NASA's Mars Exploration Rovers (MERs) sometimes capture fantastic images of Mars while they're exploring the planet on other missions. According to Discovery, the Opportunity Rover was recently searching for clay deposits on a slope near the Endeavour Crater when it turned and managed to take a very cool photo of a dust devil that had formed behind its back.

Dust devils are harmless tunnels of swirling wind and dirt that form when air is heated by the Sun. The first dust devils recorded on Mars date back to the 1970s, and they are capable of reaching sizes that are 10 times taller and 50 times wider than those that form on Earth. According to NASA's Jet Propulsion Lab blog, dust devils have been spotted in the past by MER-A, better known as the Spirit Rover, but it's rare for the Opportunity to witness the vortexes.

The black-and-white image doesn't offer much in the way of details, but for a Rover-shot image, it is pretty impressive. The tracks and ridges in the terrain lead the viewer's eye to the ghostly spiral in the valley below, while the rest of the landscape looks calm and undisturbed. Check out the image below and head to the Jet Propulsion Lab blog for more interesting photos taken of the fourth planet from the Sun.

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[h/t Discovery]