- The Washington Times - Thursday, December 7, 2006

LOS ANGELES (AP) — New photographs from space suggest that water occasionally flows on the frigid surface of Mars, raising the tantalizing prospect that the Red Planet is hospitable to life, scientists reported yesterday.

The images, taken by NASA’s Mars Global Surveyor before it lost contact with Earth, do not show flowing water, but reveal changes in craters that provide the strongest evidence to date that water coursed through them as recently as several years ago and may be doing so even now.

“This is a squirting gun for water on Mars,” said Kenneth Edgett, a scientist at San Diego-based Malin Space Science Systems, which operates a camera on the Global Surveyor.

The news excited scientists who hunt for extraterrestrial life. If the finding is confirmed, they say, all the ingredients favorable for life on Mars are in place: liquid water and a stable heat source.

In all of its Mars exploration missions, NASA has pursued a “follow the water” strategy to determine whether the planet once contained life or could support it now.

Scientists think ancient Mars was awash with pools of water. At present-day Mars’ north pole, researchers have spotted evidence of water ice, but they have not seen water in liquid form.

“This underscores the importance of searching for life on Mars, either present or past,” said Bruce Jakosky, an astrobiologist at the University of Colorado at Boulder, who had no role in the study. “It’s one more reason to think that life could be there.”

Some researchers were skeptical that liquid water was responsible for the surface feature changes seen by the spacecraft. They said other materials such as sand or dust can flow like a liquid and produce similar results.

“Nothing in the images, no matter how cool they are, proves that the flows were wet, or that they were anything more exciting than avalanches of sand and dust,” said Allan Treiman, a geologist at the Lunar and Planetary Institute in Houston.

The findings will appear in tomorrow’s issue of the journal Science.

The Global Surveyor previously spotted tens of thousands of gullies that scientists thought were geologically young and carved by fast-moving water coursing down cliffs and steep crater walls. Scientists retook photos of thousands of gullies in a search for evidence of recent water activity.

Two craters in the southern hemisphere that were photographed in 1999 and 2001 were examined again in 2004 and 2005, and the images yielded changes consistent with water flowing down the crater walls, according to the study.

The Global Surveyor, managed by NASA’s Jet Propulsion Laboratory, abruptly lost radio contact with Earth last month. Several attempts to locate the spacecraft, which has mapped Mars since 1996, have failed, and scientists fear the mission was likely at an end.

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