A new study may shed light on the origin of the mysterious spider-like structure discovered on Jupiter's moon Europa in 1998. This formation could be key to understanding the processes occurring on the icy moon and could also have implications for future NASA missions, says Trinity College Dublin.
Mysterious structure
In March 1998, the Galileo spacecraft, which was exploring Jupiter and its moons, discovered an unusual dendritic shape on Europa in the center of Manannan crater, an icy crater about 22 kilometers in diameter.
Initially, scientists thought that this structure formed due to the impact of Jupiter's gravity or hydrothermal activity on the ocean floor below Europa's surface. However, none of these explanations answers all the questions.
The study was published at Planetary Science Magazine, offers another explanation: the arachnid form may be formed through a process called “starring”. This also exists on Earth. This happens when snow melts on frozen lakes and water seeps through tiny holes in the ice, creating unique patterns.
Scientists have created a model under laboratory conditions that simulates the formation of such a structure on Europa. In addition, they gave the mysterious figure a name – Damkhan Alla, which is translated from Irish as “spider” or “devil on the wall”. The name is inspired by Celtic mythology, in which Manannan is the god whose name bears the crater's name.
“Lake stars are a common sight on frozen lakes and ponds covered with snow or mud. This could help understand processes occurring on Europa, as well as on other icy worlds in the solar system,” said Laura McKeon, lead author of the study and a planetary scientist at the University of Central Florida.
Basic difference
However, unlike lake stars on Earth, which are formed by the movement of water through ice, Damkhan Alla was likely created by an asteroid impact. This collision created a crack in the ice shell, through which salt water seeped onto the surface, creating the characteristic pattern.
In addition, researchers also noted similarities between the “spiders” on Europa and the famous “Mars spiders” – dust structures that appear on the surface of Mars. These formations are formed by the sublimation of carbon dioxide ice. McKeon explains that the similarities between structures on different planets can be explained by the way liquids flow across porous surfaces.
This research could help inform work on NASA's Europa Clipper mission, which will arrive at Europa in 2030 to study the moon in detail.
“If similar features are discovered during the mission, this could indicate the presence of subsurface bodies of water, which would be important for the search for extraterrestrial life,” McKeon concluded.
