Near-Earth object atmosphere, passing Earth's surface only away (about one Earth radius or one-sixtieth of the distance to the Moon). Because it was very small (6 meters/20 feet), FU was detected only hours before its closest approach. If it had collided with Earth, it probably would have disintegrated harmlessly in the atmosphere. On February 4, 2011, an asteroid designated , estimated at in diameter, passed within of the Earth, setting a new record for closest approach without impact, which still stands . On November 8, 2011, asteroid , relatively large at about in diameter, passed within (0.85 lunar distances) of Earth. On
Orbit orbital period. See also Kepler's Third Law. The application of certain orbits or orbital maneuvers to specific useful purposes have been the subject of patents. Some bodies are tidally locked with other bodies, meaning that one side of the celestial body is permanently facing its host object. This is the case for Sun-Mercury, Earth-Moon and Pluto-Charon system. Orbit In physics, an orbit is the gravitationally curved trajectory of an object, such as the trajectory of a planet around a star or a natural satellite around a planet. Normally, orbit refers to a regularly repeating trajectory, although it may also refer