The moon is shrinking and this has consequences for planned space missions

Yes, you read that right: the moon is shrinking – albeit very, very slowly. This was already proven by an analysis of moon images by the American space agency NASA in 2019. Within 100 million years the Earth’s satellite 45 meters lost its range. Although this change cannot be seen with the naked eye, it will still have an impact on future moon landings. A new study published in the Planetary Science Journal offers new insights into this. Here you can read which ones.

Of course, the moon doesn’t just shrink on a whim: the moon’s temperature was just below when it formed 4.5 billion years ago even considerably higher. The reason for the shrinking is the moon’s core, which is constantly cooling, causing the celestial body to ‘shrink’. Almost like a grape slowly becomes a raisin. This, among other things, creates wrinkles in the surface. Unlike the grape, the moon’s surface is solid and fractures, allowing tectonic plates to shift. Due to the shrinking of the moon and the resulting ‘ripples’, violent moonquakes occur again and again.

The astronauts of the Apollo missions in the 1960s and 1970s were already able to measure such moonquakes. They assumed that the earthquakes rarely occur on the surface, but deep beneath the moon dust. But new discoveries show that moonquakes occur near the moon’s surface, only about sixty miles beneath the crust.

The new research from the University of Maryland and the Center for Earth and Planetary Studies shows that future landings could be particularly dangerous at the moon’s south pole. Scientists have also noted shrinkage in this region. There, the researchers examined the curved slopes (possible shrinkage folds) on the moon’s crust. These steep slopes would reach a height of up to 150 meters and, according to the researchers, would be among the youngest landforms on the moon.

While earthquakes on Earth typically last only a few seconds or minutes, shallow moonquakes can last hours or even a whole day. These tremors could theoretically destroy entire human settlements on the moon.

Future moon landings and moon stations are doubly threatened by such moonquakes. On the one hand because of the often long-lasting and extremely strong vibrations and on the other hand because of the risk of the ground slipping and falling rocks that can be loosened on steep crater rims as a result of such earthquakes.

There has not been a manned moon landing since the 1970s. NASA’s ‘Artemis 3’ mission, which was recently postponed until 2026, aims to transport humans to the moon for the first time. But this is not the only planned lunar mission: several research stations are planned on the moon in the future. Including the lunar orbit station (“Gateway”).

As things stand, NASA wants to carry out the planned ‘Artemis 3’ mission despite the dangers. The researchers want to conduct further research with measuring stations in 2026 to minimize the risk as much as possible. The ‘Artemis 3’ mission is of particular interest because of suspected ice deposits and other potentially useful resources in the Antarctic region. The researchers also hope to gain new insights for the construction of future moon stations.