A satellite in a geostationary orbit remains fixed relative to the Earth because of what characteristic?

• A. It matches Earth's rotation and stays over the same longitude
• B. It orbits in polar plane
• C. It uses continuous propulsion to maintain position
• D. It has a very low altitude

Answer: (A)

Geostationary satellites stay fixed relative to the Earth because their orbital motion is synchronized with Earth’s rotation. Specifically, they have a period equal to one sidereal day (about 23 hours 56 minutes) and sit above the equator. This exact timing means the satellite completes one orbit in the same time it takes Earth to rotate, so it remains over the same longitude and appears stationary in the sky. If the orbit were inclined (polar) or at a very different altitude, it wouldn’t stay fixed. Continuous propulsion isn’t needed for a true geostationary orbit, since the motion is governed by gravity and orbital period.