NASA/JPL/University of Arizona
Behold the latest B-movie horror! Not really. It's just Phobos, the larger and inner of Mars's two moons, in a new image captured by instruments on NASA's Mars Reconnaissance Orbiter on March 23 from a distance of 6,800 kilometers (4,200 miles). Researchers operating the craft's High Resolution Imaging Science Experiment (HiRISE) combined this snapshot with a second one, taken 10 minutes later, to generate a stereo view suitable for the drive-in (available here
). The oblong moon measures some 22 kilometers (14 miles) in length and the image has a resolution of about 15 meters (50 feet), according to NASA. Researchers say that information gleaned from the flyby may help them to understand the origin and evolution of the moon, which is thought to be rich in ice and carbon compounds. The picture reveals that material around the rim of Stickney crater, the moon's largest surface feature [lower right
], appears bluer than its surroundings, suggesting that it hasn't been exposed to space for as long. Also visible are landslides, grooves and crater chains illuminated by sunlight reflected from Mars.