August 4, 2011

Flowing Water May Have Been Found On Mars

Researchers using NASA's Mars Reconnaissance Orbiter have found possible flowing water on Mars.

A team using the HiRISE camera aboard the Mars orbiter have tracked seasonal changes to determine that finger-like features appear and extend down some Martian slopes during the warmest months of the Mars year.

The features fade during the winter, and return during the next spring. 

Repeated observations have tracked the seasonal changes in these recurring features on several steep slopes in the middle latitudes of Mars' southern hemisphere.

"The best explanation we have for these observations so far is flow of briny water, although this study does not prove that," Alfred McEwen of the University of Arizona's Lunar and Planetary Laboratory, said in a press release.

The flows of liquid brine fit the features' characteristics better than other theories, according to NASA.

"These dark lineations are different from other types of features on Martian slopes," Mars Reconnaissance Orbiter Project Scientist Richard Zurek of NASA's Jet Propulsion Laboratory in Pasadena, California said in a statement. "Repeated observations show they extend ever farther downhill with time during the warm season."

The features are only about 0.5 to 5 yards wide, with lengths up to hundreds of yards.  Some of the locations display over 1,000 individual flows.

The images taken by the HiRISE camera show that flows lengthen and darken on rocky equator-facing slopes from late spring to early fall.

When the team checked flow-marked slopes with the orbiter's Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), there was no sign of water that appeared.

NASA said the features may quickly dry on the surface, or could be shallow subsurface flows.

"The flows are not dark because of being wet," McEwen said. "They are dark for some other reason."

"It's a mystery now, but I think it's a solvable mystery with further observations and laboratory experiments."

The researchers published their results in the journal Science.


Image 1: An image combining orbital imagery with 3-D modeling shows flows that appear in spring and summer on a slope inside Mars' Newton crater. Image credit: NASA/JPL-Caltech/Univ. of Arizona

Image 2: This map of Mars shows relative locations of three types of findings related to salt or frozen water, plus a new type of finding that may be related to both salt and water. Image Credit: NASA/JPL-Caltech/ASU/UA/LANL/MSSS


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