Dust devils galore: Mars Express visits Mamers Valles on Mars. Credit: ESA/DLR/FU Berlin
The European Space Agency's Mars Express has captured part of Mars's Mamers Valles, a fascinating valley system speckled with brief, tornado-like whirlwinds known as dust devils.
Dust devils form as parts of Mars warm in the sun, causing the air just above the surface to swirl upward and carry dust with it. Mars's dust devils are similar to those seen in dry, dusty landscapes on Earth, but far larger. They tower up to 8 kilometers (5 miles) high, rove about for kilometers at a time, and reach top speeds of 45 meters per second. They play a key role in moving dust across the planet.
Mars Express is uniquely equipped to spot these mini whirlwinds. To form a single image using its High Resolution Stereo Camera—the instrument responsible for these new snapshots—the spacecraft combines sequential views from up to nine separate camera channels (which look at Mars in a different color, from a different direction, or a mix of the two). If nothing changes on the Martian surface while these are being taken, the multiple perspectives align—but if something is moving about, it stands out clearly from its surroundings.
