Scientists have discovered substantial deposits of water ice buried in shallow soils near Mars’s equator. The find could spur hopes for astrobiologists seeking life on Mars or future colonists seeking a supply of water, but it also raises a mystery for climate scientists.
The findings come from a reanalysis of data from NASA’s Odyssey spacecraft, which began orbiting Mars in 2001 and is the oldest functioning mission at the planet. One of Odyssey’s instruments measures the neutrons kicked up from the martian surface by cosmic rays striking the planet. From these neutron counts, scientists can infer the amount of hydrogen—and thus, presumably, the amount of water—present in the uppermost meter or so of soil. In small amounts, the water can take many forms—either in hydrated minerals or as small ice particles stuck between particles of sand or silt. But when the inferred abundances rise above 26%—as they do in some regions—scientists are pretty sure that bulk ice sits just below the surface, says Jack Wilson, a planetary scientist at Johns Hopkins University’s Applied Physics Laboratory in Laurel, Maryland.To read more, click here.