Spirit tracks Mars’s dusty winds hustling across a plain inside the Gusev Crater. Clusters of images, which are captured every 20 seconds by the Spirit’s navigation camera, reveal the speed of the Martian dust devils, which scientists could only hypothesize about previously from static images. “This is the best look we’ve ever gotten of the wind effects on the Martian surface as they are happening,” says Mark Lemmon, a rover team member who studies Mars’s harried atmosphere.
The dust devils have also helped out the mission. The winds have occasionally swept away the dust from Spirit’s solar panels, allowing the rover to draw more power from the sun and extending Spirit’s lifespan.