Mars images suggest recent water flow

larger   Liquid water may have recently flowed through deep craters and canyons on Mars, like this one in the Noachis Terra area

June 21, 2000
Web posted at: 5:34 p.m. EDT (2134 GMT)

In this story: Hot springs on Mars? 'Chance to find extant life' Mighty Valles Marineris RELATED STORIES, SITES

By Richard Stenger
CNN.com Writer

(CNN) -- Despite its cold and arid surface, Mars displays signs of recent liquid water activity in numerous places, bolstering theories that simple life forms could have emerged on the red planet, scientists said Wednesday.

Researchers detected evidence of past water seepage while looking at images snapped by the Mars Global Surveyor spacecraft, sources said.

A NASA scientist said the Surveyor images suggest the water flowed on the surface "recently," which in geologic terms could mean anywhere from a few days to a thousand years ago.

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The photos suggest the water activity occurred at various locations and elevations, a senior space agency scientist said.

Scientists have long thought 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 today as ice in the northern polar 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, said a scientist who has looked at the report.

"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 bubbled to the surface. But the presence of deep 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, if they exist, could 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 would not comment on the report, but had planned a major science announcement the day Science publishes the Mars paper. The space agency and Science have since decided to announce the findings Thursday morning at separate press conferences.

Principal investigators Michael Malin and Ken Edgett will take part in the NASA news event, NASA said.

Extending for thousands of miles, the colossal Valles Marineris canyon could be one of many places on Mars that has liquid water

Some of the research could focus on the Valles Marineris region, a colossal canyon that dominates the martian landscape, according to NASA Watch, an independent news Web site that monitors the space agency.

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.

Correspondent Miles O'Brien contributed to this report.

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NASA
Mars Global Surveyor
Science
NASA Watch
Malin Space Science Systems
The Mars Society

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