NASA Study Says Water Flowed Freely On Mars

By K.C. Jones
InformationWeek
July 18, 2008 11:56 AM

Scientists have studied data from NASA's Mars Reconnaissance Orbiter and they believe Mars once had large lakes, flowing rivers, and other wet environments that could have supported life.

A study published in the July 17 issue of Nature shows that large ancient highlands of Mars contain clay minerals, which needed water to form. Volcanic lava buried the highlands, which cover about half of Mars' surface, but craters later exposed them in thousands of locations, NASA said.

NASA said the minerals record the interaction between water and rocks about 4.6 billion to 3.8 billion years ago, soon after scientists believe the solar system formed. Scientists based their findings on information from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on the Reconnaissance Orbiter.

"The big surprise from these new results is how pervasive and long-lasting Mars' water was, and how diverse the wet environments were," Scott Murchie, CRISM's principal investigator at Johns Hopkins University Applied Physics Laboratory, said in an announcement.

John Mustard, a member of the CRISM team from Brown University, and lead author of the Nature study, said many rocks were slightly altered by water, "but in a few locations they have been so altered that a great deal of water must have flushed though the rocks and soil.

"This is really exciting because we're finding dozens of sites where future missions can land to understand if Mars was ever habitable and if so, to look for signs of past life," he said.

An earlier study, published in the June 2 issue of Nature Geosciences, concluded wet conditions existed on Mars thousands to millions of years after the clays formed. Scientists believe that rivers flowed through the highlands and through a delta into a crater lake a little larger Lake Tahoe in California.

"The distribution of clays inside the ancient lakebed shows that standing water must have persisted for thousands of years," Bethany Ehlmann, CRISM's team member and lead author of the study of an ancient lake on Mars, said. "Clays are wonderful at trapping and preserving organic matter, so if life ever existed in this region, there's a chance of its chemistry being preserved in the delta."

Murchie said his team will use the findings to create a list of sites to explore and search for organic chemistry and "perhaps determine whether life ever existed on Mars."