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Despite its cold and arid surface, Mars displays signs of water springs possibly heated by volcanism, bolstering theories that simple life forms could have emerged on the red planet, according to reports.
Looking at images snapped by the Mars Global Surveyor spacecraft, researchers have detected evidence of springs on the surface, USA Today reported Wednesday. The discovery focuses in part on the Valles Marineris region, a colossal canyon that dominates the martian landscape.
Scientists think Mars' surface coursed with water billions of years ago, based on evidence of liquid erosion and signs of ancient channels and seas. But the water all but disappeared as the planet cooled and its atmosphere thinned.
Water is known to exist in the present as ice in the northern ice cap and as vapor in faint clouds. But vast quantities could remain trapped under the surface, according to planetary geologists.
Many theorize that such groundwater remains in a frozen state. But the Surveyor images suggest that recent underground volcanic forces have heated water into a liquid state, according to a colleague of a Mars scientist who made the discovery.
"What was known before, there was evidence of volcanism occurring in the recent past, say tens of millions of years ago," said MIT planetary geologist Maria Zuber.
"This will be better than that," she said, declining to give specifics. The report will be published in the June 29 issue of Science magazine.
Groundwater would likely turn into vapor or ice soon after it reached the surface. But the presence of hot springs could strengthen the theory that life exists, or once existed, on Mars.
Some unusual forms of microscopic life flourish near hot springs in the recesses of the Earth. Similar springs on Mars might harbor life as well, some scientists speculate.
"This is incredibly exciting. What this means is that we have a chance to find ... extant life," Mars Society president Robert Zubrin said.
NASA officials would not comment on the report, but the agency plans to make a major science announcement the day Science publishes the Mars paper.
Liquid water may have recently flowed through deep craters and canyons on Mars, like this one in the Noachis Terra area
Michael Carr, an expert on martian hydrology, co-authored the report with fellow U.S. Geological Survey scientist Baerbel Lucchita, who has researched Antarctic ice flows and mapped the Valles Marineris, said NASA Watch, quoting unnamed NASA sources.
NASA Watch, an independent Web site that monitors the space agency, first reported news of the Mars discovery earlier this week.
The diverse terrain of the Valles Marineris displays many types of landforms as it snakes across Mars for more than 3,700 miles (6,000 km): volcanic deposits, ancient sea sediment and windblown rock avalanches.
The canyon descends well below the usual surface level of Mars. And scientists have searched the low recesses of Mars in the past for signs of water.
The Surveyor took other photos of deep craters thought to show evidence of past water seepage. One 1997 image of the southern Noachis Terra region reveals crater wall depressions possibly left by leaking groundwater, according to Malin Space Sciences, which operates the Surveyor camera.
Liquid water on Mars would make colonization of the planet much easier. Colonists could convert water into hydrogen and oxygen, using both as rocket fuel and the second for breathing gas.
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