naure.com
SpaceSurprise 3/5Difficulty 3/5Reviewed on September 18, 2026

The Moon is drifting away from the Earth by almost four centimetres a year.

Why it is true

The friction of ocean tides slightly slows down the Earth's rotation, which transfers energy to the Moon, pushing it into a progressively wider orbit each century.

Source: NASA

Would you rather be asked first?

This is the reading side of the site, so the answer is in the sentence above — that is the whole point of it. Test yourself works the other way round: the question comes on its own, and the fact and the explanation only appear once you have answered.

Test yourself →10-question challenge

Related facts

More in Space

See all →