Other evidence comes from Lunar Reconnaissance Orbiter images that show boulders at the bottom fault scarfs. Weathering from solar radiation gradually darkens material on the lunar surface, and because these boulders are surrounded by brighter material it suggests that these regions were recently exposed to space, as expected if a recent moonquake had sent material sliding down the cliff.Does the Moon’s shrinkage affect Earth?The shrinking Moon doesn’t cause any effects on Earth. Although it’s contracting, the Moon’s mass isn’t changing. This means that lunar effects on Earth’s rotation and tides won’t change due to its size reduction.The Moon is getting farther away from EarthAs well as shrinking in volume and surface area, the Moon is also shrinking in apparent size from Earth’s perspective as it gradually moves farther away from our planet. The Moon moves about 4 centimeters (1.5 inches) farther away from us every year. This slow but steady distancing is primarily caused by the two-way gravitational interaction between Earth and the Moon. Most people are familiar with the Moon’s gravitational effects on Earth, which cause tides. But you may not know that these tides in turn pull back on the Moon. Tides are essentially bulges on Earth, both in water and on land. There are always two bulges on Earth: one on the side facing the Moon and one on the opposite side. These bulges move around the planet along with the Moon. But because Earth is also rotating at a faster rate than the Moon’s orbit around it, the bulge closer to the Moon is always pulling slightly ahead of the Moon, tugging it along in the process. This slight pull from the passing bulge causes a very gradual increase in the Moon’s orbital speed. As the Moon speeds up it moves to a higher orbit, farther away from the Earth, which in turn slows it down.
Is the Moon shrinking? | The Planetary Society
