Evidence of water on Mars found

WASHINGTON -- Mars may have vast deposits of frozen water just beneath its dusty red surface, boosting the possibility of life on the Red Planet and perhaps providing a source for drinking water and rocket fuel for future exploration, researchers report.

In three studies appearing this week in the journal Science, researchers say remote sensing data from the Mars Odyssey spacecraft suggest that large deposits of water ice are buried just one to two feet below the planet's surface.

Instruments aboard the spacecraft which measure the flux of gamma rays and neutrons detected a strong signature for the presence of hydrogen, a sign for dense deposits of water ice.

The ice is covered by a thin layer of dust and broken rock, the researchers say, but the signals suggest that 20 to 35 percent of the icy layer is water, filling the pores the soil.

Earlier studies had shown strong evidence that Mars was once covered with water. The planet has valleys, gullies and channels, characteristic marks of the flow of water. This lead to speculation about how a planet so covered with water could lose its oceans. The new studies suggest that the water drained downward until it was trapped as ice just below the protective layer of soil.

The presence of vast stores of water could simplify exploration of Mars. Astronauts could use the water to drink or to grow crops in shelters. The water could also be split apart chemically, providing oxygen and hydrogen for rocket propellant.

Proof that water is common on Mars also strengthens speculation that the planet could harbor some microbial life forms. Water is considered essential for the evolution of life and some scientists believe they have evidence, from a Martian rock, that the planet once had life.