Earth tide reason, it is believed that many of the exoplanets are captured in higher spin-orbit resonances with their host stars. Earth tide Earth tide (also known as solid Earth tide, crustal tide, body tide, bodily tide or land tide) is the displacement of the solid earth's surface caused by the gravity of the Moon and Sun. Its main component has meter-level amplitude at periods of about 12 hours and longer. The largest body tide constituents are semi-diurnal, but there are also significant diurnal, semi-annual, and fortnightly contributions. Though the gravitational forcing causing earth tides and ocean tides is the same, the
Geostationary ring km below GEO to 75 km above GEO and from -15 degrees to 15 degrees declination. Geostationary ring The geostationary ring is a volume segment around the geostationary orbit defined by variations in altitude and declination that can occur for uncontrolled objects left in the geostationary orbit. The geostationary orbit is subject to orbit perturbations caused by anomalies in the gravitational field of the Earth, by the gravitational effects of Sun and Moon, and by solar radiation pressure. A precessional motion of the orbit plane is caused by the oblatedness of the Earth (formula_1), and the gravitational effects of Sun