NASA scientists have confirmed that the Moon is gradually “escaping” Earth, moving away by approximately 3.8 cm each year. This data was obtained through laser measurements using special mirrors left on the lunar surface by astronauts.
The average distance between the Earth and the Moon today is about 385,000 kilometers. However, the Moon’s orbit is not a perfect circle, so this distance fluctuates by as much as 20,000 kilometers each month. These monthly changes are what allow us to observe phenomena like a Supermoon, when the Moon appears exceptionally large and bright.
According to experts, the reason for the Moon’s gradual retreat is related to tides. The Moon’s gravity creates bulges of water on Earth. Because of our planet’s rotation, these bulges are carried slightly ahead of the Moon, and their gravitational pull effectively “tugs” on the Moon, pushing it into a higher orbit. In this process, Earth loses some of its rotational momentum, causing its spin to slow down and making our days longer—by a fraction of a second every few million years.
Scientists note that in the distant past, the Moon was much closer. Fossilized mollusk shells show that around 700 million years ago, an Earth day lasted only 23.5 hours. In the far future, billions of years from now, the Earth and Moon may reach a state of synchronization where the Moon stops moving away. However, humanity will not be around to witness this event, as by then the Sun will have expanded into a red giant, consuming both planets.
