New images of ancient cracks on Mars suggest that liquid may have percolated through underground rock, providing a possible habitat for primitive life.
NASA’s Mars Reconnaissance Orbiter, which carries the most powerful magnifying camera yet sent to the Red Planet, captured the images in September 2006 as it flew over a Martian canyon called Candor Chasma.
While analyzing the images, geologist Chris Okubo of the University of Arizona in Tucson and his colleagues noticed that faults and fractures appeared to be lighter in color than surrounding rock. That’s an indication that the flow of a fluid made minerals leach from and react chemically with material along cracks, the team reported last month in San Francisco at the annual meeting of the American Association for the Advancement of Science.
The researchers estimate that millions of years ago, the minerals were deposited about a kilometer underground. Signs of their activity became visible only after overlying layers of rock eroded.
If organisms arose within an underground water flow, the rock layers could have sheltered them from the harsh environment at the surface, Okubo says.
The data suggest new places to search for signs of past life on Mars, says Dave Des Marais of NASA’s Ames Research Center in Mountain View, Calif.