An analysis of two Martian meteorites — Northwest Africa (NWA) 7034 and Allan Hills (ALH) 84001 — shows that Mars likely received water from at least two vastly different sources early in its history; the variability implies that Mars, unlike Earth and the Moon, never had a global ocean of magma. This computer-generated view depicts part of Mars at the boundary between darkness and daylight. At top right is NWA 7034. Image credit: NASA...
