For example, 600 million years ago the Earth rotated once on its axis every 22 hours and took 400 days to orbit the Sun. But the tides of the seas have the strange effect of transferring energy from the rotation of the Earth to the Moon, which results in the Earth’s rotation slowing down and the Moon gradually moving away from us. Similar effects are causing the Earth and Sun to drift apart, changing the time it takes to complete an orbit.
