For more than a decade, scientists have wondered about the nature of the dark material that coats long, linear fractures, and other relatively young geological features on Europa’s surface. Its association with young terrains suggests the material has erupted from within Europa, but with limited data available, the material’s chemical composition has remained elusive.
Previous telescope observations have shown tantalizing hints of the spectral features seen by the researchers in their irradiated salts. But no telescope on or near Earth can observe Europa with sufficiently high resolving power to identify them with certainty. The researchers suggest this could be accomplished by future observations with a spacecraft visiting Europa.
The presence of sea salt on Europa’s surface suggests the ocean is interacting with its rocky seafloor — an important consideration in determining whether the icy moon could support life.