Facts About the Moon Drifting Away from Earth and Its Impact on Humanity

The average distance from Earth to the Moon is about 384,400 kilometres. However, that distance is not constant. Over time, the Moon is slowly moving away from Earth.

Changes in the distance between Earth and the Moon can be measured using the Lunar Laser Ranging Experiment. During the Apollo missions in the 1960s, astronauts placed special reflectors on the Moon’s surface to determine the exact distance from Earth.

The way to calculate this distance is by measuring the time it takes for a laser beam to be reflected back by the reflector. From these calculations, it is known that the two are continuously moving apart at a rate of 3.8 cm per year.

This change certainly has an impact, at least on the phenomenon of total solar eclipses in the future.

IFL Science explains that the Moon’s recession will make total solar eclipses no longer visible, given that the apparent size of the Moon’s disc is becoming smaller from Earth.

At present, the apparent sizes of the Sun and the Moon are almost the same. Therefore, people on Earth can still see the Moon cover the entire surface of the Sun when the eclipse phenomenon occurs.

“Over time, the number and frequency of total solar eclipses will decrease. About 600 million years from now, Earth will witness the beauty of a total solar eclipse for the last time,” said NASA scientist Richard Vondrak in 2017.

In terms of physical size, the Sun is indeed 400 times larger. However, its distance from Earth is also 400 times farther than the distance from Earth to the Moon.

Meanwhile, the apparent size of the Moon in the sky is also reported to be continuously shrinking. Four billion years ago, it appeared much larger from Earth. In fact, when it had not yet settled into its current orbit, its apparent surface size could reach three times larger than what is seen today.