Wind streaks

Wind streaks

. The wind is always blowing the lighter particles around, leaving light and dark streaks across the Martian surface. With changing seasons, the winds alter direction, blowing dust away from some regions to reveal darker rocks beneath and covering other dark rocky regions with the brighter dust. This image shows wind streaks formed in the lee of craters and hills in Daedalia Planum, a broad, wind-swept volcanic plain southwest of the Arsia Mons volcano. It covers an area 7.6 thousand by 9.3 thousand meters, and was taken from the Mars Global Surveyor in March 1999. Similar wind streaks have been recorded at mid-latitudes of Mars using cameras aboard the Mariner 9 and Viking 1 and 2 orbiting spacecraft. As seen from Earth, these steaks can combine to form large bright or dark patches on Mars. (Courtesy of NASA, JPL and Malin Space Science Systems.)

Copyright 2010, Professor Kenneth R. Lang, Tufts University