Extreme Close-Up of Mars's Moon Phobos

coondoggie writes "The European Space Agency's Mars exploring satellite will make a number of close-up passes of the Martian moon Phobos. The Mars Express, which the agency launched in 2003, has begun a series of flybys of Phobos, the largest moon of Mars, that will ultimately set a new record for the closest pass to Phobos — skimming the surface at 50 km, or about 31 miles. This is only about 5 times the irregular moon's average radius. The data collected by the satellite could help solve some of the mysteries about the moon, beginning with that of its origin."