Research done at NASA led by Kevin Hand suggests that the dark features on the surface of Jupiter's moon Europa could be sea-salt. The current theory is this salt was deposited there by recent geological activity and changed colour as Europa was blasted with radiation from Jupiter's strong magnetic field. Tests at NASA's Jet Propulsion Laboratory with a set up nicknamed "Europa in a can" subjected multiple materials to electron beams similar to Jupiter's radiation that simulate centuries of exposure. When doing tests with sodium chloride (common salt), it gave off a similar spectra to the features on the surface of Europa. If there is sea-salt in Europa's hidden sea, it would be great evidence for life to exist there.