Back to menu Earth Orbits A satellite travelling in orbit around the Earth is actually falling, just like a thrown ball, towards Earth. If the Earth were flat, the satellite would hit the ground. But the Earth's surface curves away from the satellite, leaving it in free fall. The nearer a satellite's orbit is to Earth, the stronger the gravity pull on it. The satellite must go faster to remain in the lower orbit.
All orbits are elliptical, having two focal points.
A circular orbit is a special case with both focal points in the same spot. The plane of a satellite's orbit must pass through the centre of gravity of the Earth. The Moon orbits the Earth at an average altitude of 400,000 km. A satellite in this orbit, directly above the equator, going eastward as the Earth does, stays above the same point on Earth. This is the geostationary orbit.