Solar conjunction the line of sight to an interior planet (Mercury or Venus) being very close to the solar disk. If the planet passes directly in front of the sun, a solar transit occurs. Solar conjunction Solar conjunction occurs when a planet or other solar system object is on the opposite side of the sun from the Earth. From an Earth reference, the sun will pass between the Earth and the object. Communication with any spacecraft in solar conjunction will be severely limited due to the sun's interference on radio transmissions from the spacecraft. When in reference to Satellite Communications, solar conjunction
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