Tag Archives: Europas

New Findings Reveal Europa’s Ice Shell is Significantly Thicker Than Previously Believed

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Recent microwave measurements from NASA’s Juno spacecraft indicate that Europa’s icy shell could extend nearly 29 kilometers (18 miles) deep, significantly altering planetary scientists’ understanding of how this intriguing moon facilitates the exchange of vital chemicals between its hidden ocean and surface.

Artist’s concept showing a cross-section of Europa’s icy shell. Image credit: NASA / JPL-Caltech / SwRI / Koji Kuramura / Gerald Eichstädt.

Europa has captivated planetary scientists for over 40 years.

The question of whether Jupiter’s icy moons can support life has sparked extensive debate among researchers.

Interest in Europa’s potential habitability surged when NASA’s Galileo spacecraft revealed an ocean of saline water beneath its icy crust, complemented by surface cracks.

On September 29, 2022, NASA’s Juno spacecraft flew by Europa at an altitude of 360 km (220 miles).

During this flyby, Juno’s Microwave Radiometer (MWR), which is primarily designed to analyze Jupiter’s atmosphere, gathered brightness temperature data at various depths within Europa’s icy crust.

Juno project scientist Steve Levin and his team utilized this MWR data to conclude that the icy shell averages approximately 29 kilometers in thickness.

“The estimated thickness of 29 km pertains to the cold, dense, electrically conductive outer layer of Europa’s water ice shell,” Dr. Levin stated.

“If a slightly warmer convective layer exists beneath, the total thickness could be even greater.”

“Conversely, if the ice shell contains a moderate amount of dissolved salts, as some models suggest, the thickness could decrease by around 5 km (3 miles).”

“A thicker shell implies that oxygen and nutrients have longer distances to travel to connect Europa’s surface with its subsurface ocean, as indicated by the MWR data.”

Understanding this exchange process is crucial for future studies on Europa’s habitability.

Furthermore, MWR data shed light on the composition of Europa’s subsurface ice.

This technology uncovered “scatterers,” irregularities such as cracks, pores, and voids that scatter microwaves reflected off the ice.

These scatterers, estimated to be only a few inches in diameter, are believed to extend hundreds of feet below the surface.

The small size and shallow depth of these features suggest they are unlikely to serve as significant pathways for transporting oxygen and nutrients from the surface to the salty ocean beneath.

“The thickness of the ice shell, along with the presence of cracks and pores, adds complexity to our understanding of Europa’s potential for habitability,” remarked Scott Bolton, Ph.D., Juno’s principal investigator at the Southwest Research Institute.

“These findings provide essential context for NASA’s Europa Clipper and ESA’s Juice missions, both en route to the Jupiter system.”

“The Europa Clipper is expected to arrive in 2030, followed by Juice the next year.”

The team’s new results were published in the Journal on December 17, 2025, in Nature Astronomy.

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S.M. Levin et al. 2026. Characterization of Europa’s ice thickness and subsurface structure using the Juno microwave radiometer. Nat Astron 10, 84-91; doi: 10.1038/s41550-025-02718-0

Source: www.sci.news

Breakthrough Model Reveals How Nutrients Might Access Europa’s Icy Shell to Nourish Its Hidden Ocean

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Geophysicists from Washington State University and Virginia Tech have uncovered a potential pathway for nutrient transport from the radioactive surface of Jupiter’s icy moon, Europa, to its subsurface ocean.

Artist’s concept of the oceans of Jupiter’s moon Europa. Image credit: NASA/JPL-Caltech.

Europa is believed to host more liquid water than all of Earth’s oceans combined, but this vast ocean lies beneath a thick, ice-covered shell that obstructs sunlight.

This ice layer means that any potential life in Europa’s oceans must seek alternative sources of nutrition and energy, raising important questions about how these aquatic environments can support life.

Moreover, Europa is under constant bombardment from intense radiation emitted by Jupiter.

This radiation interacts with salts and other surface materials on Europa, producing nutrients beneficial for marine microorganisms.

While several theories exist, planetary scientists have struggled to determine how nutrient-rich surface ice can penetrate the thick ice shell to reach the ocean below.

Europa’s icy surface is geologically active due to the gravitational forces from Jupiter; however, ice movements primarily occur horizontally rather than vertically, which limits surface-to-ocean exchange.

Dr. Austin Green from Virginia Tech and Dr. Katherine Cooper from Washington State University sought inspiration from Earth to address the surface recycling challenge.

“This innovative concept in planetary science borrows from well-established principles in Earth science,” stated Dr. Green.

“Notably, this approach tackles one of Europa’s persistent habitability questions and offers hope for the existence of extraterrestrial life within its oceans.”

The researchers focused on the phenomenon of crustal delamination, where tectonic compression and chemical densification in Earth’s crust lead to the separation and sinking of crustal layers into the mantle.

They speculated whether this process could be relevant to Europa, especially since certain regions of its ice surface contain dense salt deposits.

Previous investigations indicate that impurities can weaken ice’s crystalline structure, making it less stable than pure ice.

However, delamination requires that the ice surface be compromised, enabling it to detach and submerge within the ice shell.

The researchers proposed that dense, salty ice, surrounded by purer ice, could sink within the ice shell, thereby facilitating the recycling of Europa’s surface and nourishing the ocean beneath.

Using computer simulations, they discovered that as long as the surface ice is somewhat weakened, nutrient-rich ice laden with salts can descend to the bottom of the ice shell.

This recycling process is swift and could serve as a reliable mechanism for providing essential nutrients to Europa’s oceans.

The team’s study has been published in the Planetary Science Journal.

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AP Green and CM Cooper. 2026. Dripping into destruction: Exploring the convergence of viscous surfaces with salt in Europa’s icy shell. Planetary Science Journal 7, 13; doi: 10.3847/PSJ/ae2b6f

Source: www.sci.news

How Europa’s Thick Ice May Obstruct the Hunt for Ocean Life

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Europa’s Ice: A Thick Shell Over a Salty Ocean

Claudio Caridi / Alamy

Europa, one of Jupiter’s intriguing moons, features a liquid ocean possibly encased beneath a thick layer of ice, estimated to be six times the depth of Antarctica’s icy crust, complicating our efforts to detect any potential lifeforms.

This moon is a leading candidate in the search for extraterrestrial life, primarily due to its significant volume of liquid water.

Previously, estimates regarding the thickness of Europa’s ice have varied dramatically—ranging from under 10 kilometers to nearly 50 kilometers. Researchers initially believed certain defects in the ice might permit nutrient exchange between the surface and the ocean below.

Now, a research team, led by Stephen Levin from the California Institute of Technology, has analyzed data collected by the Juno spacecraft, which has been orbiting Jupiter since 2016.

On September 29, 2022, Juno came within 360 kilometers of Europa, utilizing its microwave radiometer to scan the surface and perform the first direct measurements of the ice layer. Levin noted that this instrument assessed the heat emitted by Europa’s icy exterior, enabling the measurement of ice temperatures at various depths and detecting temperature fluctuations resulting from imperfections in the ice sheet.

The researchers estimate that the most accurate thickness of the ice sheet is approximately 29 kilometers, aligning with the higher range of previous estimates while presenting a possible thickness that could range from 19 kilometers to 39 kilometers.

Crucially, their findings indicate that the fissures, pores, and other imperfections likely extend only a few hundred meters beneath the surface, with pore diameters measuring only a few centimeters.

“This indicates that the observed defects in the microwave radiometers are insufficiently deep or expansive to facilitate significant nutrient transport between the ocean and the surface,” asserts Levin.

Nonetheless, this does not diminish the potential for life on Europa. Levin further explains, “Though the observed pores and cracks are too minute and shallow to transport nutrients, alternative transportation mechanisms may exist.”

There may also be unexplored regions of the moon where conditions differ, he adds.

Researchers including Ben Montet from the University of New South Wales in Sydney, express concerns that the ice thickness could hinder life’s search. “While this protection may sustain life for extended durations, it complicates our ability to penetrate the ice and study the ocean beneath,” he notes.

He argues that life could exist without a direct link between Europa’s surface and its subterranean ocean, though such a connection would enhance the chances of discovering life. Helen Maynard-Casley of the Australian Nuclear Science and Technology Agency emphasizes that without that transport link, “you’re essentially confined to whatever was in the ocean initially.”

NASA has plans to launch the Europa Clipper spacecraft in 2024, aiming to embark on its mission to Jupiter’s moons in 2030. This spacecraft is expected to provide clearer insights into Europa’s icy layer, according to Maynard-Casley.

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Researchers Say Europa’s Spider-Like Structures Mirror Earth’s Lake Stars

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Europa, Jupiter’s frigid moon, is an oceanic environment that stands out as a key player in the quest for extraterrestrial life. Its surface is characterized by various landforms believed to originate from salty water sources beneath its icy crust, potentially making it the most accessible body of liquid water in the solar system. Notably, the asterisk-shaped “spider” located in the center of Manannan Crater was identified during NASA’s Galileo mission. Planetary scientists have recently introduced a novel hypothesis regarding the formation of this spider-like structure, drawing on morphological analysis and initial analog modeling. They propose that it may have formed through a process akin to the creation of dendritic “lake stars,” a seasonal phenomenon observed in frozen terrestrial ponds and lakes.

Damkhan Alla topographic map of Manannan. Image credit: McCune et al., doi: 10.3847/PSJ/ae18a0.

“The spider-like feature may have resulted from an eruption of molten salt water following the Manannan impact,” explains Dr. Elodie Lesage from the Planetary Science Institute.

“This presents an opportunity to understand the subsurface characteristics and the salt water composition at the impact’s time.”

Dr. Lesage and colleagues are also researching similar “spiders” on Mars, which are tree-like formations in the regolith near the planet’s south pole.

Their findings on Mars have been applied to other celestial bodies, including Europa.

Martian spiders develop as a result of gases escaping beneath a seasonal dry ice layer; however, the Europa study speculates that the “asterisk-shaped” features could have emerged post-impact.

“Lake stars are radial branching designs that occur when snow accumulates on a frozen lake, creating holes in the ice due to the snow’s weight, allowing water to flow through and spread out energetically,” stated Dr. Lauren McCune from the University of Central Florida and NASA’s Jet Propulsion Laboratory.

“We believe a similar process could have happened on Europa, with subsurface brine erupting after the impact and dispersing through the porous surface ice.”

The research team has informally designated the Europa feature as Damhan Alla, which translates to “spider” in Irish, differentiating it from Martian spider formations.

To validate their hypothesis, they studied lake stars in Breckenridge, Colorado, and conducted field as well as lab experiments using a cryogenic glovebox equipped with a Europa ice simulator cooled by liquid nitrogen.

“In our experiments where we passed water through these simulants at various temperatures, we observed similar star-like formations even at extremely low temperatures (-100 degrees Celsius or -148 degrees Fahrenheit), lending support to the idea that such mechanisms could occur on Europa after the impact,” Dr. McCune remarked.

Scientists also created models showing how the saltwater beneath Europa’s surface would react following an impact, including an animation illustrating the process.

While observations of Europa’s icy features are primarily reliant on images captured by the Galileo spacecraft in 1998, the researchers aim to explore this further with high-resolution images from NASA’s Europa Clipper mission, anticipated to arrive at the Jupiter system in April 2030.

“Although lake stars offer significant insights, terrestrial conditions differ vastly from those on Europa,” Dr. McCune notes.

“Earth possesses a nitrogen-rich atmosphere, while Europa’s environment features extremely low pressures and temperatures.”

“This investigation combined field data and laboratory trials to better simulate Europa’s surface conditions.”

The team will further examine how low-pressure systems affect the formation of these landforms and explore whether such structures can form beneath Europa’s icy crust, akin to how flowing lava generates smooth, rope-like textures known as pahoehoe on Earth.

While the primary focus was geomorphology, this discovery sheds light on subsurface activity and habitability, crucial for future astrobiological studies.

“By employing numerical modeling of saline reservoirs, we assessed the potential depth of the reservoir (up to 6 km, or 3.7 miles below the surface) and its longevity (potentially several thousand years post-impact),” Dr. Lesage stated.

“This data is invaluable for upcoming missions investigating viable ecosystems beneath ice shells.”

The team’s results were published in Planetary Science Journal.

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Lauren E. McCune et al. 2025. A lake star as an Earth analogue of Europa’s Manannan Crater Spider feature. Planet. Science. J 6,279; doi: 10.3847/PSJ/ae18a0

Source: www.sci.news

Can ‘iron snow’ potentially sustain life in Europa’s oceans?

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The only example of life in the universe is Earth, a rocky planet with over 70% water on its surface. As far as we know, all life on Earth relies on water to survive and thrive, so scientists refer to other planets where liquid water is known to exist as “habitable.”

But scientists also know that a puddle of water alone is not enough to sustain life. Life depends on a constant flow of electrons between molecules, which Electronic GradientTo create energy, electrons move away from areas of high electron density. Reducelow density areas, so-called Oxidize.

Scientists have found several planets and moons in our solar system that have liquid water. Researchers are particularly intrigued by Jupiter's moon Europa, because remote sensing has revealed that it has a salty liquid ocean about 100 kilometers (60 miles) deep on top of a crust of iron-rich rock, with a layer of ice about 10 kilometers (6 miles) thick on top of that.

Europa has no atmosphere to protect it from the sun's radiation, which allows chemical reactions to take place that consume electrons on its surface, creating an oxidizing environment. In contrast, its iron-rich crust creates a reducing environment beneath its oceans. This means that an electron gradient naturally forms along the path from Europa's oxidizing surface to its reduced ocean floor. Scientists want to know if life could harness this electron gradient to obtain enough energy to sustain itself and survive.

Researchers studying Europa From the data Cassini and Galileo The mission found that Europa's ocean temperatures range from 0 to -13 degrees Celsius, or 32 to 9 degrees Celsius. They found that the hottest temperatures are found closest to the ocean floor, where heat is generated by reactions between water and rock, similar to Earth's hydrothermal systems. They also found that some of the most abundant molecules near Europa's surface are all oxide molecules, such as carbonates and sulfates.

Based on these temperature constraints and the amount of energy provided by oxidizing molecules on Europa's surface, a team of researchers from the University of Akron and the University of Southern California calculated the amount of energy available for life in Europa's ocean and investigated whether three types of Earth microorganisms could live beneath Europa's ocean. The microorganisms they tested generate energy using carbonates, sulfates, or iron particles. They reasoned that because all three of these oxidizing molecules are found on Europa's icy surface, if delivered to the ocean floor, the organisms could combine with reducing molecules on the ocean floor to generate energy.

The researchers calculated that in Europa's environment, molten iron near the surface layer of ice would form solid particles when exposed to penetrating radiation from the sun, and slowly fall to the ocean floor — like snow falling from the sky on Earth, except instead of water ice particles, the ocean rains down in the form of rust-like, reddish iron particles.

The scientists calculated that iron oxide snow would provide a larger electron gradient than carbonates or sulfates, ultimately generating more energy for life. They estimated that iron snow could provide up to 2.5×1026 More than 100 microbial cells are found on Europa's ocean floor per year, which represents about 0.1% of the total number of microbial cells currently living in Earth's oceans.

However, the authors caution that only around 10% of the energy produced by organisms on Earth is used to generate cells — the remaining 90% is used to maintain metabolism, meaning that the number of cells that microbial life could actually generate from Europa's underwater iron pathways would be much lower than the authors estimate.

Nevertheless, the authors suggest that these cell count calculations could be used to design missions to search for life on Europa: When future satellites orbit Europa, researchers could estimate how much cell mass we might expect from microbes living in the iron passages on the Europa ocean floor.


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Source: sciworthy.com

Europa’s oxygen production is lower than previously believed

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Using data from Jupiter aurora distribution experiment (JADE) Instrument equipped NASA spacecraft Junoplanetary scientists calculated that the proportion of oxygen produced on Jupiter's icy moon Europa is significantly lower than in most previous studies.

This diagram shows charged particles from Jupiter impacting Europa's surface, splitting frozen water molecules into oxygen and hydrogen molecules. Scientists believe that some of these newly produced oxygen gas may migrate toward the moon's subsurface ocean, as depicted in the inset image. Image credit: NASA / JPL-Caltech / SWRI / PU.

With an equatorial diameter of 3,100 km (1,940 miles), Europa is the fourth largest of Jupiter's 95 known moons and the smallest of the four Galilean moons.

The moon has an internal liquid ocean and potentially habitable conditions beneath its frozen crust.

Its surface is constantly bombarded with radiation, which breaks down the icy crust into oxygen and hydrogen, most of which is either released from the surface and escapes into space, or remains and forms Europa's atmosphere.

The abundances of these atmospheric gases and ions, and consequently their production rates at the Earth's surface, are inferred primarily from remote sensing observations and are subject to large uncertainties.

“Europa is like an ice ball that slowly loses water in a flowing river,” said Dr. Jamie Zareh, a JADE scientist and researcher at Princeton University.

“However, the flow in this case is a fluid of ionized particles that are swept around Jupiter by Jupiter's unusual magnetic field.”

“When these ionized particles hit Europa, they break up the water ice on the surface molecule by molecule, producing hydrogen and oxygen.”

“In a sense, the entire ice shell is being continuously eroded by the waves of charged particles being launched.”

In the new study, Zarai and colleagues analyzed data from a flyby of Europa conducted by the Juno spacecraft on September 29, 2022. On this flight, the spacecraft flew 353 kilometers (219 miles) above Europa's surface.

They used a JADE instrument to extract abundant amounts of different pickup ions. Pick-up ions are charged particles produced by the destruction of atmospheric neutrals when they collide with high-energy radiation or other particles.

From these data, they calculate that about 12 kg of oxygen is produced every second on Europa's surface.

This is at the lower end of the range of 5 to 1,100 kg per second estimated from previous models.

The results suggest that Europa's surface may have less oxygen than previously thought, meaning that Europa's oceanic habitat is narrower. .

“Flying so close to the Galileo satellite during its long-duration mission allowed us to begin working on a wide range of science, including the unique opportunity to contribute to the study of Europa's habitability,” Juno Principal Investigator said researcher Dr. Scott Bolton. Southwest Research Institute.

“And we're not done yet. More moon approaches and the first exploration of Jupiter's close rings and polar atmosphere are still to come.”

of findings It was published in the magazine natural astronomy.

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JR Zarai other. Production of oxygen by dissociation of Europa's water and ice surfaces. Nat Astron, published online March 4, 2024. doi: 10.1038/s41550-024-02206-x

Source: www.sci.news

There May Be Less Oxygen in Europa’s Ocean, the Essential Fuel for Life, Than Previously Believed

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Jupiter’s moon Europa is covered with an icy shell

NASA/JPL-California Institute of Technology

Jupiter’s moon Europa may not be as ripe for life as we think. Beneath the icy shell is an ocean of water, but as we know, the frigid moon may lack the oxygen needed to support life.

On Europa, oxygen is produced when radiation hits the surface and breaks down the water ice there into its constituent parts hydrogen and oxygen. Models of this process suggest that oxygen production rates can range from 5 kilograms per second to more than 1000 kilograms per second.

Jamie Zareh Researchers at Princeton University made the new estimate using data from the Juno spacecraft, which flew just 353 kilometers above Europa’s surface in 2022. They discovered that oxygen is only produced at a rate of about 12 kilograms per second at the Earth’s surface. This corresponds to the lower bound of previous estimates.

“In a sense, the shell is like Europa’s lungs. It’s continually producing oxygen,” Zaray says. “That said, we can’t say what happens after the oxygen is produced at the surface. How much of the oxygen makes it into the ocean remains a question.”

But if less oxygen is produced in the first place, less oxygen will enter European waters. As a result, researchers may be less likely to discover organisms similar to those living on Earth.

One of the next steps is to figure out how much of that oxygen can penetrate through the alien moon’s icy shell. NASA’s European Clipper mission, scheduled to launch in October, should help solve that problem. It is hoped that this will allow researchers to measure the thickness of the ice and determine whether elements and compounds useful for life can pass through it.

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Source: www.newscientist.com