At 6:42am BST on Thursday, 12 October our best orbit prediction for a 20-metre-wide space rock designated 2012 TC4 indicates that it will hurtle by Earth just 43,800 kilometres (27,215 miles) above the ocean between Australia and Antarctica. If UK skies are clear on 11 October and you have an 8-inch or larger telescope, you might just see it too.
Back in October 2012, the near-Earth asteroid 2012 TC4 had a close encounter with Earth. It passed our planet at a distance only a quarter of that between the Earth and the Moon. In October 2017, this small asteroid, with a size of only about 15 to 30 metres, will return for another very close fly-by, making it the perfect object to test the asteroid detection and tracking network.