Asteroid passing Earth is 'really unusually close'

An asteroid the size of an Olympic swimming pool will pass the Earth at a distance of just 27,700km (17,200mi) on Friday night.

People will need good binoculars or a telescope to see the asteroid at its closest - which in the UK will be at 19:25 GMT.

Jodrell Bank's Tim O'Brien explained just how "really unusually close" the asteroid would get to the Earth, and how scientists were so sure it would not come any closer.