A celestial close shave

Help

On Friday at about 2000 GMT an asteroid will pass very near the Earth.

At 50 metres across the mass is about the size of the object which hit Tunguska in 1908.

While it won't hit the planet, it will come within about 21,000 miles of the surface which is closer than many orbiting satellites and a close shave by astronomical standards.

Donna Traynor went to Armagh Observatory, one of the oldest in the world, where scientists are tracking the asteroid's progress.

BBC © 2014 The BBC is not responsible for the content of external sites. Read more.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.