Friday, March 16, 2007

Ice boosts terraforming dream

One of the abiding dreams of science fiction writers and space scientists is the idea of turning Mars into a planet capable of supporting life on an Earth-like scale. This dream now looks a step closer to reality (though we probably couldn’t do it anytime in the next few hundred years) with the confirmation that huge new deposits of ice water have been discovered on Mars. In fact, Mars's southern polar ice cap contains enough water to flood the entire planet approximately 36 feet deep if melted. Radar measurements from the Mars Express orbiter have found ice fields that are up to 2.2 miles (3,500 meters) thick in places. Equally intriguingly, the ice is very pure, with only about 10 percent dust contamination. Yet this still only accounts for a small percentage of the original water volumes thought to once exist on Mars. Either it is still there, locked up beneath the surface in as yet undiscovered places, or it has leaked slowly away into space through the thin Martian atmosphere. But the more water is discovered, the more plausible becomes the idea that we might one day be able to melt it and start the stupendous job of creating a second Earth in the solar system.