Since NASA’s Dawn spacecraft took pictures of spooky bright spots on the surface of the dwarf planet Ceres back in March, 2015, astronomers and the public alike have been wondering over what could be producing them. Ice deposits? Volcanoes? Geysers? But now we've at last got our hands on the actual data from Dawn’s most recent fly-by, and different groups of scientists have come up with a couple of interesting theories: the material that is giving these spots their unique shine looks could be some sort of icy salt, and it comprises deposits of ammonia-rich clays, which also provide clues about how Ceres formed.
Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
According to the research paper publishes in Nature, the simplest explanation is that the sublimation procedure of water ice initiate after a combination of ice and salt minerals is uncovered by an impact, which pierces the insulating dark upper crust.
Simply observable against the naturally dark surface of the dwarf planet, these bright spots emit an extensive range of brightness, with some of them reflecting up to 50 percent of the sunlight.
Another team led by Maria Cristina De Sanctis from Italy's National Institute of Astrophysics has proclaimed the finding of ammonia-rich clays in the surface material of Ceres. By means of data from Dawn’s visible and infrared mapping spectrometer, the scientists define how ammonia ice would vanish in the atmosphere of Ceres, but if chemically bound to other minerals, it could stay in a stable form on the surface.
NASA says "The presence of ammoniated compounds raises the possibility that Ceres did not originate in the main asteroid belt between Mars and Jupiter, where it currently resides, but instead might have formed in the outer Solar System. Another idea is that Ceres formed close to its present position, incorporating materials that drifted in from the outer solar system - near the orbit of Neptune, where nitrogen ices are thermally stable."
De Sanctis told Maddie Stone at Gizmodo "The results are quite unexpected. We are now analysing the data taken at higher resolution that could reveal more details about the variegation in composition of the surface."
These results have been issued in different research paper in Nature.