NASA's Dawn Spacecraft Achieves Orbit Around Ceres
After a seven-year journey, NASA has confirmed that Dawn has successfully achieved orbit around the dwarf planet Ceres. The spacecraft is now officially the first to orbit a dwarf planet.
Ceres is the largest object in the asteroid belt, which lies between Mars and Jupiter. Dawn has spent the last several years making a slow approach towards the dwarf planet, before it was gently picked up by Ceres's gravitational pull early this morning. NASA received the telltale signal at 8:36 am ET, which indicated that Dawn was functioning properly and thrusting its ion engine.
Dawn will spend the next 14 months in Ceres's orbit, studying the celestial object in unprecedented detail. At its closest approach, it will be a mere 40,000 km from the object's surface.
"That's about 10 times closer than the Moon is to the Earth," said Robert Mase, Dawn's project manager. "Over the next month, we'll re-shape the orbit and get ready to begin the prime science phase."
During Dawn's scientific mission, NASA researchers hope to answer several burning questions about the dwarf planet itself, including the nature of those mysterious white spots and the possibility of a liquid ocean. Scientists currently believe that Ceres has a rocky interior covered by an icy surface, which some models indicate may cover a layer of liquid water.
Carol Raymond, the mission's deputy principal investigator, stated that Dawn's observations will also provide insight into the beginnings of our Solar System:
"Both Ceres and Vesta, we believe, are proto-planets. They were on their way to forming larger planetary embryos and they were the type of object that merged to form the terrestrial planets. But these two stopped before they reached that evolutionary stage, and so they are essentially these intact 'time capsules' from the very beginning of our Solar System; and that's really the motivation for why Dawn is going there to explore them in detail."