As the week draws to a close, NASA's Dawn spacecraft will begin the final climax of its long journey as it enters orbit around the dwarf planet Ceres, the largest body in the Main Asteroid Belt between Mars and Jupiter.
Once it arrives, it's long eight year journey will be complete although there will still be much work for the spacecraft to do. Dawn first let Earth in 2007, first traveling to Vesta, the asteroid belt's second largest body.
During its visit to Vesta, Dawn beamed back more than 30,000 images of the rocky asteroid before it left orbit to head to Ceres, its final destination. It has been two-and-a-half years since it left Vesta, and Dawn will now spend the next 15 months studying Ceres. For the journey, Dawn had to travel approximately 3 billion miles to reach Ceres and during its orbit it will get as close as 235 miles above the surface of the 950 kilometer wide asteroid.
Dawn mission principal investigator Professor Chris Russell of the University of California, Los Angeles, said that Dawn's arrival will be smooth and gentle as it will glides into Ceres' orbit, without using rockets to slow down. He said "Unlike other missions where everyone's gathered in the control room timing down to the critical engine burn and then the whole room erupts in cheers when the engines light up on time, most of us will be at home sleeping as Dawn slips into orbit as the gravity of Ceres begins to dominate the spacecraft's trajectory over that of the Sun."
It is a busy time for NASA, as another spacecraft from the agency, New Horizons, is zooming toward the former planet Pluto and is expected to arrive in July. Dwarf planets are spherical in shape but unlike traditional planets they are smaller and share the same space with other objects in the solar system.
Dawn's approach to Ceres originally began in December and the craft began to snap images of the dwarf planet highlighting bright spots inside one of the crafters. These spots have caused a high amount of interest among scientists as to what is causing the spots. However, scientists and the world will have to wait until Dawn gets close to Ceres before they can discover exactly what is causing the spots to appear in the images.
Once the craft arrives in orbit it will begin to send back more data and images allowing scientists to better understand this and other objects in our solar system with the hope of bringing a better understanding of how the solar system and the planets, including Earth, first began.
