Discovery and exploration of the Solar System Soviet "Lunokhod 1", which landed on the Moon in 1970. The first to visit another planet was Sojourner, which travelled 500 metres across the surface of Mars in 1997. The only manned rover to visit another world was NASA's Lunar rover, which traveled with Apollos 15, 16 and 17 between 1971 and 1972. Overview of some missions to the Solar System. See also the categories for missions to , , , and . Crewed exploration of the Solar System ended in 1972. The first human being to reach space (defined as an altitude of over 100 km) and to orbit
Minor planet more are discovered each month. The Minor Planet Center has documented over 188 million observations and 757,626 minor planets, of which 516,386 have orbits known well enough to be assigned permanent official numbers. Of these, 21,264 have official names. , the lowest-numbered unnamed minor planet is , and the highest-numbered named minor planet is 495759 Jandesselberger. There are various broad minor-planet populations: All astronomical bodies in the Solar System need a distinct designation. The naming of minor planets runs through a three-step process. First, a provisional designation is given upon discovery—because the object still may turn out to be a