Avalanches on Mars - Mars: avalanches on North Polar Scarps - At the top, the...

Avalanches on Mars - Mars: avalanches on North Polar Scarps - At the top, the images show the area where these avalanches occurred. Part of the cliff has become detached in different places creating avalanches of dust. Photo in false colors obtained on 19 February 2008 by the HIRISE camera on board the Mars Reconnaissance orbiter probe. HIRISE is a 50 cm telescope that observes visible and near infrared. Amazingly, this image has captured at least four Martian avalanches, or debris falls, in action. It was taken on February 19, 2008, by the High Resolution Imaging Science Experiment (HiRise) camera on Nasa's Mars Reconnaissance Orbiter. The image to the top shows the context of where these avalanches occurred, with white boxes indicating the locations of the more detailed image portions. All images are false color. Material, likely including fine - grained ice and dust and possibly including large blocks, has detached from a towering cliff and cascaded to the gentler slopes below. The occurrence of the avalanches is spectacularly revealed by the accompanying clouds of fine material that continue to settle out of the air. The largest cloud traces the path of the debris as it fell down the slope, hit the lower slope, and continues downhill, forming a billowing cloud front. This cloud is about 180 meters (590 feet) across and extends about 190 meters (625 feet) from the base of the steep cliff. The scarp in this image is on the edge of the dome of layered deposits centered on Mars' north pole. From top to bottom this impressive cliff is over 700 meters (2300 feet) tall and reaches slopes over 60 degrees. The top part of the scarp, is still covered with bright (white) carbon dioxide frost which is disappearing from the polar regions as spring progresses. The upper mid - toned (pinkish - brownish) section is composed of layers (difficult to see here) that are mostly ice with varying amounts of dust. The darkest deposits below f