NASA’s Dawn mission became the first spacecraft to orbit two different extraterrestrial bodies.
Launched in September 2007, Dawn used solar-electric ion propulsion to travel through the asteroid belt. It first entered orbit around Vesta in July 2011, studying the large protoplanet’s geology, composition, and enormous impact basin.
Dawn then departed Vesta and reached the dwarf planet Ceres in March 2015. This made it the first spacecraft to orbit a dwarf planet and the first to orbit two extraterrestrial bodies during one mission. Its observations of Ceres revealed bright salt deposits in Occator Crater and evidence of a complex icy interior.
Dawn is often confused with NASA’s Galileo or Juno missions, both of which explored Jupiter. MESSENGER orbited Mercury, but it did not orbit two separate worlds.