Moon is shrinking and wrinkling due to quakes, says study

The moon is steadily shrinking, causing wrinkling on its surface and quakes, according to an analysis.

An image of wrinkle ridges in the moon surface taken by NASA this week. Picture: NASA/AFP

The moon is steadily shrinking, causing wrinkling on its surface and quakes, according to an analysis published yesterday of imagery captured by NASA’s Lunar Reconnaissance Orbiter.

A survey of more than 12,000 images revealed that lunar basin Mare Frigoris near the moon’s north pole — one of many vast basins long assumed to be dead sites from a geological point of view — has been cracking and shifting.

Unlike our planet, the moon doesn’t have tectonic plates. Its tectonic activity occurs as it slowly loses heat from when it was formed 4.5 billion years ago.

This in turn causes its surface to wrinkle, similar to a grape that shrivels into a raisin. Since the moon’s crust is ­brittle, these forces cause its surface to break as the interior shrinks, resulting in so-called thrust faults where one section of crust is pushed up over an adjacent section.

As a result, the moon has become about 50m “skinnier” over the past several hundred million years. The analysis was published in Nature Geoscience and examined the shallow moonquakes recorded by the Apollo missions, establishing links between them and very young surface features.

AFP