First of all, what is a dust devil?
A dust devil is something that happens both on Earth and on Mars and looks somewhat like a mini-tornado. As with tornadoes, dust devils are spinning columns of air. Such a column is called a vortex–you might see the same effect when you let water run down a bathtub drain. Unlike tornadoes, dust devils aren’t usually associated with storms.You typically see them on dry, sunny summer days when there is anywhere from a little to no breeze. You might say they look something like that Tazmanian Devil cartoon character — he spins ’round and ’round like a tornado when he moves. A dust devil is actually a visual apparition of a wind vortex. If there isn’t any dust on the ground, a vortex might still form but no one would see it. An example of a vortex without dust might be the scene in the film American Beauty where the plastic shopping bag is caught on videotape, spinning, spiraling, and dancing in the air. Dust devil vortices form when the air is fairly calm and the ground is heated by sun
