New research finds water on icy moons defies the laws of physics

Scientists have recreated the extreme conditions found on the frozen moons of the outer solar system and uncovered something startling: water behaves in a way never seen on Earth. In the near-vacuum of space, water does not follow the rules you learned in school. Instead of freezing below 0°C and boiling above 100°C, it does both at once.

Under such alien conditions, liquid bubbles violently while turning solid, setting the stage for dramatic eruptions of icy material. These strange reactions may explain how moons far from the warmth of the Sun manage to reshape their surfaces with bursts of water instead of molten rock.

Moons like Europa, which orbits Jupiter, and Enceladus, which circles Saturn, are covered by thick shells of ice. Beneath those frozen crusts lie hidden oceans of liquid water, kept warm by tidal heating and other forces. Temperatures on Enceladus can plummet to -193°C at the equator, yet giant plumes of vapor have been seen shooting into space. These eruptions are part of a process called cryovolcanism, in which icy material takes the place of molten lava.

Some eruptions are explosive, blasting columns of vapor and particles outward. Others may be effusive, where liquid water spreads across the surface much like a lava flow does on Earth. The second type has been more difficult to study, since direct evidence is rare.

A team of scientists from the University of Sheffield, the Open University, and the Czech Academy of Sciences decided to tackle the mystery. By creating a miniature version of these frozen environments in the lab, they hoped to see how water might behave and whether effusive cryovolcanism could be possible.

The group used a special chamber at the Open University known as the Large Dirty Mars Chamber, affectionately called “George.” Inside, they could mimic the near-zero pressure conditions found on icy moons. For the first time, researchers used large amounts of water in such an experiment and recorded the results with cameras placed at observation windows.

As the pressure inside George dropped, the cold water did something strange. It began to boil, even though it was nowhere near hot. The boiling drove off vapor, which cooled the remaining liquid. Soon, ice crystals started to form and float. These crystals grew quickly, spreading across the surface until much of the water was capped by a fragile frozen layer.

What happened next surprised the scientists. Beneath the thin crust, liquid water kept boiling. Bubbles forced their way upward, cracking and deforming the ice. In some cases, water broke through and spilled out before freezing again in the low-pressure environment.

Earlier studies, which used smaller volumes of water, suggested that ice would quickly form a thick barrier, cutting off further boiling. But the new research showed that the crust is weak, filled with bubbles and gaps. The constant pressure of vapor keeps breaking it apart.

Dr. Frances Butcher, a research fellow at the University of Sheffield, explained what this means. “The ice layer that forms is weak and full of holes and bubbles,” she said. “If the ice was stronger, it would likely seal-off the liquid water below and prevent further boiling. But our experiments show that as the water boils, the gas that is released gets trapped under the icy crust. Pressure builds, the ice cracks, the gas escapes, and liquid water can briefly seep through the cracks onto the surface of the ice—only to be exposed again to the low-pressure environment. As soon as new fractures appear, water begins to boil again, and the entire process repeats itself.”

On Earth, the behavior of water is simple and predictable. But in the harsh environment of a moon, water becomes unstable. The findings, published in Earth and Planetary Science Letters, highlight how alien these processes truly are.

Dr. Petr Brož, lead author from the Czech Academy of Sciences, emphasized the importance of the discovery. “We found that the freezing process of water under very low pressure is much more complex than previously thought,” he said. “In such conditions, water rapidly boils even at low temperatures, as it is not stable under low pressure. Simultaneously, it evaporates and begins to freeze, driven by the intense cooling effect caused by the evaporation itself. The ice crust that forms is repeatedly disrupted by vapor bubbles, which lift and fracture the ice, significantly slowing down, complicating, and prolonging the freezing process.”

This unstable behavior does more than create odd patterns of ice in a laboratory chamber. It may explain why cryovolcanism occurs on moons across the solar system. The cycle of boiling, freezing, and cracking can allow liquid water to escape through the crust, creating flows and eruptions that reshape the surface. When bubbles rise beneath the ice and deform it, the surface becomes uneven, with bumps and depressions. These topographic features might be visible to spacecraft equipped with radar or imaging instruments.

Professor Manish Patel, a planetary scientist at the Open University who oversees the simulation facility, explained the potential. “These topographic irregularities—caused by trapped vapor beneath the ice—may leave distinct signatures that could be detectable by orbiting spacecraft, for example by those equipped with radars, offering a potential new way to identify ancient cryovolcanic activity. This could provide valuable clues for planning future missions to these remote worlds—and help us better understand the still mysterious process of cryovolcanism.”

The study goes beyond understanding frozen landscapes. Where water flows, life may follow. Europa and Enceladus have become prime targets in the search for extraterrestrial biology because their subsurface oceans might harbor the ingredients needed for living organisms.

Explosive cryovolcanism has already given scientists hope. Jets from Enceladus have been sampled by the Cassini spacecraft, revealing water, salts, and organic molecules. If effusive cryovolcanism is also possible, then liquid water may have reached the surface in the past, leaving behind chemical traces that orbiting missions could detect.

The boiling-and-freezing cycle might also help explain how surface cracks form and widen, allowing more exchanges between the ocean below and the icy crust above. That process could spread nutrients or energy sources, making these moons more dynamic and possibly more habitable.

Future spacecraft such as NASA’s Europa Clipper and ESA’s Jupiter Icy Moons Explorer will scan the icy surfaces of these distant worlds in greater detail than ever before. If the irregular features predicted by the Sheffield–Open University–Czech Academy team are found, they will serve as markers of past cryovolcanism.

By understanding how water reacts under extreme conditions, scientists are not just solving a geological puzzle. They are preparing for the next era of exploration, when robotic probes may one day land on these moons and test their icy crusts for signs of hidden oceans and even life.

Note: The article above provided above by The Brighter Side of News.

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