Comet Strikes on Jupiter's Europa Could Have Delivered Ingredients for Its Hidden Ocean, Study Reveals

Jupiter's moon, Europa, is thought to hold a large ocean of liquid water under its frozen surface. The hidden ocean is regarded as one of the most promising locations in the Solar System for searching for signs of life beyond Earth.

Researchers from the University of Texas discovered that comet impacts might have carried the required elements for life on the moon's surface to its hidden ocean, where it could help support any life that may exist in the dark. According to an institutional news release, the transit of components is feasible even if the comet does not breach the gas giant's ice moon shell.

Comet Strikes on Jupiter's Europa Could Have Delivered Ingredients for Its Hidden Ocean, Study Reveals — The puzzling, fascinating surface of Jupiter's icy moon Europa looms large in this newly-reprocessed color view, made from images taken by NASA's Galileo spacecraft in the late 1990s. This is the color view of Europa from Galileo that shows the largest portion of the moon's surface at the highest resolution. NASA / Jet Propulsion Lab-Caltech / SETI Institute

Computer Model Shows How Comet Strikes Affect Europa's Icy Surface

Researchers at the University of Texas at Austin constructed a computer model to investigate what occurs when a comet or asteroid collides with the ice shell of Europa's ocean, which is thought to be tens of kilometers thick.

The model predicts that if an impact penetrates at least halfway through the moon's ice shell, the heated meltwater it generates will sink through the remaining ice. It brings oxidants, a type of chemicals required for life, from the surface to the ocean, where they could aid in the survival of any potential life in the sheltered waters.

The team compared the huge melt chamber's slow descent to a sinking ship. Lead author and doctoral student Evan Carnahan said it is like the Titanic multiplied by 10.

Impacts have been postulated as a route for transporting oxidants on Europa, but scientists believed the hits would have to break through the ice. Marc Hesse, a professor in the Department of Geological Sciences at the University of Tennessee and a co-author of the study, noted that the study implies that a broader spectrum of impacts can accomplish the job.

He added that the comet impact increases the chances of having the required chemicals for life on Europa's icy ocean. NASA's forthcoming Europa Clipper mission to the ice moon is to collect data that will aid in the search for answers of whether oxidants can travel from where they naturally develop on Europa's surface to the ocean.

For the time being, comet and asteroid collisions are among the most likely processes. Hundreds of craters have been discovered on Europa's surface, many of which have a characteristic rippling look, implying frozen meltwater and post-impact activity beneath the crater.

Three Conclusions on How Comet Impacts Affect Europa's Ocean

According to Universe Today, the team reached three conclusions from their study, "Surface-To-Ocean Exchange by the Sinking of Impact-Generated Melt Chambers on Europa," published in Geophysical Research Letters.

Melt chambers are formed when comets collide with Europa's icy shell. These chambers distort and descend viscously through the shell. That activity changes the form of the surface craters, as seen by the concentric rings and spider terrain in the Tyre and Manannan craters.
If the transitory hole under the impact site is deeper than half the ice depth, the melted ice can transport chemicals from the surface to the ocean.
Impact melts that drain into the ocean form a porous channel, which may allow ocean water to escape to the surface.