That little Martian humanoid we posted about before wasn't the only thing that was strange about the Red Planet. Turns out, it also has circular "crop circles" (yes, I know, there are no crops on Mars, but you know what I mean) left behind by dust devils!
The Martian dust devil documented on March 15, 2005, was spinning across the surface of Gusev Crater just before noon on Mars. NASA's Spirit rover took a series of images that were later assembled to a spectacular 21-frame animation with its navigation camera.
The event occurred during a period of 9 minutes and 35 seconds beginning at 11:48 a.m. local Mars time, recording the dust devil's progress in a northeasterly direction about 1.0 kilometer (0.62 mile) away from Spirit's perch on the slopes of the "Columbia Hills." The whirlwind was travelling at about 4.8 meters per second (16 feet per second) and covered a distance of about 1.6 kilometers (1 mile). The dust devil is about 34 meters (112 feet) in diameter.