Spiders from Mars? Try Europa.<\/p>\n
A team of planetary scientists from Ireland have examined and named an intriguing feature on the surface of Jupiter\u2019s icy moon that resembles the shape of an arachnid \u2014 or perhaps an exploded asterisk.<\/p>\n
They\u2019re calling it \u201cDamh\u00e1n Alla,\u201d which is Gaelic for \u201cspider,\u201d or in a particularly evocative phrasing, \u201cwall demon.\u201d<\/p>\n
The team\u2019s analysis, published as a study<\/a> in The Planetary Science Journal, suggest that Damh\u00e1n Alla, and other features like it, may be the festering wounds formed by torrents of water erupting through Europa\u2019s icy shell.<\/p>\n \u201cThe significance of our research is really exciting,\u201d lead author Lauren Mc Keown, a physicist at the University of Central Florida, said in a statement<\/a>. \u201cSurface features like these can tell us a lot about what\u2019s happening beneath the ice. If we see more of them with Europa Clipper\u201d \u2014 NASA\u2019s new space probe currently en route to Jupiter \u2014 they could point to local brine pools below the surface.\u201d<\/p>\n Europa is the smallest of Jupiter\u2019s four Galilean moons, and is of interest to astronomers because it\u2019s suspected to harbor a saltwater ocean underneath its icy surface, making it one of the most promising candidates for off-world life in the solar system. Its spider-like feature was first observed by NASA\u2019s Galileo mission, which lasted between 1989 and 2003, during which the spacecraft performed 11 flybys of Europa.\u00a0<\/p>\n For the study, Mc Keown\u2019s team compared Damh\u00e1n Alla, which is roughly a kilometer across, with similar formations on Earth called lake stars, sometimes called ice stars. Typically a few feet in size, lake stars form when snow falls on the surface of a frozen lake and holes form in the ice, letting water melt away some of the snow in radial, branching patterns. Scientists call these patterns dendritic, and that they\u2019re seeing such patterns on Europa\u2019s surface suggest another sign of water<\/a> breaking through its surface<\/a>.\u00a0<\/p>\n The hypothesized scenario, in this case, is that some sort of impact to the moon\u2019s icy shell allowed briny water to seep through the shattered ice. This would also point to the existence of a vast subsurface ocean, or at least small pools of water right beneath the surface.<\/p>\n \u201cLake stars are really beautiful, and they are pretty common on snow or slush-covered frozen lakes and ponds,\u201d Mc Keown said. \u201cIt 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.\u201d<\/p>\n