Sequence of Events During and After Emplacement of Cerealia Facula Deposits on Ceres
Abstract
The extraordinarily bright deposits found within the young 92 km crater Occator on Ceres have sparked interest and discussion since they were first observed as the Dawn spacecraft approached this dark dwarf planet of the asteroid belt in 2015. Analyses of prime mission integrated global data from an altitude as low as 385 km resulted in a series of detailed papers soon to appear as a special issue devoted to Occator crater (summarized in Scully et al., 2018, Icarus, in press). The Dawn spacecraft is completing a special series of final orbits that are elliptical with a perigee as low as 35 km from the surface, providing exceptionally high spatial resolution data for priority targets such as Occator crater. We are using these remarkable new data to evaluate the sequence of events involved with the (volatile-driven) emplacement process of the bright faculae deposits along with subsequent local adjustments within the crater. Initial data shows that thick portions of the bright deposits appear to be coherent and have a sharp boundary with underlying dark material. There are places where originally contiguous deposits have been separated by a prominent topographic shift, implying significant post depositional local adjustment. Streamers from the bright deposit can be observed flowing to lower elevations. Nearby smaller faculae also exhibit limited central continuous bright deposits (as evidenced by superimposed small bright craters) with distal deposits being thin (as evidenced by what appear to be small dark craters that have excavated underlying dark material). Discrete small individual deposits of bright material 10s of m in size can be observed up to several kilometers away. As the final Dawn data are collected, we will further investigate the complex sequence of events that emplaced the bright deposits and also produced a plethora of associated features across the floor of the crater. Our goal is to constrain the origin of these remarkable deposits in order to determine whether they are unusual or simply the youngest version of a common sequence of events on this dwarf planet.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.P33D3860P
- Keywords:
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- 6024 Interiors;
- PLANETARY SCIENCES: COMETS AND SMALL BODIESDE: 6055 Surfaces;
- PLANETARY SCIENCES: COMETS AND SMALL BODIESDE: 6063 Volcanism;
- PLANETARY SCIENCES: COMETS AND SMALL BODIESDE: 6205 Asteroids;
- PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS