This movie clip shows a dust devil seen by NASA's Mars Exploration Rover
Spirit during the rover's 532nd martian day, or sol (July 2, 2005). The
dust-carrying whirlwind is moving across a plain inside Gusev Crater and
viewed from Spirit's vantage point on hills rising from the plain. The
clip consists of frames taken by Spirit's navigation camera, processed to
enhance contrast for anything in the images that changes from frame to
frame. The total elapsed time during the taking of these frames was 8
minutes, 48 seconds.
Spirit began seeing dust devil activity around the beginning of Mars'
spring season. Activity increased as spring continued, but fell off again
for about two weeks during a dust storm. As the dust storm faded away,
dust devil activity came back. In the mid-afternoons as the summer
solstice approached, dust devils were a very common occurrence on the
floor of Gusev crater. The early-spring dust devils tended to move
southwest-to-northeast, across the dust devil streaks in Gusev seen from
orbit. Increasingly as the season progresses, the dust devils are seen
moving northwest-to-southeast, in the same direction as the streaks.
Scientists are watching for the big dust devils that leave those streaks.