After an almost eight-year journey, the NASA spacecraft Dawn has finally arrived and slipped into orbit of the dwarf planet Ceres making history as the first craft to ever visit a dwarf planet.
"It went exactly the way we expected. Dawn gently, elegantly slid into Ceres' gravitational embrace," said Marc Rayman, chief engineer for the $473 million mission managed by NASA's Jet Propulsion Laboratory in Pasadena.
But now that is has arrived, what lies ahead now that it has finally arrived? In addition to exploring the now famous bright spots found on the surface of Ceres, scientists have much planned for the little history making craft.
Before any serious research can begin, Dawn still has to position itself in order to begin scientific investigations. In fact, the craft won't even be in position to take any new photos of Ceres until April 10.
Dawn "is working now to reshape its orbit around Ceres," Dawn mission director and chief engineer Marc Rayman, who's based at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, wrote in a blog post Friday.
The spacecraft's "orbital acrobatics first will take it up to an altitude of 47,000 miles (75,000 kilometers) on March 19 before it swoops down to 8,400 miles (13,500 km) on April 23 to begin its intensive observations in the orbit designated RC3," Rayman added.
For now it seems the world has to wait to get any serious Ceres fix but patience should be rewarded. Once it has reached position, Dawn will spend almost 16 months studying and photographing the icy surface. Scientists hope that by studying Ceres, they can learn much about how the solar system was formed in its earliest stages.
Ceres, like Vesta, is essentially a protoplanet whose growth was halted by the strong gravitational forces of Jupiter. The observations made by Dawn should provide researchers with insights into the solar system's earliest days and could reveal how rocky planets such as our own planet, Earth, are put together.
Dawn will map much of Ceres' surface in great detail helping scientists learn what it is made of and how it was originally formed. While there, it will also take the time to investigate the bright spots found in some of the first picture of the dwarf planet, which scientists believe to be either water ice or salts and it will also seek to confirm and characterize water-vapor plumes spotted recently by Europe's Herschel Space Observatory.
"By the time we finish in mid-2016, we're going to know Ceres in exquisite detail," Dawn Deputy Principal Investigator Carol Raymond, also of JPL, said during Friday's news conference. "We're going to understand why it has very, very bright spots - which are unique to any body in the solar system that has been explored thus far - and we're going to understand what Ceres means in terms of a building block for planets in our solar system."
Many researchers believed that Ceres once had a subsurface ocean that may have been capable of supporting life, Rayman said. Some researchers believe that Ceres might still harbor some underground liquid water.
"We've been creeping up on Ceres for months, and the anticipation has been growing," Raymond told the Slooh Community Observatory during a Ceres webcast on Friday. "This is certainly a big milestone for us, but mainly, we're already in the frame of mind that Dawn is at Ceres. We've been getting some beautiful data images ... and it's looking like a very interesting world, so we're all very anxious to get a better look."
