15 February 2013 Last updated at 14:28 ET
By Jason Palmer Science and technology reporter, BBC News
Nasa coverage of the moment the asteroid passed closest to Earth
An asteroid as large as an Olympic swimming pool has raced past the Earth at a distance of just 27,700km (17,200mi) – the closest ever predicted for an object of that size.
It passed far closer even than the geosynchronous satellites that orbit the Earth, but there was no risk of impacts or collisions.
Its closest approach was at 19:25 GMT.
For regions in darkness, it should have remained visible until about midnight through good binoculars or a telescope.
The asteroid’s arrival was preceded by a damaging meteor event in Russia on Friday – but indications from the meteor’s path suggest that the two events are entirely unrelated – just a “cosmic coincidence”, as Alan Fitzsimmons of Queens University Belfast told BBC News.