PRELIMINARY INVESTIGATION OF POLYGONAL CRATERS ON (1) CERES
We use a mosaic composed of FC images to interpret the distribution and geologic setting of polygonal craters on Ceres.
We find polygonal craters with a size of up to 250 km in diameter. A preferential hexagonal shape is observed. Some polygonal craters exhibit central peaks or relaxed crater floors, while other polygonal craters are simple bowl-shaped. Polygonal craters show both relatively distinct and degraded crater rims indicating a continuous formation period. Areas showing a higher density of polygonal craters are evident in the higher latitudes. In the eastern hemisphere, polygonal craters are associated with a set of regional linear structures. The crater rims tend to align with these structures.
We will analyze polygonal crater density, orientation and morphology with respect to Ceres’ geology and thus aim to infer structural information on geologic units. Assuming that polygonal craters are caused by fractures in the impacted material, structural regolith variations as well as tectonics of surface units will be discussed and related to Ceres’ evolution.
[1] Russell, C. T. et al., 46th LPSC, #1131, 2015. [2] Öhman, T. et al., GSA Special Paper 465, pp. 51-65, 2010. [3] Beddingfield, C. B. et al., 46th LPSC, #1159, 2015.
Supported by E. Kersten, K.-D. Matz, A. Naß, F. Preusker, T. Roatsch, S. Schröder, K. Stephan, R. Wagner, C. A. Raymond and C. T. Russell.