An unmanned Soviet space satellite has sent back to Earth the first images of the larger of Mars' two moons, the Tass news agency said. The space probe, launched July 12, began orbiting Mars on Jan. 29 as part of a program to unlock the secrets of the red planet and its larger moon, Phobos, which is seven miles in diameter. The Phobos II probe was moved into a closer orbit Saturday and began beaming broadcasting images of the moon at midday Tuesday, Tass said.