Preliminary Geological Map of the Ac-H-5 Fejokoo Quadrangle of Ceres: An Integrated Mapping Study Using Dawn Spacecraft Data

In order to enable methodical geologic mapping of the surface of Ceres the Dawn Science Team divided its surface into fifteen quadrangles. A preliminary map of the Fejokoo quadrangle is presented here. This region, located between 21˚-66˚N and 270-0˚E, hosts four primary features: (1) the centrally located, 90 km diameter, distinctly hexagonal impact crater Fejokoo; (2) a small unnamed crater midway up the eastern boundary of the quadrangle which contains and is surrounded by bright material; (3) an unnamed degraded crater NW of Fejokoo that contains lobate material deposits on both sides of the crater's S rim; and (4) a heavily cratered unit in the NW portion of the quadrangle. Key objectives for the ongoing mapping of this quadrangle are to assess the types of processes that may be responsible for the creation of the hexagonal Fejokoo crater, identifying the source and nature of the bright material on the eastern boundary, establishing possible mechanisms for the emplacement of lobate material deposits in Fejokoo and the unnamed crater to its NW, and establishing a detailed geological history of the quadrangle. The Fejokoo region is not associated with any major albedo feature identified by the Hubble Space Telescope (Li et al., 2006). At the time of this writing geologic mapping was performed using Framing Camera (FC) mosaics from the Approach (1.3 km/px) and Survey (415 m/px) orbits, including grayscale and color images and digital terrain models derived from stereo images. Future images from the High Altitude Mapping Orbit (140 m/px) and Low Altitude Mapping Orbit (35 m/px) will be used to refine the maps. Support of the Dawn Instrument, Operations, and Science Teams is acknowledged. This work is supported by grants from NASA, and from the German and Italian Space Agencies.