Ceres High Altitude Mapping Orbit (HAMO), Late summer through fall 2015 Options

[Holder of the Tw...]

DAWN arrived in its new lower mapping orbit on August 13th. The DAWN team is preparing to resume science observation tomorrow on the 17th.

From the Current Mission Status page at the DAWN website:

August 13, 2015 - Dawn Arrives in Third Mapping Orbit

Dawn completed the maneuvering to reach its third mapping orbit and stopped ion-thrusting this afternoon. This was a little ahead of schedule because the spiral descent went so well that some of the allocated thrusting time was not needed. Since July 14, the spacecraft has reduced its orbital altitude from 2,700 miles (4,400 kilometers) to approximately 915 miles (1,470 kilometers). The orbit period has correspondingly decreased from 3.1 days to 19 hours.

Dawn is scheduled to begin its new observations on the evening of Aug. 17 (PDT) and continue for more than two months. First, however, the mission control team will measure the actual orbit parameters accurately and transmit them to the spacecraft.

[Ken2]

Dawn HAMO 89 (I'll let ZLD post the picture!)

Caption: "This view of Ezinu Crater on Ceres was taken by NASA's Dawn spacecraft on Oct. 19, 2015. Ezinu is the large crater in the top left corner of the image and contains a canyon-like feature near its center."

Here is a boring hypothesis of the canyon. Fresh craters are excavated cones, so the center is the deepest and has the most ejecta in-fill. Given the numerous landslides elsewhere on Ceres, it appears that the ejecta is relatively fluffy, so as subsequent large impacts cause Ceres-quakes, it is easy to imagine settling, and the center would be the logical place for cracks to form being the deepest. I plan to try shaking a cone of flour to see how this hypothesis holds up in a simple analog !