Astronomy Picture of the Day: 12/20/13 - Dust Devil Trails on Mars

When most of us think of the Red Planet, we picture a dead planet, home to a seemingly endless red horizon, chock-full of rock and dust, with the sun appearing as a much smaller point in the sky than the huge, blindingly bright orb we are used to. All of those are true, but Mars is actually much more than that. Images such as this help showcase its true marvels.

The image, taken by the HiRISE camera (belonging to the Mars Reconnaissance Orbiter) at around noon (Martian-time), captures one of the most magnificent dust devil trails ever seen on Mars. These storms tend to be unpredictable and can quickly grow from a contained storm, to almost engulf the entire planet in howling wind. (some of the "dust devils," which are essentially miniature tornadoes, can become up to 8 kilometers in height.)

The storms generally occur when warm air rises and cool air sinks, creating horizontal winds that began spinning until they form a vortex. On Mars, we can clearly see the color of the sand (which is actually dark grey beneath the thin film of iron oxide, due to the presence of basalt). The dust devils are known to disrupt the outermost layer, revealing the colorful landscape pictured here.

Sources and Further Reading: http://www.fromquarkstoquasars.com/astronomy-picture-of-the-day-122013-dust-devil-trails-on-mars/

Image Credit: HiRISE, MRO, LPL (U. Arizona), NASA