When objects orbit something else, such as a planet orbiting a star or a satellite orbiting the Earth, they are under the influence of gravitational forces. These forces are responsible for keeping the objects in their orbits and preventing them from flying off into space.
Gravity is a fundamental force of nature that attracts objects with mass towards each other. The force of gravity between two objects depends on their masses and the distance between them. When an object is in orbit around a larger object, such as a planet, the gravitational force between them provides the necessary centripetal force to keep the smaller object in its orbit.
The centripetal force is the force that acts inward toward the center of the circular path. In the case of an orbit, gravity acts as the centripetal force, pulling the orbiting object toward the larger object. This force allows the object to continuously change its direction and maintain a stable orbit instead of flying off in a straight line.
The velocity of the orbiting object also plays a crucial role. To maintain a stable orbit, the object must have a specific velocity known as the orbital velocity. The orbital velocity depends on the mass of the larger object and the distance from the center of mass of the larger object to the orbiting object. If the object's velocity is too low, it will be pulled closer to the larger object and eventually crash into it. On the other hand, if the velocity is too high, the object will move away from the larger object and escape its gravitational pull.
In summary, objects orbiting something else stay in their orbits due to the gravitational force between them and the larger object. The combination of the gravitational force and the object's velocity provides the necessary centripetal force to keep it in a stable orbit instead of flying off into space.