THE MOON IS SHRINKING

Yes, the moon is indeed shrinking, albeit very slowly. This shrinkage is due to the cooling of the moon's interior, which has caused it to contract by more than 150 feet in circumference over the last several hundred million years.

The shrinking process is similar to how a grape wrinkles when it becomes a raisin. However, unlike a grape's flexible skin, the moon's surface is brittle. This brittleness leads to the formation of "thrust faults" where sections of the crust push up against each other.

The formation of these faults is often accompanied by seismic activity, known as moonquakes, which are similar to earthquakes on Earth.

These moonquakes can last for hours and even an entire afternoon, posing potential risks to future human missions, particularly in areas near or within these fault zones.

A recent study has linked a group of faults in the moon’s south polar region to a powerful moonquake recorded in the past. This region is of particular interest as it is where NASA hopes to land during the crewed Artemis III mission.

The study also found that some areas in this region are unstable due to the moon's ongoing shrinkage, which could lead to landslides and other surface instabilities.

This new understanding of the moon's shrinkage and the associated seismic risks is crucial for the safe planning of future moon missions.