At 11:28 pm on the night of the 8th November 2011, a 400 metre wide lump of rock will SAFELY pass within 325,000 km (202,000 miles) of the Earth's surface. The asteroid, known as 2005 YU55, will then pass within 239,000 km of the Moon before heading off into the outer solar system. During the close approach this Near-Earth Object (NEO) should be visible through a good telescope or pair of binoculars, but will sadly remain invisible to the human eye. No doubt many observatories will be tracking the object as it flies past, so decent images should start appearing in a few days.

Thankfully, it is rare to see such large asteroids whizz past any closer than the Moon; the last time it happened was back in 1976, when 2010 XC15 came within 192,000 km of the Earth (roughly half the distance to the Moon). You'll be glad to hear that the next close encounter with a "known asteroid" will not be until 2028, when 2001 WN5 will pass by at around 248,000 km. Like many asteroids, 2005 YU55 will continue to rattle around the solar system, and calculations show that it will pass around 280,000 km (180,000 miles) from Venus on the 19th January 2029. How it behaves during that encounter will determine how close the asteroid will pass the Earth in 2041. Once again, it could be as close as 300,000 km.