As NASA's Dawn spacecraft closes in on Ceres, new images show the dwarf
planet at 27 pixels across, about three times better than the calibration images
taken in early December. These are the first in a series of images that will be
taken for navigation purposes during the approach to Ceres.
Over the next several weeks, Dawn will deliver increasingly better and better
images of the dwarf planet, leading up to the spacecraft's capture into orbit
around Ceres on March 6. The images will continue to improve as the spacecraft
spirals closer to the surface during its 16-month study of the dwarf planet.
"We know so much about the solar system and yet so little about dwarf planet
Ceres. Now, Dawn is ready to change that," said Marc Rayman, Dawn's chief
engineer and mission director, based at NASA's Jet Propulsion Laboratory in
Pasadena, California.
The best images of Ceres so far were taken by NASA's Hubble Space Telescope
in 2003 and 2004. This most recent images from Dawn, taken January 13, 2015, at
about 80 percent of Hubble resolution, are not quite as sharp. But Dawn's images
will surpass Hubble's resolution at the next imaging opportunity, which will be
at the end of January.
“Already, the [latest] images hint at first surface structures such as
craters," said Andreas Nathues, lead investigator for the framing camera team at
the Max Planck Institute for Solar System Research, Gottingen, Germany.
Ceres is the largest body in the main asteroid belt, which lies between Mars
and Jupiter. It has an average diameter of 590 miles (950 kilometers), and is
thought to contain a large amount of ice. Some scientists think it's possible
that the surface conceals an ocean.
Dawn's arrival at Ceres will mark the first time a spacecraft has ever
visited a dwarf planet.
"The team is very excited to examine the surface of Ceres in
never-before-seen detail," said Chris Russell, principal investigator for the
Dawn mission, based at the University of California, Los Angeles. "We look
forward to the surprises this mysterious world may bring."
The spacecraft has already delivered more than 30,000 images and many
insights about Vesta, the second most massive body in the asteroid belt. Dawn
orbited Vesta, which has an average diameter of 326 miles (525 kilometers), from
2011 to 2012. Thanks to its ion propulsion system, Dawn is the first spacecraft
ever targeted to orbit two deep-space destinations.
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