October 31, 2011
An asteroid the size of an aircraft carrier could provide vital clues about the formation of the Earth when it flashes past us next week.
The huge space rock will miss our planet by just 200,000 miles on Tuesday, November 8, giving scientists a front-row seat for such a rare event.
The last time a rock of a comparable size passed so close was in 1976, but it was missed by everybody, including Nasa. This asteroid, which is known as 2005 YU55 and is in orbit around the Sun, has not been this near to Earth for some 200 years.
It will not be visible to the naked eye, but amateur astronomers could see it if they use a telescope at least 6in in diameter.