A Beautiful Impact

Young impact craters sometimes present a striking array of tones in their ejecta. Illumination is from the southeast, image is ~500 m across, LROC NAC M156964572L [NASA/GSFC/Arizona State University].

Yesterday's Featured Image post focused on soils of contrasting reflectivity within the ejecta blanket of a 3 km diameter impact crater. Today's post shows another example of recently disturbed lunar soils, but associated with a crater only 80 meters in diameter. Impacts from space debris occur randomly across the lunar surface. The target for this event just happened to be a fault slump along the western wall of Lomonosov crater in the farside highlands.

The white square shows the Featured Image location within a larger context portion of the NAC frame. Image is ~2.4 km across. [NASA/GSFC/Arizona State University].

Once again we see space-weathered, low-albedo deposits mixing with fresher materials of higher albedo excavated from beneath the surface layer. Because of space weathering, the Moon is actually a dark object in the solar system. This overall low reflectance is not apparent to the human eye when seeing the Moon at night because the Moon is in direct sunlight against the inky black background of space. In spacecraft images showing the Earth-Moon system (properly exposed as a pair), the low albedo of the Moon becomes obvious.

The WAC moasic shows the Featured Image location on the rim of Lomonosov crater. Image is ~108 km wide. [NASA/GSFC/Arizona State University].

Lomonosov may be a highland crater, but its floor more closely resembles a mare deposit, being composed of a smooth lava plain. Compare Lomonosov with Plato crater in the 29 May 2012 post. Some of the brighter patches of material in the northernmost portion of the floor are ejecta from the young crater Giordano Bruno to the northeast, demonstrating once again the effects on albedo that recent craters can have. Examine the full NAC frame below. Additional examples of recent small craters can be found in On the Shore of the Bay of Rainbows, in Recent Impact in Oceanus Procellarum, and Crater in 3D!

Published by James Ashley on 31 May 2012