NASA photos show Martian avalanches

PASADENA, Calif., March 4 (UPI) -- Debris tumbling from four Martian avalanches has been photographed by U.S. spacecraft orbiting around Mars, NASA reported.

Ingrid Daubar Spitale of the University of Arizona in Tucson, who helps target the High Resolution Imaging Experiment camera on the Mars Reconnaissance Orbiter and has studied hundreds of its images, was the first person to notice the landslides, the space agency said on its Web site.

"It really surprised me," Spitale said. "It's great to see something so dynamic on Mars. A lot of what we see there hasn't changed for millions of years."

The photos were taken Feb. 19 and released Monday.

The camera frequently revisits selected places on Mars to track seasonal changes, NASA's Jet Propulsion Laboratory in Pasadena, Calif., said.

"We don't know what set off these landslides," said Patrick Russell of the University of Berne, Switzerland, a High Resolution Imaging Experiment team participant. "We plan to take more images of the site through the changing Martian seasons to see if this kind of avalanche happens all year or is restricted to early spring."