Impact on a Slope

An unnamed crater ejecta inside Dante C crater (54 km in diameter). LROC NAC M1137707212L, center 28.463°N, 182.491°E, width is 1728 m, downslope is to the lower-right [NASA/GSFC/Arizona State University].

Dante C is a ~54 km diameter crater, located in the central farside highlands. In the northwestern portion of the crater floor, there is an unnamed crater (~3 km in diameter) with a spectacular diffuse asymmetric ejecta pattern (see next WAC no-shadow context view, right side).

The uphill side (upper-left) shows a distinctive wavy pattern of ridges and grooves (seen in the opening picture) within about 3 km of the rim. Probably due to the background slope (Dante C crater wall, downslope is to the lower-right), the ejecta hit the ground and stopped in a shorter distance than on the downhill side, leaving partially wrinkled edges in the ejecta deposits. The downhill side shows a smooth surface without the wavy pattern, implying that the thin layer of ejecta spread out homogeneously on the downslope. Also, the thickness of the ejecta itself might have been asymmetric due to the local slope. The uphill slope can interrupt ejecta's lateral motion, leaving unique ridges and grooves, another example of the range of crater forms found on the Moon.

Context view of Dante C crater and surrounding areas in LROC WAC monochrome mosaic overlayed with the WAC stereo DTM (GLD100, left) and WAC no-shadow mosaic (right, 100 m/pix). Image center is 28.57014°N, 182.63728°E, width is 62 km, north is to the top. The NAC footprint (blue box) and the location of opening image (yellow arrow) are illustrated [NASA/GSFC/Arizona State University].

Explore the asymmetric ejecta with clear wave patterns in full NAC frame and in LROC QuickMap!

Related posts:

Impact Art

Bright and Dark Ejecta

Dynamic Textures

Ejecta Patterns

Lassell D Ejecta

In the Wake of Giordano Bruno

Ground Hugging Ejecta

Published by Hiroyuki Sato on 22 April 2014