This unnamed 740 m diameter crater has bouldery walls and is
morphologically similar to many <1 km diameter craters in the
mare. Image width is 847 m, LROC NAC M127328861L
[NASA/GSFC/Arizona State University]. The LROC NAC has imaged
thousands of blocky craters similar to this example found in
Oceanus Procellarum. The numerous boulders may be fragments of
bedrock, regolith breccias formed by the impact itself, or a
combination of both. Since a crater depth of excavation is
roughly one tenth its diameter, this small crater has probably
distributed material from about 75 meters depth around its rim.
Usually, ejecta material on the rim comes from the deepest part
of the crater, and ejecta farther away from the crater comes
from shallower depths. Thus astronauts can walk towards a crater
rim, sampling material from greater depths as the rim is
approached in a radial cross-section of the ejecta blanket. As
you look at these boulders, you are witnessing a history of the
emplacement of this mare. If we could just pi