Bright streaks are also associated with craters and other topographic features. They are thought to be deposits of dust, which is much more difficult to remove by erosion; hence the bright streaks change much more slowly than do dark streaks. The leading explanation for the formation of bright streaks is that they are deposited in the waning stages of a dust storm. The dusty atmosphere is more stable than in the case in which dark streaks form. A topographic obstruction creates an aerodynamically “dead” zone in its lee, allowing preferential settling out of the dust to form the bright streak.
Location: Latitude 2°, Longitude 289°, in southern Syrtis Major Planitia. Viking photograph 245B31, NGF orthographic version, red filter.