Newspaper article The Christian Science Monitor

Evidence of Water on Mars: Could It Boost Possibility of Life?

Newspaper article The Christian Science Monitor

Evidence of Water on Mars: Could It Boost Possibility of Life?

Article excerpt

Mars appears to weep, sending salty water down the slopes of canyon and crater walls to form dark streaks that appear and disappear with the seasons.

The analysis that paints this picture represents the strongest evidence yet that water is responsible for these streaks. It is heightening anticipation that useful amounts of water are accessible in many places on the red planet.

Water is a potential resource for humans exploring Mars, as a raw material for rocket fuel as well as for slaking astronauts' thirst. It also is key to making a place livable for simple forms of life. Thus, the dark streaks may be potential destinations for missions that aim to hunt for current life on Mars.

The evidence that water is producing the dark streaks is indirect, but powerful, researchers say. It's based on an abundance of water-bearing salts. The salts are more abundant along the streaks than in the soils in between them, suggesting repeated deposits from current sources, the researchers announcing the results say. And they are capable of soaking up moisture from the atmosphere to become a briny solution.

The results "strongly suggest" that the streaks "are formed by liquid water on present-day Mars," says Mary Beth Wilhelm, a scientist at the National Aeronautics and Space Administration's Ames Research Center at Moffett Field, Calif., and a member of the team reporting the results in Nature Geoscience.

The analysis is most exciting "because it suggests that it would be possible for there to be life today on Mars," says John Grunsfeld, NASA's associate administrator for the agency's science mission directorate.

The amounts of water so far appear to be modest. The team estimates that the minimum amount of water needed to explain the streaks at its study sites, a section of Valles Marineris, would fill 40 Olympic-size swimming pools.

"That sounds like a lot if it's all in one place. But that's dispersed over a very wide area," says Alfred McEwen, a researcher at the University of Arizona's Lunar and Planetary Laboratory in Tucson. "So what we're dealing with is thin layers of wet soil."

But Mars has a large surface area, so the volume of water planet- wide could be quite large, adds Dr. McEwen, another member of the team reporting the results in Nature Geoscience.

Researchers have been puzzling over these dark streaks since they first were spotted in 2010. They often track gullies carved into slopes. They typically appear on sun-facing slopes during each hemisphere's warm season, only to disappear the rest of the year.

After analyzing a growing number of these streaks, a team led by McEwen concluded last year that the streaks probably come from locally abundant amounts of briny water. The streaks appeared too often to come from melting underground ice, which probably wouldn't be in the equatorial region anyway. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.