After 7.5 years of travel, NASA has confirmed that its Dawn probe has gone into orbit around the dwarf planet, Ceres. It will spend the next 14 months mapping it out and will hopefully provide us with clues to the origin and formation of our Solar System.
Dawn has already provided scientists with their first mystery: the appearance of two bright spots on the surface. The dots could be the reflection of ice or water vapor, or could even be a sign of seismic activity.
Dawn also recently took 27 photos of Ceres during its rotation in order to make an animated view of the dwarf planet rotating. The publicly released version of this animation had been stretched to make Ceres’ disk appear circular. Ceres is, in fact, quite oblate, so this version has had Ceres’ shape corrected.
The spacecraft previously visited asteroid Vesta in the same neighborhood – the asteroid belt between Mars and Jupiter. Ceres is the larger of the two at 950 km across, while Vesta has a diameter of 525km.
The Dawn probe reached Ceres using an ion propulsion system, or ion engine. The ion propulsion system’s efficient use of fuel and electrical power enable modern spacecraft to travel farther, faster, and cheaper than any other propulsion technology currently available. Ion thrusters are currently used for stationkeeping on communication satellites and for main propulsion on deep space probes. Ion thrusters expel ions to create thrust and can provide higher spacecraft top speeds than any other rocket currently available.
The infographic below helps to describe the anatomy of an ion engine.