Sunday, March 18, 2007
Mars Is Drier Than Expected
A spacecraft orbiting Mars has discovered deposits of ice at its south pole so thick that they would cover the planet in 36 feet of water if they were melted, said scientists. The scientists used the joint NASA-Italian Space Agency radar instrument on the European Space Agency Mars Express spacecraft to estimate the thickness and volume of ice deposits at the Martian south pole. These ice deposits cover an area larger than Texas.
But researchers are baffled by what happened to the water -- perhaps only 10 percent of the water that once existed on Mars is now trapped in the polar ice caps.
"Even if you took the water in these two (polar) ice caps and added it all up, it's still not nearly enough to do all of the work that we've seen that the water has done across the surface of Mars in its history."
The amount of water in the Martian past may have been the equivalent of a global layer hundreds of meters deep, while the polar deposits represent a layer of perhaps tens of meters. Other water may exist below the planet's surface or perhaps some was lost into space through the atmosphere.
But researchers are baffled by what happened to the water -- perhaps only 10 percent of the water that once existed on Mars is now trapped in the polar ice caps.
"Even if you took the water in these two (polar) ice caps and added it all up, it's still not nearly enough to do all of the work that we've seen that the water has done across the surface of Mars in its history."
The amount of water in the Martian past may have been the equivalent of a global layer hundreds of meters deep, while the polar deposits represent a layer of perhaps tens of meters. Other water may exist below the planet's surface or perhaps some was lost into space through the atmosphere.
# posted by uv : 12:26 PM
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