Three Dust Devils
Last month we were struck by this photo of a monster dust devil on Mars that stretched 12 miles high. A spectacular image, for sure, but smaller versions frequently form across the martian landscape. Here are three in one shot, from NASA's HiRISE mission, which explains on its website, "Dust devils are driven by the heat of the surface, absorbed from sunlight and re-radiated to warm the atmosphere. The warm air rises and spins as it contracts, much as a figure skater spins faster as she draws her arms to her sides." They occur on Earth, too.
Photo: NASA/JPL/University of Arizona