After completing nearly five months scrutinizing the giant asteroid Vesta at its lowest orbit altitude, NASA’s Dawn spacecraft began its final major science data-gathering phase at Vesta on June 15 at an average altitude of 680 kilometers above the surface.
Shown above is an artist’s conception of Dawn orbiting Vesta.
Over six weeks, Dawn spiraled up from its lowest orbit — 210 kilometers above the surface — to the final planned science orbit. Observations obtained from this orbit will provide a companion set of data and images to those obtained during the first high-altitude mapping orbit phase, completed in October 2011. A key difference will be that the angle of sunlight hitting Vesta has changed, illuminating more of its northern region.
Following this final data-gathering phase, Dawn will spend almost five weeks spiraling out from the giant asteroid to the point at which Vesta will lose its gravitational hold on the spacecraft. That departure day is expected to be around August 26. Then Dawn will set its sights on the dwarf planet Ceres, and begin a two-and-a-half year journey to investigate the largest body in the main asteroid belt. Dawn will enter orbit around Ceres in 2015.
The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the Dawn mission team.