In outer space, an object that remains stationary without any movement is commonly referred to as a "stationary object" or a "stationary satellite." To maintain a stationary position, such an object needs to be in a specific type of orbit called a geostationary orbit.
A geostationary orbit is a circular orbit around the Earth, located directly above the equator, where the satellite's orbital period matches the Earth's rotational period. This means that the satellite completes one orbit around the Earth in the same amount of time it takes the Earth to rotate once on its axis, resulting in the satellite appearing stationary when observed from the surface.
The reason a satellite in a geostationary orbit can remain stationary is due to the balance of two forces: gravitational force and centrifugal force. Gravitational force pulls the satellite toward the Earth, while centrifugal force pushes it away from the Earth due to its orbital motion. When these two forces are in equilibrium, the satellite can maintain a fixed position relative to the Earth.
This equilibrium is achieved by carefully choosing the satellite's altitude, speed, and orbital radius. By placing the satellite at an altitude of approximately 35,786 kilometers (22,236 miles) above the Earth's surface and giving it the correct orbital velocity, the centrifugal force exactly balances the gravitational force, allowing the satellite to remain stationary.
It's important to note that although the satellite appears stationary relative to an observer on Earth, it is still moving in its orbit around the Earth. The term "stationary" refers to the satellite's fixed position relative to a specific point on the Earth's surface.
In summary, a stationary object in outer space is typically a satellite in a geostationary orbit. It remains stationary because its orbital period matches the Earth's rotational period, resulting in the satellite appearing fixed when observed from the Earth. This is achieved by carefully balancing the gravitational and centrifugal forces through specific orbital parameters.