MOON IMPACTS

New research has been able to find accurate ages for the Moon’s larger craters formed in the last billion years.  Here you can listen to these 11 impacts occur within 1 minute with larger craters producing louder and deeper notes. The sustained cello-like drone in the background is created by converting the elevation of the Moon’s entire surface directly into a sound wave (see below).

The craters were dated by studying how fast the ejected material cools during the lunar nighttime. The debris from older craters has crumbled more over time and the smaller pieces are able to cool very fast. Younger craters are still surrounded by ejected boulders which stay warmer for longer. Surprisingly, the data shows that lunar impacts became more frequent about 290 million years ago. This indicates that the Earth likely also faced a greater rate of impacts at that time, although many of the impact craters have long disappeared. This increased rate may have been the result of a large asteroid breaking up in the asteroid belt, which could send its debris towards Earth for hundreds of millions of years.

The precise elevation of the Moon’s entire surface has been mapped by the Lunar Reconnaissance Orbiter’s laser altimeter (LOLA) to create a topographic map. This is the coloured image that appears during the video with the highest elevations being red and the lowest being blue. We have scanned through every row of this image (spiralling around the Moon) and converted the elevation measurements directly into a sound wave. Since each line of the image is similar to the lines before and after, a periodic wave emerges that slowly morphs as it moves South across the Moon’s surface. This is like spinning the Moon under a giant record needle!