Dawn at Ceres: The First Exploration of the First Dwarf Planet
- Paper number
IAC-17,A3,4A,2,x39024
- Author
Dr. Marc D. Rayman, Jet Propulsion Laboratory - California Institute of Technology, United States
- Year
2017
- Abstract
Dawn has conducted an extensive exploration of dwarf planet Ceres, the largest object between the Sun and Pluto that had not previously been visited by a spacecraft. Following its arrival at Ceres in March 2015, Dawn acquired all the planned data from four circular polar orbits ranging in altitude from 13,600 km to 385 km. After the successful conclusion of its primary mission in June 2016, Dawn's mission was extended one year. New investigations, not previously considered, were conducted from three new orbits. The mission has provided a uniquely detailed view of the first dwarf planet discovered. With a mean diameter of 940 kilometers, Ceres contains about 30\% of the mass in the entire main asteroid belt. It displays extensive evidence of active geological processes, including many areas of high albedo that have been determined to be salts left behind when water sublimated. Dawn also observed ice exposed on the surface and a cryovolcano that was formed within the last 240 million years. The overall strategy for exploring Ceres was based strongly on the extremely successful 16 months of Vesta operations. Nevertheless, the loss of two of the spacecraft's four reaction wheels necessitated some important changes in order to conserve hydrazine. These changes were so effective that Dawn has been able to operate beyond the expected end of life, acquiring significantly more data than planned. This paper will describe Ceres operations in the primary and extended missions as well as the major findings there.
- Abstract document
- Manuscript document
IAC-17,A3,4A,2,x39024.pdf (🔒 authorized access only).
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