PASADENA, Calif., Jan. 25 (UPI) -- NASA says its Mars Reconnaissance Orbiter has seen seasonal changes on sand dunes caused by warming of a winter blanket of frozen carbon dioxide.
Springtime on the Red Planet sees changes caused when seasonal coverings of dry ice thaw, going directly from solid to gas as on Earth, and the trapped gas builds up pressure and breaks out in various ways, NASA's Jet Propulsion Laboratory in Pasadena, Calif., said Friday.
The Mars orbiter has captured images of transient grooves formed on dunes when the carbon dioxide gas finds an escape point and rushes out, carrying out sand with it, forming dark fans or streaks on top of the ice layer, scientists with the orbiter program said.
"It's an amazingly dynamic process," Candice Hansen of the Planetary Science Institute in Tucson, Ariz., said. "We had this old paradigm that all the action on Mars was billions of years ago. Thanks to the ability to monitor changes with the Mars Reconnaissance Orbiter, one of the new paradigms is that Mars has many active processes today."