Table Salt Compound Spotted on Europa

Using a visible-light spectral analysis,
planetary scientists at Caltech and NASA’s Jet Propulsion Laboratory in
Pasadena, California, have discovered that the yellow color visible on portions
of the surface of Europa is actually sodium chloride, a compound known on Earth
as table salt, which is also the principal component of sea salt. Meanwhile, JPL scientist Kevin Hand had used sample ocean
salts, bombarded by radiation in a laboratory under Europa-like conditions, and
found that several new and distinct features arose in sodium chloride after
irradiation. By taking a close look with the NASA/ESA Hubble Space
Telescope, the research team was able to identify a distinct absorption in the
visible spectrum at 450 nanometers, which matched the irradiated salt
precisely, confirming that the yellow color of Tara Regio reflected the
presence of irradiated sodium chloride on the surface.

Source: www.jpl.nasa.gov