The Dawn spacecraft has lifted the veil on another corner of the Solar System by taking its best image yet of the dwarf planet Ceres. The nine-pixel-wide image was taken from a distance of 740,000 mi (1.2 million km) from Ceres as part of the final calibration of Dawn's science camera as the unmanned probe approaches the 590 mi (950 km) wide planetoid, which it will rendezvous with and orbit in March of next year.
At its current distance from Dawn, Ceres is as bright as Venus as seen from Earth. Until now, the best images of Ceres came from the Hubble Space Telescope, but NASA says that as Dawn draws closer to its rendezvous, much higher resolution images will be sent back.
Dawn was launched on September 27, 2007 atop a Delta II rocket from Space Launch Complex 17B at Cape Canaveral Air Force Station, Florida. After making a flyby of Mars on February 4, 2009 in a slingshot maneuver, it went into orbit around the protoplanet Vesta on July 16, 2011, where it carried out a 14-month survey of the surface.
The 1,240 kg (2,730 lb) spacecraft then used its ion thruster to send it on a three and a half year passage to Ceres. When it arrives in March 2015, it will mark the first visit to a dwarf planet by any spacecraft. In addition, by visiting Vesta and Ceres, Dawn will have visited the two most massive objects in the asteroid belt, with Ceres the largest object in the asteroid belt between Mars and Jupiter and making up a third of the mass of the entire belt.
"Now, finally, we have a spacecraft on the verge of unveiling this mysterious, alien world," says Marc Rayman, chief engineer and mission director of the Dawn mission at NASA's Jet Propulsion Laboratory in Pasadena, California. "Soon it will reveal myriad secrets Ceres has held since the dawn of the solar system,"
Dawn begins its final approach to Ceres on December 26.