Photos Reveal Mars Had Water Underground New, detailed photographs of Mars show evidence of subterranean streams of liquid, including water, that once flowed long enough that they could have sustained simple forms of life, researchers say.
Photos from the Mars Reconnaissance Orbiter of the National Aeronautics and Space Administration reveal a landscape of hills and sand dunes punctuated by rock bleached by minerals in ancient underground streams.
Those streams of water, or water mixed with liquid carbon dioxide, flowed for weeks or longer — long enough to have supported bacteria or other simple life forms, according to a study by the American Association for the Advancement of Science appearing in today’s issue of the journal Science.
“The most interesting aspect we found in these new photos is that we can see that the water, with most likely other dissolved chemicals in it, resided in these areas for weeks or months or longer,” said the study co-author, Chris Okubo, of the Lunar and Planetary Laboratory at the University of Arizona.
“It means these areas would have been potentially habitable,” Mr. Okubo said in an interview.
Mars is the only planet in the solar system besides Earth where scientists believe life might have existed. While previous photos of the planet showed dry river channels and lakebeds, there has been no proof as to whether those surface areas were wet long enough to have supported life, Mr. Okubo said.
Orbiter’s Mars camera photographed canyons in a Martian valley, the Valles Marineris, that is as wide as the United States and seven times deeper than the Grand Canyon in places. The camera, which can pick out detail within a foot, showed rock formations with fractures and with bleached areas that on Earth are “a clear indication” that chemicals in liquids have circulated within the fractures, the study said.
Source:
http://www.nytimes.com/2007/02/16/science/space/16mars.html
'Halos' May Prove Water Flows on Mars WASHINGTON (Feb. 15) - An orbiting spacecraft has sent back new evidence for the presence of water on Mars. Scientists long have debated whether water flowed on the red planet, with evidence increasing in recent years. The presence of water would raise the possibility of at least primitive life forms existing there.
Images from a camera aboard NASA's Mars Reconnaissance Orbiter show alternating layers of dark- and light-toned rock in a giant rift valley.
Within those deposits are a series of linear fractures, called joints, that are surrounded by "halos" of light-toned bedrock, according to researchers from the University of Arizona.
Their findings, published in Friday's edition of the journal Science, were being presented at the annual meeting of the American Association for the Advancement of Science in San Francisco.
Lead author Chris H. Okubo said the "halos" indicate areas where fluids, probably water, passed through the bedrock. Minerals in the fluid strengthen and bleach the rock, he said, making it more resistant to erosion than other areas.
On Earth, bleaching of rock surrounding a fracture is a clear indication of chemical interactions between fluids circulating within the fracture and the host rock," Okubo and co-author Alfred S. McEwen reported in the paper.
The researchers also said that layered outcrops can indicate cycles with materials deposited by regular episodes of water, wind or volcanic activity.
Just last December scientists reported evidence that water may be flowing through Mars' frigid surface. Images from Mars Global Surveyor showed changes in craters that provide the strongest evidence yet that water moved through them as recently as several years ago, and is perhaps doing so even now.
The Surveyor previously had spotted tens of thousands of gullies that scientists believed were geologically young and carved by fast-moving water coursing down cliffs and steep crater walls. Scientists decided to retake photos in a search for evidence of recent activity.
Two craters in the southern hemisphere that were originally photographed in 1999 and 2001 were examined again in 2004 and 2005, and the images yielded changes consistent with water flowing down the crater walls, according to the study.
Source:
http://news.aol.com/topnews/articles/_a/halos-may-prove-water-flows-on-mars/20070215213209990001
.png)
