LIVERMORE, Calif., Oct. 12 (UPI) -- Mars' largest moon, Phobos, is well known for its resemblance to the Death Star, the mobile space station and planet-destroying weapon from Star Wars. Now, scientists know how Phobos' unique appearance came to be.
A massive crater, spanning nearly half the moon, lends Phobos its Death Star-like appearance. Until now, astronomers couldn't figure out how an impact could leave such a sizable mark without destroying the satellite.