MILLEDGEVILLE — Every once in a while Mars makes the news even when nobody is landing there and the rovers are quietly hibernating. Last week, an orbiting spacecraft snapped some beautiful images of a dust devil on Mars, and it made headlines in many places.

You’ve probably all seen dust devils before; I remember sitting on the front steps of Russell Auditorium one sunny Sunday afternoon last fall when a dust devil entertained me for well over a minute, whirling dry leaves around in a rotating column a good 15 feet tall. You can observe dust devils most easily on dry, large, hard surfaces such as parking lots.

Martian dust devils are quite famous, and there are actual videos out there that the Mars rovers captured while observing the landscape around them. Dust devils are a Mars rover’s best friends because they provide a good cleaning of solar panels and other vital surfaces. The air on Mars is incredibly thin — nothing like here on Earth — so for a dust devil to form, it takes some doing. It’s also very cold on Mars, so circumstances have to be just right for the thin air to be heated properly to result in a dust devil. But Mars is also unbelievably dusty because it’s so dry there, so when a dust devil does form, it’s visible from a long way off — even from orbiting satellites!

But what is a dust devil, anyway?

Relax, there’s nothing evil about them — they’re one of Mother Nature’s quirkier children that rarely do harm, although some have reportedly wreaked some havoc in very isolated cases. So don’t go lying awake at night worrying about dust devils!

They may look like tornadoes, but they are formed quite differently, generally on clear and sunny days with very little wind. As the air directly above two different surfaces is heated to different temperatures (such as a grassy area bordering a parking lot) the air rises at different speeds, and sometimes the rising air streams begin to rotate and pick up speed. Because warm air rises, it sucks up dust and other lightweight material and pulls it upward, and you can actually see the size of the vortex then.

My Russell Front Steps Dust Devil was only about four feet across, but in wide open spaces they can grow to tornado-sized funnels of hundreds of feet across and wind speeds of 75 miles per hour in extreme cases.

Fall and spring are especially good times to observe dust devils here in Milledgeville — when the ground can be cool and the sun warms the air directly above it. So the next time you find yourself waiting for a ride or a friend in a parking lot, be on the lookout for dust devils. Most of them last only seconds, but others might entertain you for much longer. Either way, you can pretend you’re Mars rover “[insert your name]” and quickly take a picture, or if you want to get all fancy, snap a video of it.

We’ll watch it later on YouTube.

Watch a short video of a Martian dust devil here: http://www.youtube.com/watch?v=bY59iEWeMFw&feature=related