And it's not going to be a short visit, NASA Jet Propulsion Laboratory Director Charles Elachi said during a news conference Monday. "We're planning to move in and stay," he said.
Dawn, which is able to enter and exit planetary orbits with finesse because of its unique ion propulsion system, previously visited Vesta, a large asteroid in the belt between Mars and Jupiter. Vesta and Ceres have both preserved many of the elements present during their formation in the early days of the solar system, but Vesta — a rocky body — has burned off many of its lighter elements and become dry. Ceres is thought to have ice and water vapor, and scientists hope to learn much about the formation of the early solar system by comparing and contrasting the unique features of the two.
"Dawn [the mission name] is not an acronym, which is most unusual here at NASA," Jim Green, director of planetary science for NASA, said Monday. "It really refers to what this mission is all about, which is going back in time."
When the New Horizons mission reaches Pluto this summer, the NASA representatives said during Monday's news conference, they'll be quick to add this larger, much more distant dwarf planet's data to the mix.
Everything is looking good for Friday, when Dawn is expected to swing into an orbit of Ceres. But even though the encounter is set to begin in the wee hours of the morning, we can't expect a dramatic view of bleary-eyed scientists watching from mission control.
That's because Dawn won't be in the right position to transmit data back to Earth until several hours after it enters orbit. Sometime later Friday morning, NASA should get the signal that Dawn has accomplished the entry.
Scientists are eager to see what secrets Ceres can reveal to us, but we'll have to wait a while. For the first month in orbit, Dawn will be in blackout mode on the dark side of the planet. It will start taking its first scientific readings (and more amazing pictures) sometime during late April. Then, Dawn will alternate between taking readings and making controlled spirals ever closer to the dwarf planet. In December, it will be at its closest approach, less than 250 miles above the surface of Ceres.
By then, JPL deputy project scientist Carol Raymond said during Monday's event, Ceres's mysterious white spots will surely have an explanation.
Raymond said that the two bright spots, which are still too small to resolve in the latest images of Ceres (which show around four kilometers per pixel) might be ice or salts. It's possible that the crater they sit within means that an impact revealed parts of a subsurface ice layer.
"The team is really, really excited about this feature, because it is unique in the solar system," Raymond said. "The mystery will be solved, but it's one that's really got us on the edge of our seats."