What is a geostationary satellite?

A geostationary satellite is one that maintains a fixed position relative to a specific location on the Earth's surface. This means that as the Earth rotates, the satellite orbits at the same rotational speed and in the same direction, allowing it to stay directly above the same point on the equator.

This special orbit occurs at an altitude of approximately 35,786 kilometers above the Earth's equator. Due to this altitude and the synchronization with the Earth’s rotation, the satellite appears stationary to observers on the ground. This characteristic makes geostationary satellites very useful for communications, weather forecasting, and surveillance, as they can provide continuous coverage of a specific area.

Other options describe satellites that do not have this fixed relationship with the Earth. For instance, satellites that move across the Earth or operate in low Earth orbit have significantly different behaviors and applications. They do not stay above one location and instead cover various areas over time as they orbit at different altitudes and speeds.