Cliffs on Devon Island, in the Canadian High Arctic.

Geologists note that some photos unveiled on June 22 from Mars Global Surveyor of wet Martian gullies appear amazingly similar to water-carved features found on Earth.

The Martian gullies pictured are on cliffs, typically in crater or valley walls. At the end of a gully, debris has cascaded down the slope.

On Devon Island, Rice and co-investigator Pascal Lee, a researcher at the SETI Institute in Mountain View, California, and a planetary scientist at NASA's Ames Research Center, studied what are called "active-layer-detachment slides."

The island shows evidence that the thawed ice first builds-up behind an ice barrier, then bursts the dam and slides downhill in the form of a muddy slush. The slush moves in slow pulses and creates an apron of deposits in its wake.

These deep channels on the surface of Mars that seem to flow down-slope could have been formed by water seeping out of an underground aquifer layer. How frozen ice would melt and flow downhill is a great mystery.

The geological phenomenon found at the Arctic impact crater appears similar to features found on Mars, Rice said. He plans to return to Devon Island this summer to carry out more studies.

"Im not saying they are exactly the same. The process may or may not be occurring on Mars. But it fits. It makes a lot of sense. But then youve got to ask where that liquid water is coming from," Rice said.

"Mars is getting really interesting. It never lets us down. As long as we get there in one piece, it always has surprises for us," Rice said.

While these features may be a few million years old, they cannot be ruled out as having been formed days ago, said Michael Malin, principal investigator for the spacecraft's camera, which was built at Malin Space Science Systems in San Diego, California.

A subsurface water supply on Mars, similar to an aquifer, is believed to responsible for the features. Still a puzzle, however, is the process that started water flowing on Mars.

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Christopher McKay, a Mars researcher at NASA's Ames Research Center in Moffett Field, California, also sees a link between the new Mars pictures and cold springs in the permanently frozen subsoil at Earth's polar regions.

McKays research has taken him to a fiord in western Axel Heiberg Island in the Canadian Arctic.

At that location, McKay and his colleagues have found cold springs that punch up through nearly 2,000 feet (610 meters) of soil year-round.

Like the Arctic spring water that is salty, saturated salt water on Mars would be stable even under the thin Martian atmosphere, McKay said.

If confirmed, the presence of liquid water on Mars would have great implications for the search for past or present life on the planet.

"If life ever did develop there and if it survives to the present time, then these landforms would be great places to look," said Edward Weiler, NASA's space science chief.

Jack Farmer, a specialist in Mars biology and geology at Arizona State University in Tempe, said interpreting the Martian landforms as being shaped by liquid water "is pretty robust."

"These kind of features could be common on Mars. It kind of opens up a whole new way to look at the planet," he said.

Flowing water may be tied to a deep groundwater system on Mars, in which water is pushed up through cracks in the crust.

Simulations in Earth laboratories under realistic Martian conditions are needed to determine if Mars Global Surveyor really is seeing evidence of recent water, Farmer said.

Ground ice on Mars may be a natural place to look for life, Farmer said. "In my view, thats the first place to go," he said.

"Organisms living in subsurface habitats would be entrained in the water. When they come up they are quickly incorporated in ground ice. So the organisms are cryo-preserved in the ice," he said.

Bruce Jakosky, head of the Center for Astrobiology at the University of Colorado in Boulder, said the Mars Global Surveyor data is compelling.

"Im convinced beyond any doubt," he said.

Scientists have suspected for three decades that there was water somewhere on Mars, perhaps deep within its interior. The geological record shows that the planet once was warm and wet -- as Earth is today.

"This is the first time we have evidence that says there is liquid water at the present," Jakosky said. "Maybe not yesterday, but within the last 1 [million] or 10 million years. And its near the surface."

But the mystery of Mars will remain until more spacecraft can get there and examine the planet up close.

"Its clear that theres so much we dont know about Mars," he said. "Were still picking around the edges of the problem. Is there life or was there ever life? Hopefully, well answer that over the next decade."