On Earth, its hard to track events that reshape its surface, as the surface itself is being reshaped constantly by weather and tectonic or volcanic upheavals. However, the Moon is much more static, and scientists have been slowly unraveling a pattern that is noticeable in its craters - that something dramatic happened around 800 million years ago. A new paper by researchers at the Southwest Research Institute (SwRI), led by Dr. William F. Bottke, and accepted for publication in the Planetary Science Journal, suggests they might have found a culprit - the parent body of a family of asteroids now known as Eulalia.