|VOICE OF AMERICA|
SLUG: 2-313857 Mars/Water (L)
TITLE=MARS / WATER (L)
INTRO: A U-S Mars rover has found more hints that water once existed on the planet. The latest evidence is on the other side of the planet from where scientists showed earlier this week that water once drenched the region. V-O-A's David McAlary reports from Washington.
TEXT: The rover "Spirit" drilled about two millimeters into a volcanic rock nicknamed Humphrey and found holes and cracks filled with minerals.
According to mission scientist Ray Arvidson of Washington University in St. Louis, this suggests that the minerals were carried by water through the lava as it hardened and collected in its tiny openings.
/// ARVIDSON ACT ///
We're not talking about gobs [huge amounts] of water. We're talking perhaps about a little aqueous fluid that's moving through this rock. But it again demonstrates that when rocks are made on Mars, fluids are involved.
/// END ACT ///
On Tuesday, mission scientists announced that a rock on the other side of Mars yielded clues that it had been modified by large amounts of water. They could not say, however, whether the water was a large body like a lake or ocean or whether it was subsurface water that coursed through the rock.
They might be able to answer the question if they can determine how the rock formed. It is not volcanic rock, as in the latest case of Humphrey. Instead, it is what geologists call sedimentary rock, formed in layers either by sediments sinking in water or by volcanic ash that has compacted and hardened. If it formed in water, that would suggest a large body was involved.
In the case of Humphrey rock, Mr. Arvidson says that the water might not have been ground water, but water that had already been mixed with the molten lava as it rose to the martian surface and hardened.
/// 2nd ARVIDSON ACT ///
It means Mars is a diverse planet and it really behooves us to continue to look at these rocks, particularly dark rocks, and looking for Mother Nature to have broken some apart so we can see inside.
/// END ACT ///
Scientists want to see deeper into other volcanic rocks like Humphrey to make sure that the minerals inside were truly deposited by water and are not simply remains of dust that infiltrated down a few millimeters from the surface.
Sites where water once flowed on Mars will become targets for a future U-S mission around 2010 to collect soil and rock samples for return to Earth. Scientists will scour them for signs of life. (SIGNED)
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