Launched in 2007, NASA’s Dawn spacecraft has a mission of studying the two most massive objects in the asteroid belt between Mars and Jupiter: the protoplanet Vesta and the dwarf planet Ceres. Currently en route to Ceres, Dawn has just sent back a series of images of the dwarf planet that will be useful for navigational purposes. At 27 pixels across, the images are three times as detailed as images returned in December. Dawn is expected to deliver pictures every few weeks before it arrives at the dwarf planet on March 6, 2015 to begin a 16-month-long investigation.
Ceres is the largest body in the asteroid belt, with a diameter of 950 kilometers (590 miles), which is around 27% of the size of the moon. It is composed of rock and ice, though there has been some speculation that it may have oceans beneath the surface. As Dawn was able to take 30,000 images and measurements of Vesta from close range between 2011-2012, researchers are hopeful that similar observations of Ceres will help explain mysteries regarding its formation and composition.
"We know so much about the solar system and yet so little about dwarf planet Ceres. Now, Dawn is ready to change that," Dawn’s mission director Marc Rayman said in a press release.
The images were obtained with Dawn’s framing camera from a distance of 383,000 kilometers (238,000 miles). The optical camera is currently used to navigate the probe as it traverses from Vesta to Ceres, though it will later take images of the surface after it enters the dwarf planet’s orbit. The images have been stitched together into an animation.
Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI
"Already, the [latest] images hint at first surface structures such as craters," added Andreas Nathues, who is leading the framing camera team.
Currently, the most detailed images of Ceres come from observations from the Hubble Space Telescope, obtained in early 2004. The images returned from Dawn’s most recent batch are about 80% the resolution of the Hubble images. The next bundle is expected at the end of January, and those images are expected to surpass the quality of those obtained by Hubble.
Ceres imaged by Dawn (left) Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI. Hubble image (right) NASA/ESA/J. Parker/P. Thomas/L. McFadden/M. Mutchler/Z. Levay
"The team is very excited to examine the surface of Ceres in never-before-seen detail," explained Dawn mission’s PI, Chris Russell. "We look forward to the surprises this mysterious world may bring.”
This year should provide a great deal of informations about dwarf planets in our solar system. As scientists prepare for Dawn’s arrival at Ceres in March, they also look forward to the New Horizons spacecraft making its closest approach to dwarf planet Pluto in July. New Horizons will come within 10,000 kilometers (6,200 miles) of Pluto, and will take the first up-close images of the former ninth planet.