Editor's note: Now is the best time to look for Jupiter and Venus in the evening sky, with their closest conjunction occuring on Tuesday (June 9) after sunset. You can see the two bright planets with the naked eye, but a good pair of stargazing binoculars will let you zoom in on both planets at once.

In one of 2026's skywatching highlights, the two brightest planets in the night sky will appear very close to each other for a string of several evenings.

This conjunction of Venus and Jupiter will occur in the western sky during twilight and be easily visible to the naked eye. The best time to look will be from about 45 minutes to two hours after sunset on Tuesday, June 9, though the evenings on either side will offer almost the same view. Find a location with a clear view of the western horizon for the best show.

On June 9, the two worlds will appear to be just 1.6 degrees apart — about three times the width of a full moon. To measure that distance in the night sky, hold up either a single index finger or two pinky fingers side-by-side at arm's length. It's a close enough conjunction to fit comfortably within the field of view of standard binoculars — a rare opportunity for skywatchers.

For all of its beauty, the conjunction is an optical illusion. Jupiter, an outer planet with respect to Earth, will be much farther away. The gas giant will be about six astronomical units (au), or six times the Earth-sun distance, from Earth at the time of the conjunction. Venus, an inner planet, will be just 1.2 au away — five times closer than Jupiter.

What's happening is that Venus is rising while Jupiter is receding in Earth's sky. Sooner or later, they must appear to pass closely in the night sky. To understand why, consider the speeds of the three planets involved — Venus, Earth and Jupiter.

Venus takes 224.7 days to orbit the sun, Earth takes 365.25 days, and Jupiter takes 11.86 years. As can be seen on The Planets Today, Earth is currently racing away from Jupiter, causing it to appear to sink in our evening sky. On July 29, Jupiter will be lost in the glare of the sun. However, the faster-moving Venus is approaching Earth, causing it to rise in our evening sky. Venus will shine brightly as the "Evening Star" all summer, reaching its farthest distance from the sunset in mid-August.

As well as being dramatically closer to Earth, Venus will also be vastly brighter in the sky. During the conjunction, Venus will shine at -3.9 magnitude with Jupiter at -1.7 magnitude (in skywatching, a lesser magnitude corresponds to a brighter object). That makes Venus about 7.5 times brighter than Jupiter as seen from Earth. As well as being closer than Jupiter, Venus reflects significantly more sunlight because of its thick cloud layers.

Although you can see the conjunction with the naked eye, a pair of stargazing binoculars will help you see both planets together, while with a good backyard telescope, you may see some of Jupiter’s four large Galilean moons — Ganymede, Europa, Callisto and Io — as dots of light in a line on either side of the giant planet. A decent camera will also let you take stunning photos of the conjunction.

The next major planetary conjunction will take place before sunrise on Nov. 15, when Jupiter and Mars will appear just 1.2 degrees from each other.

Editor's note: This article was updated on Monday (June 8) to add context around the event.

Jupiter's giant moon Ganymede is the only known moon to have its own magnetic field — and it may be heating up in a process "not yet observed anywhere else," new research suggests.

One of the four Galilean satellites swirling around Jupiter, Ganymede is the largest moon in the solar system. At nearly 3,300 miles (5,300 kilometers) in diameter, it's more than 1,000 miles (1,600 km) wider than Earth's moon and slightly bigger than Mercury, our tiniest planetary tot. (Jupiter has more than 100 confirmed moons, with the largest four known as the Galilean moons.)

This standout satellite's intrinsic magnetic field — discovered by NASA's Galileo spacecraft in 1996 — is generated through a process called a dynamo, powered by the electrically conductive, churning liquid iron in its core.

Yet the mechanism through which this process emerged is hotly debated.

"Many formation studies suggest that Ganymede formed too cold to start with a metal core," study co-author Kevin Trinh, a planetary scientist at Caltech, said in a statement. "Meanwhile, many modeling studies of Ganymede's dynamo assume that Ganymede formed its metal core roughly when the moon itself formed, as Earth did. Both of these things cannot be simultaneously true."

So, in a paper published May 6 in the journal Science Advances, researchers propose a new topsy-turvy mechanism that may have formed Ganymede's mysterious metallic core and dynamo later rather than earlier, as molten iron blobs sank into the massive moon's core. This activity may be ongoing today.

Hot or cold start?

The "warming-driven dynamo" presented in the study is the opposite of traditional dynamo-origin ideas, which propose that they form early in large bodies like Earth and then gradually cool.

For example, metallic core formation in planetary bodies is thought to have occurred within around 200 million years of the solar system's formation. Yet moons may be too small to hold enough heat from their birth to power this process.

But all hope is not lost, because a body formed from a "cold start" may still be able to grow a magnetic-field-generating core, the researchers' new model suggests.

This model integrates and simplifies Ganymede's characteristics, such as its composition and core temperature, assuming its core is composed of iron and iron sulfide, because these components have lower melting temperatures.

In this model, molten metal blobs sink into Ganymede's innards to feed its core and whip up its magnetic field. They are warmed through two main mechanisms: radioactive heating and tidal heating.

First, as heavier radioactive isotopes decay into lighter elements, they release heat. Second, Jupiter's gigantic gravitational influence squeezes and stretches Ganymede as the moon whirls nearer and farther from its parent, as if "kneading" a planet-size piece of rocky, icy dough. The resulting inner friction generates heat. This heat powers the dynamo that gives Ganymede its magnetic field.

Altogether, this hypothesis does not preclude the possibility that Ganymede formed with a magnetic-field-producing core.

Alien implications?

But if "cold start" cores exist throughout the universe, it could present a previously unexplored process for magnetic fields to form and protect aging worlds, perhaps facilitating an intriguing implication in the search for extraterrestrial life.

Magnetic fields are necessary to protect life from harmful solar and cosmic radiation, making them a prerequisite in most searches for habitable planets. But a little magnetism can go a long way: As is apparent on Earth, with a magnetic field significantly weaker than a fridge magnet, even a modest magnetosphere can transform the outlook of planetary bodies.

"There could be young rocky exoplanets or exoplanets with lower radioactive isotope abundances (i.e., slower heating) that would be favorable for a recent warming-driven dynamo," Trinh told Live Science in an email. "The challenge is that no one has detected an exoplanet dynamo so far."

Jupiter's ice-covered moon Europa appears to have life-friendly molecules on its surface.

Al Emran, a researcher with NASA's Jet Propulsion Laboratory, spotted ammonia on the surface of Europa while looking through old data from the Galileo mission, which studied Jupiter and its moons from 1995 to 2003.

Data gathered from Galileo's near-infrared mapping spectrometer in 1997 showed "faint signals of ammonia" near cracks on the frozen moon's surface, NASA officials wrote in a statement describing the findings, which were published late last year in The Planetary Science Journal.

It is the "first such detection at Europa" and therefore has important implications for the habitability of the icy moon, which is considered one of the most likely places in the solar system to host extraterrestrial life, according to the statement.

Alien ice moon

Ammonia is a nitrogen-bearing molecule and one of the ingredients of life as we know it, alongside carbon, hydrogen, oxygen and water. In the new paper, Emran said the finding was therefore of "astrobiological significance, given nitrogen's essential role in the chemistry of life."

The Galileo spacecraft worked in the Jupiter system between 1995 and 2003, before it ran low on fuel. Engineers deliberately steered the spacecraft into the giant planet to avoid any risk of contaminating Europa or other icy moons. Although the mission concluded operations more than 20 years ago, scientists sometimes find new insights in older datasets, either by using newer tools or knowledge, or by examining information that was not previously scrutinized.

In the new research, NASA spotted traces of ammonia near fractures on the icy surface of Europa. It is believed that these fractures included liquid water with ammonia compounds; the ammonia lowers the freezing point of water, sort of like antifreeze, the agency said.

The ammonia may have come "from either the moon's subsurface ocean, or its shallow subsurface," NASA officials said in the statement. That's because ammonia doesn't last long in space because it gets broken down by ultraviolet light and cosmic radiation. Cryovolcanism, or icy volcanism, likely pushed the ammonia compounds to the surface, they explained.

A follow-up mission may reveal more insight: Europa Clipper, which launched in October 2024, is expected to arrive at the Jupiter system in April 2030. The mission will specifically look for chemical signs of habitability on the icy moon.

Jupiter is slightly smaller and flatter than scientists thought for decades, a new study finds.

Researchers used radio data from the Juno spacecraft to refine measurements of the solar system's largest planet. Although the differences between the current and previous measurements are small, they are improving models of Jupiter's interior and of other gas giants like it outside the solar system, the team reported Feb. 2 in the journal Nature Astronomy.

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

Until now, scientists' understanding of Jupiter's size and shape have been based on six measurements performed by the Voyager 1 and 2 and Pioneer 10 and 11 missions. Those measurements, which have since been adopted as standard, were performed around 50 years ago using radio beams, according to the statement.

But the Juno mission, which has been gathering data on Jupiter and its moons since it arrived at the gas giant in 2016, has collected much more of this radio data in the past two years. With that additional data, researchers have now refined measurements of Jupiter's size down to about 1,300 feet (400 meters) in each direction.

"Just by knowing the distance to Jupiter and watching how it rotates, it's possible to figure out its size and shape," Kaspi said. "But making really accurate measurements calls for more sophisticated methods."

Bending light

In the new study, the scientists tracked how the radio signals from Juno back to Earth bent as they passed through Jupiter's atmosphere, before cutting out when the planet blocked the signal entirely. Those measurements allowed the team to account for Jupiter's winds, which slightly alter the shape of the gaseous planet. Then, they used that information to make precise calculations of the planet's shape and size.

With the new data, the team calculated that the planet's radius from its pole to its center is 41,534 miles (66,842 km) — 7.5 miles (12 km) smaller than previous measurements. The newly calculated radius at the equator is 44,421 miles (71,488 km) — 2.5 miles (4 km) smaller than previously thought.

"These few kilometers matter," study co-author Eli Galanti, an expert on gas giants at the Weizmann Institute of Science, said in the statement. "Shifting the radius by just a little lets our models of Jupiter's interior fit both the gravity data and atmospheric measurements much better."

The updated measurements will improve our understanding of Jupiter's interior, as well as help scientists interpret data from gas giants beyond the solar system, the researchers wrote in the study.

"This research helps us understand how planets form and evolve," Kaspi said in the statement. "Jupiter was likely the first planet to form in the solar system, and by studying what's happening inside it, we get closer to understanding how the solar system, and planets like ours, came to be."

This weekend brings a prime opportunity to see the biggest planet in the solar system shining at its brightest all year.

After dominating the night sky for more than a month, Jupiter will reach opposition this Saturday (Jan. 10). This marks the point when Earth lies directly between Jupiter and the sun, putting the gas giant opposite our star in Earth's sky. The result is a brilliant, unmissable light in the eastern evening sky that shines all night long. At magnitude -2.7, Jupiter will outshine every star for many weeks.

(In astronomy, a lower magnitude corresponds to a brighter object. Sirius, the brightest star in the night sky, has an apparent magnitude of about -1.4.)

Shining in the constellation Gemini near the bright stars Pollux and Castor, Jupiter's opposition is the best time to see the giant planet because it rises at sunset, climbs highest around midnight, and sets at dawn. It's a prime opportunity for both novice and experienced skywatchers to get an extraordinary look at the "king of the planets."

How to see Jupiter and its moons

To marvel at Jupiter's dominance at night, you'll need nothing more than a clear sky. However, even a modest pair of binoculars (8×42 or 10×50) will reveal Jupiter as more than just a bright dot; you'll see a small, steady disk and the planet's four largest moons: Io, Europa, Ganymede and Callisto. Known as the Galilean moons, they appear as tiny points of light lined up beside the planet, changing position each night.

With a small telescope, the view becomes even more impressive. Use a low-power eyepiece to center Jupiter in your field of view, and then switch to a higher magnification. Two or more dark cloud bands should be visible crossing the planet's disk — signs of Jupiter's powerful jet streams. Under steady atmospheric conditions, the famous Great Red Spot — a massive storm that's been raging on Jupiter for around 190 years — also may come into view in the planet's southern hemisphere.

While Jupiter steals the show, Saturn is also visible in the early evening sky, hanging lower in the southwest after sunset. Though fainter, its iconic rings are still visible through a telescope — a treat for any observer.

Jupiter will remain well placed for evening viewing throughout January and into February. It's an ideal time to observe it under dark skies, before it gradually shifts westward in the coming months.

Jupiter won't disappear after opposition. On June 9, it will form a striking triple conjunction with Venus and Mercury in the twilight sky. Then, on Nov. 15, it meets Mars in a spectacular close conjunction just before sunrise.

The next opposition of Jupiter will occur on Feb. 6, 2027.

Saturday, Jan. 3 will mark the first full moon of 2026. Known as the Wolf Moon, it will be at its fullest at 5:02 a.m. EST and best seen rising in the east at dusk later that day. It will also be a "supermoon," meaning it will appear brighter and larger than usual.

According to the Old Farmer's Almanac, January's full moon gets its name because wolves were more likely to be heard howling at this time of year. Other Native American names for this full moon include the Cold Moon, the Frost Exploding Moon, the Freeze-Up Moon, the Severe Moon, the Hard Moon, the Center Moon, and the Canada Goose Moon. In Europe, it's often called the Moon After Yule, after the ancient festival that stretches from the winter solstice on Dec. 21 through Jan. 1.

The best time to see the Wolf Moon will be at moonrise on Jan. 3, when it will appear at dusk between a star and a very bright planet. On its left will be Pollux, a bright star in the constellation Gemini, and Jupiter will be on its right. The "king of planets" will be just a week away from its bright opposition — the most luminous it will get from our perspective in 2026.

Because it's the full moon closest to the winter solstice on Dec. 21, the Wolf Moon will also make the highest arc through the night sky of any full moon, as seen from the Northern Hemisphere. That happens because a full moon is always opposite the sun, so the winter sun mimics the summer sun.

The Wolf Moon is also the fourth consecutive supermoon, though it will not be particularly large. It is also the last one until November. It's called a supermoon because it turns full close to perigee, the closest the moon gets to Earth. As it turns full on Jan. 3, the full moon will be 225,130 miles (362,312 kilometers) from our planet.

By chance, that will happen as Earth reaches perihelion — its closest point to the sun — when it will be 91.4 million miles (147.1 million km) from our star, compared with the average distance of 93 million miles (150 million km).

After the Wolf Moon, the next full moon will be the Snow Moon, on Feb. 1.

A NASA spacecraft designed to hunt for signs of extraterrestrial life has turned its lens toward comet 3I/ATLAS — but not for the reason you might think. The spacecraft just happened to be in the right place at the right time.

Zooming through the solar system at an estimated 153,000 mph (246,000 km/h), the beguiling interstellar comet will reach its closest point to Earth overnight tonight (Dec. 18-19). At its closest, 3I/ATLAS will swoop within about 168 million miles (270 million kilometers) of our planet.

It's close enough that amateur astronomers can spot it with a good backyard telescope, though skywatchers should temper their expectations of seeing much more than a speedy green dot. (See astrophotographer Andrew McCarthey's latest image for a preview.)

Meanwhile, the latest image from NASA — taken with the Europa Clipper spacecraft — cuts the distance to 3I/ATLAS by a third. Snapped on Nov. 6 from a distance of about 102 million miles (164 million km), the new image is the result of seven hours of observations with the craft's Europa Ultraviolet Spectrograph (Europa-UVS) instrument.

Seeing the unseen

Human eyes can't see UV light. But by splitting the observations into their constituent wavelengths and stacking them together, NASA scientists offer a hint of what 3I/ATLAS would look like beyond the visible spectrum. (See also the James Webb telescope's infrared observations and XMM-Newton's X-ray view.)

Clipper happened to be in a prime spot to observe 3I/ATLAS as both objects zoom toward Jupiter; the swift interstellar comet makes its closest approach to the gas giant in March 2026, while Clipper isn't due to arrive there until April 2030.

When it does reach the Jovian neighborhood, Clipper will begin its mission to hunt for signs of extraterrestrial life. The spacecraft's UV instruments will analyze the surface and atmosphere of Europa — one of Jupiter's giant, ice-encrusted moons — and look for geysers carrying chemical clues to the moon's interior. NASA models hint that a liquid water ocean lurks beneath the Europa's crust, which could contain alien life.

An evolving mystery

But the Clipper isn't looking for aliens in this case. (And there's no evidence that 3I/ATLAS is anything other than a natural comet.)

Using the same technology that will ultimately plumb the secrets of Jupiter's moon, Clipper's observations of 3I/ATLAS will be key in analyzing the elements spewing out of the comet and forming the makeshift atmosphere, or coma, around it.

There's no spectroscopic data from Clipper's new UV image yet, but NASA will share its findings as soon as they're available. We do know from prior observations that 3I/ATLAS is rich in carbon dioxide ice, and is releasing diatomic carbon (C₂) gas that gives it the greenish glow seen in recent optical light images.

Until more information rolls in, enjoy this rare close-up view of our solar system's most famous visitor from abroad.

A mysterious, spider-like structure lurking on Jupiter's fourth-largest moon, Europa, may finally have a proper explanation nearly 30 years after it was discovered. The arachnid imposter has also been given a demonic new name.

In March 1998, NASA's Galileo spacecraft — which studied Jupiter and its major moons between 1995 and 2003 — made a close flyby of Europa, a frozen ocean moon often considered one of the most likely places for extraterrestrial life to exist in the solar system. During this flyby, the probe mapped out a roughly 13.7-mile-wide (22 kilometers) impact structure, dubbed Manannán Crater, on the moon's icy surface, and found something strange lurking within it.

Hidden inside a deep pit near the crater's center was a sprawling dendritic shape. The researchers initially believed the dark feature was caused by the extreme gravitational force exerted on Europa by Jupiter, which is responsible for carving multiple fracture lines across the water world's surface. Other experts have since proposed that it was created by eruptions from hydrothermal vents on the floor of Europa's subsurface ocean. However, neither of these explanations fully explain this unusual shape.

But in a new study, published Dec. 2 in The Planetary Science Journal, researchers proposed an alternative explanation: that the Jovian spider formed in a similar way to how dark dendritic patterns on Earth, known as "lake stars," typically do. These features form when snow falls on frozen lakes and water seeps up through tiny holes in the ice.

With this in mind, the researchers used a similar technique to partially recreate the Manannán Crater's mysterious shape in the lab. The study team also finally named Europa's arachnid-like asterisk Damhán Alla, meaning "spider" or "wall demon" in Irish. (Manannán is a Celtic god from Irish mythology, which partly inspired the new name.)

"Lake stars are really beautiful, and they are pretty common on snow or slush-covered frozen lakes and ponds," study lead-author Lauren Mc Keown, a planetary scientist at the University of Central Florida, said in a statement. "It is wonderful to think that they may give us a glimpse into processes occurring on Europa and maybe even other icy ocean worlds in our solar system."

However, rather than water rising through tiny holes, as happens when lake stars form on Earth, Damhán Alla was likely birthed by an asteroid impact — which created a small crack in Europa's icy shell that enabled salty water to seep upward and paint the spider-like pattern on the surface. (This asteroid impact likely happened after the Manannán Crater was already formed.)

The researchers also noted similarities between Damhán Alla and the infamous "spiders on Mars," which are dusty deposits on the Martian surface that look like swarming spiders when viewed from above. These fake arachnids, known as araneiform terrain, form when submerged carbon dioxide ice sublimates, or turns directly into a gas. Mc Keown's team has previously recreated these features on Earth too.

The similarities in shape between Damhán Alla and the spiders on Mars are due to how "fluid flows through porous surfaces," Mc Keown said. In theory, similar spider features could also form on other frozen ocean worlds, such as Saturn's moon Enceladus, Jupiter's other moon Ganymede and the dwarf planet Ceres, which resides in the asteroid belt beyond Mars.

Mc Keown is now setting up a new laboratory, which will focus on studying how these various spider-like features may form on different solar system moons. She hopes to be able to provide valuable insight that could help inform NASA's Europa Clipper mission, which launched in October 2024 and will arrive to extensively study Jupiter's watery moon in 2030.

"The significance of our research is really exciting," Mc Keown said. "Surface features like these can tell us a lot about what's happening beneath the ice. If we see more of them with Europa Clipper, they could point to local brine pools below the surface," she added.

And these pools could be a good place to start looking for signs of extraterrestrial life.

Who hasn't looked into the sky and wondered if there's life out there, somewhere, looking back at us? Is it possible there's alien life closer to home — within the bounds of our solar system?

The short answer is yes, there are several places researchers are looking for signs of life within our solar system, and there are some hints that life might be hiding in unexpected places.

Is there life on Mars?

While there don't seem to be any "little green men" inhabiting Mars, it's possible there was microbial life in the past. Mars is currently a frigid desert, but thanks to Mars rovers that have studied the planet's rocks, we know that a long time ago, it had liquid water — an important condition for life.

"The Curiosity rover was built to search for habitable environments, the kind that could have supported microbial life on Mars in the past, if life ever arose on the Red Planet," said Amy Williams, a geology professor at the University of Florida and a member of both NASA's Curiosity and Perseverance science teams. "Curiosity's payload was selected to accomplish this task by looking for the conditions that we know life on Earth requires — liquid water, a source of carbon, and chemical energy to power a metabolism," she told Live Science.

In addition to studying the Martian environment, the Perseverance rover has been collecting promising rock samples to be returned to Earth for advanced analysis. The Mars Sample Return mission is currently under development by NASA and ESA to travel to Mars, collect the sample cores, and bring them back to Earth. (The Donald Trump administration has proposed cutting NASA funding to pay for this mission, however.)

"At least one of the cores collected has qualities that fit the definition of a possible indicator of ancient microbial life," Williams said of a particularly interesting rock sample. "Returning samples to Earth with the Mars Sample Return architecture would enable us to address some of humanity's most profound questions, including whether we are alone in the universe."

Related: How would we give aliens directions to Earth?

Could there be life on Venus?

Even though it's commonly called Earth's "twin," Venus is probably not the first place anyone might look for life in the solar system. Its surface temperature is hot enough to melt lead, and the average surface pressure is more than 90 times that of Earth. It's wrapped in thick, dense clouds that are mostly made from sulfuric acid, a highly corrosive substance that mixes with water to form acid rain on Earth, damaging flora, fauna and soil.

Despite those hostile conditions, extremophile microbial life might be able to survive high in Venus' atmosphere, where the temperatures and pressures aren't so extreme; perhaps life could find ways to protect itself from sulfuric acid's destructive nature. To find out, MIT is putting together the Morning Star Missions, which will travel to Venus' atmosphere with the ultimate goal of collecting a sample of the planet's clouds and returning it to Earth for better analysis.

"Microbial life might exist in Venus's clouds, despite their composition of concentrated sulfuric acid," Sara Seager, a professor at MIT and the director of the Morning Star Missions, told Live Science. "If we find compelling signs of life on Venus, it would upend our understanding of habitability and prove that life can exist in non-water solvents, opening up the range of worlds where life is possible."

When looking for life, scientists often focus on the search for liquid water because it's a requirement for life on Earth. Finding life on Venus would shatter that limitation — meaning alien life could be a lot stranger than we've thought and there could be a lot more places to look for it.

In 2020, a possible detection of phosphine gas in Venus' clouds became the center of a controversy about signs of life on Venus. Phosphine gas was an unexpected find because most known chemical processes that produce it come from living organisms or from extreme pressures on gas giants. However, the signal was small and critics said it might have been noise in the data. The Morning Star Missions to Venus will give us much more information about the planet's chemistry and possibly confirm if there's phosphine floating in the clouds.

Is there life on the moons of Saturn and Jupiter?

Further out in the solar system, there are several moons orbiting Saturn and Jupiter that could potentially host life, particularly Enceladus and Europa.

Saturn's moon Enceladus has a global subsurface ocean hiding underneath a thick icy shell. The moon constantly spits giant plumes of salty water into space that give scientists a rare opportunity to directly sample the interior of a celestial body other than Earth. The Cassini mission performed several flybys of Enceladus from 2005 through 2017, collecting images and even direct samples from the plumes that are still being analyzed. A 2023 paper in Nature announced that scientists had detected phosphates on Enceladus — meaning scientists have now detected all the basic chemical ingredients for life in the moon's ocean.

Several missions to study astrobiology on Enceladus, with the goal of collecting more samples from the plumes, have been in the works by teams at ESA and NASA, although they're still a long way from getting to the launch pad.

Like Enceladus, Jupiter's moon Europa is an icy world with a global subsurface ocean and water plumes erupting from its surface. Jupiter's massive gravitational pull on the moon provides energy and motion that fuels active geologic activity, and is thought to be the main reason the ocean is warm enough to be liquid. Interactions between the salty ocean and the rocky interior could possibly host life similar to the life found around hydrothermal vents on Earth.

ESA's Jupiter Icy Moons Explorer (Juice) launched on April 14, 2023 with an expected arrival at Jupiter in July 2031, where it will study Jupiter and three of its moons: Europa, Callisto and Ganymede. NASA's Europa Clipper mission launched on Oct. 14, 2024 to reach Jupiter in 2030 and conduct flybys of Europa to study if conditions for life are present.

Titan, another of Saturn's moons, is an extremely unique place in the solar system. It has a methane cycle like Earth's water cycle and a thick nitrogen and methane atmosphere. The Cassini mission performed over 50 flybys of Titan from 2004 through 2017 and launched the Huygens probe that landed on the moon's surface in 2005. These two missions collected data that indicated Titan's atmosphere could probably create complex molecules that are building blocks for life. NASA is putting together a car-sized octocopter to fly on Titan and collect samples at different landing sites.

Where else could life be in the solar system?

There are quite a few other places we might find life in the solar system, including dwarf planets like Ceres. Ceres is thought to have a lot of liquid water under an icy and rocky crust, thanks to images taken by NASA's Dawn mission which visited it in 2015.

The more we explore the solar system, the more places we find that have conditions that could support life. If there is life out there, it's likely not advanced enough to reach out to us, so we'll have to be the first to say hello.

Extraterrestrials quiz: Are you an alien expert, or has your brain been abducted?

Six planets — Mercury, Venus, Jupiter, Saturn, Uranus and Neptune — will appear in a dark night sky together for almost a week, beginning Sunday, Aug. 17. The fairly rare "planetary parade," which is sometimes mistakenly called a planetary alignment, will continue through Wednesday, Aug. 20.

The celestial gathering, last seen in February, will appear in the eastern sky about an hour before sunrise. Although most of these planets have been visible in the morning sky for weeks, Mercury will join the fray, bringing the planet count from five to six.

Under clear skies, you should be able to spot Venus, Jupiter and Saturn. Mercury will be closer to the horizon but still bright enough to be seen by most observers. However, Uranus (appearing between Jupiter and Saturn in the sky) and Neptune (close to Saturn in the sky) are too dim and distant to be seen with the naked eye. The only way to see these two ice giants is by using a good telescope.

Although it's relatively rare for six planets to appear in the sky simultaneously, the beauty of the view will be vastly increased by the waning crescent moon.

Related: How to photograph the moon: Tips on camera gear, settings and composition

On Aug. 17 and Aug. 18, a crescent moon will rise above Jupiter and Venus. The two brightest planets in the night sky are now slowly moving apart after an incredibly close conjunction on Aug. 12.

Mercury may be visible below Jupiter and Venus, but it will be easier to see it on Aug. 19. On that morning, and on Aug. 20, a slim crescent moon will be very close to Jupiter and Venus — a visual highlight of the "planetary parade."

By around Aug. 21, Mercury will begin to fall back into the sun's glare and will become more difficult to see.

According to the Star Walk app, there will be two six-planet parades in 2026: one after sunset in February and another before sunrise in August.

A space rock that punched a hole through a Georgia resident's home earlier this summer may be 20 million years older than our planet, researchers say.

The meteorite streaked across the sky as a fireball on June 26, just before a piece of it struck a house in the city of McDonough. A researcher at the University of Georgia (UGA) studied material recovered from the house and found that the meteorite formed around 4.56 billion years ago — making it about 20 million years older than Earth.

"This particular meteor that entered the atmosphere has a long history before it made it to the ground of McDonough," Scott Harris, a researcher in the geology department at UGA, said in a statement.

Harris' analysis revealed that the newly named McDonough meteorite came from beyond Mars and is linked to a much larger asteroid that broke up around half a billion years ago.

"It belongs to a group of asteroids in the main asteroid belt between Mars and Jupiter that we now think we can tie to a breakup of a much larger asteroid about 470 million years ago," Harris said. "But in that breakup, some pieces get into Earth-crossing orbits, and if given long enough, their orbit around the sun and Earth’s orbit around the sun end up being at the same place, at the same moment in time."

Related: Perseid meteor shower 2025: How to see 'shooting stars' despite the full moon

The McDonough meteorite made quite an entrance on June 26. NASA's Meteoroid Environment Office estimated that the 3-foot-wide (1 meter) object was travelling at 29,000 mph (47,000 km/h), while the American Meteor Society received more than 240 sighting reports of a fireball across the Southeast. Many people also heard and felt a sonic boom, which some mistook for an earthquake, the Smithsonian Magazine reported shortly after the event.

The meteorite slowed down a lot as it traveled through our atmosphere and broke apart as it got closer to the ground, but it was still moving fast enough to cause damage on impact.

"When they [meteorites] encounter Earth, our atmosphere is very good at slowing them down," Harris said. "But you're talking about something that is double the size of a 50-caliber shell, going at least 1 kilometer per second [0.6 miles per second]. That's like running 10 football fields in one second."

When part of the meteorite hit the house in McDonough, it went straight through the roof, ceiling, and heating, ventilation and air conditioning (HVAC) duct. It left a dent in the living room floor and made a noise and vibration that sounded like a close-range gunshot, according to the statement. The piece of rock was pulverized into fragments on impact, scattering space dust around the room that the resident of the house is still finding today.

Harris used optical and electron microscopy to analyze 0.8 ounces (23 grams) of rock fragments recovered from the house. Based on this analysis, he believes that the meteorite is a stony meteorite (chondrite) that's low in metal content, according to the statement.

Researchers will continue to analyze the rock fragments at UGA, while some additional pieces that landed in the area will go on display at the Tellus Science Museum in Cartersville.

Meteorites are relatively rare in Georgia; this is only the 27th documented in the state's history and the sixth to have been witnessed falling, according to the statement. However, Harris noted that they are now being recorded more frequently.

"This is something that used to be expected once every few decades and not multiple times within 20 years," Harris said. "Modern technology in addition to an attentive public is going to help us recover more and more meteorites."

Just as the Perseid meteor shower approaches its peak, two luminous planets are getting in on the night-sky action.

Venus and Jupiter, the two brightest planets in the sky, will meet in a conjunction very early tomorrow morning (Aug. 12). On this morning, the two planets will be less than a degree apart — approximately the length of your pinkie when held up to the sky at arm's length. Because they'll appear close together, you'll be able to view both simultaneously through skywatching binoculars or a backyard telescope.

If you want to see the conjunction, you'll have to either stay out late or get up early: Venus and Jupiter rise together around 3 a.m. local time and set together around 6 a.m. local time. However, these times vary slightly depending on your exact location. You can use Time and Date to check the precise rise and set times for your area.

Venus and Jupiter will rise in the east with the constellation Gemini and will ascend to about 20 degrees above the horizon before sunrise. Because they're fairly low on the horizon, you'll want to observe them in a mostly flat area without many trees, buildings or other obstructions to the east.

You can easily find Venus and Jupiter with the naked eye thanks to their exceptional brightness. Venus is the second-brightest object in the night sky, after the moon, followed by Jupiter. However, seeing these planets with a decent backyard telescope or pair of binoculars is a treat you won't want to miss.

Jupiter and Venus skywatching

If you look through a backyard telescope or pair of skywatching binoculars, you'll see Jupiter's cloud bands and maybe even its famed Great Red Spot. The Red Spot, a giant storm in Jupiter's cloud bands that spans twice the width of Earth, faces our planet about once every 10 hours when Jupiter completes a rotation.

Related: How to photograph the moon: Tips on camera gear, settings and composition

Jupiter's Red Spot is most visible when it crosses Jupiter's meridian, the imaginary line between its north and south poles. You can use this tool from Sky & Telescope to see the Red Spot's transit times — the times it crosses the meridian.

Skywatching equipment also reveals hidden wonders on Venus, such as its phases. Like the moon, Venus goes through phases — new, crescent, quarter, gibbous and full— because of its position relative to Earth and the sun.

But unlike the moon's phases, Venus' phases are visible only through skywatching equipment. And while the moon completes all of its phases in less than a month, it takes Venus 584 days.

The moon will somewhat disrupt viewing conditions for this event. The planets are best viewed under dark, moonless skies. However, the moon on conjunction night will be a waning gibbous, about 90% to 95% illuminated after the peak of the full Sturgeon Moon, and will rise around 9:30 p.m. and set around 10 a.m. local time.

Fortunately, though, Jupiter and Venus are bright enough to avoid being totally washed out by moonlight. The moon will also be far to the west while Venus and Jupiter rise in the east, so you can view this conjunction away from the bright face of the moon. For an even better viewing experience, try to observe this conjunction from a location where the moon is obscured by trees or other obstacles that block its glare.

And if you miss this conjunction, don't worry — Venus and Jupiter will remain close together for the next couple of nights, although they will slowly drift apart as August comes to a close.

Editor's note: This story was updated on Aug. 11 with up-to-date information about the conjunction

A tiny meteorite is rewriting what scientists thought they knew about the origins of our solar system.

New evidence found in shavings from a meteorite known as Northwest Africa 12264 — a 50-gram (1.8 ounces) piece of space rock that is believed to have formed in the outer solar system — suggests that rocky planets like Earth and distant icy bodies may have formed at the same time. This challenges the long-standing belief that planets closer to the sun formed before those in the outer solar system, the ones that lie beyond the asteroid belt between Mars and Jupiter.

Planets form within the rotating disks of gas and dust that surround young stars, where particles collide and stick together through a process known as accretion. As developing rocky planets heat up, they begin to differentiate, forming separate internal layers known as the core, mantle and crust.

Scientists have thought that our solar system's inner rocky planets — Mercury, Venus, Earth and Mars —formed first (around 4.566 billion years ago), while gas giants and icy bodies in the outer solar system came together slightly later (4.563 billion years ago), due to the colder temperatures at a greater distance from the sun. Rocky planets farther out were also thought to form more slowly because their higher water and ice content would have delayed internal heating and core development.

Analyzing the composition of the meteorite (which was purchased from a dealer in Morocco in 2018) revealed a ratio of chromium and oxygen that indicates it came from the outer part of the solar system. Using precise isotopic dating methods, the researchers found that the rock formed 4.564 billion years ago — just two to three million years after the solar system’s earliest solid materials.

Related: How many meteorites hit Earth every year?

Until now, such early formation was thought to be limited to bodies from the inner solar system, according to a statement announcing the new study.

Evidence that rocky planets beyond Jupiter formed as rapidly, and at the same time, as the inner planets could transform our understanding of how planets take shape — not only in our solar system, but in planetary systems throughout the universe, the researchers said.

Their findings were published on July 4 in the journal Communications Earth & Environment.

This article was originally published on Space.com.

A lunar crater immortalized in one of the most famous photographs ever taken has just played a key role in the hunt for alien life in our solar system.

Stretching nearly 25 miles (40 kilometers) across the far side of the moon, the lunar impact crater formerly known as "Pasteur T" may be the most-viewed lunar crater in history. Countless Earthlings have seen it spreading prominently through the foreground of the iconic "Earthrise" photo snapped by American astronaut William Anders on Dec. 24, 1968, during the Apollo 8 mission. The majestic photo, which shows a half-lit Earth rising majestically above the lunar horizon, became so famous that the crater was renamed "Anders' Earthrise" in 2018.

Now, nearly 60 years after Anders' flyby put his eponymous crater on the map, another spacecraft has glimpsed it from orbit — this time, with extraterrestrial science in mind.

The Jupiter Icy Moons Explorer (JUICE) spacecraft, which launched from Earth in April 2023 and is expected to reach Jupiter's orbit in 2031, flew past the moon nearly a year ago. Mission scientists used this encounter to test the spacecraft's 10 science instruments, which will eventually be used to hunt for signs of habitability on the many moons of Jupiter.

This lunar flyby presented the first opportunity to test the performance of JUICE's instruments on a solid surface in space, representatives from the European Space Agency (ESA) said in a statement. Of particular importance was the Radar for Icy Moon Exploration (RIME) instrument, which uses radio wave echoes to measure elevation on rocky bodies.

"RIME's task at Jupiter is to peer below the icy surfaces of moons Europa, Ganymede and Callisto to map the invisible rocky layers below," ESA representatives wrote in the statement.

Related: 32 strange places scientists are looking for aliens

Because RIME needs to "listen" for precise changes in radio waves, the instrument requires as much silence as possible to get the best readings. That's where Anders' Earthrise crater comes into play. While JUICE sailed past the famous crater, ESA scientists silenced all of the probe's other instruments to let RIME observe it in peace for eight uninterrupted minutes.

RIME's radar mapped the moon's elevation in and around the crater, which researchers compared to earlier measurements taken by other spacecraft, such as NASA's Lunar Orbiter Laser Altimeter (LOLA). The team found that electronic noise within JUICE was throwing off RIME's measurements — kicking off a months-long project to correct the issue with a new algorithm.

ESA now reports that this project was a success. The new elevation map of Anders' Earthrise crater (above) shows peaks and valleys that perfectly match the elevations captured by LOLA during earlier lunar flybys. The data prove that RIME is ready for its big job: charting the subsurface depths of the largest moons in the solar system — and, hopefully, aiding in the search for extraterrestrial life.

With a long journey still ahead, JUICE is now headed toward Venus, where our neighboring planet's gravity will give the spacecraft a boost on the path to Jupiter. Ultimately, JUICE will complete 35 flybys of Jupiter's most massive moons, before settling into orbit around Ganymede from December 2034 to September 2035, according to ESA. Studying Jupiter and its moons will not only provide new insights about the formation of gas giants and planetary systems at large but also help to tease out signs of life and habitability beneath the icy shells of the enormous moons.

Astronomers have spotted a monster-sized planet that could be up to ten times the size of Jupiter emerging from the stellar fog surrounding a young star.

Prior observations of the roughly 13 million-year-old star MP Mus (also known as PDS 66) located around 280 light-years away had failed to distinguish features in the swirling cloud of gas and dust, or protoplanetary disk, that surrounds it.

However, when astronomers reexamined the apparently featureless protoplanetary disk of this star using combined data from the Atacama Large Millimeter/submillimeter Array (ALMA) and the European Space Agency (ESA) Gaia mission, they found it may not be quite so lonely after all.

The team detected a huge gas giant dwelling in the protoplanetary disk of MP Mus, which had been previously hidden. This represents the first time Gaia has spotted an extrasolar planet or "exoplanet" sitting in a protoplanetary disk, the disks of material around young stars that birth planets.

Such detections have typically been tough due to interference from the gas and dust of the protoplanetary disk. Until now, astronomers have only made three strong detections of planets within protoplanetary disks.

This new finding could help astronomers hunt more recently formed planets around infant stars.

Young exoplanets get into the groove

Planets form within protoplanetary disks through a process called core accretion, when larger and larger particles stick together via gravity, forming planetesimals, asteroids, and eventually planets.

As material from the protoplanetary disk is swallowed up by this process, the planets created begin to carve channels in the disk, akin to the grooves in a vinyl record.

When this team initially observed the protoplanetary disk around MP Mus in 2023 with ALMA, these were the kind of structures they had expected to see. Structures that were missing.

"We first observed this star at the time when we learned that most discs have rings and gaps, and I was hoping to find features around MP Mus that could hint at the presence of a planet or planets," team leader Álvaro Ribas from Cambridge's Institute of Astronomy said in a statement.

What the team found instead was a seemingly lonely star surrounded by a featureless disk of gas and dust that had none of the hallmarks of forming planets.

"Our earlier observations showed a boring, flat disc," Ribas said. "But this seemed odd to us, since the disc is between seven and ten million years old.

"In a disc of that age, we would expect to see some evidence of planet formation."

With their curiosity piqued, the team set about relooking at MP Mus again using ALMA, but in longer wavelengths of light. This allowed them to probe deeper into the disk, revealing a cavity in the disk close to the young star and two further "holes" further out, all of which were absent in the prior observations.

Further evidence of a planetary companion to MP Mus was about to be delivered.

More than just a first for Gaia

As Ribas and colleagues were examining MP Mus with ALMA, European Southern Observatory (ESO) researcher Miguel Vioque was looking at the young star using the now-retired star tracking spacecraft Gaia.

What Vioque discovered was that this young star is "wobbling." This is something that would usually be the effect of a planet in orbit gravitationally tugging on a star, but Vioque was aware that MP Mus' protoplanetary disk had, until that point, come up empty in terms of planets.

"My first reaction was that I must have made a mistake in my calculations, because MP Mus was known to have a featureless disc," Vioque explained. "I was revising my calculations when I saw Álvaro give a talk presenting preliminary results of a newly-discovered inner cavity in the disc, which meant the wobbling I was detecting was real and had a good chance of being caused by a forming planet."

The researchers came together, combining the Gaia and ALMA data with some computer modeling assistance to determine that the wobbling is likely caused by a gas giant with a mass between three and ten times that of Jupiter.

This giant planet appears to orbit MP Mus at a distance of between one and three times the distance between Earth and the sun.

"Our modelling work showed that if you put a giant planet inside the newfound cavity, you can also explain the Gaia signal," Ribas said. "And using the longer ALMA wavelengths allowed us to see structures we couldn’t see before."

As well as being the first time Gaia has spotted a planet within a protoplanetary disk, this is the first time an embedded exoplanet has been indirectly discovered by combining precise star movement data from Gaia with deep observations of the disk courtesy of ALMA.

"We think this might be one of the reasons why it's hard to detect young planets in protoplanetary discs, because in this case, we needed the ALMA and Gaia data together," said Ribas. "The longer ALMA wavelength is incredibly useful, but to observe at this wavelength requires more time on the telescope."

Ribas is hopeful that future ALMA upgrades, in addition to forthcoming telescopes, could be used to probe even deeper into protoplanetary disks.

This would not only reveal a hitherto undiscovered population of young embedded exoplanets, but it could help us understand how the solar system came to be around 4.5 billion years ago.

The team's research was published July 14 in the journal Nature Astronomy.

This article was originally published on Space.com

The James Webb Space Telescope (JWST) has captured its first direct image of a planet in a remote solar system, and it's lighter than any seen before.

The planet, named TWA 7b, is a gas giant with a size comparable to Saturn's. Orbiting a star just over 6 million years old, the planet is still glowing hot from its formation.

The planet is the first observation of hypothesized yet previously unseen "shepherd" planets, which clear gaps of material found inside planetary rings. The researchers behind the discovery published their findings June 25 in the journal Nature.

"It tells us that indeed, planets can form gaps in disks (which was theorised, but not observed) and trojan-like structures can indeed be present in exoplanetary systems," lead study author Anne-Marie Lagrange, an astronomer and research director at the French National Center for Scientific Research (CNRS) in Paris, told Live Science.

"It is the first time that such a light planet is imaged, ten times lighter than the lightest [previously known] planet," she said. "This is thanks to the extreme sensitivity of JWST in the thermal domain."

Astronomers study exoplanets because they help them to understand how planetary systems, such as our own, form. Yet while thousands have been seen indirectly — through the dimming of host stars as they pass in front of them or the wobble the planets' gravitational tugs give them — the light bouncing off exoplanets is usually drowned out by the light from the star, making them effectively invisible.

Related: 'Eyeball' planet spied by James Webb telescope might be habitable

To peer through this glare, JWST uses a coronagraph attached to its Mid-Infrared Instrument (MIRI); this device blocks out a star's light and makes it easier to spot objects orbiting around it. To further boost the effectiveness of this search, astronomers select young stars whose planetary disks are pole-on to the telescope, enabling them to “look down” over star systems whose satellites are still glowing hot from their formation.

The system containing TWA 7b, called TWA 7, is 110 light-years from Earth and contains three concentric rings of rocky debris and dust, one of which was narrow and flanked by two empty bands of space. Within the heart of this narrow ring, the scientists found a hole containing a source of infrared-radiation.

Follow-up simulations suggested that this radiation source is a planet roughly 30% the size of Jupiter that's orbiting its star at 52 times the distance that Earth orbits the sun. Its presence in a gap inside the planetary ring is also intriguing; while observations of holes in the discs surrounding stars have been made before in other systems, this is the first clear detection of the shepherd planets believed to create them.

To further investigate the new system and others like it, Lagrange said that she and her colleagues will obtain "more data to study TWA7 b atmosphere, to search for other light, cold young planets in imaging" and "to search for cold old massive planets."

Researchers have captured a mesmerizing image of what they believe to be a giant planet forming in the orbit of a young star, according to a new study.

The image, taken with the European Southern Observatory's Very Large Telescope in Chile, shows the star surrounded by an eye-shaped disk of swirling gas and dust. A dark ring within the disk suggests that the gravity of a newborn planet, likely a gas giant, is accumulating material as it carves a path around the star.

"We are talking about a fairly massive planet here, a few times the mass of Jupiter most likely," study lead-author Christian Ginski, a lecturer in the physics unit at the University of Galway in Ireland, told Live Science in an email. "It clears out a gap as it orbits because material falls down onto the planet. One might almost think of the planet like a hoover in that sense sucking up all the dust."

This could be a rare example of a planet detected while still in its infancy. Ginski and his colleagues released a simulation of the potential giant exoplanet within the disk and hope to confirm its presence using the James Webb Space Telescope in the coming months.

The researchers posted their findings Monday (June 9) to the preprint database arXiv, with the paper accepted for future publication in the journal Astronomy & Astrophysics.

Related: Ginormous planet discovered around tiny red star challenges our understanding of solar systems

Ginski and his colleagues are trying to learn more about the diversity of planetary systems and the forces needed to create a solar system similar to our own. They do this by seeking out young stars, which could be actively giving birth to new planets. Ginski noted that while researchers have detected several thousand planets around distant stars, these are all quite old.

"We are basically looking at the meal after it is fully cooked," he said. "Young planets inside their forming disk help us to understand all the ingredients and how they interact with each other. So far we only have 1 confirmed such planet in its infancy and 2-3 more candidates which are not fully conf[i]rmed yet."

The young star at the center of the new image is named 2MASSJ16120668-3010270, or 2MASSJ1612 for short, and is located 430 light-years from our solar system. A 2024 study noted the presence of a gap in the star's disk, so researchers already suspected that there could be a planet forming there.

In the new study, 2MASSJ1612 was viewed in scattered near-infrared light for the first time, revealing previously unseen details, including two spiral arms emanating from the center of its disk. Ginski explained that the arms form because the planet is perturbing, or altering the disk, as it moves, creating what are known as density waves. He likened this effect to the ripples created by throwing a stone in a pond.

"The stone is perturbing the water, sending out waves, somewhat similar to the planet in the disk," Ginski said. "Now think about the stone skipping over the water instead of just plunging into it. Ever more complex wave pattern are the result. In the disk, where the planet circles around the star, this leads eventually to the formation of these spiral patterns."

Ginski noted that he has observed around 100 young star systems and that researchers typically find either the carved-out ring or the spiral structures, but in this case, the images revealed both — as theoretical models of planet formation predict. He said he felt like "a kid on Christmas morning" when he first saw the images.

"Basically it appears we may be looking at an absolute textbook case here," Ginski said. "So that makes us think that we can predict what kind of planet is in this disk, and we think it should be one that we can actually take an image of with the right equipment (which is why we secured follow-up time at the James Webb Space Telescope)."

You'd think that icy worlds are frozen in time and space because they're — well — icy. However, planetary scientists know that all worlds can and do change, no matter how long it takes. That's true for Europa, one of Jupiter's four largest moons. Recent observations made by the James Webb Space Telescope (JWST) zero in on the Europan surface ices and show they're constantly changing.

Dr. Ujjwal Raut of the Southwest Research Institute (SWRI) reported on the changes reflected in the JWST studies. Not only does Europa's surface have amorphous ice, but there's evidence of crystalline ice scattered around there. That indicates the presence of an active water source, such as the subsurface ocean. It also points toward geologic processes that affect the surface. The changes seen at Europa are very short-term, perhaps two weeks in some places.

"Our data showed strong indications that what we are seeing must be sourced from the interior, perhaps from a subsurface ocean nearly 20 miles (30 kilometers) beneath Europa's thick icy shell," said Raut. "This region of fractured surface materials could point to geologic processes pushing subsurface materials up from below. When we see evidence of CO₂ at the surface, we think it must have come from an ocean below the surface. The evidence for a liquid ocean underneath Europa's icy shell is mounting, which makes this so exciting as we continue to learn more."

What happens to Europa

As a Galilean moon, Europa orbits near the planet and within its strong magnetic field. Thus, the surface gets bombarded by radiation. It is tidally locked, meaning it shows the same face to Jupiter as it orbits. Europa has a rocky and metallic interior, covered by an ocean and topped by an icy shell that's fairly young in geological terms. It appears to be no more than 180 million years old. That tells us it has been resurfaced from within. JWST's spectral studies of the surface show that the ice crystallizes in different ways in various places. Generally, water ice freezes into hexagonal crystals. That's what we see on Earth when it snows or when rain freezes. However, Earth's surface is largely protected from outside influences such as radiation and the ice stays in crystalline form much longer.

Related: 'Previously unimaginable': James Webb telescope breaks its own record again, discovering farthest known galaxy in the universe

On Europa, charged particles trapped in Jupiter's magnetic field bombard the surface. That disrupts the crystalline structure of the ice, turning it into amorphous ice. If that's all that ever happened to Europa's surface, you'd expect to see amorphous ice everywhere. Instead, the JWST spectral studies showed evidence of crystalline ice. There are also other surface "units", such as ridges and cracks. Radiation doesn't explain them, but other processes can create them. Combined with the new data collected by JWST, Raut said they are seeing increasing evidence for a liquid ocean beneath the icy surface.

Resurfacing Europa

Scientists thought that Europa's surface was covered by a very thin (perhaps half a meter thick) layer of amorphous ice protecting crystalline ice below. The new evidence of crystalline ice on the surface also shows up in other areas, especially an area known as the Tara Regio. According to co-author Richard Cartwright of the Johns Hopkins Applied Physics Laboratory, the surface may be different than expected in places. "We think that the surface is fairly porous and warm enough in some areas to allow the ice to recrystallize rapidly," said Cartwright. "Also, in this same region, generally referred to as a chaos region, we see a lot of other unusual things, including the best evidence for sodium chloride, like table salt, probably originating from its interior ocean. We also see some of the strongest evidence for CO₂ and hydrogen peroxide on Europa. The chemistry in this location is really strange and exciting."

Related: How many moons does Jupiter have?

The CO₂ found in this area includes the most common type of carbon, with an atomic mass of 12 and containing six protons and six neutrons, as well as the rarer, heavier isotope that has an atomic mass of 13 with six protons and seven neutrons. That raises questions about the origin of the CO₂. "It is hard to explain, but every road leads back to an internal origin, which is in line with other hypotheses about the origin of ¹²CO₂ detected in Tara Regio," Cartwright said.

Sources of water and resurfacing

So, how is water forced to the surface? There are two main sources of heat at work: tidal heating and radioactive decay at the core. Both of these processes warm the subsurface ocean and force water to the surface. What causes the chaotic terrain seen at Europa in such places as Tara Regio? There are several possible ways. One way is through the formation of chaos regions — those places that appear to be cracked and jumbled. They could be the result of material forcing its way via diapirs (think of them as stovepipes from below that convey warmer water and slush up to the surface). Once that water gets to the surface, it freezes rapidly into the crystalline ice JWST detected. The water also brings up dissolved CO₂ and other materials.

Another method for water delivery to the surface is through plumes. These geysers shower the surface with ice grains. Other mechanisms that could be forming crystalline ice are migration from other parts of the surface and impact exposure. Impacts are well known to "garden out" fresh ice in a short period of time. Such a collision may well explain the ice seen at Tara.

This resurfacing with crystalline ice is relatively short-lived. That's because the constant bombardment of charged particles works immediately to create amorphous ice. The authors of the paper (see below) state that the charged particle-driven process that changes the ice may work in as little as 15 days on Europa's leading hemisphere. In other places, that might work faster. So, given that Europa is constantly refreshing its surface and charged particles are rapidly breaking that ice down, Europa is a busy, constantly changing place. The upcoming Europa Clipper mission should be able to study these regions in more detail during its many close passes of this tiny moon.

The original version of this article was published on Universe Today.

Jupiter, the solar system's largest planet, used to be even bigger, according to a new study.

The cloud of gas and dust from which the sun and planets formed dissipated around 4.5 billion years ago. At that time, Jupiter was at least twice its current size, and its magnetic field was about 50 times stronger, researchers found. The findings, which the team described in a study published May 20 in the journal Nature Astronomy, could help scientists develop a clearer picture of the early solar system.

"Our ultimate goal is to understand where we come from, and pinning down the early phases of planet formation is essential to solving the puzzle," study co-author Konstantin Batygin, a planetary scientist at Caltech, said in a statement. "This brings us closer to understanding how not only Jupiter but the entire solar system took shape."

Jupiter's immense gravity — along with the sun's — helped fashion the solar system, shaping the orbits of other planets and rocky bodies. But how the giant planet itself formed remains opaque.

To gain a better picture of Jupiter's early days, the researchers studied the present-day, slightly tilted orbits of two of Jupiter's moons, Amalthea and Thebe. The paths these moons chart are similar to what they were when they first formed, but the moons have been pulled slightly over time by their larger, volcanically active neighbor Io. By analyzing the discrepancies between the actual changes and those expected from Io's nudges, the researchers could work out Jupiter's original size.

Related: 'This has left us scratching our heads': Astronomers stumped by James Webb telescope's latest views of Jupiter

When the solar nebula dissipated, marking the end of planet formation, Jupiter's radius would have been between two and 2.5 times its current size to give Amalthea and Thebe their current orbits, the scientists calculated. Over time, the planet has shrunk to its current size as its surface cools. Then, the team used the radius to calculate the strength of the planet's magnetic field, which would have been around 21 milliteslas — about 50 times stronger than its current value and 400 times stronger than Earth's.

"It's astonishing that even after 4.5 billion years, enough clues remain to let us reconstruct Jupiter's physical state at the dawn of its existence," study co-author Fred Adams, an astrophysicist at the University of Michigan, said in the statement.

The findings sharpen researchers' view of the solar system at a critical transition point in its history. The calculations also don't depend on how Jupiter formed — a process that's still not understood in detail — relying instead on directly observable quantities.

"What we've established here is a valuable benchmark," Batygin said in the statement. "A point from which we can more confidently reconstruct the evolution of our solar system."

Jupiter is currently shrinking by about 2 centimeters per year, according to Caltech. This is due to the Kelvin-Helmholtz mechanism — a process by which planets grow smaller as they cool. As Jupiter slowly cools, its internal pressure drops, causing the planet to steadily shrink. It's unclear when this process began.

On Christmas Day in 2023, scientists trained the James Webb Space Telescope (JWST) on Jupiter's auroras and captured a dazzling light show.

The researchers observed rapidly-changing features in Jupiter's vast auroras using JWST's infrared cameras. The findings could help explain how Jupiter's atmosphere is heated and cooled, according to a study published May 12 in Nature Communications.

"What a Christmas present it was — it just blew me away!" study coauthor Jonathan Nichols, a researcher studying auroras at the University of Leicester in the UK, said in a statement. "We wanted to see how quickly the auroras change, expecting them to fade in and out ponderously, perhaps over a quarter of an hour or so. Instead, we observed the whole auroral region fizzing and popping with light, sometimes varying by the second."

Auroras form when high-energy charged particles, often released from the sun, slam into gases in a planet's atmosphere, causing the gas to glow. Jupiter's strong magnetic field scoops up charged particles such as electrons from the solar wind — and from eruptions on its highly volcanic moon Io — and sends them hurtling toward the planet's poles, where they put on a spectacle hundreds of times brighter than Earth's Northern Lights.

Related: NASA reveals 'glass-smooth lake of cooling lava' on surface of Jupiter's moon Io

In the new study, the team looked closely at infrared light emitted by the trihydrogen cation, H₃⁺. This molecule forms in Jupiter's auroras when energetic electrons meet hydrogen in the planet's atmosphere. Its infrared emission sends heat out of Jupiter's atmosphere, but the molecule can also be destroyed by fast-moving electrons. To date, no ground-based telescopes have been sensitive enough to determine exactly how long H₃⁺ sticks around.

But by using JWST's Near Infrared Camera, the team observed H₃⁺ emissions that varied more than they expected. They found that H₃⁺ lasts about two and a half minutes in Jupiter's atmosphere before being destroyed. That could help scientists tease out how much of an effect H₃⁺ has on cooling Jupiter's atmosphere.

But the scientists don't have the full picture yet. They also found some puzzling data when they turned the Hubble Space Telescope toward Jupiter at the same time. Hubble captured the ultraviolet light coming from the auroras, while JWST captured infrared light.

"Bizarrely, the brightest light observed by Webb had no real counterpart in Hubble's pictures," Nichols said in the statement. "This has left us scratching our heads. In order to cause the combination of brightness seen by both Webb and Hubble, we need to have a combination of high quantities of very low-energy particles hitting the atmosphere, which was previously thought to be impossible. We still don't understand how this happens."

In future work, the researchers plan to study the source of this unexpected pattern using additional JWST data as well as observations from NASA's Juno spacecraft, which has been observing Jupiter from orbit since 2016.

When you think of a planet with rings, majestic Saturn almost definitely comes to mind. But it's not the only planet in the solar system with these breathtaking bands. So which planets in our solar system have rings?

All four giant planets — Jupiter, Saturn, Uranus and Neptune — sport these spectacular structures. Plus, many other objects in the solar system, including the dwarf planet Haumea and asteroid Chariklo, have rings. Whether or not we can see these rings easily from Earth depends on what they're made of.

Unlike a diamond ring, planets' rings don't last forever — not even the most iconic ones in the solar system. Scientists think Saturn's rings will vanish as the debris that makes up the rings falls into Saturn's atmosphere, but that won't happen for a long time.

"We still have hundreds of millions of years to enjoy them," Saunders said. "But it makes me think about how lucky we are to live at a time when Saturn has beautiful, icy, visible rings."

The weather forecast for Jupiter now includes softball-size hailstones, known as "mushballs," that are brewed by violent thunderstorms raging in the planet's turbulent atmosphere, a new study finds.

The findings confirm these bizarre, ammonia-rich mushballs are also the source of Jupiter's missing ammonia. The absence of this gas in pockets of Jupiter's atmosphere has perplexed scientists for years.

Decades ago, astronomers spotted intensely turbulent cloud tops in telescope images of the gas giant. The discovery led scientists to conclude that Jupiter's atmosphere churns and mixes constantly, like a pot of boiling water.

Yet recent data from Earth-based radio telescopes and NASA's Juno spacecraft revealed deep pockets of missing ammonia — reaching 90 miles (150 kilometers) deep across all latitudes. This depletion is so significant in the planet's atmosphere that no known mechanism could explain it.

Now, the new study's analysis of the aftermath of a massive 2017 storm observed by Juno offers compelling evidence that Jupiter's raging storms are the key to this atmospheric puzzle. The findings also reveal that even localized storms can strip ammonia from the planet's upper atmosphere and plunge it unexpectedly deep, indicating that the long-held vision of a thoroughly mixed atmosphere swirling around Jupiter is an illusion.

"The top of the atmosphere is actually a pretty poor representation of what the whole planet looks like," study lead author Chris Moeckel, a researcher in the Space Sciences Laboratory at the University of California, Berkeley, told Live Science. "As time goes by, we have to dig deeper and deeper into the atmosphere to find the place where it appears well-mixed."

Moeckel and his colleagues described their findings in a study published March 28 in the journal Science Advances.

'That's the moment I conceded'

Because of the dense cloud cover blanketing Jupiter, scientists cannot directly observe what lies beneath the planet's turbulent cloud tops. The role of ammonia is like a splash of color in a flowing stream of water, Moeckel said: It acts as a tracer, revealing otherwise-invisible patterns and processes deep within Jupiter's atmosphere.

To explain the missing ammonia in Jupiter's atmosphere, in 2020 scientists theorized that the planet's violent storms generate strong updrafts that rapidly lift ammonia-rich ice particles to high altitudes, where they combine with water ice into a slushy liquid. Much like Earth's hailstones, Jovian mushballs grow by accumulating ice layers as storm currents repeatedly cycle them, eventually reaching softball size and falling deep into Jupiter's atmosphere, far below their origin. This process, the theory posited, left upper regions depleted of ammonia and water that Juno and ground-based telescopes detected.

A distinct signature within the radio observations beamed back by Juno confirmed that this exotic process is indeed occurring, the new study found. During its February 2017 flyby, the spacecraft passed over an active storm region, and its instruments showed a higher concentration of both ammonia and water nestled beneath the storm cloud.

"I was actually sitting at the dentist's office waiting and I was playing with the code," Moeckel said. "All of a sudden I saw a signal much deeper at the same location as the storm clouds were at the top, and I remember being like 'Huh,' I didn't expect anything down here."

The peculiar signal, which persisted even a month after the storm began, could only be explained by either a drop in temperature consistent with melting ice or an increase in ammonia concentration, which would occur if the ammonia within the mushballs was being released as they melted.

"Both theories led me to the same conclusion — the only known mechanism was these mushballs," Moeckel said. "That's the moment I conceded."

The researchers suspect Jupiter is unlikely to be unique in this regard, as gases such as ammonia are swept into forming planets and are likely circulating in the atmospheres of hydrated gas giants both within our solar system and beyond.

"I won't be surprised if this is happening throughout the universe," Moeckel said.

A massive solar windstorm in 2017 compressed Jupiter's magnetosphere "like a giant squash ball," a new study reports.

The discovery stemmed from an unusual temperature pattern scientists observed in Jupiter's atmosphere using the Keck Observatory in Hawai'i. Normally, Jupiter's powerful polar auroras inject significant heat into the gas giant's upper atmosphere near the poles.

These spectacular lights resemble those seen on Earth, where they're generated when energetic particles interact with our planet's magnetic field, but Jupiter's auroras are believed to proceed through a different mechanism and are far more intense and energetic.

When scientists from Reading University in England detected unexpectedly high temperatures stretching across half of Jupiter's circumference — reaching over 930 degrees Fahrenheit (500 degrees Celsius), significantly higher than the typical atmospheric background temperature of 660 degrees F (350 degrees C) — they were baffled.

Related: The chaotic heart of the Milky Way like you've never seen it before

"Typically, temperatures decrease gradually toward the equator, reflecting how auroral energy is redistributed across the planet," the team wrote in their paper, which was published April 3 in the journal Geophysical Research Letters.

As "there are no known heating mechanisms capable of producing a feature with these temperatures outside of the auroral region," the team proposed that the superheated region was likely "launched" toward the equator from the poles.

To figure out how this might have occurred, the researchers combined ground-based observations from the Keck telescope with data from NASA's Juno spacecraft, which has been exploring Jupiter and its moons since 2016. They traced the cause of this sudden heat displacement to a dense burst of solar wind that compressed Jupiter's enormous magnetosphere — a magnetic bubble surrounding the planet, shaped by its own magnetic field. (Earth has one, too! In fact, life would not be possible without it.)

"We have never captured Jupiter's response to solar wind before — and the way it changed the planet's atmosphere was very unexpected," study lead author James O'Donoghue of the University of Reading said in a statement. "This is the first time we've ever seen a thing like this on any outer world."

The compression of the magnetosphere by the solar wind appears to have intensified auroral heating at Jupiter's poles, causing the upper atmosphere to expand and spill hot gas typically confined to the poles down toward the equator, team members said.

"The solar wind squished Jupiter’s magnetic shield like a giant squash ball," O'Donoghue said. "This created a super-hot region that spans half the planet. Jupiter's diameter is 11 times larger than Earth's, meaning this heated region is enormous."

And such solar wind events are believed to hit Jupiter two to three times per month!

Scientists had previously thought that Jupiter's fast rotation would shield it from such effects, keeping auroral heating confined to the polar regions due to barriers created by the planet's strong winds. However, the new findings challenge that assumption, revealing that even the solar system's largest planet is at the sun's mercy.

"We've studied Jupiter, Saturn and Uranus in increasing detail over the past decade. These giant planets are not as resistant to the sun's influence as we thought — they're vulnerable, like Earth," O'Donoghue said in the statement.

"Jupiter acts like a laboratory, allowing us to study how the sun affects planets in general," he added. "By watching what happens there, we can better predict and understand the effects of solar storms which might disrupt GPS, communications and power grids on Earth."

Originally posted on Space.com.

Astronomers have discovered 128 never-before-seen moons orbiting Saturn — giving it almost twice as many moons as all the other planets in the solar system combined.

The findings have further bolstered Saturn's status as our solar system's "moon king." With an updated total of 274 known natural satellites orbiting the gas giant, it is leagues ahead of its main competitor Jupiter, which has just 95 confirmed moons.

This week, the International Astronomical Union officially recognized the team's discovery. The researchers published their findings March 10 in the journal arXiv, so they have not yet been peer-reviewed.

"Our carefully planned multi-year campaign has yielded a bonanza of new moons that tell us about the evolution of Saturn's irregular natural satellite population," study lead author Edward Ashton, an astronomer at Institute for Astronomy and Astrophysics at Academia Sinica, Taiwan, said in a statement.

The newfound moons are situated within the Norse group of Saturn's moons — a group of moons that orbit in retrograde (travelling in the opposite direction to the planet’s rotation) along elliptical paths outside Saturn's rings. The 128 newly discovered objects are considered "irregular" moons, meaning they're only a mile or two in size and far from spherical.

Related: NASA finds key ingredient for life gushing out of Saturn's icy moon Enceladus

Their diminutive sizes and location means these moons are likely fragments of larger moons that were smashed apart by a cataclysmic collision — probably with Saturn's other moons or a passing comet. This collision could have occurred as recently as 100 million years ago, the astronomers said in the study.

The discovery was made using the Canada France Hawaii Telescope (CFHT), which combed the sky around Saturn between 2019 to 2021 and discovered an initial 62 additional moons in its orbit. The team also found faint signals of an even larger number of orbiting bodies but were unable to confirm them at the time.

"With the knowledge that these were probably moons, and that there were likely even more waiting to be discovered, we revisited the same sky fields for three consecutive months in 2023," Ashton said. "Sure enough, we found 128 new moons. Based on our projections, I don't think Jupiter will ever catch up."

The researchers say they are now finished moon-spotting for the foreseeable future, at least until telescopes capable of spotting even fainter signatures are developed.

"With current technology I don't think we can do much better than what has already been done for moons around Saturn, Uranus and Neptune," Ashton said.

A stunning photo has captured all seven of our neighboring planets in Earth's sky at the same time, possibly for the first time ever.

The composite image, captured by astrophotographer Josh Dury, shows Mars, Jupiter, Uranus, Saturn, Venus, Neptune and Mercury in alignment thanks to a rare "planetary parade" taking place this weekend for the first time since 1982. (Here's how you can see it for yourself tonight).

While spacecraft, such as NASA's Voyager 1, have snapped all the planets in the sky from space, terrestrial cameras have only recently become advanced enough to capture them from the ground — meaning Dury's photo is likely the very first of its kind.

"Seven (arguably, 8) is a feat that to my prior knowledge has not been achieved before," Dury told Live Science in an email — suggesting that if we include Earth itself, visible in the foreground, the image's planet total comes to eight. "This image could hold a record for being the first of its kind to photograph all the planets of the solar system, blended into a stitched panoramic image."

Dury captured the image just after sundown on Feb. 22 from The Mendip Hills — a range of limestone hills in Somerset in the U.K.

Related: Have all 8 planets ever aligned?

To achieve this photographic feat, Dury created a composite shot made up of several panes, with each pane captured in multiple exposures.

To locate Saturn, Neptune and Mercury, which were dimmer and closer to the western horizon, Dury used astronomy software to generate models of the night sky and match planetary locations to nearby star fields. He then used a high dynamic range (HDR) camera setting to capture the planets' faint light.

"I noted that when I took the image that it would not, of course, be possible to photograph the lowest planets at the moment of sunset — glare from the sun rendering this task impossible," Dury said. "Therefore, this image is a record of the first possible glimpse of the planets as light from the sun diminished." The night-sky models enabled him to later identify the planets in the image.

Planetary conjunctions occur when two or more planets appear to be close together in the sky. Of course, this is only from our perspective of the cosmos on Earth — in reality the planets remain extremely far apart.

These conjunctions aren't rare, but they get rarer with each planet added to the chain. For example, the three innermost planets — Mercury, Venus and Earth — align within 3.6 degrees in the sky every 39.6 years. For all of the solar system's eight planets to align as closely, it would take 396 billion years, something that has never happened and won't happen before the sun becomes a red giant, consuming Mercury, Venus and likely Earth in the process.

However, it is a little less unusual for all seven planets to appear spread out on the same side of the sun, as they do in Dury's image and in the night sky right now. Another seven-planet parade is expected to be visible from Earth in 2040.

If you'd like to see a planetary alignment for yourself, tonight (Feb. 28) is one of the best times to look. Time and Date and Stellarium are two great online tools for finding viewing times based on your location.

Seven planets in the solar system — Mercury, Venus, Mars, Jupiter, Saturn, Uranus and Neptune — will line up in the night sky Friday (Feb. 28) in an incredibly rare "planetary parade."

Although most of these planets have been visible in the night sky since January, Mercury will be joining the procession for just a few days, before Saturn gets lost in the sunset's glare in early March.

Five of these worlds will be easily visible to the unaided eye, but you will need a good telescope to see the full show, according to NASA.

That's because at least two of the planets — Uranus and Neptune — will be too dim to see with the naked eye and will likely be masked by the glare of the setting sun at twilight, NASA said. Saturn will also be trickier to see in some locations due to its position close to the horizon.

If you have a good telescope to catch the full display, the best time to view all seven planets in the Northern Hemisphere will be after sunset on Friday (Feb. 28) at around 8:30 p.m. local time, according to SkyatNightMagazine.

Related: Have all 8 planets ever aligned?

Planetary conjunctions occur when two or more planets appear to be close together in the sky. Of course, this is only from our perspective on Earth; in reality, the planets remain extremely far apart.

Conjunctions happen because the planets of the solar system orbit the sun along roughly the same flat plane as Earth, and they occasionally align when their different orbital distances and speeds bring them into a cluster on Earth's nightside.

These conjunctions aren't rare, but they do get rarer with each planet added to the chain. The three innermost planets — Mercury, Venus and Earth — align within 3.6 degrees in the sky every 39.6 years. For all of the solar system's eight planets to align that closely, it would take 396 billion years — something that has never happened and won't happen before the sun becomes a red giant, consuming Mercury, Venus and likely Earth in the process.

We recommend Time and Date and Stellarium as two great online tools for finding viewing dates and times based on where you are in the world. On mobile phones, Sky Tonight is a free app that will do the same job.

A striking new "planetary parade" photo combines images of six solar system worlds alongside the moon, providing a rare opportunity to compare the sizes of these celestial objects as they currently appear from Earth.

French astrophotographer Gwenaël Blanck created the stunning image by combining individual shots of each of the objects captured Feb. 2 from Paris, where he also took an exceptional photo of Venus and the moon aligning above the Eiffel Tower a day earlier.

The individual images were captured between 6:30 p.m. and 7:50 p.m. local time, using a digital camera attached to a telescope. Blanck then made a composite image of the six worlds in a straight line for the final photo. The objects are arranged from closest to Earth (left) to farthest from our planet (right): the moon, Venus, Mars, Jupiter, Saturn, Uranus and Neptune.

"I had to start quite early, shortly after sunset, to image Venus and Saturn before they were too low on the horizon," Blanck told Live Science in an email. "Neptune was also not far away [from the horizon]," he added. "It was probably the most difficult to capture."

"The Moon, Uranus, Jupiter and Mars were easier to capture, as they were higher in the sky," Blanck said. "The only missing planet was Mercury, which will become visible towards the end of the month and early March."

Related: Have all 8 planets ever aligned?

In reality, the objects in the image were scattered across the night sky. However, Blanck used the same magnification settings for each image, meaning the objects' sizes are perfectly scaled. That is why the moon looks so massive compared with Uranus and Neptune and why Venus and Jupiter appear to be around the same size, despite the latter being more than 10 times wider than the former.

"This gives a pretty good idea of the apparent size of each planet," Blanck said.

Planetary parade

We are currently in the midst of one of the most impressive planetary alignment events in recent years. Under the right circumstances, five planets — Mercury, Venus, Mars, Jupiter and Saturn — will be visible to the naked eye over the next few weeks. Uranus and Neptune are also present in the night sky, but you'll need a good telescope to see them alongside their brighter neighbors.

The event has already delivered some special moments, including an earlier alignment of six of the seven planets in late January and an occultation of Mars by the moon on Feb. 9. However, the parade will not peak until late February and early March, when all seven planets will align in a near-straight line along the horizon, according to Live Science's sister site Space.com.

Venus will be the brightest planet in the night sky during this period; it will be closest to the moon in the sky, making it easy to spot on most clear nights. The "love planet" will reach its peak brightness in time for Valentine's Day (Feb. 14).

If you want to see the best of the planetary parade for yourself, we recommend using a decent telescope or a pair of stargazing binoculars.

The next time we will see a similar alignment of the planets will be in October 2028.

The bright moon is hosting some special guests in the night sky this week: Following a close conjunction of Jupiter and the moon on Thursday (Feb. 6), the Red Planet Mars is ready to rise alongside Earth's natural satellite this Sunday (Feb. 9).

In a rare celestial event, the moon and Mars will be just 1 to 2 degrees apart, providing great viewing opportunities all night.

To get the best views of the close approach, find a spot under clear skies and away from artificial light (although both planets are still visible amid city light pollution). Allow some time for your eyes to adjust to the darkness, and if you have to use a flashlight, opt for red light instead of white light to preserve your night vision. You can easily see Mars and Jupiter with your naked eyes, but these planets are best viewed through a pair of skywatching binoculars or a good backyard telescope.

Planets hugging the moon

On Feb. 6-7, Jupiter and the moon rose about 5 degrees apart, in what's known as a conjunction. The conjunction of Jupiter and the moon occured at 10:36 p.m. EST, and the two celestial bodies remained very close together all night, according to Stellarium.

Related: The 10 best stargazing events of 2025

A few nights later, on Feb. 9, Mars and the moon will be in conjunction around 2:36 p.m. EST, according to Starwalk. When they reach conjunction, they will be about half a degree apart, although that will vary slightly depending on your exact location. Mars and the moon will rise and set together, rising shortly after 2 p.m. on Feb. 8 and setting shortly before 6 a.m. on Feb. 9.

Although Mars will be closest to the moon during daylight hours for viewers in the United States and Canada, Mars will remain very close to the moon all night. Shortly after sunset, the moon and Mars will be about 2 degrees apart, although this could vary slightly depending on your location. Look for them in the eastern sky, in the constellation Gemini. Mars will appear above and slightly to the west of the waxing gibbous moon, which will be about 90% illuminated.

Skywatchers in northern latitudes might even be able to catch a lunar occultation, when the moon appears to swallow a planet from the sky. Mars will vanish behind the moon around 1:09 p.m. EST and emerge from behind the moon around 4:30 p.m. EST, according to Starwalk. The lunar occultation of Mars will be visible from parts of Canada, most of Scandinavia and Russia, and parts of Asia. The occultation will barely graze the northernmost part of the U.K.

This map from In-the-Sky shows the locations where the lunar occultation will be visible; you can type your location into the sidebar on In-the-Sky to check if the lunar occultation will be visible from your location.

Editor's note: This article was updated on Friday (Feb. 7) after the conjunction of Jupiter and the moon ended.

Mars quiz: Is your knowledge of the Red Planet out of this world?

A NASA spacecraft orbiting Jupiter has just witnessed some of the most extreme volcanic eruptions ever seen in the solar system, coming from a giant underground magma chamber on the "tormented" Jovian moon Io. The energy pouring from this record-breaking hot spot far exceeds the amount of power we are producing on Earth, researchers say.

Io is Jupiter's third-largest moon, spanning roughly 2,300 miles (3,700 kilometers) across, which makes it slightly bigger than Earth's moon. It orbits Jupiter at a distance of around 262,000 miles (422,000 km) — also similar to how far away the moon orbits Earth — but it travels much faster than its lunar counterpart, whipping around Jupiter every 42.5 hours. This is due to the gas giant's immense gravity, which has also turned Io into a fiery hellscape covered with up to 400 volcanoes and multiple lava lakes.

Io is frequently monitored by NASA's Juno spacecraft, which has been circling Jupiter in a highly elliptical, or stretched, orbit since 2016. Juno passes by Io once every few months and fixes its gaze on the volcanic satellite so scientists can learn more about the moon's fiery insides.

During Juno's latest flyby of Io, on Dec. 27, 2024, the spacecraft's Jovian Infrared Auroral Mapper (JIRAM) instrument detected a massive new infrared hot spot in the moon's southern hemisphere where multiple eruptions, likely fueled by a single giant magma chamber, were taking place, NASA representatives wrote in a statement.

The giant hot spot was chucking out around 80 trillion watts of energy, which is equivalent to "six times the total energy [output] of all the world's power plants," according to NASA.

Related: Space photo of the week: An eerie look at Io, the most volcanic world in the solar system

"The data from this latest flyby really blew our minds," Scott Bolton, a space physicist at the Southwest Research Institute in San Antonio and principal investigator of the Juno mission, said in the statement. "This is the most powerful volcanic event ever recorded on the most volcanic world in our solar system — so that’s really saying something."

Juno also captured photographs of Io, which revealed that a large dark patch has emerged on the moon's surface. This area is likely covered in solidified lava flows that poured out during the eruption, according to NASA. However, the spacecraft was too far away during the recent flyby to capture detailed images of the dark spot, so its true nature remains unclear.

Based on the size of the mysterious surface feature and the levels of thermal radiation, researchers estimated that the magma chamber that feeds this hot spot likely spans an area of around 40,000 square miles (105,000 square kilometers) — around 30% larger than Lake Superior, Earth's largest freshwater lake. This makes the chamber the largest volcanic feature on Io, surpassing Loki Patera — a giant lake of lava covering an area of around 8,000 square miles (21,000 square km) in Io's northern hemisphere.

Extreme volcanism

Io's intense volcanic activity is the result of "tidal flexing," where the moon is continuously being squeezed and released like a stress ball by Jupiter's crushing gravity. This external force superheats the rock beneath Io's surface, transforming it into magma that then erupts onto the surface.

This is different from volcanic activity on Earth, which is driven by internal heating from our planet's molten metal core.

For decades, researchers speculated that the entire subsurface of Io was one big magma ocean. However, last year, researchers conclusively demonstrated that this was not the case. Instead, only specific areas, like the newly discovered magma chamber, accumulate concentrations of magma beneath each of the moon's visible volcanic features.

Juno will perform a closer flyby of Io on March 3, which should give researchers a better idea of what is happening inside the newly discovered magma chamber and provide clues about volcanism elsewhere in the solar system.

"While it is always great to witness events that rewrite the record books, this new hot spot can potentially do much more," Bolton said. "The intriguing feature could improve our understanding of volcanism not only on Io but on other worlds as well."

A planet-size object that possibly once visited the solar system may have permanently changed our cosmic neighborhood by warping the orbits of the four outer planets, a new study suggests. The findings may shed light on why these planets' paths have certain peculiar features.

For decades, astronomers have debated how the solar system's planets formed. However, most hypotheses agree on the type of orbit the planets should have: circles that are arranged concentrically around the sun and lie on the same plane. (If you viewed them edge-on, you would see only a line.) However, none of the eight planets, including Earth, have perfectly circular orbits. Plus, the planets' paths don't lie precisely on the same plane.

Compared with Mercury (whose orbit, within our planetary family, is the most egg-shaped and tilted), the paths of the four outer giant planets — Jupiter, Saturn, Uranus and Neptune — show minor deviations from the ideal orbits. Yet explaining these niggling discrepancies has been challenging, said Renu Malhotra, a planetary scientist at the University of Arizona in Tucson and a co-author of the new study.

"[T]he puzzle for theoretical astrophysics has long been to figure out how the orbits later became out-of-round and tilted from their mean plane by not too much and not too little," she wrote in an email to Live Science. While previous research has focused on how interactions between these planets reshaped their orbits, Malhotra said, "these hypotheses are not consistent with certain important details of the observed orbits."

An interstellar visitor

To tackle this puzzle, Malhotra and colleagues considered a less-examined scenario: that a visiting star-size object tweaked these planets' paths around 4 billion years ago.

Related: Giant 'kidney beans' spotted in Mars satellite images could point to signs of water and life

Using computer models of the four outer planets, the team carried out 50,000 simulations of such flybys, each over 20 million years, while altering certain parameters of each visitor, including its mass, speed and how close it approached the sun. The researchers also expanded their search compared with previous studies by considering objects much smaller than stars — as tiny, in fact, as Jupiter. They also looked at situations with superclose passes, focusing on scenarios where the interloper came within 20 astronomical units (AU) of the sun. (One AU is approximately 93 million miles, or 150 million kilometers, roughly the average distance from Earth to the sun.)

Although most simulations created conditions very unlike the current solar system, the researchers found that in approximately 1% of the simulations, the visitor's passage altered the giant planets' orbits to approximately their current state. The interlopers in these near matches dove straight into the solar system, traveling way past Uranus' orbit, with some even grazing Mercury's path. And they were relatively tiny, ranging from two to 50 times the mass of Jupiter.

"This range includes planetary masses to brown dwarf masses," Malhotra said. (Brown dwarfs, often called "failed stars," are odd celestial bodies that are heavier than planets but not as massive as stars.)

Because many close-matching simulations had the planet-like object swooping through the inner solar system, the researchers created an additional 10,000 simulations including the terrestrial planets as well. In these cases, too, the flybys that had previously altered the giant planets' orbits to their present states recreated the solar system's current appearance.

The simulation that produced the most realistic results involved an object eight times Jupiter's mass swooping as close as 1.69 AU from the sun. That puts it only slightly farther than Mars' current orbit of 1.5 AU from the sun.

The simulations show that just one substellar object flyby was sufficient to alter the giant planets' trajectories. Because observations suggest substellar bodies are fairly numerous in the cosmos, visits by such objects may be more commonplace than flybys of stars.

The study, which hasn't been peer-reviewed yet, was published in the arXiv preprint database in December.

Another spectacular year for stargazers lies ahead. From the appearance of a brilliantly bright Venus to the first total lunar eclipse since 2022, there will be plenty of reasons to look skywards at night this year. Other highlights will include a deep partial solar eclipse in North America, four moonless meteor showers and three supermoons. While many of these events will be visible to the naked eye, investing now in a good beginner telescope can greatly enhance your experience.

Quadrantid meteor shower

When: Jan. 3/4, 2025

The Quadrantid meteor shower, the first meteor shower of the year for the Northern Hemisphere, can often impress — if you can stand the cold — with between 25 and 200 shooting stars per hour during its peak. It's also the last meteor shower until April's Lyrids.

Venus at its brightest

When: Feb. 19, 2025

As Venus reaches its closest point to Earth, it will shine at -4.5 magnitude — as bright as it ever gets — but the dazzling sight will reveal something else if you point a small telescope at it. As an inner planet, when it nears Earth, it appears as a crescent; watch from Jan. 11 to Feb. 19, and you'll see it shrink each night.

Total lunar eclipse

When: March 13 to 14, 2025

The first total eclipse of the moon since late 2022 will turn the lunar surface a gorgeous orangey-reddish color for 65 minutes. North America will get a ringside seat, with the event seen throughout the continent during the night. Europe isn't so lucky, as it will get just a glimpse of the phenomenon during moonset.

Northern lights at equinox

When: March 20 and Sept. 22, 2025

The equinoxes, when Earth's axis is tilted neither toward nor away from the sun, create the ideal geometry for reliable and spectacular displays of auroras around the poles — and this year, these light shows will likely occur farther north and south. With the sun at solar maximum in 2025, expect increased solar activity, including aurora-triggering outbursts, particularly in the few weeks after the equinoxes.

Partial solar eclipse

When: March 29, 2025

Although it won't match the total solar eclipse of April 8, 2024, for sheer drama, those in northeastern U.S. states and eastern provinces in Canada may glimpse an eclipsed sunrise if skies are clear. This partial solar eclipse will see as much as 94% of the sun blocked by the moon, and it will also occur across Europe and northwest Africa.

Lyrid meteor shower

When: April 21 to 22, 2025

With 2024's Perseids — the most prolific and popular meteor shower of the year — marred by bright moonlight, other meteor showers will have to pick up the slack. With a crescent moon setting early in the evening, expect a good show from the Lyrids, which deliver about 10 to 20 shooting stars per hour and a few super-bright fireballs. April is also a good month to begin looking for the Milky Way later at night.

Eta Aquariid meteor shower

When: May 6 to 7, 2025

Expect about 60 shooting stars per hour during the peak of the Eta Aquariids, which will take place under ideal astronomical conditions. It is one of two meteor showers caused by dust and debris left in the inner solar system by Halley's comet (the other being November Orionids). The Eta Aquariids are best seen from the Southern Hemisphere.

Saturn at opposition

When: Sept. 21, 2025

Saturn will be at its brightest and best in late September as Earth passes between the gas giant and the sun. This will be the best time to see Saturn, though you'll need a small telescope to see its rings. There will be no opposition from Jupiter in 2025 — the giant planet will align with Earth and the sun early in 2026.

Venus and Jupiter conjunction

When: Aug. 12, 2025

Get up before sunrise on this date, and you'll likely see the beautiful sight of Jupiter and Venus shining just a degree from each other. That's less than the width of your little finger held out at arm's length against the sky. Jupiter will shine at -1.8 magnitude and Venus at -3.9 magnitude.

Beaver supermoon

When: Nov. 5, 2025

There will be three supermoons in 2025, the closest of which will be November's Beaver Moon at 221,726 miles (356,833 kilometers) from Earth. It will be the closest full moon this year and the closest since 2019. It will be preceded by October's Hunter's Moon and December's Cold Moon, with January 2026's Wolf Moon also being a supermoon.

This year will be an exciting time for space missions.

2025 kicks off with two moon landing attempts in January, followed by SpaceX's daring demonstration to transfer propellants between two Starship vehicles in low Earth orbit — a critical step in testing the company's ability to use the spacecraft to reach the moon and Mars. Later in 2025, Europe will launch an uncrewed robotic laboratory, and NASA's Juno spacecraft may reach the end of its extended mission and burn up in Jupiter's dense atmosphere.

Here are the coolest space missions to look forward to in 2025.

Blue Ghost 1 and Intuitive Machines' moon landings

In mid-January, Texas-based Firefly Aerospace will launch the "Ghost Riders in the Sky" mission, which aims to ferry a moon lander with 10 NASA payloads. The moon lander will head to Mons Latreille, a volcanic feature on the near side of the moon that was formed by volcanic eruptions over 3 billion years ago.

The lander, called Blue Ghost 1, is expected to operate during the daylight hours of one lunar day, or roughly 14 Earth days, during which it will gather data about the moon's regolith, or rocky surface, and how that rock interacts with the solar wind (the stream of charged particles that flows out of the sun's outer atmosphere) and Earth's magnetic field.

Toward the end of its mission, Blue Ghost 1 will take images of the moon's sunset and collect data about what changes occur on the lunar surface at dusk.

Meanwhile, Texas-based Intuitive Machines hopes to land its IM-2 spacecraft at the moon's south pole in February. The spacecraft aims to measure the regolith's volatiles, or delicate chemical compounds, using a drill and mass spectrometer. The spacecraft will also carry a small satellite, Lunar Trailblazer, which is designed to map water deposits on the moon to help NASA identify future landing sites for its Artemis missions IM-2 will fly a more direct route than Blue Ghost 1 and aims to land on the moon just a week after launch.

SpaceX's attempt at daring in-orbit propellant transfer

SpaceX is gearing up for a groundbreaking test to transfer propellant from one Starship to another while docked in low Earth orbit. The demonstration, scheduled for March 2025, will involve launching two windowless Starship vehicles about three to four weeks apart, with the second serving as a refueling tanker for the first.

This test is a crucial step in demonstrating that the spacecraft can be used to reach the moon and, eventually, Mars. Current NASA plans to reach the moon and Mars rely on the Human Landing System variant of Starship. In theory, astronauts who board the Human Landing System as a part of the Artemis 3 mission will reach the moon no sooner than mid-2027.

First NASA-ISRO Earth science mission

Also in March 2025, NASA and the Indian Space Research Organisation (ISRO) are teaming up to launch the first of their spacecraft on the Earth-observing NASA-ISRO Synthetic Aperture Radar (NISAR) mission, which will scan much of Earth's land and ice nearly every week. Using a pair of radar instruments that can see through clouds in both day and night, the spacecraft will measure the motion of Earth's surface down to fractions of an inch. Such precise measurements will help scientists track land movements that may be precursors to volcanic eruptions and earthquakes, as well as monitor changes in forests and agricultural lands.

The U.S. and India are also partnering on a high-profile effort to send the first Indian astronaut — Indian Air Force test pilot Shubhanshu Shukla — to the International Space Station no sooner than April 2025 on the private Axiom Mission 4.

Liftoff of delayed "Blue" and "Gold" Mars satellites

NASA's two Mars-bound satellites, which were designed at the University of California, Berkeley, will study how and when the Red Planet lost its atmosphere. They are now slated to launch no earlier than spring 2025, following a delay of the mission's original October 2024 launch.

The satellites — named "Blue" and "Gold" as a nod to UC Berkeley's school colors — will orbit Mars at different altitudes to gather simultaneous data on the planet's plasma and magnetic fields. With this information, scientists hope to learn how atoms are stripped from the Red Planet's atmosphere.

The mission, called Escape and Plasma Acceleration and Dynamics Explorers (ESCAPADE), was paused in September due to concerns that the delivery vehicle, Blue Origin's New Glenn rocket, wouldn't be ready. The alignment of Earth and Mars creates an ideal launch window every 26 months, so even small schedule changes can cause months-long delays. The spring 2025 launch will include a necessary gravity assist past Venus, which will lengthen the flight time by 1.5 years.

China's mission to snag samples from a near-Earth asteroid

China is preparing for an ambitious mission to scoop up pieces of a near-Earth asteroid, return them to Earth, and then explore a comet in deep space. The Tianwen-2 spacecraft, which is scheduled to launch in May 2025, will rendezvous with 469219 Kamo'oalewa, a quasi-moon of our planet that was discovered in 2016. Ground-based observations suggest that, unlike most near-Earth asteroids, 469219 Kamo'oalewa may have been blasted from the moon's surface by a major impact between 10 million and 1 million years ago, relatively recently in the solar system's history.

Tianwen-2 will carry out remote sensing observations to assess potential landing sites before attempting to collect samples from the space rock. Then, the spacecraft will deliver the extraterrestrial bounty to Earth and use our planet's gravity to fling itself into a seven-year trajectory that will take it to the main-belt comet 311P/PANSTARRS in the mid-2030s.

Juno's potential death swirl into Jupiter

NASA's $1.1 billion Juno spacecraft has been studying Jupiter and its moons since 2016. The mission, which had been extended, will finally end in September 2025 as the spacecraft swirls into the gas giant, unless it survives Jupiter's intense radiation.

According to the mission plan, Juno's orbit will degrade naturally, allowing Jupiter's gravity to pull the probe into the planet's dense clouds. The final hurl, which will last about 5.5 days, will ensure the spacecraft and any Earthly bacteria that may have hitched a ride don't accidentally contaminate Jupiter's ice-crusted moon Europa, which scientists consider one of the best places in our solar system to search for alien life.

Europe's launch of reusable uncrewed robotic laboratory

The European Space Agency's (ESA) Space Rider, an uncrewed robotic laboratory about the size of two minivans, is expected to launch in the third quarter of 2025. The space plane will stay in low Earth orbit for two months, during which the robotic laboratory will automatically conduct technology demonstrations and experiments in microgravity.

At the end of its mission, Space Rider will deorbit and land on a runway at Europe's spaceport in French Guiana and get refurbished for at least five more flights. The space plane is ESA's bid to provide commercial customers with affordable end-to-end launch services, with a broader strategy to help Europe maintain independent, routine access to and from low Earth orbit.

New James Webb Space Telescope (JWST) findings are giving scientists a fresh look at an "oddball" space rock that has features similar to both comets and asteroids.

Astronomers observing the hybrid, known as (2060) Chiron, detected frozen carbon dioxide and carbon monoxide in its icy nucleus, as well as carbon dioxide and methane in the surrounding gas cloud. The findings could help scientists better understand comets and centaurs — so named because they have properties of both asteroids and comets — and could offer a peek at the conditions in the early solar system.

Discovered in 1977, Chiron orbits the sun about once every 50 years, traveling in an oblong loop in the region between Jupiter and Neptune. In the new study, published Dec. 18 in the journal Astronomy and Astrophysics, researchers described their observation of the centaur on July 12, 2023 at a range of more than 18 times the distance from Earth to the sun.

Related: Comets played a 'major' role in making life on Earth possible, new study hints

The team found carbon dioxide and methane gases in Chiron's coma, the cloud of gas and dust around the nucleus. Though previous studies had detected carbon monoxide gas in the coma as well, the new JWST observations found carbon monoxide only in its frozen form on Chiron's surface. The finding suggests a complex scenario of gas emissions from different reservoirs on Chiron, the researchers wrote in the study. In general, carbon monoxide is more volatile, and therefore more likely than CO2 to sublimate, or transform directly from a solid on the surface to a gas released in the coma.

Detecting gas in our solar system

"These results are like nothing we've seen before," study co-author Charles Schambeau, a planetary scientist at the University of Central Florida (UCF), said in a statement. "Detecting gas comae around objects as far away from the sun as Chiron is very challenging, but JWST has made it accessible. These detections enhance our understanding of Chiron's interior composition and how that material produces the unique behaviors as we observe Chiron."

Astronomers also detected water ice and lightweight carbon-containing molecules like ethane and propane for the first time on a centaur. Chiron could have picked up simpler molecules like carbon dioxide and water left by the nebula that formed our solar system, study co-author Noemi Pinilla-Alonso, a planetary scientist at UCF and the University of Oviedo in Spain, said in the statement. Objects like Chiron haven’t changed much since the solar system first formed, she said, so observing how they interact on Chiron could help scientists better understand the early solar system. Molecules like ethane and propane, meanwhile, likely formed when light hit the surface and reacted with the methane and water ice there.

However, fully understanding the compositions of the nucleus and coma, and how they change during Chiron's orbit, will require additional data.

"We're going to follow up with Chiron," Pinilla-Alonso said in the statement. "It will come closer to us, and if we can study it at nearer distances and get better reads on the quantities and nature of the ices, silicates, and organics, we will be able to better understand how seasonal insolation variations and different illumination patterns can affect its behavior and its ice reservoir."

NASA scientists have revealed the secrets of the most volcanic body in our solar system, according to new research. The discovery solves a 44-year-old mystery of why, and how, Jupiter's violent moon, Io, became so volcanically active.

Io is only slightly larger than our moon, with a diameter of 2,237 miles (3,600 kilometers), and has an estimated 400 volcanoes, according to NASA. Plumes from these volcanoes' eruptions can stretch for miles out into space, and can even be seen from Earth when viewed through large telescopes.

This dramatic volcanism was first identified in 1979 by scientist Linda Morabito, then at NASA's Jet Propulsion-Laboratory, in an image taken by NASA's Voyager 1 spacecraft.

"Since Morabito's discovery, planetary scientists have wondered how the volcanoes were fed from the lava underneath the surface," Scott Bolton, principal investigator for NASA's Juno spacecraft from the Southwest Research Institute in San Antonio, said in a statement. "Was there a shallow ocean of white-hot magma fueling the volcanoes, or was their source more localized?"

The Juno spacecraft, which was launched in 2011 to study Jupiter and the moons that orbit it, made two very close flybys of Io in 2023 and 2024, approaching within 930 miles (1,500 km) of its bubbling surface. "We knew data from Juno's two very close flybys could give us some insights on how this tortured moon actually worked," Bolton said.

During these approaches, the spacecraft collected data that allowed scientists to measure Io's gravity.

Related: New thunderstorms wider than Earth are spewing out green lightning on Jupiter — and could make one of the gas giant's massive bands disappear

Io orbits close to Jupiter at an average distance of 262,000 miles (422,000 km), completing its elliptical cycle once every 42.5 hours. Due to the shape of its orbit, the moon's distance from its parent planet varies, and so too does Jupiter's gravitational pull. This means the moon is continuously being squeezed and released like a stress ball in a process known as tidal flexing.

"This constant flexing creates immense energy [in the form of heat,] which literally melts portions of Io's interior," Bolton said.

In the past, it was thought that, because of this flexing, Io's interior might be home to a large magma ocean, stretching beneath its entire surface like a layer of tiramisu. However, research led by Bolton, published Dec. 12 in the journal Nature, suggests that this is not the case.

"If Io has a global magma ocean, we knew the signature of its tidal deformation would be much larger than a more rigid, mostly solid interior," Bolton said.

Instead, the team's data suggested that Jupiter's volcanic moon has a mostly solid interior, with each of Io's volcanoes having their own underground chamber of roiling magma.

"Juno's discovery that tidal forces do not always create global magma oceans does more than prompt us to rethink what we know about Io's interior," study lead author Ryan Park, a Juno co-investigator and supervisor of the Solar System Dynamics Group at NASA's Jet Propulsion Laboratory, said in the statement.

The study findings have implications for Jupiter's moon Europa and Saturn's moon Enceladus, as well exoplanets beyond our solar system. "Our new findings provide an opportunity to rethink what we know about planetary formation and evolution," Park said.

Astronomers analyzing archival images from the James Webb Space Telescope (JWST) have discovered an unexpectedly vast population of the smallest asteroids ever seen in the asteroid belt between Mars and Jupiter. The finding could lead to better tracking of the tiny but powerful space rocks that are likely to approach Earth.

The newfound asteroids range in size from that of a bus to several stadiums — tiny compared to the massive space rock that wiped out most dinosaurs, but they nevertheless pack a significant punch. Only a decade ago an asteroid just tens of meters in size took everyone by surprise when it exploded over Chelyabinsk, Russia, and released 30 times more energy than the atomic bomb detonated over Hiroshima in WWII.

These so-called "decameter" asteroids collide with Earth 10,000 times more frequently than their larger counterparts, but their small size makes it challenging for surveys to detect them well in advance.

In recent years, a team of astronomers including Julien de Wit, an associate professor of planetary science at MIT, has been testing a computationally-intensive method to identify passing asteroids in telescope images of faraway stars.

By applying this method to thousands of JWST images of the host star in about 40 light-years distant TRAPPIST-1 system, which is the best-studied planetary system beyond our own, the researchers found eight previously known and 138 new decameter asteroids in the main asteroid belt. Among them, six appear to have been gravitationally nudged by nearby planets into trajectories that will bring them close to Earth. An early, unedited release of the findings was published Dec. 9 in the journal Nature.

"We thought we would just detect a few new objects, but we detected so many more than expected — especially small ones," de Wit said in a statement. "It is a sign that we are probing a new population regime."

Fresh look at archival data

For the new study, de Wit and his colleagues compiled roughly 93 hours worth of JWST images of the TRAPPIST-1 system in order to enhance faint, fast-moving objects like asteroids above the background noise.

While such an approach rarely works for objects with unknown orbits, the team bypassed the limitation by using powerful graphics processing units (GPUs) to rapidly sift through large datasets, enabling a "fully blind search" across all possible directions to locate the newly-discovered asteroids, and then stacking those images.

Related: 'Spectacular' asteroid blazes over Siberia just hours after it was detected

"This is a totally new, unexplored space we are entering, thanks to modern technologies," study lead author Artem Burdanov, a research scientist in MIT's Earth, Atmospheric, and Planetary Sciences department, said in the statement. "It's a good example of what we can do as a field when we look at the data differently — sometimes there's a big payoff, and this is one of them."

The newfound asteroids, which are remnants of collisions among bigger, kilometer-sized space rocks, are the tiniest yet to be detected in the main asteroid belt. JWST has proven to be ideal for the discovery, researchers say, thanks to the telescope's sharp infrared eyes that detect the asteroids' thermal emissions. These infrared emissions are much brighter than the faint sunlight reflected off the asteroids’ surfaces — the type of visible light that traditional surveys typically rely on.

Upcoming JWST observations will focus on 15 to 20 faraway stars for at least 500 hours, which could lead to the discovery of thousands more decameter asteroids in our solar system, according to the new study.

And newer telescopes will also help uncover thousands of small asteroids in our solar system. Chief among them is the Vera C. Rubin Observatory in Chile — which, starting next year, will use the world's largest digital camera to photograph the southern sky every night for at least a decade, capturing images that each cover an area equivalent to 40 full moons. The high frequency and resolution are expected to detect up to 2.4 million asteroids — nearly double the current catalog — within its first six months.

"We now have a way of spotting these small asteroids when they are much farther away, so we can do more precise orbital tracking, which is key for planetary defense," said Burdanov.

New photos have revealed a pair of gigantic white thunderstorms raging in one of Jupiter's large reddish brown belts. The swirling storms, which are likely spewing giant green lightning bolts through the gas giant's cloudy atmosphere, could end up diluting the belt's rusty color, drastically changing the planet's appearance, experts say.

Astrophotographer Michael Karrer captured the stunning new images on Nov. 30 using an 8-inch Celestron telescope from near his home in Austria. The photos show two large white patches sitting side by side in the gas giant's Southern Equatorial Belt (SEB) — an enormous dark band of clouds that spins around Jupiter as it rotates.

"These [white patches] are giant thunderstorms," John Rogers, an astronomer at the British Astronomical Association who specializes in Jupiter, told Spaceweather.com. "The last time we saw storms like this [on Jupiter] was 8 years ago in 2016-17."

The storms likely extend around 60 miles (100 kilometers) below Jupiter's swirling surface and, although their exact widths have not been calculated yet, both storms "are wide enough to swallow Earth with room to spare," according to Spaceweather.com.

Related: 7 solar system worlds where the weather is crazy

The storms are not large enough to stay intact for long periods, like Jupiter's famous Great Red Spot, and will instead get pulled apart, Rogers explained. As this happens, the thunderstorm’s ghostly hues will mix in with the rest of the SEB’s rusty clouds, "causing the familiar brown belt to fade as its color is diluted by the white storm front," Spaceweather.com reported. If you look closely at the image, you can already see this starting to happen as several thin streams of white trail behind the thunderstorms.

This color-changing has happened before. In fact, the SEB had previously become so diluted by storms that it "disappeared" between 1973 and 1991, and briefly in 2010, according to Astronomy Magazine. However, it's too soon to say whether these new storms will erase the current rust-colored belt.

Thunderstorms on Jupiter are powered by convection, or churning, within clouds similarly to their terrestrial counterparts, and also produce lightning. However, unlike Earth's lightning, which often has a blue hue caused by water vapor, Jovian lightning bolts tend to be green, thanks to atmospheric ammonia, according to NASA.

Jupiter has just passed its closest point to Earth, known as "opposition," making it bright enough to clearly see with the naked eye and a great target for backyard astronomers and photographers like Karrer. The planet reached its closest point to us on Friday (Dec. 6) when Earth is directly between the solar system's largest world and the sun, but will remain clearly visible for the next few weeks.

If you have a decent backyard telescope or a pair of stargazing binoculars then you can get a good look at Jupiter for yourself by searching for it in the Taurus constellation.

As the final full moon of both 2024 and fall, the rise of the Cold Moon will provide a spectacular, if frosty, finale to the celestial calendar.

Officially full at 4:01 a.m. EST this Sunday (Dec. 15), the full moon will be best seen rising in the east later that day at the time of moonrise where you are. It will be in the constellation Taurus, surrounded by some of the night sky's brightest stars and the planet Jupiter.

The moon will also appear bright and full on Saturday (Dec. 14) and Monday (Dec. 16).

Although it can easily be seen with the naked eye, a pair of binoculars or a small beginners' telescope will give you a terrific close-up of the orangey lunar surface as it appears above the eastern horizon.

The Cold Moon is so named because it rises just a week before the December solstice, the longest night of the year in the Northern Hemisphere, which signals the beginning of astronomical winter. It's also known as the Long Nights Moon and the Moon Before Yule, referring to a Pagan festival coinciding with the solstice.

Related: Geminid meteor shower 2024: How to see the year's last big display of 'shooting stars' before it's too late

While the name Cold Moon comes from Mohawk culture, according to the Old Farmer's Almanac, other Native American names include Drift Clearing Moon, Hoar Frost Moon, Snow Moon and Winter Maker Moon. According to Timeanddate, the Cold Moon and Oak Moon are also names from Celtic culture that refer to December's full moon.

Since the moon will be opposite the sun, the moon will mirror the sun's movements. When the sun is at its lowest point in the daytime southern sky, as seen from the Northern Hemisphere, the Cold Moon will be at its highest.

On the night of the full moon, our natural satellite will shine below Capella in the constellation Auriga and above Betelgeuse in the constellation Orion, with Jupiter to its right. The largest planet will be clearly visible all month long in the night sky.

The Cold Moon also rises near the peak of the Geminid meteor shower, one of the year’s most prolific displays of "shooting stars." Unfortunately, the bright moon’s glare will make it harder to spot as many meteors as usual.

The next full moon after the Cold Moon will be the Wolf Moon, which will turn full on Jan. 13, 2025.

This article was updated on Dec. 12 to reflect that the full moon rises this weekend.

On Earth, a compass can be a vital tool. Compasses have provided a constant point of reference for humans for over 800 years, enabling us to successfully navigate to the far reaches of the planet.

But our species has started to journey farther, into the cold abyss of space. Is the compass still useful outside the bounds of our planet: And if so, where would it point?

"A compass in space is going to measure different things [depending on] where exactly in space you are," Jared Espley, a planetary scientist at NASA Goddard Space Flight Center in Maryland, told Live Science. A compass would still technically work in space, but it wouldn't necessarily point you back to Earth. Instead, it would point to the north pole of whatever magnetic field is the strongest, relative to where in space the compass is located.

A compass on Earth responds to our planet's magnetic field. The compass itself is a magnet, and its north pole naturally aligns with the south pole of our planet's own magnetic field. The magnetic field is generated by electric currents flowing through the molten, metallic core of our planet, which spin into an engine called a geodynamo. Earth is the only rocky planet in the solar system with such a strong magnetic field.

Related: What if Earth's magnetic field disappeared?

This magnetic field bubbles out from the planet about 23,000 miles (37,000 kilometers) on the side that faces the sun and trails at least 230,000 miles (370,000 km) behind the planet, according to NASA. This region around a planet dominated by the planet's magnetic field is known as the magnetosphere.

An astronaut who wanted to use a compass to get back to Earth would likely need to be within this magnetosphere for the compass to register the planet's magnetic field. However, the magnetic field isn't a particularly hard boundary. "Even beyond the classical magnetosphere, where you would say it's the Earth's field that is dominant or noticeable, you can still detect things really far away," Espley said.

Evidence from lunar rocks suggest that the moon once had a magnetic field, but the natural satellite's inner core has since slowed and cooled, causing it to lose its geodynamo. And, like the moon, other celestial bodies in our solar system now lack a strong magnetic field. For example, around 3.9 billion years ago, Mars' geodynamo mysteriously slowed down, dramatically weakening its magnetic field, which eventually resulted in the loss of its atmosphere.

But even without these celestial bodies' planetary magnetic fields intact, an astronaut standing on the moon or Mars would still pick up some magnetic signals. This is the crustal magnetic field, Espley said — rocks on the outer crust that still hold evidence of the planet's old geodynamo.

Of all the planets in the solar system, a compass is most likely to point toward Jupiter. This is because Jupiter's magnetosphere is massive. According to NASA, Jupiter's magnetosphere is the largest structure in the solar system, at 12 million miles (21 million km) wide. This giant magnetosphere is generated by the planet's metallic hydrogen core and is currently being studied by the Juno spacecraft to better understand how magnetic fields are created.

But what if an astronaut isn't within a planet's magnetosphere? Most of space is seemingly empty. But within our solar system, one magnetosphere dwarfs all others: that of the sun.

"If you're in this stereotypical deep space vacuum in between the planets, [a compass] is mostly going to measure what magnetic field is coming from the solar wind," Espley said.

The sun's magnetosphere, known as the heliosphere, spirals out from the star and extends three times farther out than Pluto. This is because the sun's solar wind carries its own faint magnetic field as it blasts out into the solar system, according to the National Magnetic Field Laboratory.

The magnetic field directly on the sun is also rather messy, which can be seen in images of the sun's coronal loops. These arches of plasma follow the sun's magnetic field lines, which grow larger and more complex as the sun reaches its solar maximum, the peak period in its activity. It's so complex that the true north and south of the star begin to get a little bit blurry, and eventually swap places, according to Space.com.

Ultimately, a traditional compass that relies on an "up" and "down" to calibrate it would be rather pointless in space as a navigational tool. There are a few commercially available "3D" compasses that could theoretically point you toward magnetic north in space. However, they still wouldn't necessarily point you back to Earth — only to whichever magnetic field is closest.

However, highly powerful compasses called magnetometers are useful in space, just not for navigation. NASA uses these instruments to understand more about plasma interactions in space and to pick up ancient signs of geodynamos that died billions of years ago. "Measuring the magnetic field is super useful for understanding what is going on inside of a planet," Espley said.

On Oct. 14, NASA's Europa Clipper mission launched from Kennedy Space Center in Florida toward one of Jupiter's largest moons. The launch was eagerly anticipated by scientists around the world, in part because Europa, with its plumes of liquid water and icy crust, is thought to be one of the best places in the solar system to search for life beyond Earth.

But Europa isn't Jupiter's only moon — far from it. Officially, Jupiter has 101 moons recognized by the International Astronomical Union. But the question of how many natural satellites the planet truly has is a bit more complicated.

Jupiter's four best-known moons are the Galilean moons, discovered by Galileo Galilei in 1610. They are named Ganymede, Callisto, Io and Europa, after figures in Greek mythology associated with the god Zeus. ("Jupiter" is the ancient Roman name for Zeus.) These moons are big — each is roughly the size of Earth's moon or larger, and together, they make up around 99.97% of the mass of all the material orbiting the gas giant. Due to their size and the presence of geologic processes like volcanism, these moons produce and maintain their own thin atmospheres.

Related: NASA reveals 'glass-smooth lake of cooling lava' on surface of Jupiter's moon Io

Each of Jupiter's other nearly 100 official moons has a diameter greater than 0.6 mile (1 kilometer) — but only 57 have names, and just eight have regular, nearly round orbits. However, they are "generally too small to hold onto any [atmospheric] vapor," Statia Cook, an astronomer at New York University, told Live Science in an email.

In addition to Jupiter's certified moons, thousands of smaller "moonlets" — most of which are captured asteroids and chunks of debris — circle the planet.

Jupiter isn't the only planet in the solar system with myriad moons. For decades, it has vied with its neighboring gas giant Saturn over which has the most natural satellites.

How many moons does Saturn have?

Saturn's eight largest moons were discovered between 1671 and 1848 by several astronomers. For much of the 20th century, the moon counts for Jupiter and Saturn remained relatively stable at 12 and eight, respectively. But in 1979, NASA's Voyager probes uncovered two previously unknown Jovian moons and added three moons to Saturn's repertoire.

These discoveries hinted that both planets might have more in their orbits, kicking off more than 40 years of moon hunting. Between 2018 and 2023, the leader flip-flopped several times. For now, though, Saturn holds the title for the most moons, with a whopping 146.

Saturn's biggest moon by far is Titan, with almost twice the mass of Earth's moon. "Titan is really special — it has clouds and rain, rivers and lakes — but made of hydrocarbons like methane instead of water," Cook said. Currently, it's one of the best candidates for extraterrestrial life in the solar system, alongside Europa.

Future research will tell whether moons like Titan and Europa harbor the necessary ingredients for life. Europa Clipper will begin investigating its moon in 2030, and NASA's Dragonfly probe is scheduled to launch in 2028 and arrive at Titan in 2034. They represent "an exciting step forward in our mission to investigate whether the conditions for life could exist beyond Earth, right here in our own solar system," Cook said.

NASA has successfully launched the Europa Clipper, the agency's biggest-ever interplanetary spacecraft, into space and it's now headed for Jupiter's frozen moon Europa.

"Congratulations to our Europa Clipper team for beginning the first journey to an ocean world beyond Earth," NASA Administrator Bill Nelson said in a statement.

The craft took off Oct. 14 on top of a SpaceX Falcon Heavy rocket from NASA's Kennedy Space Center in Florida. It was originally slated to launch Oct. 10, but the mission was pushed back because of Hurricane Milton, which smashed into Florida Oct. 9.

When the Europa Clipper arrives in 2030, the orbiter will study the frozen moon's hidden ocean, which is locked beneath an icy shell, to determine how habitable the ocean is and whether it could potentially support life.

Related: Jupiter's moon Europa lacks oxygen, making it less hospitable for sustaining life

How big is the Europa Clipper?

Once it spreads its solar arrays, the orbiter will measure around 100 feet (30 meters) wide — bigger than a basketball court. It is about 16 feet (5 m) high, according to NASA. The giant arrays are needed to collect solar energy to power the craft when it arrives at Europa, which is about 470 million miles (760 million kilometers) from the sun.

How long will it take the Europa Clipper to reach Jupiter?

The craft will take 5.5 years and travel 1.8 billion miles (2.9 billion km) to Jupiter's fourth-largest moon, according to NASA's Jet Propulsion Laboratory (JPL). It will swing close to Mars for a "gravity assist" in February 2025, before heading back to Earth to slingshot around our planet in December 2025 to make its way to Jupiter. It will reach the colossal planet and its moons in June 2030.

Once there, the orbiter will perform flybys around several of Jupiter's moons, before making its first pass of Europa in spring 2031. In total, the craft will perform 49 flybys of Europa.

What is the purpose of Europa Clipper?

Europa Clipper's mission is to peer beneath Europa's frozen surface to look for key signs of habitable conditions. These are water, organics — essential chemical building blocks — chemical energy sources under the surface, and signs of stable conditions, according to NASA.

Scientists believe that Europa has a vast saltwater ocean that holds twice as much water as Earth's oceans — even though the moon is just one-quarter the size of our planet. Because of this water, scientists consider Europa one of the likeliest places in the solar system to find habitable conditions. Scientists still aren't sure how thick the icy shell is, so one of Europa's main scientific aims is to determine this and work out the composition of the ice and the vast ocean beneath it, according to NASA.

The findings could give scientists clues about where to spot potential life across the universe.

"By exploring the unknown, Europa Clipper will help us better understand whether there is the potential for life not just within our solar system, but among the billions of moons and planets beyond our Sun," Nelson noted.

However, Europa Clipper will not look directly for signs of alien life in the moon's ocean.

How much does Europa Clipper cost?

Europa Clipper cost about $3.8 billion to make and launch, and it will cost another $1.2 billion to operate until it completes its core mission in 2034, according to the Planetary Society. The spacecraft is carrying a collection of advanced equipment, which accounts for some of this cost. The nine instruments include an array of cameras to view the moon in visible light and infrared; a spectrometer and spectrograph to reveal Europa's composition; instruments to monitor gravity, magnetic fields and plasma; radar to peer beneath the surface; and instruments to perform chemical analysis.

The instruments are encased in a vault lined with aluminum and titanium to protect them from the extremely high levels of radiation around Jupiter, according to NASA. These radiation levels are the second-highest in the entire solar system — second only to the sun, according to JPL.

Will Europa clipper land on Europa?

The spacecraft will not land on Europa. Instead, it will stay in an elliptical orbit around Jupiter, which will help it survive the radiation levels that exist closer to Jupiter and Europa. At the end of its life, Europa Clipper will likely "deorbit," meaning deliberately crash, into the surface of Ganymede — Jupiter's and the solar system's largest moon.

The venerable Hubble Space Telescope has watched Jupiter's Great Red Spot (GRS) oscillating, as though it were being squeezed in and out roughly every 90 days.

Why this huge anticyclone, which has been shrinking over the decades and currently measures about 9,165 miles (14,750 kilometers) across (although astrophotographer Damian Peach has reportedly measured it to be just 7,770 miles, or 12,500 km, wide), is behaving in such fashion is a mystery.

"With Hubble's high resolution, we can say that the GRS is definitely squeezing in and out at the same time as it moves faster and slower," said Amy Simon, of NASA's Goddard Space Flight Center in Maryland, in a statement. "This was very unexpected, and at present there are no hydrodynamic explanations."

Astronomers led by Simon used Hubble to observe the Great Red Spot for 88.5 days between December 2023 and March 2024. A timelapse of images taken during that period shows that the GRS periodically expands and shrinks along its semi-major axis (the widest part of an ellipse).

"While we know its motion varies slightly in longitude, we didn't expect to see the size oscillate as well," said Simon.

Related: Jupiter's Great Red Spot is 40 times deeper than Mariana Trench

Located 22 degrees south of Jupiter's equator, positioned on the edge of the Jovian atmosphere's South Equatorial Belt, the GRS is buffeted from above and below by mighty jet streams that whip around the giant planet at 266 mph 428 kph. The jet streams stop the huge vortex from wandering into other latitudes, although it is seen to drift westward with respect to the rest of the atmosphere. This drift isn't constant, but it has been measured to accelerate and decelerate over an approximately 90-day oscillation.

"As it accelerates and decelerates, the GRS is pushing against the windy jet streams to the north and south of it," said Mike Wong of the University of California, Berkeley.

Seemingly connected to this approximately 90-day oscillation in its westward drift is the squeezing of the GRS' shape seen by Hubble.

"It's similar to a sandwich where the slices of bread are forced to bulge out when there's too much filling in the middle," said Wong.

The degree of squeezing seems to be anti-correlated with the rate at which the GRS is drifting. During the periods when the GRS' drift has decelerated, the width of the vortex and the size of its core are at their greatest. The core also shines brighter in ultraviolet light when it is at its largest, indicative of there being less haze absorption in the atmosphere above it. When the drift accelerates, the width of the GRS and the size of its core contracts. This may be the result of the GRS interacting with the surrounding atmosphere when its drift rate speeds up.

So far, only one oscillatory period has been observed in full by Hubble. Simon leads the Outer Planet Atmospheres Legacy (OPAL) program, which uses Hubble to image each of the four giant planets in the outer solar system — Jupiter, Saturn, Uranus and Neptune — at least once per year. However, Hubble's studies of the GRS were a separate project in addition to that.

A group of top amateur astronomers, such as Damian Peach, also routinely image Jupiter in high resolution, and their data is so good that Simon and the OPAL team often work with them. It's possible that this squeezing of the spot is evident in amateur images, although Simon thinks it might be slightly too subtle for amateur data to have captured it with any reliability, with the width of the spot varying by just 0.3 degrees in longitude over a two-week period. Nevertheless, now that we know it is occurring, amateurs may be able to finesse their image capture in order to spot it.

Simon also wants to take another look at the GRS with the James Webb Space Telescope, which previously imaged the Jovian storm in near-infrared light earlier this year and found atmospheric waves above the GRS. By being able to probe deeper into the GRS at longer mid-infrared wavelengths, Simon hopes to see whether wind velocities within the storm are also changing in time with the oscillations.

The overall shrinking of the GRS, now coupled with the oscillatory squeezing, mean that the storm is undergoing some interesting changes. Where will it end?

"Right now, it's over-filling its latitude band relative to the wind field," said Simon. "Once it shrinks inside that band, the winds will really be holding it in place." When this happens, it may stabilize in size, but for now that remains speculation until more data can be gathered.

The discovery was reported on Oct. 9 in a paper published in The Planetary Science Journal.

Originally posted on Space.com.

In the coming weeks, NASA will launch a hotly anticipated new mission to Jupiter's fourth-largest moon, Europa.

Called Europa Clipper, the spacecraft will conduct a detailed study of the moon, looking for potential places where Europa might host alien life. (The launch window for the mission begins Oct. 10, but the launch has been temporarily postponed due to the impending landfall of Hurricane Milton.)

Europa Clipper is the largest planetary exploration spacecraft NASA has ever made: as wide as a basketball court when its solar sails are unfolded. It has a mass of about 6,000 kilograms — the weight of a large African elephant.

But why are we sending a hulking spacecraft all the way to Europa?

Looking for life away from Earth

The search for life in places other than Earth usually focuses on our neighbour Mars, a planet that's technically in the "habitable zone" of our Solar System. But Mars is not an attractive place to live, due to its lack of atmosphere and high levels of radiation. However, it's close to Earth, making it relatively easy to send missions to explore it.

But there are other places in the Solar System that could support life — some of the moons of Jupiter and Saturn. Why? They have liquid water.

Here on Earth, water is the solvent of life: water dissolves salts and sugars, and facilitates the chemical reactions needed for life on Earth to proceed. It's possible life forms exist elsewhere that rely on liquid methane or carbon dioxide or something else, but life as we know it uses water.

The reason there's liquid water so far out in the Solar System is because Jupiter and Saturn, the gas giants, wield immense gravitational power over their moons.

Saturn's moons, Titan and Enceladus, are stretched and compressed by gravity as they go around their host planet. This movement results in vast underground oceans with a surface of solid ice, with plumes of water vapour exploding 9,600 kilometres from the surface.

It is strongly suspected that Europa is the same. While we know a lot about Europa from more than four centuries of observation, we have not confirmed it has an under-ice liquid ocean like Titan and Enceladus.

Related: Jupiter's moon Europa lacks oxygen, making it less hospitable for sustaining life

But all clues point to yes. Europa has a smooth surface despite being hit by many meteors, suggesting the surface is young, recently replaced. Ice volcanoes raining down water over the surface would make sense.

It also has a magnetic field, suggesting that like Earth, Europa has a liquid layer inside (on Earth, this liquid is molten rock).

What will Europa Clipper do?

At the surface, Europa is bombarded by high levels of space radiation, concentrated by Jupiter. But deeper down, the thick ice sheet could be protecting life in the liquid subsurface ocean.

This means it would be difficult for us to find concrete evidence for life without drilling down deep. But where to look? Through flybys of the icy moon, Europa Clipper will be looking at areas where life could be dwelling under the icy shell.

To achieve this, Europa Clipper has nine scientific instruments. These include a wide-angle camera to study geologic activity and a thermal imaging system to measure surface texture and detect warmer regions on the surface.

There's also a spectrometer for looking at the chemical composition of the gases and surface of Europa, and for any explosive plumes of water from the surface. The mission also has tools for mapping the moon's surface.

Other instruments will measure the depth and salt levels of the moon's ocean and the thickness of its ice shell, and also how Europa flexes within the strong gravitational pull of Jupiter.

Excitingly, a mass spectrometer will analyze the gases of the moon's faint atmosphere and potential plumes of water. By examining the material ejected from the plumes, we can understand what is hidden within the under-ice oceans of Europa.

A dust analyser will also look at matter that has been ejected from Europa's surface by tiny meteorites or released from the plumes.

Unfortunately, we will have to wait a while for any discoveries. Europa Clipper will take more than five years to reach Jupiter. And the mission is only equipped to look for the potential of life, not life itself. If we see evidence that might point towards life, we will need future missions to return and explore Europa in depth.

So we must be patient. But this is an exciting opportunity for humanity to get one step closer to find life beyond our own home planet.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

Around 4 billion years ago, an enormous asteroid that was at least 10 times larger than the space rock that wiped out the dinosaurs smashed into Jupiter's massive icy moon, Ganymede. The cataclysmic collision was so devastating it created the largest impact crater in the solar system and knocked the supersized satellite off its axis, new simulations show.

Ganymede is Jupiter's third-closest major moon, orbiting the gas giant roughly once every seven days. It has a diameter of 3,270 miles (5,260 kilometers), according to NASA, making it the most massive of the solar system's many moons and larger than the planet Mercury. Just like Earth's moon, Ganymede is tidally locked, meaning the same side constantly faces Jupiter's swirling, storm-covered surface. Researchers believe the moon has a roughly 60-mile-deep (100 km) ocean hidden far below its icy surface.

In the 1980s, researchers discovered that large parts of the moon's surface were covered with concentric rings of narrow trenches, or furrows, surrounding the remains of what looked like a large impact crater on Ganymede's far side (the side facing away from Jupiter). Photos from subsequent visiting spacecraft, such as NASA's New Horizons probe, revealed the moon's scarred surface is the likely result of a massive asteroid collision that occurred around 600 million years after the solar system formed.

In the new study, published Sept. 3 in the journal Scientific Reports, researcher Naoyuki Hirata — an astronomer and planetary scientist at Kobe University in Japan — reconstructed Ganymede's ancient asteroid impact using computer simulations based on the moon's furrows. This enabled Hirata to precisely calculate the size of the rock that smashed into Ganymede for the first time. The simulations also showed how the impact likely knocked the moon off its original axis.

Related: The 10 weirdest moons in the solar system

Hirata estimated that the initial impact crater was up to 1,000 miles (1,600 km) wide, making it 10 times wider than Earth's largest impact structure — the Vredefort Crater in South Africa. This means Ganymede's crater was the largest known impact crater in the solar system's history. However, it did not remain this size for long as debris from the event quickly fell back to the moon's surface and filled in most of the hole, Hirata wrote.

Based on the size of the crater, Hirata estimates the asteroid responsible for birthing it would have been around 93 miles (150 kilometers wide) — or about as long as the state of Delaware. That would make it somewhere between 10 and 15 times larger than the Chicxulub meteor, which slammed into what is now Mexico around 66 million years ago and wiped out up to 80% of animal species on Earth, including all non-avian dinosaurs.

Some media outlets have quoted a Kobe University news release reporting that the asteroid was up to 20 times larger than the Chicxulub meteor. However, this does not align with the numbers shared in the new study.

The simulations also revealed how the impact shifted Ganymede's tidal axis away from its rotational axis, making it tilt relative to Juptier. Earth's polar axis was tilted in a similar way around 4.5 billion years ago when a Mars-size protoplanet, named Theia, smashed into our planet and created the moon. This is why we have different seasons throughout the year.

Interestingly, the simulations showed that regardless of where the asteroid struck Ganymede's surface, the impact crater would always end up in the same spot on the moon's far side from Jupiter thanks to the gravitational effects of the debris ejected into space by the collision.

The new findings help fill in details about an important chapter in Ganymede's history. However, they also raise new questions about how this impact altered the evolution of the Jovian moon and its insides — especially its supposed subsurface ocean.

"The giant impact must have had a significant impact on the early evolution of Ganymede, but the thermal and structural effects of the impact on the interior of Ganymede have not yet been investigated at all," Hirata said in a statement. Further research is needed to address this, he added.

The answers to Hirata's questions could come in 2034 when the European Space Agency's Jupiter Icy Moons Explorer (JUICE) probe is due to carry out a close flyby of Ganymede. The state-of-the-art probe was launched in April 2023 and completed the first of three planned slingshot maneuvers around the Earth-moon system on Aug. 21. The spacecraft will arrive at Jupiter in 2031.

In the early hours of Wednesday morning (Aug. 14), two of the solar system's brightest and most famous planets will appear to pass exceptionally close to each other. In this rare conjunction of Jupiter and Mars,  the two planets will lie a mere third of a degree apart in the night sky. 

A planetary conjunction describes when two or more planets appear to be close to each other. This conjunction will be best seen from around 2:00 a.m. local time until dawn on Wednesday. During that time, the two planets will rise in the northeastern night sky with the constellation Taurus, and move about 50 degrees above the eastern horizon by daybreak.

Although Jupiter will be about 20 times brighter than Mars, both planets will be easily visible to the naked eye from anywhere in the world with clear skies. However, a good pair of stargazing binoculars or a small telescope will enhance the view. Not only will you see the planets more clearly with such optical aids, but the four largest moons of Jupiter will also be visible. Ganymede and Callisto will flank Jupiter, with the highly volcanic moon Io and potentially habitable Europa between Jupiter and Ganymede. Mars will appear slightly above Jupiter and its moons. 

If you can't catch the conjunction in person, the Virtual Telescope Project, based in Italy, will host a livestream of the entire celestial event as it becomes visible over Europe. The stream begins at 10:30 p.m. ET tonight (Tuesday, Aug. 13). You can catch it on YouTube, or in the embedded video below.

Although the planets will appear to be very close together during this conjunction, that is merely an optical illusion. In reality, Mars is in the foreground and Jupiter is 300 million miles (500 million km) further away, according to EarthSky. 

Related: The Perseid meteor shower is about to peak. Here's when to see the most 'shooting stars'.

This planetary conjunction is the last of the year. The next one will take place on Jan. 20, 2025, when Venus and Saturn will cross paths. However, the next planetary highlight for skywatchers will be the annual opposition of Saturn. 

On Sept. 7, Earth will be precisely between the sun and Saturn, with the ringed planet at its apparent biggest, brightest and best of the year. Any telescope will enable you to see its unique ring pattern.

Editor's note: This story was updated on Aug. 13 with information about the Virtual Telescope Project stream.

Vivid clouds swirl across Jupiter's skies like colorful brushstrokes across a painting in a new photo from NASA's Juno spacecraft. 

The image, taken during the spacecraft's 61st close flyby of Jupiter on May 12, 2024, hones in on activity in the planet's northern hemisphere. Juno was approximately 18,000 miles (29,000 kilometers) above Jupiter's cloud tops when it captured this new view, highlighting the planet's persistent storms and colorful bands created by strong winds in its atmosphere. 

"It provides a detailed view of chaotic clouds and cyclonic storms in an area known to scientists as a folded filamentary region," NASA officials said in a July 19 statement accompanying the photo. "In these regions, the zonal jets that create the familiar banded patterns in Jupiter's clouds break down, leading to turbulent patterns and cloud structures that rapidly evolve over the course of only a few days."

The raw image data was captured using the spacecraft's JunoCam instrument, which is a visible-light camera. 

This new image was made by citizen scientist Gary Eason, who applied digital processing techniques to enhance the color and clarity of the clouds tangled up in Jupiter's atmosphere, NASA officials said.

Related: NASA's Juno probe reveals 'fire-breathing' lava lakes across Jupiter's volcanic moon Io

At a latitude of about 68 degrees north of the equator, this folded filamentary region exhibits characteristic billowing white clouds created by convective outbursts that quickly turn into thinner, elongated filamentary structures. This type of region, commonly seen near Jupiter's poles, is known to be incredibly turbulent and variable due to powerful jet streams, created in part by the planet's rapid rotation.  

All of the raw images captured by JunoCam are available to the public for processing, allowing citizen scientists to create stunning views of the gas giant. 

NASA's Juno mission might have originally been all about Jupiter, but its extended mission has the spacecraft observing the gas giant's moons — and it's making some pretty interesting discoveries. Its latest find? The Jovian moon Io is covered in "fire-breathing" lava lakes.

Using its Jovian Infrared Auroral Mapper (JIRAM) instrument, a project by the Italian Space Agency originally used to peer beneath Jupiter's thick clouds, Juno has captured infrared images of these lakes peppered across Io's surface, which show hot rings of lava surrounding a cooler crust. In the images, the rings are bright white with a thermal signature between 450 and 1,350 degrees Fahrenheit (232 and 732 degrees Celsius). The rest of the lake is much cooler, measuring at some minus 45 degrees Fahrenheit (minus 43 degrees Celsius). 

"We now have an idea of what is the most frequent type of volcanism on Io: enormous lakes of lava where magma goes up and down," Alessandro Mura, a Juno co-investigator from the National Institute for Astrophysics in Rome, said in a statement. "The lava crust is forced to break against the walls of the lake, forming the typical lava ring seen in Hawaiian lava lakes."

The leading hypothesis is that magma undergoes upwelling in these lava lakes, causing the lakes to rise and fall. When the crust touches the lake's walls — which can be hundreds of meters tall — the friction causes it to break, exposing the lava along the edge of the lake.

RELATED: NASA reveals 'glass-smooth lake of cooling lava' on surface of Jupiter's moon Io

A secondary hypothesis suggests that magma wells up in the middle of the lake, pushing the crust outward until it sinks along the edge of the lake, again exposing the lava and forming those lava rings.

Researchers still have much to study on Io, particularly when it comes to Juno's infrared imagery. "We are just starting to wade into the JIRAM results from the close flybys of Io in December 2023 and February 2024," Scott Bolton, principal investigator for Juno at the Southwest Research Institute in San Antonio, said in the statement. "Combining these new results with Juno’s longer-term campaign to monitor and map the volcanoes on Io’s never-before-seen north and south poles, JIRAM is turning out to be one of the most valuable tools to learn how this tortured world works."

Originally posted on Space.com.

Low-temperature hydrothermal vents could survive on the dark ocean floors of moons like Jupiter's Europa for potentially billions of years, new computer simulations have shown, as astrobiologists strive to figure out whether these alien oceans could be habitable.

Hydrothermal vents are both a source of chemical energy and heat, and are one of the possible locations for the origin of life on Earth. Planetary scientists have theorized that hydrothermal vents at the bottom of the oceans beneath the ice on moons of Jupiter like Europa and Ganymede, and the Saturn satellite Enceladus, could help warm those oceans and kickstart the biochemistry of life.

The problem is that modeling of these vents has focused on the extremely high-temperature ones — the "black smokers" powered by volcanic activity. While these super-hot vents can siphon energy from Earth's hot core, the icy moons do not have hot cores, meaning there's been a question mark over whether such vents could survive long enough to create the long-term conditions for life. 

However, super-hot vents are not the dominant form of venting in Earth's oceans. On Earth, a much larger volume of water passes through lower-temperature vents.

"The flow of water through low-temperature venting is equivalent, in terms of the amount of water being discharged, to all the rivers and streams on Earth, and is responsible for about a quarter of Earth's heat loss," said Andrew Fisher of the University of California, Santa Cruz (UCSC), in a statement. "The entire volume of the ocean is pumped in and out of the seafloor about every half-million years."

Fisher led a team from UCSC that modeled the proliferation of such low-temperature vents on Europa and Enceladus. Given the absence of data about the oceans on these moons, Fisher's team based their simulations on the circulation system in the northwestern Pacific Ocean, specifically the eastern flank of the Juan de Fuca Ridge, where cool seawater sinks and flows down into the rock in the seabed via extinct volcanic cavities called seamounts. The water travels through the rock for about 30 miles (50 kilometers), being heated in the process, before rising up through another seamount. 

"The water gathers heat as it flows and comes out warmer than when it flowed in, and with very different chemistry," said study team member Kristin Dickerson, also of UCSC.

Related: 'Space potato' spotted by NASA Mars satellite is actually something much cooler

Applying this circulation model to Europa and Enceladus, the researchers altered properties such as gravity, temperature, the composition of the bedrock and how deep the water circulates, to better fit potential conditions on the ocean moons. 

They found that not only could moderately warm vents be maintained over a wide range of conditions on these moons, but that the low gravity allowed for warmer temperatures emanating from the vents. In addition, the low efficiency of heat extraction from the core of the moons (which are thought to be pretty cool in the first place) in the low gravity would allow such moderate- to low-temperature vents to be maintained for possibly billions of years.

"This study suggests that low-temperature — not too hot for life — hydrothermal systems could have been sustained on ocean worlds beyond Earth over timescales comparable to that required for life to take hold on Earth," said Fisher.

The research was published on June 24 in the Journal of Geophysical Research: Planets.

Originally posted on Space.com.

Using the James Webb Space Telescope (JWST), astronomers have found previously unseen structures and activity in Jupiter's atmosphere above the Great Red Spot. These odd features seem to be caused by powerful atmospheric gravity waves.

The Great Red Spot is the largest storm in the solar system, twice as big as Earth, and is believed to have been raging for at least 300 years, according to NASA. The winds of the Great Red Spot rage at around 270 to 425 miles per hour (430 to 680 kilometers per hour), up to 3.5 times as fast as a tornado here on Earth. 

Yet, despite the storm's age, size, and power, scientists had actually suspected that the atmosphere of Jupiter above the Great Red Spot wasn't all that interesting. However, these new observations delivered by the JWST's Near InfraRed Spectrograph (NIRSpec) instrument, which observed the massive scarlet storm in July 2022, show that this assumption couldn't have been more wrong.

Related: Is Jupiter's Great Red Spot an impostor? Giant storm may not be the original one discovered 350 years ago

"We thought this region, perhaps naively, would be really boring," team leader Henrik Melin of the University of Leicester said in a statement. "It is, in fact, just as interesting as the northern lights, if not more so. Jupiter never ceases to surprise."

What secrets has the Great Red Spot been hiding?

Jupiter's upper atmosphere is the point at which the planet's lower atmosphere meets its magnetic field. This leads to bright northern and southern lights, powered by bombardment by charged particles from the sun and fueled by sprays of volcanic material erupting from the Jovian moon Io, the most active volcanic body in the solar system.

Jupiter may be one of the brightest objects in the night sky over Earth, easily seen in clear skies. Yet, apart from its northern and southern lights, the atmosphere of the solar system's largest planet only glows weakly, making it difficult for ground-based telescopes to see in detail through Earth's atmosphere. 

From the JWST's position a million miles away from Earth, our planet's atmosphere is no hindrance to this $10 billion space telescope. In addition to this, the JWST's sensitivity in the infrared spectrum allows it to see the gas giant's atmosphere in intricate detail, including the region over the Great Red Spot.

Aiming to discover if this region is a bit dull, Melin and colleagues targeted it with NIRSpec, the main instrument of the JWST. This led to the discovery of a variety of intricate structures across the JWST's field of view, including dark arcs and bright spots.

Though incident sunlight is responsible for the majority of the light seen from Jupiter's atmosphere, the team thinks there must be another that is giving rise to changes in the shape and structure of the upper Jovian atmosphere.

"One way in which you can change this structure is by gravity waves - similar to waves crashing on a beach, creating ripples in the sand," Melin explained. "These waves are generated deep in the turbulent lower atmosphere, all around the Great Red Spot, and they can travel up in altitude, changing the structure and emissions of the upper atmosphere."

These gravity waves are very different from gravitational waves, the latter of which are tiny ripples in space and time predicted by Albert Einstein in his 1915 theory of general relativity. Gravity waves propagate through an atmosphere, as opposed to the fabric of spacetime as gravitational waves do. 

These atmospheric gravity waves are also seen on Earth occasionally, but these Earthbound waves are much less intense and powerful than the same phenomenon occurring over Jupiter.

The team now hopes to follow up on the detection of these newly found Great Red Spot features and the intricate wave patterns underlying them with the JWST. This future investigation could reveal how the waves flow through the gas giant's upper atmosphere and how this causes the observed structures to move. 

The findings are expected to help better understand the distribution of energy across Jupiter and could help support the European Space Agency (ESA) mission Jupiter Icy Moons Explorer (JUICE).

JUICE launched on 14 April 2023 and will reach Jupiter and its moons in 2031 when it makes detailed observations of Jupiter and its three large ocean moons, Ganymede, Callisto, and Europa.

The team's results are published in the journal Nature Astronomy. 

Originally posted on Space.com.

NASA has posted a stunning photo of a "space potato" on social media — but it is actually Phobos, the Martian moon that is locked on a slow collision course with the Red Planet.

The space agency imaged the lumpy, starchy-looking moon using the High Resolution Imaging Science Experiment (HiRISE) camera on board NASA's Mars Reconnaissance Orbiter, which has been studying the Red Planet since arriving in its orbit in 2006.

Phobos, named after the Greek god of fear, is roughly 157 times smaller than Earth's moon and is one of Mars' two natural satellites, alongside the even smaller Deimos, whose name comes from the Greek god of dread. 

Scientists believe that the brother moons were once roaming rocks and were snared into Mars' orbit by the planet's gravitational field. A recent image analysis of Phobos' craggy yet highly reflective surface suggested the moon was once a comet and came from the asteroid belt located between the Red Planet and Jupiter.

Related: Hundreds of black 'spiders' spotted in mysterious 'Inca City' on Mars in new satellite photos

The two moons' orbits are unstable, and scientists predict that in tens of millions of years Deimos will spin out into space while Phobos will either break up into a ring or slam into the Martian surface.

However, with Phobos drifting only 6 feet (1.8 meters) closer to Mars every hundred years, our solar system's space potato is unlikely to be mashed for another 50 million years, according to NASA.

That leaves us with plenty of time to study and admire the starchy celestial body, whose characteristic features include streaks of white ice and the Stickney Crater — a 6-mile (10 kilometers) indent named after Chloe Angeline Stickney Hall, the mathematician and wife of the two moons' discoverer Asaph Hall, who first oberved them in 1877.

In 1665, Italian astronomer Giovanni Cassini observed a giant dark spot on Jupiter, which he called the "Permanent Spot." (English scientist Robert Hooke might've discovered it a year earlier, in 1664, but I digress.) Though astronomers mysteriously lost track of the spot for centuries, we've always thought that the original "Permanent Spot" might be the Great Red Spot — a massive storm on Jupiter's surface — we know and love today.

Well, we were wrong. A new study of the Great Red Spot suggests it most likely is a newer, younger storm.

After the "Permanent Spot" was first observed in the 17th century, we lost track of it. The last observation of that spot was in 1713. More than a century would pass before we caught sight of a new spot — one that happened to be on the same latitude as the original. This spot, discovered in 1831, is the Great Red Spot of today.

"From the measurements of sizes and movements, we deduced that it is highly unlikely that the current Great Red Spot was the ‘Permanent Spot’ observed by Cassini," Agustín Sánchez-Lavega, a planetary scientist at the University of the Basque Country in Bilbao, Spain, who led the research, said in a statement. "The 'Permanent Spot' probably disappeared sometime between the mid-18th and 19th centuries, in which case we can now say that the longevity of the Red Spot exceeds 190 years."

Related: Uranus and Neptune aren't made of what we thought, new study hints

Using data concerning the Great Red Spot's changes over time, Sánchez-Lavega and his colleagues ran computer simulations to establish how the vortex might've formed. The leading theory is wind instability which ultimately produced the "elongated atmospheric cell" we see today.

What we do know for sure about the Great Red Spot is that it's shrinking. An 1879 observation placed the size of the spot at 24,200 miles (39,000 kilometers) along its longest axis. But now, it currently spans 8,700 miles (4,000 kilometers) on its longest axis. The team will conduct further simulations to predict whether or not the Great Spot will eventually disappear like Cassini's Permanent Spot — and perhaps be reborn some centuries later as a new vortex.

The team's research was published on June 16 in the journal Geophysical Research Letters.

Originally posted on Space.com.