Chuck Bednar for redOrbit.com – Your Universe Online
New images of Ceres captured by NASA’s Dawn spacecraft during its approach to the dwarf planet are the best yet obtained by the spacecraft, and appear to show evidence of craters as well as a mysterious white spot first discovered by the Hubble Space Telescope in 2003.
According to the US space agency, the new pictures show Ceres at 27 pixels across, roughly three times better than the calibration of the previous best images of the dwarf planet, which had been captured by Dawn back in December. These new photographs are the first in a series taken for navigation purposes during the probe’s approach to this unexplored planetoid.
In the next few weeks, Dawn will deliver increasingly higher-resolution images of Ceres as it prepares to enter orbit around it on March 6. Those images will keep improving as Dawn moves closer to the surface during a scheduled 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,” Marc Rayman, Dawn’s chief engineer and mission director at the Jet Propulsion Laboratory (JPL) in Pasadena, California explained on Monday.
While these latest pictures are the best yet obtained by Dawn, they still pale in comparison to those captured by Hubble more than a decade about. The new images are roughly 80 percent of the resolution of those taken by the telescope in 2013 and 2014, and are not quite as sharp.
However, Dawn will surpass Hubble’s resolution during its next imaging opportunity, which will take place at the end of the month, according to NASA. Even so, the new pictures “hint at first surface structures such as craters,” said Andreas Nathues, lead investigator for the Dawn framing camera team at the Max Planck Institute for Solar System Research in Gottingen, Germany.
Ceres, the largest body in the main asteroid belt that lies between Mars and Jupiter, has an average diameter of 590 miles (950 kilometers). It is also believed to contain a large amount of ice, and some scientists think that its surface could conceal an ocean, the agency said.
According to CNET, astronomers believe that Ceres may be a planetary embryo or protoplanet that was formed inside a star’s protoplanetary disc during the creation of the solar system. It has a differentiated interior produced by internal melting, but is not large enough to be a full planet.
Dawn will be the first probe to ever visit a dwarf planet once it arrives at Ceres, and CNET said that experts believe that studying the mysterious planetoid could provide valuable data about the formation of our solar system. The spacecraft was launched in 2007 with the goal of studying both Ceres and Vesta, the largest and second largest objects in the solar system, respectively.
“The team is very excited to examine the surface of Ceres in never-before-seen detail,” Chris Russell, principal investigator for the Dawn mission at the University of California, Los Angeles (UCLA) said. “We look forward to the surprises this mysterious world may bring.”
Dawn orbited Vesta during 2011 and 2012, capturing and delivering over 30,000 images from the planetoid. Thanks to its ion propulsion system, the probe has become the first spacecraft ever targeted to orbit two deep-space destinations. It will enter orbit around Ceres on March 6.
So what is that white spot visible in the new images? According to EarthSky, that’s one of the mysteries that Dawn will have to try and solve once it gets closer to Ceres. One hypothesis, the website said, is that it could be “a frozen pool of water ice at the bottom of a crater” that reflects the sun’s light. Astronomers will have to wait at least a few more months to find out for sure.
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