Agence France-Presse “House-sized asteroid will pass by Earth at just above satellite altitude” https://www.theguardian.com/science/2017/oct/10/house-sized-asteroid-will-pass-by-earth-at-just-above-satellite-altitude
As its name suggests, the object was first spotted five years ago when it called on Earth at about double Thursday’s projected distance, before disappearing from view.
It is 15 to 30 metres (50 to 100ft) wide – about the size of the meteoroid that exploded in the atmosphere over Chelyabinsk in central Russia in 2013, with 30 times the kinetic energy of the atomic bomb dropped on Hiroshima.
While the Chelyabinsk event caught everyone unawares, TC4 is one of thousands of space rocks whose whereabouts are known.
*2:See Agence France-Presse “Close encounter: asteroid the size of a house set for near miss with Earth” https://www.theguardian.com/science/2017/aug/11/close-encounter-asteroid-2012-tc4-size-of-a-house-near-miss-with-earth
*4:See Howard Amos “Meteorite explosion over Chelyabinsk injures hundreds” https://www.theguardian.com/world/2013/feb/15/hundreds-injured-meteorite-russian-city-chelyabinsk