Ceres High Altitude Mapping Orbit (HAMO), Late summer through fall 2015 |
Ceres High Altitude Mapping Orbit (HAMO), Late summer through fall 2015 |
Aug 17 2015, 01:42 AM
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Member Group: Members Posts: 540 Joined: 17-November 05 From: Oklahoma Member No.: 557 |
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: QUOTE 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. |
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Sep 1 2015, 01:09 AM
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Member Group: Members Posts: 714 Joined: 3-January 08 Member No.: 3995 |
Some observations and thoughts on the recent HAMO release (some points mentioned in posts above):
1. The bits of white stuff in the upper parts of the crater wall are interesting as always. Similar features in craters on Vesta and Phoebe come to mind. 2. There is an almost complete (if not complete) lack of discernable craters of any size within the big fresh crater or its ejecta sheet. This is an indication of a very young crater, very recent mass-wasting events, or both. 3. The ejecta sheet has a degraded look to it. It is as if the material subsided or collapsed in places. 4. There is a straight linear feature (fracture?) running along the base of the wall from 9:30 to 11:30. 5. There appears to be a sinuous 'rille' running the length of the large valley on the north side. |
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Sep 1 2015, 09:00 PM
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Junior Member Group: Members Posts: 20 Joined: 9-August 08 From: Lucens, CH Member No.: 4309 |
Some observations and thoughts on the recent HAMO release (some points mentioned in posts above): 1. The bits of white stuff in the upper parts of the crater wall are interesting as always. Similar features in craters on Vesta and Phoebe come to mind. 2. There is an almost complete (if not complete) lack of discernable craters of any size within the big fresh crater or its ejecta sheet. This is an indication of a very young crater, very recent mass-wasting events, or both. 3. The ejecta sheet has a degraded look to it. It is as if the material subsided or collapsed in places. 4. There is a straight linear feature (fracture?) running along the base of the wall from 9:30 to 11:30. 5. There appears to be a sinuous 'rille' running the length of the large valley on the north side. The feature at 9 o'clock (number 3) reminds me of "half Tall Mountain". Tall Mountain is also very close to the rim of a crater. Could it be that the impacts lifted part of the surface à la pingo? Maybe the angle of impact makes a difference? |
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