Almost everything in the universe travels in a circular path. The moon goes around the earth, the earth goes around the sun, and even the sun revolves around the center of our galaxy. This is because of two basic laws of science.
First, an object moving in space, where there is no air to slow it down, will continue to move forever once it begins in motion. The moon has been moving through space ever since it was formed billions of years ago.
But the gravity of the earth pulls the moon toward us. This gravity isn’t strong enough to pull the moon into the earth, but it holds the moon at a certain distance from the earth, where the gravity of the earth, the sun, and the planets are balanced.
So the moon keeps moving around the earth at that distance, traveling in a circular path called an orbit. And the earth goes around the sun for the same reason.
