September 27, 2008

UA Camera Hints Mars Was Wet Far Longer Than Thought


Mars may have had water coursing through its red soil for a billion years longer than scientists previously had thought, increasing the possibility that the planet could have supported life, research conducted by a Tucson-based institute shows.

Using high-resolution images from a camera developed at the University of Arizona, researchers with the Planetary Science Institute examined soil deposits on plains that surround a vast canyon network that runs around the planet's equator.

With the close-up views of the region provided by the orbiting HiRISE camera - which stands for High Resolution Imaging Science Experiment - scientists were able to see clay and other soil deposits that are normally formed by the presence of water.

Scientists previously had seen similar phenomena in the nearby canyons of Mars, hinting that water had disappeared as the surface of the planet evolved.

By finding similar features in the plains above the canyons, the images show that water was still shaping the surface long after the canyons were formed, said Cathy Weitz, the research scientist who led the project.

"It's very surprising that you see these valley networks," she said.

"It tells you that something had to have been there to have water flowing for a sustained period."

Though Weitz, who is based in Virginia, said other geological processes, such as wind, could have caused the features, it appears as though there was some precipitation in the area.

The team's findings are scheduled to be published in the journal Geophysical Research Letters.

Expanding the window in which water flowed on the planet opens all sorts of possibilities, said Mark Sykes, director of the institute.

"If you've got 2 billion years where liquid water is present, what that does is increase the chances for life to have evolved," he said. "It's a very interesting result."

Scientists still aren't sure what caused the liquid water to disappear or where it might have gone, but the research points to the possibility that water flowed in several areas of the planet, Weitz said.

"It wasn't like there were big Mississippi Rivers flowing, but for some reason something about that location allowed water to be maintained on the surface."


The HiRISE camera, developed at the University of Arizona, has been circling Mars aboard the Mars Reconnaissance Orbiter since March 2006.

The camera has captured a series of historic and detailed pictures of Mars' surface and in May captured an image of the Phoenix Mars Lander as it descended to the red planet.

Images taken from the orbiter by the HiRISE camera are sent back to Earth as radio signals, received by giant dish antennae in the Mojave Desert, Spain and Australia and relayed to the UA, where they are examined.

* Contact reporter Aaron Mackey at 807-8012 or at [email protected] Get all the latest UA news by visiting correspondent.

Originally published by AARON MACKEY, ARIZONA DAILY STAR.

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