'Wall demon' discovered on Jupiter's moon likely to harbor off-world life
Scientists have discovered what they're calling a 'wall demon' on Jupiter's icy ocean moon of Europa, one of the prime candidates for discovering life in our solar system.
The unique star-shaped pattern, which has been nicknamed 'Damhán Alla,' a Gaelic word for spider or wall demon, was found inside the 13-mile-wide Manannán crater on Europa by NASA's Galileo spacecraft.
The US-based team believes this massive 1.8-mile-wide pattern is not just a set of cracks in the moon's surface, but a preserved record of salty liquid water, or brine, that once flowed and froze on the surface.
The strange formation likely developed under the frozen surface, created by the heat of a meteor impact that formed the crater and melted part of Europa's icy shell.
This dark, branching pattern is similar to 'lake stars' on Earth, which are short-lived patterns on frozen ponds and lakes formed when water pushes up through holes in the ice and spreads out, melting and refreezing snow in a unique design.
Finding the same pattern on Europa suggests that material which could harbor life in the moon's subsurface ocean could reach or mix with undiscovered microbes on the surface, making potential life easier to find than on other worlds.
Europa's global liquid ocean is believed to be trapped under a thick crust of ice, but may still be active to this day, making it one of the best places in our solar system to search for extraterrestrial life.
Study author Lauren Mc Keown, a physicist at the University of Central Florida, said: 'Surface features like these can tell us a lot about what's happening beneath the ice. If we see more of them with [the NASA space probe] Europa Clipper, they could point to local brine pools below the surface.'
Scientists have revealed a massive 1.8-mile-wide pattern on Jupiter's moon Europa that could point to signs of life-generating conditions on the ocean world
Jupiter's watery moon Europa, photographed by NASA's Galileo spacecraft (Stock Image)
The brine researchers discovered came from Europa's own icy shell and ocean, not from another planet, but its presence has made the moon one of two prime candidates within the solar system for future probes to look for aliens.
The other candidate has been Enceladus, the small icy moon of Saturn, which studies have shown contains phosphorus, a vital building block for all life on Earth.
However, the presence of salty liquid water on Europa is a major development because liquid water is the most essential ingredient for life as we know it.
Every living organism on Earth requires it, and Europa is believed to have a vast ocean of salty water hiding under its thick outer crust.
NASA believes Jupiter's moon may have twice as much liquid water hiding under the ice as all of Earth's oceans combined.
Moreover, that water has been able to avoid freezing because of the heat created by Jupiter's gravitational pull, causing massive tidal forces - just like our moon affects Earth's tides to a much lesser extent.
For life to exist in the galaxy, scientists have looked for three main things: liquid water, chemical building blocks like carbon, hydrogen, oxygen, and salts, and a source of energy.
Europa has a liquid ocean. Scientists have found traces of these building blocks in the icy surface. The final ingredient could be hiding on the moon's seafloor, just like Earth's deep sea has hydrothermal vents that allowed life to thrive without sunlight.
Scientists were able to recreate the conditions on Europa to prove that the wall demon seen on the moon was the same as a lake star on Earth
The researchers also went to real frozen lakes and ponds on Earth to compare the discovery
Damhán Alla was first noticed in images taken by the Galileo spacecraft in the late 1990s and early 2000s.
The new research team examined the old Galileo photos and created maps of the crater's shape and features.
They then compared the pattern to similar ones on other worlds, such as wall demons found on Mars, which are believed to have formed because of soil erosion on the Martian surface.
This years-long project then compared the wall demons to real lake stars at two frozen ponds in Breckenridge, Colorado in 2022.
Scientists also recreated Europa-like conditions in a cold chamber cooled by liquid nitrogen at NASA's Jet Propulsion Laboratory in California to prove this giant spider was a legitimate lake star.
The simulated lab results revealed that the brine on Europa likely came from a pocket of salty water up to 12miles wide that was sitting roughly 3.7miles below the ice.
'Lake stars are really beautiful, and they are pretty common on snow or slush-covered frozen lakes and ponds,' Mc Keown said in a statement, according to phys.org.
'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.'
