Scientists from Ireland have identified an unusual spider-like structure on the surface of Europa, Jupiter’s icy moon. They named it Damhan Alla, which translates from Gaelic as 18spider18. Analysis has shown that Damhan Alla and similar formations may be traces of water breakthroughs through Europa’s icy crust.
“Surface features like these can tell us a lot about what is happening beneath the ice. If we spot more such formations with the help of the Europa Clipper – NASA’s new spacecraft heading to Jupiter – they might indicate the presence of local brine pools beneath the surface,” says lead author Lauren McKeown.
Source: Lauren McKeown
Europa is the smallest of Jupiter’s four Galilean moons. It holds a special interest for astronomers because it is speculated that a salty ocean lies beneath its icy surface, marking it as one of the most promising candidates for extraterrestrial life in the Solar System. Similar structures were first noticed during NASA’s Galileo mission, which took place from 1989 to 2003. The mission performed 11 flybys of Europa.
During research, McKeon’s team compared Damhan Alla, which is about a kilometer in diameter, with similar formations on Earth, known as lake stars or ice stars. Lake stars, typically about a meter in diameter, form when snow lands on frozen lakes, causing holes in the ice where water melts part of the snow, creating radial, branching patterns. Scientists call these dendritic patterns. Discovering similar patterns on Europa’s surface may indicate signs of water bursting to the surface. It is assumed that in the past, an impact on the moon’s icy crust allowed salty water to seep through broken ice. This also indicates the existence of a vast subsurface ocean or at least small pools of water right beneath the surface.
These results are important for understanding Europa’s geological activity and the potential habitability of its subsurface ocean. They will also assist in planning future mission explorations, such as the Europa Clipper, which is to arrive at Jupiter in 2030 and study Europa in greater detail. Discovering new ‘spiders’ may help pinpoint locations to search for signs of life.
