Scientists have for years enjoyed images of dark trails on the surface of Mars left by dust devils, which are atmospheric phenomena similar to tornadoes. But few are as dramatic as this NASA photo, taken in September and released earlier this month.

The Mars Global Surveyor (MGS) image shows several dark streaks created during the recent southern spring by dust devils, as they passed over and around an old, nearly filled, meteor impact crater.

The circular feature is the former crater. Dark dots and specks on its rims are boulders, said astronomers at Malin Space Science Systems, which operates the spacecraft's camera.

Dust devils create streaks by removing or disrupting thin coatings of fine, bright, dust on the surface, the astronomers said. The features will disappear before the next spring arrives in 2005. The crater is located near 57.4°S, 234.0°W. The image covers an area 1.9 miles (3 kilometers) wide and is illuminated from the upper left. [More about dust devils]

Credit: NASA/JPL/Malin Space Science Systems