Giant glaciers buried under the surface of

Mars at much lower latitudes than any previously known ice are a potential source of drinking water for future astronauts.

The discovery, made using ground-penetrating radar on NASA's

Mars Reconnaissance Orbiter, offers new possibilities in the search for life on the red planet.

"If there is life on Mars, this kind of ice would likely preserve ancient organisms and DNA," researcher Jim Head, a planetary geoscientist at Brown University, told Wired.com. "Examining the water ice could give you a good sample to try to detect if there had been life there."

The newly-discovered glaciers, reported Wednesday in Science, appear to contain the largest volume of Martian water ice outside the poles.

"Just one of the features we examined is three times larger than the city of Los Angeles, and up to one-half mile thick, and there are many more," said study leader John Holt of the University of Texas at Austin, in a press release.

Many scientists doubted that giant reservoirs of ice could exist on Mars so close to the equator, but calculations suggest these regions were once much colder than they are now, due to variations in the tilt of Mars'

rotational axis. The ice was buried under debris, and as the areas warmed, the ice was insulated by its protective layer of surface rock.

Puzzling surface features above the glaciers, such as sloping deposits of rock near larger mountains, were first noticed by NASA's

Viking orbiters in the 1970s. Some experts thought they represented rocky debris made slippery by tiny bits of ice mixed with dirt. But recent studies of buried glaciers on Antarctica, which look markedly similar, support the buried glacier hypothesis.

Recently Mars Reconnaissance Orbiter confirmed that there really are giant layers of ice hidden under the surface with data from its SHARAD

radar instrument. When the radar scanned the regions, its reflected signal bounced back in a pattern consistent with traveling though a thick layer of ice, rather than rock. Furthermore, the velocity of the radar's reflected radio waves matched that expected from passing through water ice.

The glaciers are good news for future studies on Mars, because they lie at more easily accessible latitudes than the freezing cold poles. They could even prove helpful as a source of drinkable water to future astronauts exploring Mars.

"This says there may be samples of ice within our reach," Head said. "If we're thinking ahead to human exploration of

Mars, it means we could go to some of these places and actually have water ice there."

See Also:

Citations:

"Radar Sounding Evidence for Buried Glaciers in the Southern Mid-Latitudes of Mars"

John W. Holt, Ali Safaeinili, Jeffrey J. Plaut, James W. Head, Roger J. Phillips, Roberto Seu, Scott D. Kempf, Prateek Choudhary, Duncan A. Young, Nathaniel E. Putzig, Daniela Biccari, Yonggyu Gim doi:10.1126/science.1162780

Image: ESA/DLR/FU

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