Big gully like river channel spotted on Mars

A NASA spacecraft has spotted a big gully on Mars, a feature which is believed to have formed only within the last three years.

The powerful HiRISE camera on NASA's Mars Reconnaissance Orbiter (MRO) imaged the channel, which is found on the slope of a crater wall in the Red Planet's mid-southern latitudes, on May 25, 2013.

The feature was not present in HiRISE photos of the area taken on Nov. 5, 2010. NASA unveiled the image on Wednesday, Fox News reported.

While the Mars gully looks a lot like river channels here on Earth, it likely was not carved out by flowing water, NASA officials said.

Officials wrote in a description of the gully image that the dates of the images are more than a full Martian year apart, so the observations did not pin down the Martian season of the activity at this site.

But, they added, "before-and-after HiRISE pairs of similar activity at other sites demonstrate that this type of activity generally occurs in winter, at temperatures so cold that carbon dioxide, rather than water, is likely to play the key role.