When the carbon dioxide ice on the south polar ice cap of Mars warms up, it usually leaves circular patterns behind. But in this particular stretch of the landscape, the ice has shaped itself into what Mars explorers call “fingerprint terrain” with long grooves about 90 meters apart - and no one knows why. Over the coming months, the Mars Reconnaissance Orbiter will keep a close eye on this area to see if the changing seasons will reveal more.

Location: Mars

Released: 22.August.2007