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The Dawn Framing Camera observed Ceres for an hour on January 13 from a distance of 383,000 km (near the average distance of the Moon from Earth). Ceres has a diameter of about 950 km and a rotational period of 9.1 hours, so a little more than half of its surface was observed at a resolution of 27 pixels (0.8 the resolution of Hubble observations a decade earlier). Bright and dark features can be seen in the short video constructed from the Dawn images. The bright spot to the North (up) and two larger dark spots to the South (down) were previously observed by Hubble. The dark extensions near the northern edges of the dark spots are the first new features discovered by Dawn and may represent a continuous structure extending across its mid-latitudes. As Dawn continues its approach to Ceres, it is expected that the nature of these mysterious structures will be revealed and more discoveries made.
Movie courtesy of Lucille Le Corre and Vishnu Reddy, PSI.
The mid-latitudes of Ceres evidence dark, extended surface features. They may be part of a hemisphere-long structure.
Image processed by David O’Brien, PSI.
(Left) All albedo features identified by the Hubble Space Telescope on the side of Ceres observed by Dawn were detected in addition to other features. (Right) Albedo features on Ceres through a 550 nm filter, identified in images by the Hubble Space Telescope (Li et al. 2006, Icarus 182, 143-160).
Dawn image: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI