Sketching Crater and Sunlight Rays

Abstract

Crater rays are bright ejecta from relatively recent impacts. Rays surround Copernicus, Kepler, and Tycho, and some of them are spread over nearly half of the Moon’s globe. Over the course of millions of years, they gradually fade away during a process called micro-meteoritic gardening. The Moon has no appreciable atmosphere, so that even the smallest meteorite impacts the surface with enough force to create a small pit or crater in the regolith. This constant bombardment effectively mixes the surface breccias, resulting in a gradual homogeneity that obscures the bright rays.