NASA’s Dawn mission scientists have just released a new close-up image of mysterious bright spots on the crater-pocked surface of Ceres. This is among the first snapshots from the spacecraft’s second mapping orbit, which is 2,700 miles (4,400 km) in altitude.
The bright spots on dwarf planet Ceres are seen in this image taken by Dawn on June 6, 2015. Image credit: NASA / JPL-Caltech / UCLA / MPS / DLR / IDA.
Planetary researchers are still puzzled by the nature of these spots, and are considering explanations that include salt and ice.
The spots consist of many individual bright points of differing sizes, with a central cluster. The region with them is in a crater about 55 miles (90 km) across.
“The bright spots in this configuration make Ceres unique from anything we’ve seen before in the Solar System. The science team is working to understand their source,” explained Dr Chris Russell of the University of California, Los Angeles, who is the principal investigator for the Dawn mission.
“Reflection from ice is the leading candidate in my mind, but the team continues to consider alternate possibilities, such as salt.”
“With closer views from the new orbit and multiple view angles, we soon will be better able to determine the nature of this enigmatic phenomenon.”
Numerous other features on Ceres intrigue scientists as they contrast this world with others, including protoplanet Vesta. Craters abound on both bodies, but Ceres appears to have had more activity on its surface, with evidence of flows, landslides and collapsed structures.
Dawn arrived at Ceres on March 6. It is the first mission to visit a dwarf planet, and the first to orbit two distinct Solar System bodies. From July 2011 through September 2012, the probe studied Vesta.
The space probe entered its second mapping orbit on June 3. Circling Ceres every three days, Dawn will make extensive observations when it is over the sunlit side and will transmit its findings to Earth when it is over the side in darkness.
The spacecraft will then move toward its next orbit of altitude 900 miles (1,450 km), arriving in early August, 2015.
