Tuesday, May 22, 2007

Spirit digs up more evidence for water

It was an entirely accidental event, but when a gummed up wheel on the Spirit rover scuffed up some Martian dirt it revealed something that literally had NASA scientists gasping with amazement. Beneath the regular dirty red Martian earth was a layer of intensely bright material, which analysis revealed to be extremely high in silica, so much in fact (90 percent) that it almost certainly required water to produce. One possible origin for the silica may have been volcanic activity, with the silica brought about through the interaction of water, the soil, and acid vapours from the volcano. The material could also have formed in water in a hot spring environment. Either way, it offers yet more compelling evidence for a high water presence on Mars in the past, and that can only increase speculation that Mars may once have enjoyed an environment much closer to Earth than it does today.