Lauren Mc Keown
“Spider” formed by liquid water flowing over icy Europe
20 years ago, NASA’s Galileo probe recorded a strange structure, similar to a spider or a star, Jupiter’s enigmatic moon, Europa. Only now have researchers realized that these marks could be the key to identifying underground saltwater lakes and even signs of life.
Inside the crater Manannanon the surface of Europa, there is a unique formation called God’s Spider (Irish for “spider”). It is a branched network of ridges and depressions, with an appearance resembling a web, which was first detected in the late 1990s.
However, it took two decades and in-depth analysis to explain its origin.
The explanation, found in a published at the beginning of the month in Planetary Science Journalis found in a terrestrial phenomenon known as “lake stars”.
These are formed when meltwater under the ice escapes through a crack, it spreads and dissolves the snow aroundcreating characteristic patterns, similar to branches of a tree. Europa’s “spider” looks almost the same.
In their study, a team of scientists led by Lauren Mc Keowna researcher at the University of Central Florida and NASA’s Jet Propulsion Laboratory, combined ground observations, experiments and modeling, and concluded that the spider-like structures on Saturn’s icy moon are traces of salt water (brine) which will have burst under the ice.
According to the authors of the study, one of the scenarios to explain the formation of Damhán Alla on the surface of Europa is that of the powerful impact of a meteoritewhich probably opened a fracture in the icy crust.
Brine from the subglacial ocean will then have burst through this hole, under pressure, reaching the surface. In conditions of extreme cold, it will have spread for a short time, forming branched channelsand will have frozen quickly, leaving a lasting mark.
This means that the “spider” can mark the location of a reservoir place of liquid waterhidden under a thin layer of ice.
Lauren McKeown standing in the icy water, in which the characteristic radial pattern of a “lake star” can be seen
The presence of accessible liquid water and organic matter makes Europa’s underground ocean one of the main candidates in search of life in the Solar System. Structures like Damhán Alla function as natural markers, indicating thewhere water might be hidden under the crust.
“These structures can tell us a lot about what’s going on beneath the ice”, says Lauren Mc Keown, cited by .
The current analysis is based on data from NASA’s Galileo probe, which disintegrated in Jupiter’s atmosphere in 2003. Advances are expected with the new Europa Clipper mission, also from NASA, scheduled to reach Europa in 2030.
High quality images will allow study the “spider” in detail and look for similar formations, mapping the most promising areas for research into possible signs of life.
