of the planet's famous equatorial cloud belts alongside Mercury's sharply defined silhouette.

For photographers, however, June 12 is all about landscape composition. Put away the prime-focus telescope adaptors and grab a 50 mm to 85 mm prime lens on a DSLR/mirrorless camera. Expose for the deep twilight sky colors and frame the three planets as a slanted cosmic ladder ascending over a crisp local silhouette — like a mountain ridge, a distant city skyline, or a line of pine trees.

If you're looking for a telescope or binoculars to observe the night sky in more detail, our guides for the best binocular deals and the best telescope deals can help. Our best cameras for astrophotography and best lenses for astrophotography can help you get ready to capture the next stunning skywatching event.

Jupiter and Venus put on a spectacular performance as they met in the twilight sky on June 9 during a close planetary conjunction as Mercury lurked nearby — and we've got the photos to prove it!

The planetary trio have been locked in a mesmerizing slow dance in the western sunset sky over the past few weeks, forming a spectacular line-up before breaking ranks in dramatic fashion, as Venus beat a slow but inexorable path towards Jupiter.

The cosmic dance came to a climax on June 9, as Jupiter and Venus reached conjunction while shining less than 2 degrees from one another amongst the stars of the constellation Gemini.

Read on to see spectacular images of the close planetary approach, as captured by the global astrophotography community.

June 2026 Venus-Jupiter conjunction in photos

Astrophotographer Josh Dury snapped a gorgeous view of Venus and Jupiter meeting in the skies above the prehistoric Avebury stone circles in Wiltshire, U.K., on June 8, as the bright stars Castor and Pollux glowed off to their right.

"These two stones almost appear to mirror the angle of the planets," Dury noted in an email to Space.com. "Almost like a couple gazing up to the wonders of the universe."

Our next view was captured by Cheng Xin as the planetary duo shone brightly in the skies over the city of Shenzhen in the Guangdong Province of China — close enough to fit comfortably in the field of view of a pair of 10x50 binoculars.

Photographer Riste Spiroski took this image of the planets shining above the rooftops of Skopje, the capital city of the Republic of North Macedonia. Tiny dots extending from Jupiter's disk hint at the presence of its four Galilean moons.

"While Venus and Jupiter are separated by hundreds of millions of kilometres in space, tonight they appeared close together from our perspective on Earth, creating one of the year's most beautiful celestial sights," Spirosky told Space.com in an email. "I was particularly drawn to the contrast between the couple focused on their phone and the rare astronomical event above them, this contrast inspired the story behind this series."

Yasser Al-Zayyat took this photo of Jupiter and Venus sitting above the Kuwait City skyline on June 9, as skyscrapers cast artificial light into the twilight realm at the climax of the planetary conjunction.

Our final image comes courtesy of Osama Fathi, who captured the distant worlds shining over the volcanic mountains of Egypt's Black Desert on June 6, as Venus drew closer to Jupiter in the twilight sky using a Nikon Z6 camera paired with aNikon Nikkor 24 mm lens.

"The terrestrial foreground was captured during the twilight 'blue hour,' while the star-studded sky was built by stacking multiple short exposures to reveal the faint background stars without blowing out the bright planets," Fathi told Space.com in an email.

Want to capture gorgeous images of the post-sunset realm for yourself? Then be sure to read our beginner's guide to photographing the night sky, along with our roundups of the best lenses and cameras for astrophotography available in 2026.

Editor's Note: If you would like to share your astrophotography with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

Jupiter and Venus will be separated by less than two degrees in the sunset sky on June 9! Here's how you can watch the dazzling conjunction from the comfort of your home, courtesy of a livestream from the Virtual Telescope Project.

The livestream is scheduled to start at 3:30 p.m. EDT (1930 GMT), featuring live views of Venus and Jupiter from the Virtual Telescope Project's suite of robotic telescopes in Manciano, Italy, weather permitting.

Virtual Telescope Project founder Gianluca Masi shared a gorgeous photo of Jupiter and Venus shining together on June 6, which gave us a tantalising preview of the breathtaking visuals that we can expect during the upcoming livestream.

Venus shines to the right in the image, surrounded by a diffuse haze as the sunlight reflected off its surface illuminates a wisp of cloud during its passage through Earth's atmosphere. Jupiter — the king of the planets — casts a warm light to the left, accompanied by a line of bright star-like objects that represent the gas giant's four large Galilean moons.

By June 9, Venus will sit less than two degrees to the upper right of Jupiter in the western sky — roughly the width of two little fingers held at arm's length — while Mercury's steady light will shine to the lower right of the planetary duo, almost lost in the glow of the setting sun.

Want to capture spectacular photos of the night sky for yourself? Then be sure to check out our beginner's guide to photographing the night sky, along with our roundups of the best cameras and lenses for astrophotography.

Editor's Note: If you capture a photo of Jupiter and Venus and would like to share your astrophotography with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

Shortly after sunset on June 9, Venus and Jupiter will look very close together, in what is known as a planetary conjunction.

Sunlight will reflect off the cloudy tops of Venus and Jupiter before journeying millions of miles to enter Earth's sky in almost the same place, making the planets appear very close to one another on Tuesday (June 9). But in reality, the two planets will be separated by at least four Earth-sun distances in space.

A conjunction between Jupiter and Venus also happened just ten months ago, in August 2025. Before that, in May 2024, preceded by March 2023. Its occurrence roughly once every year is a sign of a wonderful arrangement of planets that may be absent around other stars. And as it turns out, the conditions that set Venus and Jupiter up for their conjunction are the same that are critical for life to survive on Earth.

'Pie' in the sky

Thanks to the explosion of exoplanet discoveries over the past decade, planetary scientists like Kat Volk, who works at the Planetary Science Institute in Tucson, Arizona, know there are many distant worlds taking wonky and puffed-up loops around their parent stars. But the solar system is more like a pie of pizza.

The flat-disk shape means that, although the sky is a huge dome above our heads, the planets can only appear in part of it.

Venus, Jupiter, and their planetary siblings travel in almost concentric circles around the sun. That means that the planets appear just a handful of degrees above or below the sun's apparent path through the sky, called the ecliptic. (The ecliptic is really the Earth's orbital plane, but from our perspective it appears as though the sun is in motion.)

The Earth's orbital plane is only tilted a little relative to the average plane of the solar system, called the invariable plane, Volk tells Space.com.

"That's why, as we're watching them in the sky, they're all kind of following a path along the ecliptic plane."

It's all reflective of how the sun and the planets formed, said Volk.

"When the sun was being born out of some cloud of gas and dust, it was collapsing down to form the star. Then, angular momentum caused the material surrounding that [star], that didn't make it into the sun, to form a disk that is rotating and orbiting around the star. The really massive bodies in the solar system  — the planets  — tended to form within that disk," said Volk.

But no two stars are the same. Some systems deviate significantly from this proto-structure. "If there's another Earth out there, there's no guarantee that the observers on that 'Earth' would see the same kind of nice ecliptic plane that we see in our solar system."

Our cosmic neighborhood is flat and relatively circular, but that is not universal. "The sun isn't by itself in the galaxy," said Volk. "A lot of stars form in clusters. Sometimes stars actually interrupt and interact with each other," which could boot baby planets into a "wider range of inclinations."

Larger planetary tilts may have happened in the ancient past to our solar system. But after the gas giants migrated from nearer to the sun to the cold reaches they inhabit today, the inner planets and the remaining mass of small bodies like comets and asteroids likely helped to balance out their orbits.

As a result, Earth gets to inhabit what's known as a "dynamically cold" configuration. The planets coast past one another on the ecliptic, and appear to us to nuzzle one another every so often.

The planetary dance and life on Earth

These celestial musings are a symptom of a solar system that supports life on Earth. Orbital dynamics control the distance a planet is from the star, and how stable the planet will be throughout its trip.

Exoplanets with orbits tilted with respect to their invariable plane could disrupt the rest of their system. They could perturb the circular and flat configuration that supports worlds like Earth that have water — an essential ingredient for life as we know it — and the 'Goldilocks' distance year round from a star.

"If our planet's orbit was really elongated, you'd have different intensities with sunlight throughout the year. That would be an additional complication on the climate," said Volk.

"Orbital dynamics allows you to start to think about all those fun, different aspects of what makes our planet habitable, and ask how normal it is to have a habitable planet."

Get ready for a spectacular sight tonight (June 9), as Jupiter and Venus make a close approach in the evening sky, while Mercury shines close to the western horizon in the glow of the setting sun.

Stargazers in the U.S. will see the bright light of Venus glowing less than 20 degrees above the horizon at sunset — roughly the width of two clenched fists held at arm's length — with Jupiter to its lower left. Mercury, meanwhile, is more challenging to spot, as it shines approximately 10 degrees below and to the lower right of the pair, requiring a clear view to the west.

Venus and Jupiter will be separated by less than 2 degrees in the night sky — close enough to share the field of view of a pair of 10x50 binoculars. You may also be able to spot Jupiter's four Galilean moons — Io, Europa, Callisto and Ganymede — appearing as tiny star-like points of light surrounding the gas giant.

The following nights will see Venus rise above Jupiter as it tracks a path toward the heart of the nearby constellation Cancer, where it will shine with the open star cluster Messier 44 — also known as Praesepe or the Beehive Cluster — on June 20.

Jupiter, meanwhile, will be progressively harder to spot following its rendezvous with Venus on June 9, appearing fractionally lower on the horizon with each passing night. By early July, the gas giant will be a challenge to spot in the glow of the setting sun, and won't be seen again until mid-August, when it reappears in the eastern morning sky.

Want to get a closer look at the planets? Then be sure to read our roundup of the best telescopes available in 2026. If you're a photographer, then you may also want to read our guide to the top smart telescopes for capturing the night sky, along with our picks of the most capable cameras and lenses for astrophotography.

Editor's Note: If you would like to share your astrophotography with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

The June evening sky this year is exceptionally interesting.

A spectacular gathering of three planets, two bright stars, plus, later this month, a slender crescent moon, will be the chief celestial attraction in the evening sky during the next few weeks. It will, in fact, be possible for anyone with a clear and unobstructed view of the western sky to see all three planets at a single glance.

And two of these planets — Venus and Jupiter — are by far the brightest of those that are readily visible with the unaided eye. In fact, on one particular evening, Tuesday, June 9, these two worlds will seem to "call attention to themselves," even to those who normally do not look up into the night sky.

Jupiter and Venus draw together

No doubt during the past week or so, even casual sky watchers have already taken note of Venus and Jupiter in the guise of two very bright "stars" that have been evident in the west-northwest sky for at least a couple of hours after sunset.

Both shine with a silvery-white luster and one — Venus — appears considerably brighter. And especially noticeable over the course of recent nights is that they seem to be drawing closer to each other. In fact, at this moment in time, from our earthly viewpoint, they literally are like two celestial ships passing in the night. Jupiter will appear about one-seventh as bright as Venus.

On June 7, the two planets will appear side-by-side as they descend toward the horizon, with Jupiter on the left and Venus on the right. They'll be separated by 2.3 degrees. On June 8, Venus will have moved to the upper right of Jupiter, the gap between them having been reduced to 1.8 degrees.

As we have just noted, the two planets will appear closest on June 9. The actual closest approach, with Venus sliding just 1.6 degrees above (north) of Jupiter, will take place at 12 hours Universal Time (UT), which is during the daytime for North America. At that time, just over three times the apparent width of the full moon will separate these two planets. Nonetheless, even though they will already be in the process of slowly separating as darkness falls later that evening, the two planets will still appear practically as close as they were just hours before.

Thereafter, Jupiter will appear to drop rapidly away from Venus, setting progressively earlier and becoming more and more deeply immersed in the bright evening twilight during the balance of June. It will likely disappear in early July.

Venus, on the other hand, reaches its highest altitude in the western evening twilight during June for this current apparition and captures the gaze of millions. All through June, it will appear each evening more than 25 degrees high in the west right after sunset and will not drop below the horizon until at least 2.5 hours later. During this time, Venus will be setting unusually late in the evening, not disappearing beyond the west-northwest horizon until after 11 p.m.

Mercury joins the lineup

While all this is taking place, a third planet will be evident below Venus and Jupiter. That third planet will be Mercury.

Mercury is often cited as the most difficult of the five bright planets to see. Called an "inferior planet" because its orbit is nearer to the sun than the Earth's, Mercury –scarcely more than half as far from the sun as Venus is — always appears from our vantage point to be in the same general direction as the sun and it's usually lost in the sunlight. Yet it's not really that hard to see. You simply must know when and where to look and find a clear horizon.

And for those living in the Northern Hemisphere, a great "window of opportunity" for viewing this rocky little world in the evening sky has just opened. That window, in fact, will remain open through at least June 22, giving you an ample number of chances to see this so-called "elusive planet" with your own eyes.

Currently, Mercury is visible about 45 minutes after sunset. You can use Venus to guide you to Mercury. Just look low toward the west-northwest horizon and you'll readily see Venus shining brightly in the twilight sky. Then look about 15 degrees below and to the right of Venus — your clenched fist held at arm's length measures 10 degrees. Much fainter Mercury will be roughly "one and half fists" from Venus and will be shining with just a trace of a yellowish-orange tinge.

And Mercury will be shining at a very respectable magnitude of -0.2, rivaling orange Arcturus, the fourth brightest star in brilliance. Venus, however, will appear some 33 times brighter.

In the evenings that follow, Mercury will slowly diminish in brightness, but it will also slowly gain altitude as it gradually moves away from the vicinity of the sun. It will achieve its greatest eastern elongation — its greatest angular distance when it will be 25 degrees removed from the sun at magnitude +0.4 — on June 15.

By the evening of June 23, Mercury's brightness will have dropped to magnitude +1.3, equal to the star Regulus in Leo; only one-quarter as bright as it was on June 5. In telescopes, it will appear as a narrowing crescent phase. This will probably be your last view of it. Thereafter, the combination of its lowering altitude, plus its descent into a much-brighter sunset glow, should finally render Mercury invisible. It will pass through inferior conjunction — between the sun and Earth — on July 12.

Enter Gemini's twin stars

Amidst this planet array is a pair of bright stars: Pollux and Castor. They are often considered winter stars, though they remain evident in the west-northwest sky well into the spring. They are the brightest stars in the zodiacal constellation of Gemini, the Latin word for "twins." The two stars represent their heads.

Pollux is slightly brighter (1st magnitude with a slight orange-yellow color) and Castor (2nd magnitude, white). They are a scant 4.5 degrees apart, making good measuring points. In telescopes, Castor is more interesting: it is one of the many "double" stars in the sky. As a matter of fact, it's a triple star, and each of its three components is a double star (six in all!). Through it all, the Twins serve as bystanders, seemingly watching as Venus, Jupiter and Mercury scurry past them during the first three weeks of June.

The moon completes the show

The moon, our nearest neighbor in space, will join the planetary/stellar parade during the third week of June. On June 16, it will appear as a slender sliver of light, just two days past new phase and sitting a little less than 3 degrees above Mercury and 5 degrees to the lower right of Jupiter. Then on June 17, the slightly wider lunar crescent will appear just a couple of degrees to the left of brilliant Venus; the two brightest objects in the night sky adorning the west-northwest evening sky.

Here is a chance to see for yourself that nearby solar system objects generally seem to move faster than more distant ones. Indeed, on June 16 and June 17, as darkness falls, we will have a configuration laid out before us consisting of the moon at 224,000 miles (361,000 km) from Earth; Mercury at 75 million miles (120 million km); Venus at 107 million miles (171 million km) and Jupiter at 568 million miles (914 million km). The motion of the moon can be detected with the naked eye in less than an hour, that of Mercury and Venus from night to night, but Jupiter's travel among the background stars is not very noticeable in even a week. In small telescopes, each object has high interest: Mercury and Venus for their phases, Jupiter for its cloud belts and four Galilean satellites, and finally the moon for its rich surface detail.

The planets in the night sky are always shifting in and out of celestial liaisons and a wide variety of different conjunctions and configurations typically occur during any given year. It is highly unusual, however, when three or more bright planets appear to reside in the same area of the sky. So, in the evenings ahead, everyone should make a concerted effort to go out and look, since similar planet gatherings will be few and far between in the future.

Incidentally, the next time such a favorable June gathering of Mercury, Venus and Jupiter along with Pollux and Castor and the crescent moon occurs again won't come until the year 2085! In fact, on June 14 of that year, those three planets will form an eye-catching compact triangle less than 2 degrees wide.

Mark your calendars.

If you're looking for a telescope or binoculars to observe the night sky, our guides for the best binocular deals and the best telescope deals can help. Our best cameras for astrophotography and best lenses for astrophotography can help you get ready to capture the next stunning skywatching event.

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.

For years, astronomers have suspected that our solar system may have lost at least one world at some point in its 4.5-billion-year history. And now, new research suggests the moons of Jupiter and Uranus may indeed hint that our planetary neighborhood once had a third ice giant.

Evidence has shown that between 3 billion and 4 billion years ago, the solar system's largest planets likely orbited much closer to the sun (and to each other) than they do today. It's also suggested that our four giant planets — Jupiter, Uranus, Saturn and Neptune — gradually shifted into their current orbits due to a series of interactions with one another's gravity.

With this in mind, researchers ran some simulations to explore how all that jostling for position might have affected the moons of Jupiter and Uranus in particular — and the results suggest that these two planets' moons only survived that tumultuous time because of a giant planet that didn't.

Potential histories of the solar system

Clement and his colleagues ran computer simulations of 122 possible versions of the early outer solar system, using different starting combinations of planets and different scenarios for the worlds' migration patterns. They ran each simulated version of the solar system's history several times, taking note of which versions were more likely to produce something that looks like the outer solar system as we know it today. In particular, the researchers were interested in the moons of gas giant Jupiter and ice giant Uranus.

"Planetary encounters, and the [changes in orbit] that result from them, are thought to have played a key role in sculpting many small body populations throughout the solar system," wrote Clement and his colleagues in their recent paper.

Other teams of astronomers have looked for clues about the movements of giant planets in the orbits of asteroids and other small objects, studying them like footprints to reconstruct how they might have been pushed or pulled into their current orbits by the gravity of giant planets on the move. The moons of Jupiter and Uranus offer an especially good set of clues, because it's likely that they've been more-or-less in their current orbits around their planets for most of our solar system's history. Jupiter's moons are in a chain of orbital resonances that could only have formed by the moons tugging gently on each other in passing over a long period of time, and crater records also suggest that Jupiter's moons are very, very old.

We live in an unlikely solar system

As it turns out, Jupiter and Uranus are lucky to have their entourages of moons at all.

Jupiter's moons only made it through the era of migrating giants in less than 15% of simulations; Uranus's moons survived only about 9% of the time.

In fact, scenarios that worked out well for one set of moons tended to be bad for the other: Jupiter's moons had better chances in simulations that started with two extra ice giants, while Uranus's moons survived more often when there was a single, but larger, ice giant. The probability that both giants' moons survive the same scenario is only about 1%.

Clement and his colleagues found only two scenarios in which both planets' moons survived, and both of those included one extra ice giant in the beginning.

"The solar system is the result of fairly unlikely instability evolution," wrote Clement and his colleagues. In other words, picture Dr. Strange grimly holding up two fingers during that battlefield scene in Avengers: Infinity War.

Our solar system’s secret, long-lost ice giant

In the most likely scenario, the solar system starts with five giant planets: the big four we know and love today, plus an extra ice giant — sort of the Pete Best of planets. Sometime in the solar system's first billion years or so, Jupiter's migration brings it within about 4.3 million miles (7 million kilometers) of the unlucky ice giant, giving the latter enough of a gravitational shove to achieve escape velocity. That long-lost ice giant is probably still drifting somewhere out there in interstellar space, cold and alone.

The ice giant getting booted out of the solar system isn't the thing that spared Jupiter's and Uranus' moons from a similar fate. But the fact that the ice giant was ever there in the first place altered the course of the other four planets' migrations just enough to spare Uranus more than one moderately close brush with another giant world's gravity — and kept that period of migration shorter than it otherwise would have been.

Jupiter's close encounter with the long-lost ice giant would've been enough to scramble its moons' orbits a bit, disrupting that neat chain of orbital resonances, but not enough to cause them to crash into each other or fling them out into interplanetary space (and Clement and his colleagues argue that they should have had time to gradually fidget themselves back into their resonances). Meanwhile, Uranus and its moons probably suffered at least two major shakeups: one when something large slammed into the planet and knocked it onto its side, and again during the giant planets' migration. But although both incidents probably caused a few dramatic collisions between the moons, they weren't strong enough to completely wreck the systems.

We may never know the details

During their simulations, Clement and his colleagues tested several things, varying the number and mass of giant planets in the solar system, their starting orbits, and the total mass of objects out in the Kuiper belt — but "the most relevant varied parameter is the initial ice giant number," they wrote.

Clement and his colleagues however note that simulations of the so-called "Nice model" they worked with are stochastic, meaning there's an element of randomness involved in what happens once objects in motion start interacting. And that means it's pretty likely that none of their simulations re-creates exactly what happened — just the general idea.

"It is highly likely that none of the modeled instabilities in the literature contain the precise sequence of encounters necessary to exactly reproduce all aspects of the solar system," the researchers wrote. But the simulation is a strong hint about the broad strokes, like the presence of a whole other planet, now lost in the void.

Johns Hopkins University planetary scientist Matthew Clement and his colleagues published their work in the journal Icarus.

Don't miss Jupiter, Venus and Mercury put on a spectacular show as they line up in the evening sky on May 27, creating a 'planetary bridge' between the constellations of Gemini and Taurus.

Jupiter will shine as a steady point of light roughly 30 degrees above the western horizon at sunset, with Venus appearing as a bright star-like object to its lower right. Mercury will complete the line-up, glistening close to the horizon, but will prove a greater challenge to spot in the glow of the setting sun.

Wait until the sun is safely below the horizon before turning your binoculars or a small telescope on Jupiter. Don't forget, you can use a trusted resource like Time and Date's daylight tracker to discover exactly when the sun will set from your location.

With clear skies and a small telescope or pair of binoculars, you should be able to spot four bright points of light clustered around the gas giant's glowing disk, representing the four large Galilean moons Io, Europa, Ganymede and Callisto.

A 4-inch scope should allow you to pick out the moon-like phases of Venus, while a larger 6 to 8-inch telescope will help reveal the multicoloured cloud bands that line Jupiter's atmosphere, along with colossal storms that dwarf the most ferocious weather systems of Earth.

Mercury will set less than 90 minutes after the sun on May 27 for viewers in the U.S., with Venus slipping below the western horizon roughly an hour later. Jupiter, meanwhile, will linger later in the western sky, finally disappearing shortly before midnight alongside the bright stars Castor and Pollux, which represent the heads of the celestial twins in the constellation Gemini.

Want to get a closer look at Jupiter and the other worlds of the solar system? Then be sure to check out our roundups of the best telescopes and binoculars for exploring the night sky, while photographers should read up on our picks for the top cameras and lenses for astrophotography.

Editor's Note: If you snap a photo of the planetary line-up and want to share it with Space.com's readers, then please send your image(s) alongside your comments, name and location to spacephotos@space.com.

Astronomers have studied 14 years of Hubble Space Telescope observations of Jupiter's icy moon Europa, and now suspect that its infamous water vapor eruptions may not exist as was previously thought

Europa has long been a hot target for scientists aiming to investigate the habitability of nearby worlds and the possible existence of life elsewhere in the solar system. That is because this Jovian moon is thought to host a global subsurface ocean that possibly harbors some of the essential elements for life under its thick and icy shell, including complex organic chemicals and water.

The faint and difficult-to-detect plumes were previously thought to originate from the vast global saltwater ocean lurking beneath the icy shell of Europa. This material is thought to erupt from cracks in the icy shell of the moon. Now, previous evidence of the existence of these plumes has been called into question by the very scientists who initially proposed them.

"The evidence for water vapor plumes on Europa isn’t as strong as we first understood it," team member Kurt Retherford of the Southwest Research Institute (SwRI) said in a statement. Retherford was part of a team that in 2014 suggested the existence of these European water plumes, but he and his colleagues now reconsider this conclusion.

Another look at Europa

To reconsider the existence of Europa's water plume eruptions, Retherford and colleagues looked at 14 years of data regarding Europa collected by Hubble using its HST/STIS instrument (Hubble Space Telescope’s Space Telescope Imaging Spectrograph). In particular, they honed in on a specific wavelength of ultraviolet light called Lyman-alpha emissions, which is emitted and scattered by hydrogen atoms.

Retherford and team had been detecting Lyman-alpha emissions from Europa between 2012 and 2014, but this investigation was pushing Hubble to its very limits.

"One of the difficulties in interpreting the data back then was determining where to place Europa within its context," Retherford explained. "The way Hubble works left some uncertainty in terms of placement relative to the center of the image. If Europa’s placement was off even just by a pixel or two, it could affect how the data gets interpreted.”

The team feared that the detection of water vapor plumes from Europa may have been the result of "noise" in their data.

"Our reanalysis took our original 99.9% confidence in the plumes’ existence and reduced it to less than 90% confidence," team leader Lorenz Roth of the KTH Royal Institute of Technology, Sweden, said. "That's simply not enough evidence to support the certainty of claims we made at the time."

The team still can't confidently rule out the existence of Europa's water vapor, especially as similar plumes have been more confidently detected on Saturn's icy moon of Enceladus, and sulfur dioxide eruptions have been detected from Europa's fellow Jovian moon of Io, the most volcanic body in the entire solar system.

The question of the existence of these water plumes and the salty global ocean of Europa may finally be settled in 2030 when NASA's Europa Clipper mission arrives in the Jovian system.

The team's research was published on May 5 in the journal Astronomy & Astrophysics.

Look west after sunset tonight (May 21) to see the crescent moon shining alongside the Beehive Cluster in the constellation Cancer, while Jupiter, Venus and elusive Mercury line up nearby in the evening sky.

The silvery curl of the crescent moon will hang low over the western horizon as the sun slips from view, less than 5 degrees to the upper left of the Beehive star cluster, which is also known as Messier 44, or Praesepe.

Jupiter will shine brightly about 20 degrees to the lower right of the moon, while Venus and Mercury form a diagonal line beyond. Mercury — the lowest of the planetary trio — will sit less than 5 degrees above the horizon. You'll need a clear view to the west, but even then you may struggle to spot it in the yellow glow of the retreating sun.

Both the moon and the Beehive Cluster will fit neatly in the field of view of a pair of 10X50 binoculars, which help reveal the brightest of its young stars in the waxing glow of the 36%-lit lunar disk.

A small backyard telescope will bring a plethora of diverse craters and dark lunar seas into view. Look out for Theophilus crater, which sits close to the line separating night from day — known as the terminator — and the Piccolomini impact site, which scars the lunar surface further to the south.

Both craters feature prominent central peaks formed from rock that rebounded inwards following the violent impact that heralded their creation. Their terraced eastern walls will also appear filled with shadow on May 21, making for a dramatic sight.

The moon will gently drift away from M44 as the hours wear on, before finally setting below the horizon in the early hours of May 22.

Interested in capturing glorious photos of the night sky for yourself? Then be sure to read our beginner's guide to photographing the night sky, along with our picks of the best lenses and cameras for astrophotography.

Editor's Note: If you would like to share your astrophotography with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

Look west after sunset on May 20 to witness the waxing crescent moon line up with bright Jupiter. The pair will remain visible for a few hours after sunset, before slipping from view below the spring horizon.

The moon will appear to line up with the bright stars Castor and Pollux in the constellation Gemini as the sun sets, with Jupiter's dazzling light shining less than 10 degrees to its lower right — roughly the width of a clenched fist held at arm's length.

Venus, meanwhile, will hug the horizon to the right of Jupiter, appearing as a bright "evening star" that will be a fixture of the night sky over the coming months. Observing the rocky world with a 4-inch telescope or larger reveals the slow progression of its changing phases on its pale, featureless disk — just be sure that the sun is tucked safely below the horizon before you point your scope to the west.

A 6-inch telescope can reveal Jupiter's cloud bands and features like the Great Red Spot, along with its four largest moons, Io, Europa, Ganymede and Callisto.

Slew your scope over to the moon to reveal dramatic craters lining the day-night divide. You may also spot the dark oval of Mare Crisium and farther south, Mare Fecunditatis, ancient basalt plains formed by lava billions of years ago. Eagle-eyed viewers may notice the moon drift further away from Jupiter over the course of the evening, as the moon continues its orbit around Earth.

Venus will be the first of the cosmic trio to set below the horizon roughly two and a half hours after the sun, with Jupiter next and the crescent moon following roughly half an hour after midnight, for stargazers in the northeastern U.S. Remember, the exact timings that solar system bodies rise and set varies based on your location, so use Time and Date's skywatching tracker to get exact timings for your location.

Interested in exploring the wonders of the lunar surface for yourself? Then read our picks for the best telescopes for observing the night sky in 2026, along with our guide to observing the lunar surface.

Editor's Note: If you capture a photo of the moon with Jupiter and want to share it with Space.com's readers, then please send your image(s), comments and your name and location to spacephotos@space.com.

The May new moon arrives this weekend, ushering in several dark moonless nights perfect for exploring the majesty of our Milky Way, glimmering spring constellations and the ever-shifting procession of the planets.

May's new moon phase occurs at 4:01 p.m. EDT (2001 GMT) on May 16, as the moon passes close to the sun in the daytime sky.

The nights surrounding the new moon present beautifully dark skies for stargazers looking to navigate the sea of stars, nebulas and galaxies that haunt the post-sunset realm.

Visible planets

Turn your gaze west at sunset to spot Venus glowing as a bright "evening star" a little over 20 degrees above the horizon — roughly the width of two clenched fists held at arm's length against the night sky.

Jupiter glows another 20 degrees to the upper left of Venus, with Castor and Pollux, the brightest stars in the constellation Gemini, shining above. A pair of 10X50 binoculars will reveal a shoal of star-like objects surrounding the gas giant. These are Jupiter's largest natural satellites Io, Europa, Ganymede and Callisto, which are collectively known as the Galilean Moons in honor of their discoverer, the famed Italian astronomer Galileo Galilei.

Early birds are treated to an entirely different cast of planets as Saturn shines above the eastern horizon in the hour preceding dawn, with Mars rising to its lower left, chased by the golden light of the coming sun. Both Saturn and Mars will cling less than 20 degrees above the horizon at sunrise, so be sure to find a spot with a clear view to the east if you want to catch the planetary duo before they're lost in the glare of the sun.

Stars and constellations

May's new moon is a great time to spot a trio of celestial animals shining in the spring sky. Our first target is the great lion represented in the constellation Leo, whose mane and chest are represented by a sickle-like formation of stars that shines above the southwestern horizon after sunset in May, with Regulus at its lowest point.

The second-century Greek philosopher Ptolemy catalogued the constellation almost 2,000 years ago, seeing in it the Nemean Lion from the mythological tale of Heracles, which the hero was burdened with slaying as the first of his 12 labors.

Next, look 10 degrees above Leo's sickle head to find the faint stars of the constellation Leo Minor, the "little lion". This constellation was created by the Polish astronomer Johannes Hevelius in the year 1690. As a result, there are no great mythological tales of its origin, though it remains a pretty feature between the greater stellar citadels of Leo and Ursa Major.

To the lower right of Leo Minor is the magnitude +3.25 star Alpha Lyncis, which forms the leftmost point of the constellation Lynx — a serpentine formation of eight stars that stretches off to the right above the northwestern horizon for viewers in the Northern Hemisphere. Dark skies surrounding the new moon make Lynx much easier to trace, as it is often hidden in the glare of Earth's satellite.

Our final target is the glowing core of the Milky Way, which puts on a magnificent show between midnight and dawn in mid-May, as it arcs high over the southeastern horizon. A good way to spot the Milky Way is by locating the three bright stars Altair, Vega and Deneb, forming a famous asterism known as the Summer Triangle above the eastern horizon this time of year

The dense starfield and dark interstellar dust clouds of the galactic core appear as a glowing band passing through Deneb and between Vega and Altair, as it tumbles towards the horizon.

Read more: Learn the night sky without an app: May's easiest star-hops for beginners

Natural light pollution will be at a minimum, so why not also try to head away from bright city lights to make the most of the monthly pocket of darkness? You can use a trusted website like DarkSky.org to find your ideal stargazing location, along with smartphone astronomy applications like Stellarium or Star Walk 2 to find — or identify — breathtaking night sky objects and constellations in the night sky.

Want to capture your own gorgeous views of our galaxy? Then be sure to read our beginner's guide to photographing the Milky Way, along with our roundups of the top cameras and lenses for astrophotography.

Editor's Note: If you would like to share your dark sky astrophotography with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

Researchers may have just revealed a new way of looking for alien life — it's based on the idea that it isn't just the type of biosignatures that are important, but also how they are organized.

"Our approach could help make the search for life more efficient. If a molecular assemblage shows no life-like organization, that may make it a lower priority target," Fabian Klenner of the University of California, Riverside told Space.com.

Let's break down the concept.

First, it should be noted that life uses and produces a range of biologically useful materials such as amino acids, peptides, proteins, fatty acids and so forth. These compounds are therefore considered potential "biosignatures" — if we find them on another world, it is quite possible that they have been produced by life's processes (life as we know it, at least).

However, these compounds are not exclusively biological — abiotic chemical reactions that have no connection to biology can also produce them, and distinguishing between the two possible sources is one of astrobiology's greatest challenges. For example, methane plumes on Mars could be biological or geological in origin, and the same uncertainty also clouds the detection of phosphine in Venus' atmosphere, or the potential discovery of dimethyl sulfide (DMS) in the atmosphere of the exoplanet K2-18b.

This sows confusion because detecting biosignatures does not necessarily mean we have detected life.

However, Klenner is part of a team led by Gideon Yoffe of the Weizmann Institute in Israel that showed there may be a way to distinguish between biological and abiotic origins.

To do so, they took a leaf out of ecologists' book, where life is measured by two metrics: its diversity and how evenly spread its distribution is.

They focused on two biological compounds: amino acids and fatty acids. Amino acids form long chains called peptides that assemble into proteins that are the workhorses inside biological cells. Fatty acids form part of the structure of those cells. Both can be produced by life or by non-living processes.

"We focused on amino acids and fatty acids because they are central molecular classes for life as we know it and because suitable datasets exist," said Klenner.

Indeed, Yoffe and Klenner's team were able to delve into about 100 datasets including samples from asteroids, fossils, meteorites, microbes, soils and synthetic laboratory samples.

They showed that amino acids are more diverse and more evenly distributed when they are created by living organisms than when produced by non-living processes. Fatty acids are the other way around — they are less diverse and less evenly distributed when created by biology.

This is not a foolproof method of detecting life, warn the researchers. First of all, they have only shown that it works with amino acids and fatty acids. "In principle, similar organizational trends may exist for other molecular classes but this still needs to be tested," said Klenner.

Second, the diversity and distribution of these bio-compounds needs to be placed into context with other molecules, otherwise it is impossible to say how diverse and evenly distributed they really are. This means that it cannot be applied to the DMS detection on K2-18b, as we simply don't know enough about that exoplanet's atmosphere to quantify the diversity and distribution.

"For a single molecule like DMS, the situation is different," said Klenner. "For K2-18b, DMS alone would not be enough for our analysis — we'd need a broader inventory of related molecules."

However, the technique may be more useful closer to home, in our solar system, where samples and datasets are more complete. One useful facet of the research is that the organizational patterns hold up no matter how degraded the biological sample is. For example, fossilized dinosaur eggs retained traces of the distribution and diversity of amino acids and fatty acids.

This could come in useful for Mars, where astrobiologists are searching for evidence of life on the Red Planet from billions of years ago when Mars was warmer and wetter.

"Biological samples do not simply become meaningless once they degrade," said Klenner. "Some organizational information can persist, which makes this approach useful for ancient Mars."

The technique on its own cannot confirm the existence of life — in general, the discovery of alien life would be such a profound revelation that we would need multiple lines of evidence to be absolutely sure.

It can, however, direct us towards the best places to look.

One of those places may be Jupiter's moon Europa, which harbors a global ocean of water beneath a thick shell of ice. Astrobiologists are undecided as to whether that ocean is capable of supporting life or not. While NASA's forthcoming Europa Clipper mission, currently on its way to Jupiter to arrive in 2031, won't be able to look under the ice, it will be able to study possible locations where the ocean has erupted onto the surface.

"One of the instruments on board Clipper, the Surface Dust Analyzer, will be able to measure the abundance ratios of organic molecules in ice grains emitted from Europa," said Klenner. "If families of organic molecules are detected, then our diversity based approach will help interpret whether these molecules look more consistent with abiotic chemistry or biological organization."

The findings were published on May 11 in Nature Astronomy.

NASA's Juno spacecraft has snuck a peek at one of Jupiter's largest inner moons.

During a close flyby, the spacecraft got a look at Jupiter's moon Thebe from just 3,100 miles (5,000 kilometers) away.

What is it?

NASA's Juno mission made a close pass of Jupiter's moon Thebe on May 1, 2026. While about 3,100 miles (5,000 kilometers) away from the moon, the spacecraft snapped this photo using its camera known as the Stellar Reference Unit (SRU).

Jupiter has over 100 moons discovered so far and Thebe is the second largest of the planet's inner moons. Those inner moons are all smaller than the gas giant's famously huge Galilean moons — Io, Europa, Ganymede, and Callisto — which orbit farther out. The moon was first discovered in 1980 by NASA's Voyager 1 spacecraft as it flew by Jupiter.

Juno launched in 2011 to travel to, orbit around, and study Jupiter. The mission has delivered incredible images and groundbreaking data on the planet and its surrounding moons. The mission has spotted cyclones on Jupiter and watched volcanoes erupt on its moon Io.

Why is it incredible?

It is amazing to see such a far-off moon up close. But Juno's SRU was actually not designed to take cool photos of Jupiter's moons.

The SRU is primarily intended to image star fields so Juno can navigate our solar system. Juno launched to Jupiter in 2011, but after completing its primary mission in 2021, the spacecraft has continued on as part of an extended mission. Ever since, it has been exploring Jupiter and its orbiting moons with greater depth.

Similarly, the SRU is stretching its functionality. To be able to image star fields well, the instrument is designed to work in low light. As a result? We get to have awesome images like this.

On Wednesday evening (April 22), assuming your skies are reasonably clear, you can finish your day by stepping outside and enjoying a view of a rendezvous of two of the brightest objects in the night sky: the moon and the planet Jupiter. About 45 minutes after the sun sets, the eye-catching celestial duo will be visible in the western sky, roughly two-thirds up from the horizon to the point directly overhead (called the zenith).

The moon, which will be one day from reaching first quarter phase — 38% illuminated by the sun — will be situated above and to the right of Jupiter, about 3 degrees away.

To gauge how wide 3 degrees is, your clenched fist held at arm's length measures about 10 degrees, so Jupiter and the moon will appear roughly "one-third of a fist" apart.

Even without the moon, Jupiter alone readily attracts attention; currently, after Venus sets, it's the brightest "star" for the time that it's above the horizon (it currently sets at around 1:35 a.m. local daylight time), first coming into view high in the west during the early stages of twilight. Jupiter, at about magnitude -2.1, outshines everything in the night sky except Venus and the moon. As twilight fades, it is soon joined by the bright winter stars in this part of the sky — stars which are beginning to seem out of season as spring evenings warm up.

Teaming up with the Gemini Twins

Most noticeable because of their proximity to the moon and Jupiter are the yellowish Pollux and white Castor, which mark the heads of the Gemini twins, positioned about 9 degrees above Jupiter and about 6.5 degrees above the moon. In his classic constellation guide, The Stars — A New Way to See Them, author H.A. Rey wrote: "If the moon and a planet are near Castor and Pollux you have an impressive show."

And indeed, this gathering of the moon and Jupiter with Castor and Pollux in Wednesday's evening sky will be quite eye-catching.

Striking views through telescopes

In a telescope, Jupiter is a prime attraction; it is best observed during early evening when it's still high and its image reasonably calm. It's still a great big, belted ball showing tantalizing glimpses of detail. Admittedly, it appears only ¾ as big as it did at its opposition in early January, but don't let that stop you. The quirks of atmospheric seeing, which can change from minute to minute, often determine what a telescope will show on Jupiter more than the planet's apparent size. And its four bright moons are always performing.

In fact, if you look at Jupiter with a small telescope or even steadily held binoculars on Wednesday evening, you'll see three of the four satellites. Closest to Jupiter will be Io, while flanking the big planet at greater distances are Callisto (on the same side as Io) and Ganymede. Keep a sharp eye on Io, however, because at 10:39 p.m. EDT, it will disappear behind Jupiter. Then at 11:36 p.m. EDT, Europa will emerge from eclipse, having been hidden in Jupiter's shadow.

So, on Wednesday, while you enjoy the sight of Jupiter near our own satellite, keep in mind that with only slight optical aid, up to four more satellites are available. They seem like small stars, though two of them are larger than our own moon and it is indeed possible to watch them change their positions relative to each other from hour to hour and night to night.

If you're looking for a telescope or binoculars to observe the night sky, our guides for the best binocular deals and the best telescope deals can help.

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.

The April new moon has arrived bringing several nights of spectacular dark skies perfect for observing the planets of the solar system, majestic constellations and the galaxies that lie beyond.

April's new moon occurs at 7:52 a.m. EDT (1152 GMT) on April 17, when the moon is positioned between the sun and Earth, rendering it lost from sight in the daytime sky, with the entirety of its near side bathed in shadow.

The moonless nights surrounding this phase are the perfect time to indulge in skywatching and night sky photography, as subtle constellations and deep sky objects often lost behind a veil of moonlight glisten in the twilight realm.

Visible planets

Look to the west shortly after sunset on April 17 to find Venus appearing as a bright evening star 15 degrees from the horizon, with the blue-white stars of the Pleiades open star cluster glowing 10 degrees above — roughly the width of your clenched fist held at arm's length.

The ice giant Uranus can be found a little under 5 degrees to the lower left of the star cluster. It'll be too dim to spot with the naked eye — without exceptionally dark skies and perfect vision — but a pair of binoculars or a small telescope will allow you to spot its disk as a tiny greenish dot, according to telescope manufacturer Celestron.

Jupiter, meanwhile, will shine high overhead, below Castor and Pollux — the brightest stars of the constellation Gemini. Turn a 6-inch telescope on Jupiter and you may notice a line of bright dots extending outward from the gas giant's colorful disk. Those are the Galilean moons Io, Ganymede, Europa and Callisto!

Head out an hour before sunrise on April 18 and find yourself a clear view to the eastern horizon for a chance to catch a planetary triangle rising in the glow of the coming dawn.

Mars will sit higher in the sky,with Saturn below and Mercury off to the right. Neptune will also be present to the upper right of Mercury, though the distant ice giant will be far too dim to spot with the naked eye.

Stars and constellations

The dark nights surrounding the new moon are a perfect time to explore some of the subtler constellations that glisten in the northern hemisphere sky.

First, locate the sickle-like formation of stars representing the head and chest of the great lion represented in the constellation Leo, which can be found high above the southern horizon in April with the bright star Regulus at its base.

Next, look to the lower right of Regulus to find a circlet of stars representing the head of the great serpent in the constellation Hydra, along with a string of stars that wind down and to the east towards the horizon, which mark its tail. Hydra is the largest constellation in the night sky, though it's often overlooked due to its lack of bright stars.

Perched along Hydra's back are the compact constellations Corvus (the crow) and Crater (the cup). To their east is the blue-white light of Spica — the brightest star in the constellation Virgo.

For a spot of deep sky viewing, why not head out to a dark sky location and sweep your telescope over the patch of sky where Leo, Virgo and the constellation Coma Berenices meet?

First, find Denebola, the star that marks the tail of the lion in Leo, and Vindemiatrix using a handy stargazing app. Roughly halfway between the two is Markarian's Chain — a spectacular string of galaxies whose ancient light can be spied with the aid of a modest telescope.

Read more: Galaxy season: Spring brings deep space wonder to the northern hemisphere night sky.

You could also capture spectacular images of the stars with the help of our beginner's guide to photographing the night sky. Be sure to check out our picks of the best telescopes and binoculars for exploring the night sky, along with our roundups of the top cameras and lenses for astrophotography available in 2026.

Editor's Note: If you would like to share your night sky photography with Space.com's readers, then please send your photo(s) along with your name, location and comments to spacephotos@space.com.

The interstellar invader comet 3I/ATLAS is spraying enough water into space to fill 70 Olympic swimming pools each day. The discovery gives scientists a remarkable opportunity to study the elements present during the formation of planets around other stars, potentially much older than the sun.

The discovery was made by the European Space Agency (ESA) mission Jupiter Icy Moons Explorer (Juice), which is currently heading towards Jupiter and its icy moons. JUICE observed 3I/ATLAS, which is just the third object found passing through the solar system from beyond its boundaries, in November, 2025, using its MAJIS (Moons And Jupiter Imaging Spectrometer) and JANUS (Jovis, Amorum ac Natorum Undique Scrutator) instruments.

Like comets native to the solar system, 3I/ATLAS began expelling material when it passed close to the sun, with solar radiation heating its icy heart, causing solid ice to transform immediately into gas, a process called sublimation. As this gas makes its explosive escape, it forms the coma and tail that are characteristic of comets. This is accompanied by a brightening of the comet, but 3I/ATLAS brightened even more than expected.

During its observations, MAJIS identified infrared emissions from water vapor and carbon dioxide molecules. These are known as "volatiles" because they evaporate easily.

"Repeated detections of water vapor and carbon dioxide by MAJIS indicate that volatile ices buried beneath the surface were actively released into space shortly after perihelion passage," team member Giuseppe Piccioni of the National Institute for Astrophysics (INAF) said in a statement. "From the data collected, we estimated an outflow from the comet's nucleus of about two tons per second, equivalent to approximately 70 Olympic swimming pools of water vapor ejected into space every day.

"The MAJIS data will allow us to better understand the activity of this comet after perihelion and the physical and chemical properties of the materials formed around another star billions of years ago."

The JUICE observations of 3I/ATLAS were more extraordinary because they were unplanned, only occurring to the team after the discovery of 3I/ATLAS on July 1, 2025. The observations were challenging due to the short periods of time JUICE had to spot 3I/ATLAS and how faint the interstellar comet's emissions were.

These observations were followed by a prolonged wait, with the data only reaching Earth in February 2026.

"We waited a long time, but it was truly worth it," team member Pasquale Palumbo, an INAF researcher and principal investigator of JANUS, said. "The wonderful images collected reveal for the first time the comet's intense activity right around perihelion. 3I/ATLAS showed an extended coma, a tail, and various morphological structures, such as rays, jets, and filaments. The data collected will allow us to study the morphological structures, light intensity, and evolution of the comet's coma and tail on short and medium timescales.

"We are very pleased with the performance JANUS has provided us; it is an excellent preview of what it will be able to do when it operates around Jupiter and its icy moons, the final destination of the JUICE mission."

Lightning on Jupiter may pack more than 100 times the power of Earth's bolts, and may even prove to be one million times stronger, a new study finds.

Jupiter, the largest planet in the solar system, has correspondingly gigantic storms, with some of these lasting for centuries. Nearly every spacecraft that has passed by Jupiter to date has detected lightning, with flashes visible on the planet's night side.

Based on missions that could only detect the most powerful dark-side flashes, previous research had suggested that Jupiter's lightning was similar to the highest‐energy lightning flashes on Earth, known as "superbolts." However, when NASA's Juno spacecraft began orbiting the giant planet in 2016, its star-tracking camera was sensitive enough to detect what appeared to be numerous weaker, Earth-like flashes.

The problem with night-side imaging of Jupiter is that its clouds can obscure the view of lightning flashes. This can make their true power difficult to estimate, explained study lead author Michael Wong, a planetary scientist at the University of California at Berkeley.

In the new study, Wong and his colleagues instead analyzed data from Juno's core instrument, which could detect radio emissions from Jupiter's lightning. Such data could yield a more precise way to measure lightning power unaffected by obscuring clouds.

A challenge the researchers faced was how Jupiter often experiences multiple storms at the same time across belts that encircle the planet. This can make it difficult to pinpoint which storm produced any lightning Juno detected. Wong compared this problem to hearing a series of pops at a Chinese New Year's parade and not knowing if it was exploding popcorn a few feet away or firecrackers a block away.

However, in 2021 and 2022, there was a lull in storms in Jupiter's north equatorial belt. This let the scientists focus on just one large storm at a time, pinpointing its location using NASA's Hubble Space Telescope, Juno and images from amateur astronomers. Wong called these "stealth superstorms." Similar to Jupiter's true superstorms, their activity lasted for months, but unlike true superstorms, their cloud towers only reached modest heights.

Juno was close enough to four of these stealth superstorms to analyze microwaves from their lightning.

"It was so gratifying to work through the statistics and see that with our Juno data, we were really capturing the majority of lightning pulses at radio wavelengths," Wong told Space.com. "Before, there was some question about whether we might be catching only the strongest pulses and missing weaker ones."

The flashes the researchers detected averaged three per second during these flyovers. From 613 pulses measured, they calculated they ranged in power from about that of an Earth bolt to 100 or more times more powerful.

The scientists cautioned there were uncertainties in their estimates because they compared Earth lightning emissions at one radio wavelength to Jupiter emissions at a different wavelength. Jupiter's bolts may actually be a million times stronger than Earth's, they said.

Jupiter's lightning could help explain how its atmosphere and storms operate. Similar to Earth, Jupiter experiences convection — churning that transports heat from below.

Wong explained that convection on Jupiter operates differently than on Earth because air on Earth is mostly nitrogen, which is heavier than water, so moist air is more buoyant than drier air. In contrast, Jupiter's atmosphere is dominated by hydrogen, so moist air is heavier and more difficult to loft upward. This in turn means it takes a lot more energy for a storm to rise on Jupiter, and that it unleashes a lot more energy if it does reach the top of the atmosphere, leading to high wind speeds and intense lightning.

The researchers suggested that lightning on Jupiter is likely generated much like it is on Earth, with rising water vapor condensing in higher, colder altitudes into liquid drops and ice crystals that get electrically charged. However, Wong noted that it remained uncertain why Jupiter's lightning was more powerful.

"Could the key difference be hydrogen versus nitrogen atmospheres, or could it be that the storms are taller on Jupiter and so there's greater distances involved?" Wong said in a statement. Jupiter's storms are more than 62 miles (100 kilometers) tall, compared to 6.2 miles (10 km) on Earth. "Or could it be that greater energy is available because with moist convection on Jupiter, you have a bigger buildup of heat needed before you can generate the storm to create lightning?"

The scientists detailed their findings March 20 in the journal AGU Advances.

Look to the east at sunset tonight (March 26) to see the half-lit form of the waxing gibbous moon shining close to the gas giant Jupiter in the evening sky, as the bright stars of the constellation Gemini twinkle nearby.

The moon will make its closest approach to Jupiter at 9:19 EDT (1319 GMT) on March 26, at which time Jupiter will be lost to sight in the daytime sky. The pair will remain close throughout the evening, however. Viewers in the northern hemisphere will get their best view of the solar system pairing at sunset, when the moon will appear with its right side lit by sunlight high above the southern horizon, less than a day after reaching its first quarter phase.

Jupiter will appear as a steady star-like object glowing brightly 5 degrees to the lower right of the lunar disk — roughly the width of your three middle fingers held at arm's length against the sky. To the upper right shine Castor and Pollux — the bright stars that represent the heads of the celestial twins depicted in the constellation Gemini.

The moon and Jupiter will make for a gorgeous sight through the eyepiece of a 6-inch telescope, which will reveal the dark lunar seas and prominent craters lining the night-day divide on the lunar surface, along with the cloud bands of the gas giant and its most prominent moons.

As the night wears on, the lunar disk will appear to travel away from Jupiter in Earth's sky, before finally disappearing from view below the northwestern horizon shortly after 3 a.m. EDT (0700 GMT) for viewers in New York. Visit Time and Date to discover the exact times that solar system bodies like the planets rise and set from your location.

Jupiter is set to remain a prominent sight in the spring sky until mid-July, when it will become lost in the glow of the setting sun ahead of its solar conjunction on July 29, according to in-the-sky. At that time, Jupiter will be too close to the sun from our perspective on Earth to be visible.

Want to get a closer look at the moon and Jupiter? Then be sure to check out our picks of the best telescopes and binoculars for exploring the night sky. If you're into photography, then you may also want to read our picks of the best cameras and lenses for astrophotography, along with our roundups of the finest smart telescopes available in 2026.

Editor's Note: If you would like to share your astrophotography with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

A multitude of new moons have made their presence known around Jupiter and Saturn, bringing their population of moons to 101 and 285, respectively.

The new discoveries also bring the total number of known moons orbiting planets and dwarf planets in the solar system to 442 — and that's not including the many moonlets accompanying various asteroids or small Kuiper Belt objects.

The newly found moons — four for Jupiter and 11 for Saturn — were announced by the Minor Planet Center, which is the clearing house for astronomical discoveries of asteroids, comets, centaurs and, indeed, moons.

None of the newly discovered moons are very large, averaging about 1.9 miles (3 kilometers) in diameter. They have very wide orbits, far wider than the larger moons of Jupiter and Saturn, and are exceedingly faint, between magnitude 25 and 27. (For context, our moon sits at magnitude -12.6.) This puts them well beyond the range of backyard telescopes.

Instead, it took intense observations from some of our largest ground-based telescopes to snag them. The four new moons of Jupiter were all found by astronomers Scott Sheppard of the Carnegie Institution for Science and David Tholen of the University of Hawaii, using the 6.5 meter Magellan–Baade telescope at Las Campanas Observatory in Chile and the 8-meter Subaru telescope atop Mauna Kea in Hawaii.

Meanwhile, the 11 new moons of Saturn were uncovered thanks to a team led by Edward Ashton at the Academia Sinica Institute of Astronomy and Astrophysics in Taiwan. They used the 3.5-meter Canada–France–Hawaii Telescope on Mauna Kea. This comes after Ashton led a team to discover 128 new moons of Saturn as recently as 2025.

Both Sheppard and Ashton in particular are prodigious discoverers of moons in the solar system, with over 200 each to their name, many of them being co-discoveries.

While Jupiter is lagging behind Saturn in the moon stakes by quite a large number, Europa Clipper and the Jupiter Icy Moons Explorer (JUICE) missions, currently heading to Jupiter, could redress the balance when they arrive in the Jovian system in the early 2030s.

To summarize, the current tally is that for the planets, Earth has one moon, Mars has two, Jupiter has 101, Saturn has 285, Uranus has 28 and Neptune has 16 while Venus and Mercury have none. For the dwarf planets, Pluto has five, Eris has one, Makemake has one, Haumea has two and Ceres has none.

The new moons of Jupiter were announced in Minor Planet Electronic Circulars MPEC 2026-F09, F10, F11 and F12, and the 11 new moons of Saturn were declared in MPEC 2026-F14.

March's new moon phase is upon us, bringing gorgeous dark skies free of natural light pollution — perfect for exploring constellations and deep sky objects that are all too often obscured by moonlight!

This month's new moon occurs at 9:23 p.m. EDT on March 18 (0223 GMT on March 19) as the lunar disk passes between the sun and Earth. Around this time, the lunar disk is invisible from our perspective, lost in the sun's glare.

It's an ideal time to escape city lights and hunt for stars, galaxies and elusive natural phenomena in the spring skies. Here's what to look for before the waxing crescent moon returns ahead of its first quarter phase on March 25.

Visible planets

Stake out a spot with a clear view to the west for a chance to see Venus shining low on the horizon in the hour following sunset. This inner world — often referred to as Earth's twin due to its size and rocky composition — will disappear swiftly below the horizon roughly 90 minutes after the setting sun, so be quick!

With the moon tucked safely below the horizon, Jupiter will be the brightest object in the night sky. It can be found shining high overhead in the southern sky as the sun sets in mid-March, close to the bright stars Castor and Pollux in the constellation Gemini.

Uranus, meanwhile, lurks in the constellation Taurus, too dim for the unaided eye to see. To find Uranus, first locate the bright red star Aldebaran, which shines to the right of Orion in the evening sky. Uranus tiny aqua disk can be found by sweeping an 8-inch (200 mm) scope across the patch of sky 5 degrees to the lower right of Aldebaran — roughly the width of your three middle fingers held at arm's length — close to the hazy light of the Pleiades open star cluster.

Mercury is visible as a predawn planet in mid-to-late March, which will appear rising low on the eastern horizon before swiftly becoming lost in the glare of the rising sun. Mars, and Neptune remain too close to the sun to be seen.

As always, the greatest care must be taken to never point a telescope or binoculars close to the rising sun, as doing so will permanently and immediately damage your vision.

Stars and constellations

Look above the southwestern horizon in the hours following sunset to trace the bright stars of the Winter Hexagon shining defiantly in the early spring sky.

Start with Sirius — the brightest star in the night sky — which can be found above the southern evening horizon in the constellation Canis Major, the Big Dog.

Next, find the brilliant light of the blue supergiant star Rigel twinkling beneath the familiar sight of Orion's Belt to the upper right of Sirius, before leaping higher in the west to the red star Aldebaran, which forms the right eye of the celestial bull in the constellation Taurus.

Our next stop is Capella, higher still, which stands as the brightest point in the constellation Auriga, before we travel to the east to find bright Pollux to the upper left of Jupiter, which represents the head of one of two immortal twins in the constellation Gemini. The final Winter Hexagon star, Procyon, can be found shining between Pollux and Sirius, in the constellation Canis Minor, the "Little Dog".

Star clusters and deep-sky objects

The nights surrounding the new moon phase are a great time to spot the ancient diffuse light of star clusters glowing in the pristinely dark spring sky.

Allow at least 20 minutes for your eyes to adapt to the dark before turning your gaze back to the constellation Taurus and red Aldebaran. The "V" formation of stars extended from it is the Hyades open star cluster, which represents the face of a great bull charging towards Orion, the hunter.

From there, look about 15 degrees to the right of the Hyades to see the ancient light of the Pleiades star cluster, appearing as a hazy patch of light to the unaided eye from a dark sky location. A pair of 10X50 binoculars will allow you to see its seven brightest members — from which it gained the nickname of the "Seven Sisters" — while a small telescope will bring dozens more of its 1,000-strong stars into view.

To the left of Castor and Pollux lies the constellation Cancer, the crab, the core of which plays host to the 100-strong stellar population of the Beehive Cluster (M44), which is visible as a small, misty patch of light on moonless nights.

The new moon is also an ideal time to observe the light of ancient galaxies, as spring brings a string of constellations packed with wonderful galactic targets to prominence. Check out our guide to the spring galaxy season to find out more!

Zodiacal light

If you're lucky, you may spot a strange pillar of pale light extending up from the western horizon in the hours following sunset in late March. This phenomenon, known as zodiacal light, occurs when sunlight reflects off a vast cloud of dust spread along the plane of the solar system, known as the ecliptic.

Want to get a closer look at the wonders of the post-sunset realm? Then be sure to read our roundup of the top telescopes and binoculars for observing the night sky. If photography is your thing, then you'd do well to read our picks of the best lenses and camera bodies for astrophotography in 2026.

Editor's Note: If you would like to share your astrophotography with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

Jupiter's moons can have surprising effects on the world's displays of auroral lights by "stomping down" on the planet's gigantic magnetic environment.

These surprising effects, detected in observations from the James Webb Space Telescope (JWST), include a cold spot in Jupiter's atmosphere, and a rapid increase in the density of charged particles.

"The moons constantly interact with the magnetic field and plasma surrounding the planet and that interaction leads to highly energetic particles traveling down magnetic field lines and then crashing into the planet's atmosphere, creating the auroral footprints that map to where the moons orbit around Jupiter," said Katie Knowles, who is a Ph.D. researcher at Northumbria University in the U.K., in a statement.

Jupiter's auroral lights are created in similar fashion to Earth's as charged particles riding on the solar wind slam into Jupiter's magnetic field and are funneled down towards the gas giant's poles. When they enter the atmosphere, they collide with atoms and molecules, causing them to glow. However, by interacting with Jupiter's magnetic field, its four largest moons — the Galilean moons Io, Europa, Ganymede and Callisto — can leave an imprint on the aurora.

The footprints are exacerbated by a phenomenon known as the Io Plasma Torus. Io is the solar system's most volcanic body, and its volcanoes spew out tons of charged particles that drift into orbit around Jupiter, forming the plasma torus that is held in place by Jupiter's magnetic field. As the Galilean moons orbit Jupiter, they interact with the plasma torus and the magnetic field, and drive ions towards Jupiter's atmosphere, contributing to the aurora and generating electrical currents that influence how bright the auroral footprints are.

Previous multi-wavelength measurements have tracked how bright the aurora, and these footprints, can become. However, in September 2023, Northumbria's Henrik Melin and Tom Stallard used the to take snapshots of the area on Jupiter's where auroral events rotated into view. By watching the edge of Jupiter's disk, the JWST was able to probe the side profile of Jupiter's atmosphere directly beneath an aurora.

When Knowles analyzed that data, she found something unexpected.

The JWST took five snapshots, and in four of them, everything looked normal. But in one snapshot, a cold spot appeared in the atmosphere below an aurora connected to Io's footprint. While the rest of the aurora was at a steady temperature of 919 degrees Fahrenheit (493 degrees Celsius), the cold spot was a "mere" 509 degrees Fahrenheit (265 degrees Celsius).

The density of ions streaming into the upper atmosphere to power the aurora around the cold spot was also far higher than had ever been measured before. One particularly abundant ion present was the trihydrogen cation (H₃⁺) and the ion density was, on average, three times greater than the rest of the aurora. Moreover, within the cold spot, densities could vary by up to 45 times in just that small region.

"We found extreme variability in both temperature and density within Io's auroral footprint that happened on the timescale of minutes," said Knowles. "This tells us that the flow of high-energy electrons crashing into Jupiter's atmosphere is changing incredibly rapidly."

Jupiter's auroral lights are the most powerful in the solar system, but they are not the only auroral lights present in our corner of the neighborhood. Of course, there are Earth's auroral lights — but Earth's moon does not leave a footprint on our planet's aurora because it does not interact with Earth's magnetic field strongly enough. However, Saturn's moon Enceladus, which is spewing particles into space via its water geysers, does impact the aurora on the ringed planet. It is therefore possible that this cold spot phenomenon also happens there.

"This work opens up entirely new ways of studying not just Jupiter and its other Galilean moons, but potentially other giant planets and their moon systems," said Knowles. "We're seeing Jupiter's atmosphere respond to its moons in real-time, which gives us insights into processes that occur throughout our solar system and perhaps further afar."

However, questions remain.

For instance, the cold spot was only seen in one image. How often do they occur, what causes them to switch on and off, and how are they influenced by conditions in Jupiter's magnetic environment?

Knowles is already searching for answers. In January 2026 she was awarded time on NASA's Infrared Telescope Facility on Mauna Kea in Hawaii to track the various auroral footprints over six nights as they rotate with the planet, and she is currently analyzing the data.

The JWST observations are described in a paper published on March 3 in the journal Geophysical Research Letters.

The gas giant Jupiter will appear to reverse direction in the night sky from tonight (March 10) onward, bringing an end to its temporary retrograde motion that began in November 2025, which saw it travel westward through the stars of the constellation Gemini.

Under normal circumstances, the outer planets of our solar system — Mars, Jupiter, Saturn, Uranus and Neptune — travel eastward through the night sky relative to the fixed starfield beyond. However, each of the planets appears to periodically shift direction and double back on itself.

This trick of perspective is known as retrograde motion, and occurs as Earth — traveling faster in its orbit compared to the outer planets — catches up to and overtakes a planet in the period surrounding opposition, when a planet is opposite the sun in Earth's sky.

As Earth passes an outer planet, in this case Jupiter, it appears to first stand still and then travel backwards (westward) relative to the background stars, before eventually returning to its ordinary prograde motion as our planet moves further from the point of opposition.

Jupiter will then continue its regular eastward motion through the evening sky until late June, when it will become temporarily lost from sight ahead of its solar conjunction on Jul. 29. The gas giant will re-emerge as a morning planet in the predawn sky in mid-August and won't enter retrograde motion again until Dec. 12 later this year, according to in-the-sky.

Want to get a closer look at the king of the planets? Then be sure to check out our picks of the best telescopes available in 2026, along with our equipment guide for seeing and photographing the planets.

Editor's Note: If you would like to share your planetary photography with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

A fleeting flyby of Ganymede has revealed that its shimmering auroras may behave far more like Earth's than scientists expected.

During a close pass on July 7, 2021, NASA's Juno spacecraft captured the most detailed ultraviolet views yet of a Jovian moon's glowing polar lights. The new analysis, completed by a team led by the Laboratory of Atmospheric and Planetary Physics (LPAP) at the the University of Liège, shows that Ganymede's auroras are not smooth, continuous ovals. Instead, they splinter into small, bright patches — structures that mirror features seen in Earth's own auroral displays.

"Similar structures, known as 'beads', have been observed in the auroras of Earth and Jupiter, where they are linked to sub-storms and dawn storms, large-scale rearrangements of the magnetosphere that release enormous amounts of energy and produce intense auroral activity," Alessandro Moirano, a postdoctoral researcher at LPAP, said in a statement.

While we know auroras aren't unique to Earth — they've been seen on Venus, Mars, Jupiter, Saturn and Uranus — Ganymede is the only moon we know of that has its own magnetic field, which is a crucial ingredient for auroras. On Earth, the aurora occurs when charged solar particles slam into the magnetosphere, which directs them toward the poles. These particles then interact with gases in the atmosphere and glow various colors, including green and red. On Ganymede, the auroras are produced via interactions with Jupiter's vast magnetosphere rather than the solar wind.

"Observations of Ganymede's auroras prior to Juno were limited by the spatial resolution of ground-based observations, and they could not resolve the small-scale structures typical of planetary auroras," said Philippe Gusbin, whose master's thesis inspired the study. Juno's ultraviolet spectrograph resolved details just a few kilometers across, revealing the "beads" in the aurora.

Because Juno's encounter with Ganymede lasted less than 15 minutes — and the spacecraft will not return — researchers cannot yet determine how often these "bead" features appear. That task may fall to JUICE, the European Space Agency mission en route to Jupiter, which is expected to begin extended studies of Ganymede after its arrival in 2031.

A study about these results was published on Jan. 6 in the journal Astronomy & Astrophysics.

NASA's Chandra X-ray Observatory has transformed new telescope views of Jupiter, Saturn and Uranus from this month's "planetary parade" into striking soundscapes — capturing everything from Jupiter's crackling auroras to the sweeping arc of Saturn's rings.

The newly released sonifications translate X-ray and multiwavelength observations of the three outer worlds into immersive audio experiences, turning streams of data from the space telescope into layered musical compositions. Timed to coincide with the rare alignment of several bright planets in the night sky, the project continues Chandra's broader effort to observe the universe through more than just sight, according to a statement from NASA sharing the new sonifications.

Sonification is the process of converting data into sound by mapping brightness, position and energy to pitch, volume and instrument choice. The process begins with real data collected by Chandra, which detects high-energy radiation produced when solar X-rays are reflected by planets, moons and other bodies in the solar system. Those observations are then combined with imagery from other observatories, including the Hubble Space Telescope and past planetary missions, to build a fuller, multiwavelength portrait.

A digital "activation line" then sweeps across the image. As it encounters bright auroras, planetary disks or rings, the data values are translated into sound. Brighter X-ray emissions may become higher or louder notes, while vertical position can shift pitch and stereo placement.

"Sonifications expand options for people to explore what telescopes discover in space, an example of NASA's ongoing commitment to share its data as widely as possible," officials said in the statement.

In Jupiter's sonification, shimmering, wind-like tones evoke the giant planet's powerful X-ray auroras, while deeper notes roll underneath like distant thunder, reflecting the turbulence of its striped atmosphere and cloud layers. Saturn's rings sweep in rising and falling siren-like tones, while deep bass notes represent the planet itself. Uranus unfolds more subtly, with gentler, cello sounds that trace the icy planet's arcing ring, mirroring its cooler, more subdued presence at the edge of the planetary lineup.

Previous sonifications have drawn on observations of the Milky Way, distant galaxies, stars, supernovae, nebulae and black holes. One example, based on the famous black hole in Messier 87, translates its powerful jets into sweeping changes in pitch and intensity, followed by lower, sustained tones representing vast clouds of hot gas, with brief, bell-like notes marking individual stars.

Just as astronomers assign visible colors to otherwise invisible wavelengths to make images comprehensible, sonification gives numerical data distinct sonic qualities. Mapping the planets' crackle, sweep and hum into different tones brings the solar system to life through both sight and sound.

Jupiter, Saturn, Venus, Neptune, Uranus and Mercury are staring in a "planetary parade" this week, but your ability to actually spot them will depend on preparation, equipment and, as always, a spot of luck with the weather.

Most of this week's naked-eye planetary action will take place low in the western sky, which is where the aforementioned preparation comes in. Be sure to stake out a raised location with a clear view of the horizon well ahead of time — you can use a smartphone stargazing app to figure out exactly where the planets will be in your local environment, so there's no need to guess.

Do so, and you'll be granted a rare, if challenging opportunity to spot Mercury shining 10 degrees — roughly the width of your clenched fist held at arm's length — above the late winter skyline, with Venus close to its left, floundering in the glow of the setting sun. Saturn, meanwhile, will glow less than 10 degrees to the upper left of Venus, with a distant cousin lurking nearby, but more on that later.

Mercury and Venus will follow the sun out of sight roughly an hour after sunset, briefly becoming more visible as the sky darkens and they grow closer to the horizon. Jupiter, meanwhile, will shine high in the eastern sky, with the waxing gibbous moon below, obscuring the stars of the constellation Cancer with its reflected light.

The next two planets will need a little added magnification to spot — and even then, you'll have the odds stacked against you.

The ice giant Neptune will be positioned two degrees to the right of Saturn, but will be too dim to spot with the unaided eye. Under dark skies, a telescope with an aperture of 8 inches (200 millimeters) or more can reveal its tiny bluish disk. However its position low on the horizon and close to the glare of our parent star will make it a challenge to spot on the nights surrounding Feb. 28. As always the utmost care must be taken to ensure that the sun is firmly below the horizon before pointing telescopic equipment in its general direction.

Uranus, meanwhile, can be found by sweeping your scope across the patch of sky 5 degrees below the Pleiades open star cluster, to the right of the "V" formation of stars in the constellation Taurus in the hours following sunset. Again, those new to the night sky may want to use a smartphone astronomy app, which makes use of augmented reality technology to help you pinpoint everything from constellations and planets to galaxies and meteor shower radiants.

Award-winning night sky photographer Josh Dury grappled with the sheer scope of the scene along with the glow of the setting sun and other challenges to capture a gorgeous long exposure view of the planetary parade earlier this week as it brightened the sky over the south of England.

For more, check out our handy guide on the equipment needed to see and photograph the planets. If you're into photography, then why not also read our roundups of the best cameras and lenses for capturing the night sky?

Editor's Note: If you would like to share your planetary astrophotography with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

If your sky is clear early tonight (Feb. 26), be sure to check out the east-southeast sky about an hour or so after sundown. There, located about two-thirds up from the horizon, you'll find an eye-catching sight. You'll immediately see the moon, which will be at its waxing gibbous phase, en route to becoming full (and a total lunar eclipse) on March 3.

But also on this Thursday evening, you'll also notice a very bright, silvery "star" shining with a steady glow almost directly below the moon. That's not a star, however, but the biggest planet in our solar system: Jupiter. Both the moon and the planet will keep each other company as they move across the night sky.

Your clenched fist held at arm's length measures roughly 10 degrees in width. On this night, the moon and Jupiter will be separated by about 6 degrees — or a little more than a "half fist."

Casual observers looking skyward will almost certainly wonder what that bright object near the moon happens to be and I would certainly encourage all broadcast meteorologists to let their listeners and viewers in on what they're looking at on that night.

An excellent object for the eyes, binoculars and telescopes

Jupiter is ideally placed for evening viewing, shining high and free where trees and other obstructions reach in vain to hide it, and where even the ill-effects of atmospheric seeing are at their least. Jupiter currently shines in the middle of the zodiacal constellation of Gemini the Twins, not far from the bright stars Pollux and Castor. It reaches its highest point in the sky — transiting the meridian as the astronomers would say — around 8:30 p.m. It sets during the predawn hours, soon after 4 a.m.

For amateur astronomers, Jupiter is the best of the planets, a superb telescopic object. Its disk shows more illuminated surface area than all the other planets combined. Users of the very smallest telescopes or even steadily held binoculars can identify some or all four of its bright moons at any given time. Three of these will be in evidence on this night, with Ganymede (the largest) and Io shining on one side of Jupiter and Callisto on the other side.

But the planet's disk itself also draws a lot of attention. In large telescopes, one can view its cloud belts; sometimes one or more can look strongly disturbed, full of knots and sprouting festoons, or on the other side of the coin, perhaps looking like pale belts crossing the planet. And recent reports on Jupiter's Great Red Spot (GRS) show it's shrinking and becoming more circular but also reveal unexpected dynamic behavior like "jiggling" or "oscillating," with its size fluctuating over short periods, challenging the view of it as a stable, unchanging feature.

As always, seeing much detail on Jupiter requires a good quality telescope, good atmospheric seeing, and patience behind the eyepiece.

Lastly, if clouds hide your view of the moon on Jupiter, don't fret. They'll be together again on March 26.

Look to the western horizon at sunset on Feb. 20 to witness an incredible sight, as three planets shine below the slender crescent of the waxing moon, with Jupiter glowing high overhead in the winter sky.

The upturned sickle-shape of the 18%-lit moon will appear 40 degrees above the horizon as the sun sets, with a string of bright "evening stars" representing Venus, Mercury and Saturn arrayed beneath, fighting for attention in the glow of the setting sun.

Saturn will be positioned 15 degrees directly below the crescent moon, with Mercury less than 10 degrees— roughly the width of your clenched fist held at arm's length — to its lower right. Mercury is currently in prime viewing position, having just passed its point of greatest eastern elongation on Feb. 19, when it was at its furthest from the sun in Earth's sky in its current evening apparition.

Find a spot with a clear view to the west for a chance to see Venus shining directly below Mercury, less than 10 degrees above the horizon at sunset. Neptune will also be present less than 1 degree — approximately the width of your little finger — to the right of Saturn, though it'll be too dim to spot with the naked eye.

Neptune is so distant that the blue spec of its disk can only be seen with the aid of an 8-inch telescope, but utmost care must be taken to ensure that the sun is well below the horizon before pointing any telescopic equipment in its direction.

Uranus, meanwhile, will be five degrees below the Pleiades on Feb. 20 and while technically just bright enough to spot with the naked eye from a dark sky location, the planet will also benefit from the magnifying power of a telescope to spot its tiny aqua disk.

Jupiter dominates the sky this time of year and can be found high in the east at sunset, glowing with the bright stars Castor and Pollux in the constellation Gemini. A 6-inch telescope will reveal details in the cloud bands lining its surface, along with its four largest moons, Io, Ganymede, Europa and Callisto.

The lunar crescent will also make for a fascinating telescopic target, just three days out from its new moon phase on Feb. 17. Look out for the dark forms of Mare Crisium and Mare Fecunditatis darkening the sunlit wedge of Earth's satellite, which formed when ancient lava flows flooded networks of impact craters before hardening many millions of years ago.

Next, sweep your telescope across the line separating night from day on the lunar surface — known as the terminator — to spot a myriad of shadowed impact craters scarring the lunar surface.

Want to explore the planets of the solar system for yourself? Then be sure to read our roundup of the best telescopes available in 2026. If you're into photography you'll want to peruse our picks of the best cameras and lenses for capturing the night sky.

Editor's Note: If you would like to share your planetary astrophotography with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

The blissfully dark nights surrounding this month's new moon phase on Feb. 17 present a perfect opportunity to explore the wonders of the post-sunset realm while free of the glare cast by our natural satellite.

A new moon phase occurs when the moon is positioned directly between the sun and Earth, meaning the moon isn't visible at night and is hidden by the sun's glare during the day. February's new moon phase occurred at 7:01 a.m. EST (1201 GMT), heralding the onset of a spectacular annular solar eclipse visible across a swathe of Antarctica, as the lunar disk passed in front of the sun, leaving only the "ring of fire" of its outer edge on display.

Sadly, unless you're a penguin or an Antarctic researcher, you were unlikely to catch the eclipse for yourself today. Still, the new moon offers several nights of pristinely dark moonless skies, so grab your telescope and join us on a sightseeing tour of the mid-February night sky.

Visible planets

Mercury will shine low in the west in the hour following sunset on Feb. 17, appearing as a bright "evening star" less than 20 degrees above the horizon. If you're incredibly lucky — and have a clear view of the western horizon — then you may be able to spot the steady light of Venus vying for attention in the glow of the setting sun below Mercury on Feb. 17, before it follows our parent star swiftly out of sight.

Saturn will be visible less than 15 degrees to the upper left of Mercury. Its iconic rings are finally starting to reveal themselves after seeming to "disappear" in November last year, when they turned edge-on in relation to Earth, making them appear as little more than a thin line.

Dark nights around the new moon phase are the perfect time to hunt twinkling constellations through the winter sky. Look to the left of Jupiter to find Castor and Pollux — the two stars that represent the twins in the constellation Gemini.

The gleaming star directly below Jupiter in the evening sky is Procyon, the brightest member of the constellation Canis Minor, the little dog. Sirius, the brightest star in the night sky, sits at the heart of Canis Majoris — the big dog — and can be found shining roughly 20 degrees to its lower right (roughly the width of two stacked fists held at arm's length), with the stars Wezen and blue Adhara forming its rear leg.

Both stellar hounds hunt the night sky alongside their master, the hunter depicted in the constellation Orion, the colorful stars of which can be spotted to the upper right of Sirius in the hours following sunset on Feb. 17.

Look out for the red giant star Betelgeuse, which marks the right shoulder of Orion and the blue supergiant Rigel, which marks the left foot. Between are the three familiar points of Orion's Belt, and hanging below that is the milky light of the Orion Nebula — a colossal stellar nursery that orbits within the Milky Way roughly 1,500 light-years from Earth.

To the right of Orion will be the red light of Aldebaran, the star which marks the eye of the great bull in the constellation Taurus. Notice a hazy patch of light to the upper right of Aldebaran? That's the Pleiades, a vast star cluster teeming with over a thousand blue-white stars, which makes for a magnificent target, whether you're viewing with the naked eye, binoculars, or a telescope.

Next, look to the northeast to find the seven stars of the "Big Dipper" asterism standing on its end close to the horizon. Locate the two uppermost stars — Merak and Dubhe — and draw an imaginary line from the former through the latter and out into space. The next bright star you find will be Polaris, the "North Star", around which the entire sky appears to revolve.

Continue following that line and look slightly higher to find the five bright stars of Cassiopeia, arrayed in a zig-zagging formation reminiscent of a sideways "W", or "M", which is said to portray a queen who was cast into the stars after falling foul of the Greek god Poseidon.

Want to get a closer look at the night sky? Then be sure to check out our picks of the top binoculars and telescopes for exploring the planets and constellations, while photographers should read our selection of the best cameras and lenses for astrophotography.

Editor's Note: If you would like to share your astrophotography with Space.com's readers, then please send your photo(s), comments, name and location to spacephotos@space.com.

Astronomers may have just pushed the upper size limit of what counts as a planet, thanks to new insights into how giant worlds form.

New observations from NASA's James Webb Space Telescope (JWST) suggest that even extremely massive gas giants — once thought too large to form like ordinary planets — may grow through the same basic process, shifting how scientists differentiate massive planets from brown dwarfs.

The findings come from a close look at the HR 8799 system, a young, sun-like star about 133 light-years from Earth that hosts four enormous gas giants orbiting far from their parent star. Each world is between five and ten times the mass of Jupiter — the largest planet in our own solar system — placing them near the fuzzy boundary between planets and brown dwarfs, which are substellar objects that fuse deuterium, rather than hydrogen like stars, earning them the nickname "failed stars," according to a statement from the University of California, San Diego.

For years, astronomers have debated whether planets this massive could form through core accretion, the slow, bottom-up process in which solid material clumps together into a dense core that then pulls in vast amounts of gas. At extreme orbital distances, where material is sparse and protoplanetary disks fade quickly, many researchers thought this mechanism simply wouldn't allow enough time for these planets to grow so large.

To test that assumption, the research team used the JWST's powerful infrared spectrographs to analyze the chemical makeup of the planets' atmospheres. Instead of focusing on common gases like water vapor or carbon monoxide, the scientists searched for sulfur-bearing molecules — elements that typically begin as solid grains in a young protoplanetary disk and thus suggest the planet formed through core accretion, according to the statement.

The spectral data provided by the JWST revealed hydrogen sulfide in the atmosphere of HR 8799 c, one of the system's inner giants, providing strong evidence that the planet formed by first assembling a solid core before rapidly accreting gas. That chemical fingerprint is otherwise difficult to explain if the planet instead formed through a rapid, star-like collapse of gas. The team also found that the planets were more enriched in heavy elements, like carbon and oxygen, than their star, further supporting that they formed as planets.

"With the detection of sulfur, we are able to infer that the HR 8799 planets likely formed in a similar way to Jupiter despite being five to ten times more massive, which was unexpected," Jean-Baptiste Ruffio, lead author of the study, said in the statement.

Therefore, the study suggests that core accretion can operate efficiently even at extreme masses and distances, expanding the known limits of the planet-building process. If confirmed in other systems, the finding could force astronomers to rethink where — and how — the line between giant planets and brown dwarfs is drawn.

Their findings were published Feb. 9 in the journal Nature Astronomy.

Jupiter has had its length and breadth measured again, and it turns out the giant planet is skinnier and shorter than scientists had thought.

"Textbooks will need to be updated," said Yohai Kaspi of the Weizmann Institute in Israel in a statement. "The size of Jupiter hasn't changed, of course, but the way we measure it has."

Jupiter is a gas giant planet, and the largest planet in our solar system to boot. The textbooks currently state that Jupiter is 88,846 miles (142,984 kilometers) across at its equator, and 83,082 miles (133,708 km) from pole to pole. In other words, Jupiter is flatter at its poles than at its equator, the result of its fast rotation (just under 10 hours) creating an equatorial bulge. However, the new measurements, courtesy of NASA's Juno spacecraft that is currently orbiting Jupiter, shaves about five miles (8 km) off the equator and about 15 miles (24 km) off at the poles.

The previous measurements had come from NASA's Pioneer 10 and 11 and Voyager 1 and 2 missions, amounting to just six data points in total, whereas Juno has been able to add another 26 measurements.

Juno has been orbiting Jupiter on an elongated orbit since 2016, but since its mission extension in 2021, Juno has moved onto a different trajectory that gives it close fly-bys of Jupiter's Galilean moons as well as passes behind Jupiter as seen from Earth, which previously it never did.

The trick to measuring how large a planet like Jupiter is involves the spacecraft passing behind Jupiter from our point of view while beaming radio signals back to Earth. Where the signals are bent by the effect of Jupiter's upper atmosphere, or cut out completely by the bulk of the planet only to reappear on the opposite limb, tells us how large Jupiter must be.

"We tracked how the radio signals bend as they pass through Jupiter's atmosphere, which allowed us to translate this information into detailed maps of Jupiter's temperature and density, producing the clearest picture yet of the giant planet's shape and size," said the Weizmann Institute's Maria Smirnova, who developed the techniques necessary to process the raw Juno data.

And although a few kilometers off here and there doesn't sound like much, it's actually quite a big deal for accurately modeling the interior of Jupiter.

"These few kilometers matter," said Weizmann's Eli Galanti, who led the research. "Shifting the radius by just a little lets our models of Jupiter's interior fit both the gravity data and atmospheric measurements much better."

Indeed, by adjusting Jupiter's dimensions to those measured by Juno, Galanti's team found that current state-of-the-art models describing the interior density structure of Jupiter worked even better. And since Jupiter is the gold standard for understanding gas giant planets, the better we know Jupiter, the better astronomers can understand other gas giant planets too — not just in the solar system but also around other stars.

The new measurements of Jupiter are reported in a paper published on Feb. 2 in the journal Nature Astronomy.

The two planets that are in prime position for evening visibility this month are, ironically, the two planets on opposite ends of the spectrum concerning size. The solar system's biggest planet, Jupiter, is in excellent position for observation this month of February, high in the east-southeast sky at nightfall and soaring high into the sky during the mid-to-late evening hours. Meanwhile, the smallest planet — Mercury — will enjoy its finest evening apparition, readily available to those who seek it out about three-quarters of an hour after sunset, low in the west-southwest sky, for a three-week interval beginning on Feb. 6.

There are two other planets in the evening sky: Saturn is also in the west-southwest sky, but getting progressively lower with each passing day. The combination of low altitude and increasingly bright twilight will make it rather difficult to sight during the final week of the month. If only Saturn were a bit brighter, it would be easier to see. Which is why dazzling Venus, in the same general vicinity as Mercury and Saturn, will slowly emerge into prominence during the last half of February and on into March.

The only planet completely out of the viewing loop is Mars, which is much too close to the glare of the sun to be seen all month long.

In our schedule, remember that when measuring the angular separation between two celestial objects, your clenched fist held at arm's length measures roughly 10-degrees. Here, we present a schedule below which provides some of the best planet viewing times, as well as directing you to where to look to see them.

Mercury

Mercury, moving from superior conjunction, begins a fine apparition on the evening of Feb. 6, low in the west-southwest for skywatchers at mid-northern latitudes. During the first part of February, it comes into view higher in the fading dusk each evening. Currently, magnitude -1.1 (among the stars, only Sirius is brighter), and 12 degrees east of the sun, the planet will set an hour after sundown. On the evening of Feb. 18, about 45 minutes after sunset, look low toward the west-southwest horizon for a hairline-thin waxing crescent moon, just 2 percent illuminated by the sun. Sitting less than one degree above it will be Mercury. The pair is even closer together as seen from the Midwest and still closer together as seen from the western U.S.

The view through binoculars should be stunning. As a bonus, for parts of Texas, Arkansas, Louisiana, Mississippi, Alabama, Georgia and Florida, the moon will appear to pass directly in front of Mercury. On the following evening, Mercury attains its greatest elongation, only 18.1 degrees from the sun. So small an angle for an eastern elongation will not be matched until 2039. And yet around this time Mercury will be in the sky throughout evening twilight, the only such occasion in 2026. At this time, the speedy little planet shines at magnitude -0.4, and telescopes show its tiny disk exactly half lit — which isn't always the case at most of Mercury's greatest elongations. In the following week, Mercury fades by nearly a factor of five and soon sinks out of view. Inferior conjunction occurs on March 7.

Venus

Venus was at superior conjunction with the sun on Jan. 6; farthest from Earth on Jan. 8; and at aphelion — farthest from the sun in space — on Jan. 22. As February begins, Venus will be very challenging to glimpse even with optical aid, for it will be less than 4 degrees high at sunset and will set less than a half hour after the sun.

By Feb. 15, Venus may be evident to the eye without any optical aid. About 15 minutes after sunset, search very low near the west-southwest horizon. If you still can't find it, scan with binoculars, then once found, you should be able to see it with your unaided eyes shining radiantly through the bright evening twilight. On the other hand, by month's end, this brilliant -3.9-magnitude planet appears about 10 degrees high at sunset and should be reasonably easy to find before it sets about an hour after sundown.

Mars

Mars during February lies only 6 to 12 degrees west of the sun and, as such, is hopelessly lost in the solar glare.

Jupiter

Jupiter was at opposition on Jan. 10. So, February finds it already well up in the east as the sky darkens. It shines in Gemini, dimming a bit this month from magnitude -2.6 to -2.4 as it slowly retrogrades (moves westward relative to the background stars). The big planet is high for most of the night as seen from mid-northern latitudes; it's highest around 10:20 p.m. as February begins and 8:30 p.m. as the month ends. And although its apparent diameter shrinks slightly by about 6% during this month, Jupiter always appears large enough through a medium-sized telescope to see a lot of detail in its clouds if the air is sufficiently steady. As darkness falls on Feb. 26, look high in the eastern sky for the waxing gibbous moon and hovering about a half-dozen degrees below it will be "Big Jupe."

Saturn

Saturn is losing altitude rapidly with each passing night. At the beginning of the month, it's visible low in the west-southwest sky as darkness descends. Now Saturn's lower position will make locating it trickier, so tonight, use the moon as your benchmark. In telescopes, the still-narrow rings will be slowly opening like some late-winter flower, but by month's end, it will be difficult to get an image of them unruffled by Earth's quavering atmosphere. The crescent moon, which on Feb. 19 will have widened to 7% illuminated after its close encounter with Mercury on the previous evening, will sit about 4 degrees to the right of first-magnitude Saturn.

Look east at sunset on Jan. 30 to spot the near-full moon shining close to the gas giant Jupiter among the stars of the constellation Gemini.

Jupiter will appear as a steady "evening star" less than 5 degrees — roughly the width of your three middle fingers held to arm's length — to the lower right of the lunar disk in the eastern sky, with the bright stars Castor and Pollux twinkling close to its left.

The 97%-lit moon will appear full to the casual observer, just two days out from its full moon phase on Feb. 1. Jupiter, meanwhile, will look particularly bright and prominent in late January, just a few weeks after reaching opposition on Jan. 10, when it lay opposite the sun in Earth's sky and shone at its best for the year.

The moon and Jupiter will be close enough to fit comfortably in the field of view of a pair of 10X50 binoculars, which will help reveal the dark lunar seas and prominent craters scarring the surface of Earth's natural satellite. Look out for bright streaks of material called "ejecta rays" leading away from impact sites on the nights surrounding each full moon phase. These reflective masses of relatively young material were deposited many millions of years ago during cataclysmic asteroid strikes that excavated vast basins on the lunar surface.

A telescope with an aperture of 6 inches or more will reveal details in the roiling cloud bands lining the gas giant's surface, alongside the presence of its four largest "Galilean" moons, Io, Europa, Ganymede and Callisto, which line up to the right of Jupiter's disk on Jan. 30. The moon and Jupiter will soar high overhead through the winter sky as the night wears on, before finally setting on the western horizon in the hour preceding dawn on Jan. 31.

Want to see Jupiter and the moon up close? Then be sure to check out our guide to the best telescopes for exploring the night sky, along with our guide to observing the moon and finding the historic Apollo-era landing sites.

Editor's Note: If you would like to share your photo of the moon and Jupiter with Space.com's readers, then please send your photo(s), comments, name and location to spacephotos@space.com.

The most violent volcanic cataclysm ever seen in our solar system has been witnessed on Jupiter’s moon Io by NASA’s Juno spacecraft, with simultaneous eruptions covering an enormous 40,400 square miles (65,000 square kilometers). The synchronous eruptions point to a hitherto undetected network of interconnected magma reservoirs just beneath the volcanic moon’s lava-encrusted surface.

The eruptions released an amount of energy estimated to be between 140 and 260 terawatts (one terawatt is a trillion watts). The previous most energetic volcanic eruption seen on Io was about 80 terawatts, from a volcano called Surt in 2001. For comparison, the Mount St Helens eruption in Washington state in 1980 had a power of 52 terawatts.

"What makes the event even more extraordinary is that it did not involve a single volcano, but multiple active sources that lit up simultaneously, increasing their brightness by more than a thousand times compared to typical levels," Alessandro Mura of the Italian National Institute for Astrophysics (INAF) said in a statement. "This perfect synchrony suggests that it was a single enormous eruptive event, propagating through the sub-surface for hundreds of kilometers."

The volcanic event took place on Dec. 27, 2024, coinciding with one of Juno’s close fly-bys of Io, when the spacecraft was 46,200 miles (74,400 kilometers) above the moon’s charred surface. Io, which has a diameter of 2,263 miles (3,643 km), harbors approximately 400 active volcanoes scattered across its surface, and their frequent eruptions are driven by the vice-like grip of gravitational tidal forces emanating from Jupiter that squeeze and flex Io’s interior, generating more than enough heat to keep its mantle molten.

What’s most intriguing about this particular volcanic event is the way that multiple volcanoes all lit up at the same time, implying that they are connected by vast pools of magma that fuel multiple eruptions at once. Mura’s research team suggests that the sub-surface and mantle of Io may be like a sponge, in the sense that it is filled with pores filled with magma. Interestingly, not all the known volcanoes in the region erupted, suggesting that those that didn’t erupt were not connected to this particular magma network, but may be linked to others instead.

The volcanic outburst was detected by Juno’s JIRAM (Jovian InfraRed Auroral Mapper) instrument, for which Mura is the principal investigator. JIRAM had been designed to probe thermal emissions in Jupiter’s atmosphere and look for aurorae, but JIRAM’s infrared prowess also makes it suitable for spotting volcanic hotspots on Io.

As part of Juno’s extended mission, the spacecraft is making close encounters of Jupiter’s large Galilean moons after having spent most of its mission away from them. During future fly-bys of Io, Juno will survey the moon’s surface looking for new lava flows and ash deposits resulting from this spectacular volcanic eruption.

The findings are described in a paper published on Jan. 10 in Journal of Geophysical Research: Planets.

After years of debate, NASA researchers have zeroed in on the thickness of the Europa's ice shell.

We first discovered that the Jupiter moon's surface looked icy in 1979, when Voyager 2 flew by. Another NASA mission, the Galileo Jupiter orbiter, later confirmed the ice shell while it inspected the giant planet, Europa, and other Jovian moons during the 1990s.

Since then, scientists have been in two camps, championing conflicting theories on the thickness of Europa's ice shell. One theory holds that the shell — which is thought to hide a huge, buried ocean of liquid water — is less than 1 mile (1.6 kilometers) thick, while the other posits that it spans tens of miles.

Now, we appear to have an answer. Using data the Juno Jupiter orbiter gathered in 2022 using its Microwave Radiometer instrument, researchers at NASA's Jet Propulsion Laboratory (JPL) in Southern California calculate that the shell is about 18 miles (28.9 km) thick.

"The 18-mile estimate relates to the cold, rigid, conductive outer layer of a pure water ice shell," Steve Levin, Juno project scientist and co-investigator from JPL, said in a NASA statement on Tuesday (Jan. 27).

"If an inner, slightly warmer convective layer also exists, which is possible, the total ice shell thickness would be even greater," Levin continued. "If the ice shell contains a modest amount of dissolved salt, as suggested by some models, then our estimate of the shell thickness would be reduced by about 3 miles [5 km]."

Understanding the makeup and structure of Europa's icy surface is important, because NASA researchers — and many other scientists around the world — want to find out if the moon hosts alien life. Previous research suggests that the ingredients for life could exist in the moon's subsurface ocean.

"How thick the ice shell is and the existence of cracks or pores within the ice shell are part of the complex puzzle for understanding Europa's potential habitability," Scott Bolton, Juno principal investigator from the Southwest Research Institute in San Antonio, said in the NASA statement.

And a thick ice shell might not be great news for Europa's life-hosting potential. This feature "implies a longer route that oxygen and nutrients would have to travel to connect Europa’s surface with its subsurface ocean," NASA officials wrote in the statement.

This new insight into Europa will provide helpful context for the two spacecraft that are en route to the Jovian system right now. NASA's Europa Clipper should arrive in orbit around Jupiter to investigate Europa's habitability in 2030, and the European Space Agency's Juice (JUpiter ICy moons Explorer) will get there a year later.

The new Europa results were published Dec. 17 in the journal Nature Astronomy.

Jupiter's icy moon Europa may have a previously unrecognized way of delivering life-supporting chemicals to its vast subsurface ocean, according to new research.

Europa, one of the dozens of moons orbiting Jupiter, has long intrigued scientists as one of the most promising places in the solar system to search for extraterrestrial life, thanks to a hidden global ocean beneath its fractured, frozen surface that may contain twice as much salty water as all of Earth's oceans combined. Unlike Earth, however, Europa's ocean is deprived of oxygen and sealed off from sunlight, ruling out photosynthesis and requiring any potential life to rely on chemical energy instead. A key unanswered question has been how ingredients for that energy — such as life-supporting oxidants created on the moon's surface by intense radiation from Jupiter — could be transported through Europa's thick ice shell to the ocean below. Now, a new study by researchers at Washington State University suggests the answer may lie in a slow but persistent geological process that causes portions of Europa's surface ice to sink, carrying those chemicals downward.

"This is a novel idea in planetary science, inspired by a well-understood idea in Earth science," study lead author Austin Green, now a postdoctoral researcher at Virginia Tech, said in a statement. "Most excitingly, this new idea addresses one of the longstanding habitability problems on Europa and is a good sign for the prospects of extraterrestrial life in its ocean."

Scientists know from images taken during spacecraft flybys that Europa's surface is highly geologically active due to Jupiter's powerful gravitational pull. However, most of this motion appears to occur horizontally rather than vertically, according to the new study, which limits opportunities for surface materials to migrate downward, except during extreme events such as the formation of large fractures.

Additionally, the Jovian moon's near-surface ice is thought to behave as a rigid "stagnant lid," further restricting the delivery of oxidants to the subsurface ocean, the study notes.

Using computer models, the researchers found that pockets of salt-rich ice near Europa's surface can become both denser and mechanically weaker than surrounding, purer ice. Under the right conditions, these denser patches can detach and slowly sink, or "drip," through the ice shell, eventually reaching the ocean below in as little as 30,000 years, according to the study.

The process, known as lithospheric foundering, resembles a geological process on Earth in which portions of the planet's outermost layer sink into the mantle. In 2025, researchers identified this process unfolding beneath the Sierra Nevada mountain range.

To test whether a similar mechanism could operate on Europa, Green and his team modeled an ice shell roughly 18.6 miles (30 kilometers) thick under a range of ice shell conditions. In all six scenarios the team examined, surface material within the top 300 meters descends toward the base of the shell, the new study reports.

In some simulations, the sinking began after 1 to 3 million years and reached the base of the shell after 5 to 10 million years. In ice shells that were more heavily damaged or weakened, sinking began after as little as 30,000 years, the study reports.

This occurred for almost any salt content, the researchers say, provided the surface ice experienced at least some degree of weakening.

According to the study, the mechanism "may be an expedient method of transporting surface materials to the underlying Europan ocean."

The moon will be studied in greater detail in the coming years by NASA's Europa Clipper mission. Launched in 2024, the spacecraft is scheduled to arrive in the Jovian system in April 2030 and conduct nearly 50 close flybys of Europa over four years, allowing scientists to assess the depth of its subsurface ocean and further evaluate the moon's potential habitability.

The team's research is described in a paper published on Tuesday (Jan. 20) in The Planetary Science Journal.

Scientists may finally know why Jupiter and Saturn have very different weather patterns at their poles, despite having similar sizes and compositions. The discovery could help researchers probe deep into the interiors of these giant gaseous planets.

Observations of the two solar system gas giants have revealed that Jupiter's north pole hosts a central polar vortex surrounded by eight smaller vortices, while Saturn has a single, strangely hexagonal, massive atmospheric whirlpool over its north pole.

While performing complex simulations of these types of vortexes of gas giants, the team behind this research found that the difference between a single vortex configuration and a multi-vortex pattern depended on how "hard" the base of the vortex was, meaning how heavy the gas is in this region (the softer the gas, the lighter it is). This "hardness" is in turn related to the interior composition of the gas giant.

"Our study shows that, depending on the interior properties and the softness of the bottom of the vortex, this will influence the kind of fluid pattern you observe at the surface, research team member Wanying Kang, of the Massachusetts Institute of Technology (MIT), said in a statement. "I don't think anyone’s made this connection between the surface fluid pattern and the interior properties of these planets. One possible scenario could be that Saturn has a harder bottom than Jupiter."

Softer than Saturn?

Kang and colleagues were inspired to conduct their simulations after viewing images of Jupiter captured by the Juno spacecraft, which has been orbiting the solar system's largest planet since 2016, and by images of Saturn delivered by Cassini over 13 years of observations before it was deliberately plunged into the ringed planet at the end of its mission in 2017.

The Juno images revealed the immense scale of Jupiter's polar storms, which are around 3,000 miles (4,800 kilometers) wide. For context, that is around half the width of Earth. Cassini's observations of Saturn, meanwhile, showed its single hexagonal vortex is a staggering 18,000 miles (29,000 kilometers) wide.

Astronomers aren't sure why there is such a size discrepancy between the two planets' vortices. "People have spent a lot of time deciphering the differences between Jupiter and Saturn," team leader and MIT scientist Jiaru Shi said. "The planets are about the same size and are both made mostly of hydrogen and helium. It’s unclear why their polar vortices are so different."

To answer this question, the team developed a 2D model of how vortices at the poles of gas giants like Saturn and Jupiter would evolve over time, applying this to a range of different scenarios. This included changing characteristics like the planets' sizes, the speed of their rotation, their internal heating, and the hardness of rotating fluid within their vortices.

After ensuring the fluid in these vortices flowed in random patterns, the scientists were ready to determine how the fluid evolved under specific conditions. This led to the discovery that a single mechanism could determine if a single vortex or multiple vortices developed;the softer the gas rotating at the bottom of the vortex is, the smaller that vortex is. That allows for the formation of multiple vortices, just as is seen at the poles of Jupiter.

If the team is right, then this implies that Jupiter consists of softer, thus lighter, gas, while Saturn seems to be composed of heavier gaseous material.

"What we see from the surface, the fluid pattern on Jupiter and Saturn, may tell us something about the interior, like how soft the bottom is, and that is important because maybe beneath Saturn's surface, the interior is more metal-enriched and has more condensable material, which allows it to provide stronger stratification than Jupiter," Shi concluded. "This would add to our understanding of these gas giants."

The team's research has been accepted for publication in the journal Proceedings of the National Academy of Sciences.

The new moon of January will be at 2:52 p.m. EST (1952 GMT) on Jan. 18, according to the U.S. Naval Observatory.

A new moon is, technically, a conjunction of the sun and moon. The two bodies share the same celestial longitude — if one drew a north-south line from the North Celestial Pole (right near where the Pole Star, Polaris, is located) the sun and moon would both be on it.

At the new phase, you can't see the moon from Earth unless there is a solar eclipse, the illuminated side is facing away from us. On top of that new moons rise and set with the sun; even if one could light up the side of the moon facing Earth it would be lost in the solar glare. Earth-based observers won't (visually) see a new moon until Feb.17, when there will be a solar eclipse visible from the southern Indian Ocean and Antarctica.

New moon skies are dark, especially when compared to nights when the moon is out; even a half-moon (when the moon is at first or last quarter phase) is the second brightest object in the sky after the sun. That means the nights on either side of a new moon are good for observing fainter stars and seeing the naked-eye nebulas and star clusters, particularly if one can watch the sky from a place away from city lights.

Visible planets

On the night of Jan. 18, there will be two planets visible: Saturn and Jupiter. By about 6 p.m., Saturn will be about 37 degrees above the southwestern horizon. In New York City, the sun sets at 4:56 p.m.; the timing and Saturn's location in the sky will be similar for anyplace near 40 degrees north, such as Chicago, Denver, Detroit, or Sacramento. In New York, Saturn sets at 9:48 p.m.

Jupiter, meanwhile, rises at 3:58 p.m.; since the sky darkens completely by about 6 p.m., one will see Jupiter about 21 degrees high in the east. Jupiter is brighter than the surrounding stars; one way to identify Jupiter is look for a rough triangle of "stars" with two of them to the left (north) of a brighter one; the brighter, steadier light is Jupiter. Jupiter is visible almost all night; the planet does not set until 6:49 a.m. (January 19) in New York, and it reaches its highest altitude (called transit) at 11:23 p.m. Jan. 18.

Unfortunately for planet hunters, Mercury, Venus and Mars are all too close to the sun to observe; they will come out of the solar glare in the weeks following the new moon. Mercury will emerge as an "evening star" in February and Venus will do so in March. Mars will emerge into the predawn skies in March.

For Southern Hemisphere skywatchers, the sky doesn't get dark until 9:30 p.m.; as it is the austral summer, the sun sets late. In Santiago, Chile, for example, sunset isn't until 8:54 p.m. local time on Jan. 18. Santiago is about as far south of the equator — 33 degrees — as Dallas or Charleston, South Carolina is north of it, and is of a similar latitude to cities such as Cape Town and Melbourne, Australia.

From Santiago, Saturn will be 22 degrees high in the west by 10 p.m. The ringed planet sets at 11:54 p.m. Jan. 18. Jupiter, meanwhile, rises at 8:11 p.m. local time, and by 10 p.m. is in the northeastern sky about 18 degrees high.

Stars and constellations

Winter constellations are in full swing for Northern Hemisphere observers in the latter half of January. Two hours after sunset — at about 7 p.m. in New York— some of the brightest constellations have risen — Orion (the Hunter), Gemini (the Twins), Taurus (the Bull), Canis Minor (the Little Dog) and Auriga (the Charioteer). Look low in the southeast to spot the brightest star in the sky, Sirius, the alpha star of Canis Major, the Big Dog.

You can start by identifying Gemini, as this is the constellation Jupiter is in. The two stars to the left (north) of Jupiter are Castor and Pollux, with Pollux being the one closer to the horizon. almost level with Jupiter. If you look down and to the right about four times Jupiter's distance from Pollux, you will see a bright white star; this is Procyon, the brightest star in Canis Minor. Go further to the right (south) and you see Sirius, which is recognizable by its blue-white hue and its brightness.

Directly above Sirius, about a third of the way from the horizon to the zenith (the point directly overhead) is Orion. Orion can be identified by the three stars that make up his belt — early in the night, they will appear to make an almost vertical line. Going up from the horizon, the first star is Alnitak, the second is Alnilam, and the third is Mintaka. Look slightly up and to the left of the belt and one can spot a bright reddish-orange star. This is Betelgeuse (pronounced like beetle-juice), marking one of Orion's shoulders. Above and to the right of Betelgeuse is Bellatrix, his other shoulder. On the right side of Orion's Belt, about the same distance from Mintaka as Betelgeuse is from Alnitak, is a bright blue-white star; this is Rigel.

Since the night will be moonless, just to the right of Orion's Belt and below it, you can, from a dark-sky location away from city lights, trace a group of faint stars that is Orion's sword, and in that group, you might be able to spot the Orion Nebula.

Look above Orion and go two-thirds of the way to the zenith to spot another reddish star, though its color is much less vivid than Betelgeuse. This is Aldebaran, the brightest star in Taurus. Aldebaran is in a group of fainter stars (the shape is a little bit like a U on its side or a backwards C). This is the Hyades, an open star cluster. Look higher still, almost straight up from Aldebaran, to see a tiny cluster of stars that are almost too close together to separate with the naked eye. This is the Pleiades, another open cluster also called the Seven Sisters. In binoculars, it will look like a miniature version of the Big Dipper.

Speaking of which, if you draw a line through Jupiter and Pollux northwards, you'll reach the Big Dipper, a group of stars that is part of Ursa Major, the Great Bear. The Dipper will be close to the horizon, with the bowl facing upwards. You can use the two stars at the front of the bowl, Dubhe and Merak (with Merak being the lower one), to find Polaris, the Pole Star.

By 9 p.m. The Big Dipper is almost vertical and in the northeast; the "bowl" faces west (left). The Dipper can now be used to point to other stars besides Polaris. If you draw a line to the right, connecting the stars at the back of the bowl (these will be the two lower in the sky) you'll reach Regulus, the brightest star in Leo, the Lion, which will be almost due east and about 17 degrees high (this will vary depending on one's exact latitude but it will be similar in any mid-Northern latitude city).

For Southern Hemisphere observers, January is when Puppis, Carina and Vela, the three constellations that make up the Argo, the famous ship of Jason and the Argonauts, are prominent, rising in the east by 10 p.m. Though you'll see an "upside down" sky, you can still use Jupiter to orient — Pollux will appear to be directly below the planet, as opposed to being to the left of it, and Procyon is to the right of Jupiter and above it, some 27 degrees high in the northeast. Look up and to the right from Procyon and you will see Sirius, about 51 degrees high. Look to the right (southwards) and still higher — about 59 degrees, or two thirds of the way to the zenith, and one spies Canopus, the alpha Star of Carina, the Ship's Keel. Below Canopus, there is a large "loop" of seven medium-bright stars, the topmost one (closest to Canopus) is called Regor, or Gamma Velorum, the brightest star in Vela, the Sail. Above and to the right of Vela is Puppis, the Poop Deck, another group of seven stars in an elongated shape rather like a peanut. The first four stars form a four-sided diamond shape to the left of and below Canopus; these are relatively faint. Just to the left of Regor is a fifth star, Zeta Puppis (or Naos) and the remaining two are to the left of that about twice as far from Regor as Naos is.

About 13 degrees above the south-southeastern horizon you can see Crux, the Southern Cross, which from the latitude of Santiago is circumpolar — it never sets. At 10 p.m. it is upside down (or nearly so) so the crossbar is closer to the horizon and its brightest star, Acrux, is highest.

If you look southwest and about 54 degrees above the horizon, you can see a bright star in a patch of sky that seems to have few of them; this is Achernar, the end of Eridanus, the River. Achernar is not visible from much of the Northern Hemisphere but the end of the constellation Eridanus is — it starts just to the south of Orion's foot, Rigel, which from the latitude of Santiago is 61 degrees high in the north-northeast, with Orion's Belt below rather than above it.

Deep beneath Jupiter's stormy skies lies a crucial clue to how all the planets in our solar system formed.

In a new study, scientists used advanced computer models to peer beneath Jupiter's dense swirling cloud tops and tackle a question that has lingered for decades: How much oxygen does the gas giant actually contain? The study suggests that Jupiter holds about one and a half times more oxygen than the sun, helping explain not only the gas giant's origins, but also the early history of the solar system.

"It really shows how much we still have to learn about planets, even in our own solar system," study lead author Jeehyun Yang, a postdoctoral researcher at the University of Chicago, said in a statement.

Observations dating back more than 360 years show that Jupiter's skies are dominated by immense, long-lasting storms, including the iconic Great Red Spot, which is bigger than Earth. However, directly measuring Jupiter's deep atmosphere is extremely difficult. Spacecraft like NASA's Juno mission can probe the planet's gravity and magnetic fields, while past missions have sampled only the uppermost layers of gas. But oxygen on Jupiter is mostly locked away in water, which condenses deep below the visible clouds, far beyond the reach of instruments in orbit around the gas giant.

To get around that problem, researchers from the University of Chicago and NASA's Jet Propulsion Laboratory developed the most detailed simulations yet of Jupiter's interior atmosphere. Their models combine atmospheric chemistry with hydrodynamics, tracking not just which molecules are present but how gases and cloud particles move through the planet over time.

That combination turned out to be key. Earlier studies often treated chemistry and atmospheric motion separately, leading to wildly different estimates of Jupiter's water and oxygen content. By modeling both together, the new analysis shows how water vapor, clouds and chemical reactions interact as material slowly circulates from deep, hot layers to cooler higher altitudes, according to the statement.

The results point to a Jupiter that has about 1.5 times more oxygen than the sun. That finding supports formation models in which Jupiter grew by accreting icy material early in the solar system's history, likely near or beyond the so-called snow line, where water ice was abundant. Forming so far from the sun's warmth would have allowed Jupiter to naturally incorporate more oxygen-rich material locked in frozen water than the sun itself.

The simulations also suggest Jupiter's deep atmospheric circulation is slower than previously assumed, with gases taking weeks — not hours — to move between layers. That insight could reshape scientists' understanding of how heat, storms and chemistry interact inside the planet.

Planets preserve chemical fingerprints of the environments in which they formed, making them time capsules of planetary history. Understanding which conditions give rise to different kinds of planets not only clarifies the solar system's evolution, but also helps guide the search for habitable worlds beyond our own.

Their findings were published Jan 8 in the Planetary Science Journal.

Europa might not be the best place to look for alien life in the solar system after all.

A new study modeling what the floor of the Jupiter moon's hidden ocean is like concluded that tectonic activity — and the complex chemical reactions that such activity facilitates — is probably negligible.

"Ultimately, without fracturing and faulting, it's not clear to us how fresh rock would be exposed to the ocean to allow for the kinds of continued chemical reactions that microbes would need to sustain themselves," study lead author Paul Byrne, associate professor of Earth, Environmental and Planetary Science at Washington University in St. Louis, told Space.com.

Europa harbors a deep ocean beneath a shell of ice that's dozens of kilometers thick. This ocean wraps around a rocky core, but little is known about the interface between the ocean and the core. If life is to exist in Europa's ocean, it must somehow gain energy, most probably from interactions at the sea floor between water and rock. Access to fresh rock is vital in order to produce more nutrients.

On Earth, tectonic faulting in the seafloor enables water to plunge kilometers down into the rock, and as fresh faults are opened up by shifting tectonic plates, new rock is exposed, maintaining the nutrient supply released into the ocean through hydrothermal vents.

Byrne's team assessed the potential for tectonic activity on Europa's seafloor with a new model that factored in stresses from gravitational tides incurred by Jupiter, the long-term contraction of the moon as its interior gradually cools and the convection of heat energy through the mantle.

However, they found that none of these factors would be strong enough to produce tectonic activity. For example, tidal stresses occur because Europa's orbit around Jupiter is not perfectly circular but rather eccentric, in accordance with Johannes Kepler's first law of orbital motion. This means that, at certain points in each of its 84-hour orbits around Jupiter, Europa is closer to the planet than at other times, and the resulting gravitational differential leads to tides. However, for the tides to be strong enough to induce sufficient tectonic activity, the eccentricity of Europa's orbit would have to be greater — more elongated — than it is (an eccentricity of 0.441 compared to the actual value of 0.009). Even if repeated tidal stresses weaken the uppermost part of Europa's seafloor, creating shallow fractures, they aren't intense enough to extend those faults deep down to new rock.

Similarly, while theoretical models suggest that Europa's rocky core has contracted over billions of years as its interior has cooled, it would have to shrink several kilometers to fracture the bedrock and create deep tectonic faults. This would be more extensive than the process on Earth's moon, which is estimated to have contracted by several tens of meters throughout its four-and-a-half billion-year history, though less than on Mars, which is thought to have contracted by up to 7 kilometers (4.3 miles).

The lack of tectonics is bad news for the possibility of life, since life would need fresh chemical nutrients to survive. One of the main sources of these nutrients on the floor of Earth's oceans is hydrothermal vents, like the famous black smokers. But according to the new modeling, black smokers that billow out hot water filled with nutrients are not possible on Europa.

"But it turns out that there are other kinds of hydrothermal systems," said Byrne. These other kinds percolate through the bedrock to shallower depths and hence are cooler.

"In fact, these other kinds are the most common on Earth," Byrne added. "Such relatively cooler hydrothermal vents could exist on Europa, but they'd be far less energetic than the traditional images we have in our heads when we think about hydrothermal vents. And it's very far from certain how long such cooler hydrothermal systems might last and support chemosynthetic microbial life."

If hydrothermal vents and tectonic faulting are off the menu for Europa, are there any other possible sources of chemical energy and nutrients that could sustain life on the ocean moon? Maybe, said Byrne, but there are still too many unknowns to know for sure. For example, radioactive decay could be a substitute source of energy, but we don't know the numbers for this process on Europa. Alternatively, perhaps nutrients enter the ocean not from below, but from above — meteorites that strike the surface ice and become subsumed and drawn into the ocean. However, it's not clear whether there are routes through the thick ice shell into the ocean and vice versa. This is one of the unknowns that NASA's Europa Clipper mission, currently on its way to Europa, aims to discover.

The findings are also potentially bad news for other ocean moons in the solar system, and Byrne's team is currently preparing a new study that investigates this further.

"Without giving too much away, I can say that the overall findings for Europa are applicable to most other such moons, with the likely exception of [Saturn's moon] Enceladus," Byrne said.

However, despite the pessimistic outlook, Byrne is keen to emphasize that we shouldn't stop looking for life on these icy moons with their hidden oceans.

"We're not saying, and we can't say, that there's no life in Europa," said Byrne. "What we're saying is that it's a harder proposition, based on our results."

The findings were published on Jan. 6 in the journal Nature Communications.

Jupiter will be at its most spectacular in 2026 in the early hours of Jan. 10, as it shines above the eastern horizon among the stars of the constellation Gemini. Here's where to look and what to expect as the gas giant draws closest to Earth around opposition.

The visibility of planets in the night sky varies dramatically based on their orbital positions relative to the sun and Earth. The best time to view superior planets — worlds that orbit the sun at a greater distance than our Blue Marble — is at their points of opposition, when they line up in our night sky directly opposite the sun, with Earth in the middle.

Jupiter will be visible to the east at sunset tonight (Jan. 9) with the bright stars Castor and Pollux shining to its left, according to In-the-sky. Throughout the evening hours on Jan. 9, Jupiter will be the brightest point of light in the night sky, until the waning crescent moon rises to usurp it in the hour following midnight for viewers in the U.S. The planet will officially reach opposition at 3:34 a.m. EST (0834 GMT) on Jan 10, when it will shine magnitude -2.7.

The moment of opposition coincides with when a planet draws near to its closest point to Earth in its orbit. As a result, Jupiter will appear brighter and subtly larger in the eyepiece of a telescope on Jan. 10, boasting an angular size of 45.6 arcseconds at opposition, as opposed to the 31.3 arcseconds it would occupy when furthest from Earth (when it would be hidden behind the sun). For context, the full moon takes up between 29.4 and 33.5 arcminutes, with each arcminute being the equivalent of 60 arcseconds.

Look to the eastern horizon at sunset on Jan. 10 to find Jupiter shining in the constellation Gemini, with Orion the "hunter" to its right and the bright star Capella above. The gas giant will arc high overhead before finally ending the night low on the western horizon as the sun rises on Jan. 11.

Jupiter was named after the king of the Roman pantheon of gods and it's pretty easy to understand why. The gas giant makes for a dazzling astronomical target when viewed with the naked eye, which only gets more impressive when viewed through a telescope with an aperture of 4-inches (152 mm) or more, which helps reveal its colorful atmospheric cloud bands.

The four large Galilean moons Io, Europa, Ganymede and Callisto will also be visible arrayed in a line formation extending either side of the gas giant on the night of Jan. 10.

If you're using a telescope with a larger aperture, you may want to try viewing the planet with a special astronomy filter screwed into the eyepiece, which will help reduce glare while enhancing the contrast between colors in the Jovian atmosphere's stormy cloud tops.

Want to catch a glimpse of Jupiter up close? Then be sure to check out our picks of the best telescopes for exploring the planets of the solar system. If you're interested in photographing the night sky then you may also want to read up on our roundup of the best cameras and lenses for astrophotography.

Editor's Note: If you would like to share your astrophotography with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

Jupiter, the largest planet in the solar system, currently shines as a brilliant silvery "star" in Gemini the Twins, low in the east-northeast sky as dusk slowly fades. It forms an eye-catching scalene triangle configuration with the "Twin Stars" Pollux and Castor; you really can't miss it.

And at 4 a.m. EST (0900 GMT) on Saturday (Jan. 10), Jupiter will arrive at that point in the sky directly opposite to the sun, called "opposition." If all the planets' paths around the sun were true circles, this would also coincide with Earth's closest approach to Jupiter, 393.3 million miles (632.9 million kilometer). That, however, occurs 25 hours earlier, at 3 a.m. EST (0800 GMT) on Friday (Jan. 9).

Opposition occurs when Earth, moving faster in its orbit than Jupiter, overtakes the giant planet. In the four months centered on each opposition, Jupiter appears to swirl backward in a loop against the background stars. After opposition, we will leave Jupiter behind. Jupiter is also currently moving away from the sun on its own elliptical path, while, less than a week ago, Earth passed its closest point to the sun (perihelion).

Jupiter will reach its farthest point from the sun — its aphelion point, which takes it 507 million miles (815.7 million km) from our star — on Dec. 28, 2028.

'Big Jupe' almost became a star

Jupiter constantly is the most interesting object in the solar system after the moon and the sun and has always held a special place in the hearts of telescope viewers. Jupiter provides telescope users with a feast of features: a restless atmosphere and a retinue of bright satellites.

This giant planet — which has nearly 2.5 times more mass than all of the other planets put together — takes nearly 12 Earth years to go once around the sun. Thus, it spends roughly a year within each of the 12 zodiacal constellations, since the constellations are of unequal width.

With an equatorial diameter of 88,846 miles (142,984 km), Jupiter is the largest planet: a colossal ball of hydrogen and helium without a solid surface. Scientists are currently uncertain about the exact nature of Jupiter's core, but modern data suggests it is not the solid, compact rocky ball once imagined. Recent findings from NASA's Juno mission and updated scientific models suggest that, instead of a sharp boundary between a solid core and the rest of the planet, Jupiter likely has a "dilute" core. This means that heavy elements like rock and metal are dissolved and encased in a thick mantle of metallic hydrogen enveloped in a massive atmospheric cloak of multi-colored clouds of ammonium hydrosulphide.

And, in a strange sense, Jupiter might even be referred to as a stillborn star, for it has the makings (mostly hydrogen) if not the mass of a stellar body. Its relative smallness, however, prevents the initiation of the nuclear processes that could have turned it into a full-fledged star. Had Jupiter been born a bit bigger, we would have the distinction of living within a binary star system.

Cloud bands and satellites

Binoculars show Jupiter as a tiny disk, while a medium-size telescope reveals numerous dark belts, light zones and a wealth of festoons, garlands, ovals and other features extending here and there. Jupiter's rotation is the fastest of all the solar system's planets. It completes a rotation on its axis in slightly less than 10 hours, which creates an equatorial bulge easily perceived through most telescopes. And January offers nearly optimum views of its intricate cloud features; it's even possible at mid-northern latitudes to observe every longitude of the planet during the long night.

Besides its prominent cloud belts, Jupiter's greatest telescopic treasure are its four Galilean moons that run a merry race with each other around the planet, changing their respective positions from hour to hour and night to night. The smallest of telescopes – even steadily held 7-power binoculars – will reveal these four bright satellites of Jupiter as tiny stars nearly in line and changing their places in the line as they revolve around the planet in orbits nearly edgewise to us. Typically, at least two or three are visible at any given moment.

On Saturday (Jan. 10), for example, we will see three satellites on one side of Jupiter (going outward from the planet: Ganymede, Io and Europa), while the fourth (Callisto) remains all by itself on Jupiter's opposite side.

Coming attractions

Jupiter will appear to climb higher in the evening sky in the weeks to come. Currently, the giant planet is ready for telescopic observation by 7 p.m., when it will stand one-third of the way up from the eastern horizon to that point directly overhead (called the zenith). It reaches its highest position in the south around midnight and is heading toward its setting in the west during dawn. After the glory of its opposition on the midnight meridian, Jupiter will appear a bit higher in the east each evening and will engage its stellar neighbors, Pollux and Castor in a sort of celestial pas de trois in the coming weeks.

On the evening of Feb. 27, the scalene triangle will have changed into a narrow isosceles, and nearly aligned with Pollux and Castor will be a waxing gibbous moon. But the real show occurs in late May and early June, when a fascinating dance of three planets and the moon will provide evening enchantment. On the evening of May 20, a crescent moon will be positioned well to the upper left of Jupiter. During the final week of May, one hour after sunset, you can watch how Venus climbs to meet Jupiter. On June 9, they'll call attention to themselves low in the west-northwest sky. Finally, on June 16, a slender crescent moon will appear to the right of Jupiter, and below the moon will sit yet another planet, Mercury.

The heavenly ballet continuously being performed by these "wandering stars" has played a crucial role in the celestial lore of all people. It is not surprising that they were regarded as deities. The five naked-eye planets (Mercury, Venus, Mars, Jupiter and Saturn) have been known since antiquity, and it is also interesting that the members of this quintet have all been examined closely by space probes. Of course, before the advent of the telescope, virtually all peoples regarded planets as a special category of star.

Over the following month, Jupiter sinks into the sun's glare. Emerging into the morning sky of August, he will progress into the constellation of Cancer the Crab, and on Sept. 24 he will cross over into the western boundary of Leo the Lion, where he will remain for the balance of the year. A spectacular eclipse (occultation) of Jupiter will await early risers across much of North America on Oct. 6, and a brightening Mars will closely pass north of Jupiter on Nov. 16. On Dec. 13, Jupiter will begin to swirl backward into the next loop that will climax in the opposition of Feb. 10, 2027.

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 and other publications.

Want to know when each planet will be at its best or when you can catch eye-catching planetary pairings in 2026?

This guide breaks down the major planetary events of the year, from conjunctions to oppositions to close planet-star encounters.

Related: Night sky tonight live blog

Mercury

Mercury, the smallest of the planets visible to the naked eye, appears as an evening star in the western sky, setting about an hour after the sun. As a morning star, it rises about an hour before the sun in the eastern sky. To view the planet, a clear, unobstructed view of the horizon is essential. Mercury usually appears as a bright "star" with a yellowish or ochre tint.

Visibility windows in 2026

• Evenings: Feb. 5–26; June 1–22; Sept. 28–Oct. 19
• Mornings: March 27– April 17; July 26– Aug. 16; Nov. 13– Dec. 4

When will it be at its best?

• Evening: Feb. 5–26
• Morning: Nov. 13– Dec. 4

On the evening of Feb. 18, about 30 minutes after sunset, Mercury will sit just 1 degree above a slender waxing crescent moon low in the west-southwest.

Venus

Venus, with its nearly circular orbit and a diameter only 400 miles (640 kilometers) smaller than Earth's, shines with a brilliant, steady silvery light.

Visibility windows in 2026

• Evenings: March 8– Oct. 14
• Mornings: Nov. 3– Dec. 31

When will it be at its best?

Venus reaches greatest brilliancy in the evening sky on Sept. 19 and in the morning sky on Nov. 29. In late September through mid-October, and again through most of November, Venus will show a striking crescent phase in telescopes and steady binoculars.

Notable conjunctions:

• March 8: Venus passes 1 degree to the upper right of Saturn.
• June 9: Venus passes 1.6 degrees to the upper right of Jupiter — a brilliant sight in the west-northwest 45 minutes after sunset.
• Nov. 7 (morning): Shortly before sunrise, look low to the east-southeast for Venus, a crescent moon, and the star Spica, all fitting within 2.5 degrees.

Mars

Mars, long associated with Ares, the Greek god of war, shines like a star with a yellowish-orange hue and can vary considerably in brightness.

Visibility in 2026

• Mornings: March 18- Dec. 31

When will it be at its best?

This is an "off" year for Mars. The planet begins 2026 lost in the sun's glare and reaches solar conjunction on Jan. 9, sitting on the far side of the solar system about 223 million miles from Earth.

Mars begins to reappear in the third week of March, rising before sunrise among the faint stars of Aquarius. It moves into Taurus for the first half of summer, shining only around magnitude +1.3.

Sky highlights:

• Sept. 25: Castor and Pollux point directly toward Mars.
• Oct. 11: Mars passes through the Beehive Cluster in Cancer — an attractive sight in binoculars.
• Nov. 26: Mars passes 1.7 degrees above Regulus in Leo, creating a dramatic color contrast.
• By late December, Mars brightens to magnitude –0.1 and will rival Arcturus in both color and brightness.
• Feb. 19, 2027: Mars reaches its next opposition, so it steadily approaches Earth late in 2026.

Notable conjunctions:

• April 20: Mars aligns closely with Saturn and Mercury.
• July 4: Mars passes just 0.1 degree south of Uranus, offering a superb guidepost for locating Uranus.
• Nov. 16: Mars passes 1.2 degrees to the upper left of Jupiter.

Jupiter

Jupiter, the giant planet with a diameter about 11 times bigger than Earth's, shines with a bright silver-white luster.

Visibility windows in 2026

• Mornings: Jan. 1–9; Aug. 19– Dec. 31
• Evenings: Jan. 10–July 7

Jupiter reaches opposition on Jan. 10 and shines brightest from Jan. 1–22 at magnitude –2.7 in Gemini. It enters Cancer on June 22 and Leo on Sept. 24, where it remains through year's end.

On June 9, Jupiter pairs with Venus in a stunning "double planet" display low in the west-northwest at dusk.

Oct. 6 lunar occultation

On the morning of Oct. 6, observers across most of North America (excluding the far West) and northern Cuba will witness a spectacular lunar occultation of Jupiter. A waning crescent moon will slide directly in front of Jupiter, hiding it for up to an hour depending on location. Jupiter disappears behind the bright limb and reemerges dramatically from the moon's dark side.

Saturn

Saturn shines as a yellowish-white "star" of moderate brightness. Its famous rings, invisible to the naked eye, turned edge-on in 2025 and were nearly impossible to see for weeks. They are now slowly opening up again.

Constellation path in 2026:

• Starts in Aquarius (to Jan. 14)
• Enters Pisces (Jan. 14– April 8)
• Moves through Cetus (April 9– June 2)
• Back into Pisces (June 3–Sept 4)
• Back into Cetus (from Sept. 5 onward)

Visibility windows in 2026

• Evenings: Jan. 1–March 8; Oct. 4–Dec. 31
• Mornings: April 12– Oct. 3

Saturn reaches opposition on Oct. 4 and is brightest Sept. 24–Oct. 9.

Notable conjunctions:

• Feb. 15: Saturn sits less than 1 degree from Neptune, though Neptune is much fainter.
• Apr. 20: Saturn aligns with Mars and Mercury.

Uranus

Uranus can be glimpsed with the naked eye under very dark skies by keen-eyed observers. At magnitude +5.6, it is easily found with binoculars; small telescopes show a tiny greenish disk.

Uranus spends all of 2026 in Taurus.

Visibility windows in 2026

• Evenings: Jan. 1–May 5; Nov. 25– Dec. 31
• Mornings: June 9–Nov. 24

Uranus reaches opposition on Nov. 25 and is brightest Oct. 24–Dec. 30.

On July 4, Uranus sits only 0.1 degree north of Mars, making Mars an ideal pointer to the seventh planet. Mars will outshine Uranus by a factor of about 158.

Neptune

Neptune remains in Pisces throughout 2026. At magnitude +7.8, it is visible only in binoculars or a telescope and appears bluish-gray.

Visibility windows in 2026

• Evenings: Jan. 1–March 6; Sept. 25–Dec. 31
• Mornings: April. 8– Sept. 24

Neptune reaches opposition on Sept. 25 and is brightest July 28–Nov. 24.

On Feb. 15, Neptune lies less than 1 degree to the upper right of Saturn, though Neptune is only about 1/525 as bright.

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 and other publications.

Tear your eyes away from fireworks this New Year's Eve (Dec. 31) to witness a magnificent natural light show, complete with twinkling constellations and star clusters, the steady light of planets and the awe-inspiring sight of the waxing gibbous moon shining in the constellation Taurus.

The moon will be visible halfway up the eastern horizon in the hours following sunset, with the delicate light of the Pleiades open star cluster vying for attention 5 degrees — roughly the width of your three middle fingers held at arm's length — to the upper right of the 95%-lit lunar disk.

Look directly below the moon to find the stars of the constellation Orion twinkling close to the eastern horizon. The brightest point of light to Orion's left is no star at all, but rather the "king of the planets," Jupiter. On the final night of 2025, Jupiter shines in the constellation Gemini, close to its two brightest stars — Castor and Pollux.

Saturn's steady light can also be seen shining halfway up the southern horizon around this time. A telescope with an aperture of around 6 inches will help reveal its famous rings as a thin line bisecting the planet's cloud tops. The rings are currently oriented edge-on to Earth, but will gradually open up throughout 2026 to reveal their majestic, sweeping structure, including a 2,980-mile (4,800-kilometer) gap known as the Cassini Division.

By midnight, Saturn will have slipped below the horizon, while the moon and Jupiter will stand high overhead. Look roughly 40 degrees above the northern horizon — approximately the width of four clenched fists stacked on top of each other — to find the bright star Polaris, around which the entire sky appears to rotate. To its right you'll spot the familiar sight of the Big Dipper, tilted so that it appears to be standing on the end of its handle.

Those same stars will glide silently through the night as the last moments of 2025 fade and the first of a new year begins, heralding the start of another year of incredible stargazing opportunities.

If you're new to stargazing, be sure to read our article filled with expert advice on how to begin your amateur astronomy journey. We also have tips on how to observe the moon, along with superb roundups of the best telescope and binocular deals available if you're looking to upgrade your equipment.

Clear skies and a Happy New Year from everyone here at Space.com!

Editor's Note: If you would like to share your astrophotography with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.