Report: Ice, not floods, could have shaped channels on Mars

An ice stream in the Antarctica image (top) resembles an outflow channel on Mars (bottom). The large arrows in both pictures point to where the channels split around topographical rises. This and other similarities suggest the red planet once possessed an ocean, according to a planetary geologist   MESSAGE BOARD Destination Mars

By Richard Stenger
CNN.com Writer

(CNN) -- Streams of ice rather than heavy flooding could have shaped long channels that riddle the surface of Mars, according to a new NASA-funded report.

Certain channels on the red planet bear a striking resemblance to outflow arteries in the Antarctic, noted lead scientist Baerbel Lucchitta. The findings give credence to the theory that ancient Mars was a wet planet, she said.

Lucchitta compared the martian channels to frozen ice flows in streams within Antarctica's ice sheets. The features in both locations extend hundreds of kilometers or miles.

Some martian channels exhibit similar characteristics to those of Antarctic channels carved by ice streams, the U.S. Geological Survey scientist noted. The configuration of some streams is identical, she wrote in the February 1 issue of Geophysical Research Letters, a publication of the American Geophysical Union.

Looking at Ares Valles, a long valley on Mars, Lucchitta speculated that some material resembling flowing ice entered a body of water covered by ice.

"The observations strongly support the notion that an ocean once existed in the northern plains of Mars," she said in a statement.

As part of the study, funded by NASA's Planetary Geology and Geophysical Program, Lucchitta studied Antarctic channels recently mapped with improved sonar imaging.

The Flagstaff, Arizona-based scientist compared ice streams that flow from West Antarctica into the Ross and Ronne Ice Shelves with red planet channels like Kasei Valles that terminate in the northern plains, where there might have been an ocean billions of years ago.

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NASA
U.S. Geological Survey
American Geophysical Union

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