Steps in Slipher S

Boulders on the floor of Slipher S crater. Some boulders are covered with impact melt, while others are well exposed. The Sun angle is from the bottom right, and the crater floor is sloped downwards to the top left. LROC NAC M156558063RE, image width is 650 m [NASA/GSFC/Arizona State University].

Boulders are a common feature on the Moon, in and out of craters. These boulder steps occur within the crater floor of Slipher S, an Eratosthenian crater. Slipher S's floor is uneven and covered with impact melt. These boulders were likely created in the Slipher S impact event, while at the same time they were covered by impact melt. The uneven topography of the crater floor provides many sloped surfaces for the boulders to weather out of, and in this case has caused steps to form!

LROC context image of today's featured image, located within the white box. Image width is 100 km [NASA/GSFC/Arizona State University].

Look for more boulders and impact melt in the full LROC NAC image!

Related Posts: Bouncing, Bounding Boulders!, Exposed Boulders in Aitken Mare

Published by Drew Enns on 19 May 2011