Dawn mission
Dawn was a NASA mission that orbited the asteroid Vesta and the dwarf planet Ceres, using ion engines.
Dawn was a NASA spacecraft launched in September 2007. Its ion engines, which push xenon ions out at high speed, gave a gentle but continuous thrust that let it become the first spacecraft to orbit two different bodies beyond the Earth–Moon system.
Dawn orbited the asteroid 4 Vesta from July 2011 to September 2012. It mapped a huge impact basin near the south pole, named Rheasilvia, about 500 kilometres across, and found minerals matching the HED meteorites. This strongly supported the idea that howardites, eucrites and diogenites are pieces of Vesta, many probably blasted off in the Rheasilvia impact.
Dawn then orbited the dwarf planet Ceres from March 2015 until its fuel ran out in 2018. It discovered bright salt deposits, such as those in Occator crater, made of sodium carbonate left by briny water. Dawn remains in orbit around Ceres.
Related terms
Level: Enthusiast Teens and adults