Rings of Neptune narrow, dusty ringlets and even fainter broad dusty rings. The rings of Neptune, like those of Uranus, are thought to be relatively young; their age is probably significantly less than that of the Solar System. Also, like those of Uranus, Neptune's rings probably resulted from the collisional fragmentation of onetime inner moons. Such events create moonlet belts, which act as the sources of dust for the rings. In this respect the rings of Neptune are similar to faint dusty bands observed by "Voyager 2" between the main rings of Uranus. The innermost ring of Neptune is called the "Galle ring"
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