What makes it orbit?
Most Helpful Girl
Due to the gravity and it must also have velocity1
Most Helpful Guy
The balance between mass attraction (gravity) and centrifugal force. The orbiting body is moving at a high rate of speed which would normally take it in a straight line unless something acts upon it. In this case, another body---which is usually larger---influences it with gravitational pull. As a result, the smaller body moves in an arc rather than a tangent and ends up in “orbit” around the larger one.
However, this is a delicate balance. If the revolving body slows or the gravitational field of the larger one increases, the orbit will degrade and eventually result in a collision.
By the way, the two bodies can be of more or less equal mass such as binary stars. In this case they orbit each other around their common center of mass.
Why the sudden interest in Astronomy?1