Europa, a moon of Jupiter, has long been one of the most exciting targets in the search for life beyond Earth. Many scientists believe that an ocean lies below its icy surface, potentially hosting geologic activity capable of supporting life, but what happens on the moon’s seafloor is still largely a mystery. Although discussions on Europa are mostly centered around this hidden ocean, the shell of ice that envelops the moon has its own surprises. A study recently published in The Planetary Science Journal suggests that Europa’s surface ice is constantly changing. The evidence explored in the study paints a better picture of Europa’s outermost layer, and it may even reveal the interior processes that shape the moon’s unique structure. Europa's Surface IceEuropa has the smoothest surface out of any known object in our Solar System, but it’s far from lacking variety. The surface is rife with distinct geologic features, such as ridges, plains, and cracks, that cross over each other. Their disorderly appearance is linked to a fitting name, “chaos terrain.”Some regions with chaos terrain also provide insight on Europa’s surface ice. Most of Europa’s surface is made of amorphous ice, which lacks a crystalline structure. Scientists previously believed that Europa’s surface was entirely covered by a thin layer of amorphous ice, and that below this was crystalline ice (the form that most ice on Earth takes). However, the researchers involved with the new study have confirmed that certain areas of Europa’s surface contain crystalline ice, aligning with spectral data captured by the James Webb Space Telescope (JWST). This same ice also appears below the surface in these regions as well. “We think that the surface is fairly porous and warm enough in some areas to allow the ice to recrystallize rapidly,” said lead author Richard Cartwright, a spectroscopist at Johns Hopkins University, in a statement.Activity in the OceanA few other factors have convinced the researchers that an ocean exists below Europa's icy surface. The regions where ice recrystallizes show evidence of sodium chloride (what we know as table salt), carbon dioxide, and hydrogen peroxide. “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 author Ujjwal Raut, a program manager at the Southwest Research Institute. “This region of fractured surface materials could point to geologic processes pushing subsurface materials up from below.”The Europa Clipper's MissionAlthough Europa and its subsurface ocean will be a crucial target for future space exploration, some scientists have expressed doubts regarding its capacity to sustain life. A series of obstacles could make finding life on Europa more difficult. At an American Geophysical Union conference last year, scientists reported that the ice layer covering the moon's surface is thicker than expected, indicating that there may not be enough heat or activity in the subsurface ocean to support life. Scientists aren’t yet sure if an abundance of hydrothermal vents or seafloor volcanoes sit at the bottom of the ocean — these features have been crucial in driving life on our own planet. Observations of Europa haven’t fully confirmed the existence of plumes, either, which would be a clear sign that material from the ocean could be transported to the surface. About 5 years from now, in 2030, scientists will get an unprecedented view of Europa as NASA's Europa Clipper approaches the icy moon. Launched last October, the Europa Clipper will reveal many secrets that still surround the moon's surface and the ocean below. Among its various objectives, the mission will look for plumes, which would be able to eject microbes — if they truly do exist on the moon — into space for the Europa Clipper to examine. Article SourcesOur writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:The Planetary Science Journal. JWST Reveals Spectral Tracers of Recent Surface Modification on EuropaThe Planetary Society. Europa, Jupiter’s possible watery moonThe Planetary Society. Could Europa Clipper find life?Jack Knudson is an assistant editor at Discover with a strong interest in environmental science and history. Before joining Discover in 2023, he studied journalism at the Scripps College of Communication at Ohio University and previously interned at Recycling Today magazine.

Check Out Jupiter’s Stunning Auroras, Which Are Hundreds of Times Brighter Than Earth’s, in the James Webb Telescope’s Latest Images The infrared views, captured in 2023, shed light on the giant planet’s atmosphere and magnetosphere—but they also reveal something unexpected These observations of Jupiter’s auroras (shown on the left of the above image) were captured with NASA's James Webb Space Telescope’s Near-Infrared Camera on December 25, 2023. NASA, ESA, CSA, STScI, Ricardo Hueso (UPV), Imke de Pater (UC Berkeley), Thierry Fouchet (Observatory of Paris), Leigh Fletcher (University of Leicester), Michael H. Wong (UC Berkeley), Joseph DePasquale (STScI), Jonathan Nichols (University of Leicester) In May 2024, powerful solar activity triggered jaw-dropping northern lights much farther south than usual, turning the sky mesmerizing shades of pink, green and purple over wide areas of the planet. But on Jupiter, auroras are hundreds of times brighter. Now, almost exactly a year since one of Earth’s most impressive light shows, researchers have released brilliant new images of Jupiter’s auroras, captured by the James Webb Space Telescope (JWST) on December 25, 2023. As detailed in a study published Monday in the journal Nature Communications, the images literally shed new light on the magnetosphere and atmosphere of our solar system’s largest planet. “What a Christmas present it was—it just blew me away!” study lead author Jonathan Nichols, a space physicist from the University of Leicester in England, says in a NASA 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.” Webb Captures Jupiter's Aurora Watch on On Earth, auroras occur when the sun pelts our planet with charged particles ejected in solar storms. These particles interact with gases in our upper atmosphere, making them glow in different colors. Earth’s magnetic sphere actually deflects these charged particles toward the planet’s poles—that’s why the resulting auroras are called the northern or southern lights. While solar storms contribute to auroras on Jupiter, the giant planet’s magnetic field also captures additional charged particles, such as those ejected by volcanoes on its moon Io, according to the statement. These particles get accelerated toward the poles at extreme speeds, then crash into the atmosphere, causing its gases to glow. “Think northern lights, but way bigger!” reads an X post from NASA. The JWST previously documented Jupiter’s auroras in 2022. Nichols and his colleagues analyzed infrared light emitted by a positively charged molecule called the trihydrogen cation (H3+), which can form in auroras. They revealed that the molecule’s emission fluctuates more than they’d previously theorized—an observation that, with more research, will provide insight into how Jupiter’s upper atmosphere heats up and cools down. NASA's James Webb Space Telescope's recent images of the auroras on Jupiter NASA, ESA, CSA, Jonathan Nichols (University of Leicester), Mahdi Zamani (ESA / Webb) The team also found something else unexpected: When they captured images at the same time in ultraviolet light with the Hubble Space Telescope, they realized the brightest infrared light imaged by JWST didn’t correspond with Hubble’s ultraviolet version. They thought the Hubble telescope would show evidence of the aurora-creating, high-energy cosmic particles slamming into Jupiter’s atmosphere—but it didn’t. “What we’re seeing is an incredibly bright afterglow with not much evidence of the original impact,” Nichols tells Mashable’s Elisha Sauers. “The explanation currently eludes us.” This suggests Jupiter had auroras without an onslaught of high-energy particles. Instead, its auroras seen by JWST might have come from a high number of very low-energy particles raining down on the atmosphere, “which was previously thought to be impossible,” Nichols adds in the statement. If that’s not the explanation, it suggests Jupiter’s atmosphere may have some dynamics that aren’t fully understood yet. Moving forward, the team plans to continue investigating this conundrum with more JWST observations and comparisons to data from NASA’s Juno spacecraft. Get the latest stories in your inbox every weekday.