Avalanches sur Mars - Mars: avalanches on North Polar Scarps - Detail on a cliff...

Avalanches sur Mars - Mars: avalanches on North Polar Scarps - Detail on a cliff in the region of the north pole of Mars. Part of the surface, consisting of dust and carbon dioxide frost, broke off creating dust avalanches. Photo obtained on January 27, 2010 by the HIRISE camera on board the Mars Reconnaissance orbiter probe. HIRISE is a 50 cm telescope that observes visible and near infrared. This image shows clouds of particles near a steep cliff in the northern polar region of Mars. These clouds, rolling or hovering close to the ground yet reaching up tens of meters high (up to 180 feet), are likely the result of an avalanche or fall of mostly carbon - dioxide frost. The frost clings to the scarp in the darkness of winter and may be disrupted by sunlight and thermal processes with the coming of spring. The cliff, approximately 700 meters (2000 feet) high is made up of layers of water ice with varying dust content, roughly similar to the polar ice caps on Earth. On top is bright white carbon - dioxide ice and frost. Image taken by Mars Reconnaissance orbiter (MRO) on 27 January 2010