Moon and Earth :
It used to be much closer! A billion years ago, the Moon was in a tighter orbit, taking just 20 days to go around us and make a month. A day on Earth back then was only 18 hours long. The Moon is still moving away – about 1.6 inches (4 centimeters) a year.
Meanwhile, Earth's rotation is slowing down, lengthening our days. In the distant future, a day will be 960 hours long!
Walang komento:
Mag-post ng isang Komento