Near-Earth object the largest explosion in recorded history, equivalent to 20,000 megatons of TNT. It attracted widespread attention because it was discovered only after the closest approach. In March 1998, early orbit calculations for recently discovered asteroid showed a potential 2028 close approach from the Earth, well within the orbit of the Moon, but with a large error margin allowing for a direct hit. Further data allowed a revision of the 2028 approach distance to , with no chance of collision. By that time, inaccurate reports of a potential impact had caused a media storm. From the late 1990s, a typical frame
Orbit of the Moon frequencies. See also tidal acceleration for a more detailed description. The Moon is gradually receding from Earth into a higher orbit, and calculations suggest that this would continue for about 50 billion years. By that time, Earth and the Moon would be in a mutual spin–orbit resonance or tidal locking, in which the Moon will orbit Earth in about 47 days (currently 27 days), and both the Moon and Earth would rotate around their axes in the same time, always facing each other with the same side. This has already happened to the Moon—the same side always faces Earth—and is