Asteroid security

30-metre asteroid skimming past Earth in October will test Nasa's doomsday 'planetary defence system'

On October 12, a 30-metre is set to make a 'close' flyby of Earth.

The asteroid, named 2012 TC4, will pass just 4,200 miles (6,800 kilometres) from Earth for the first time since it went out of range in 2012.

Nasa is using this opportunity to test it's 'planetary defence system' put in place to protect Earth from a doomsday asteroid threat. 

Asteroid 2012 TC4 is estimated to be between 10 and 30 metres in size.

Michael Kelley, a scientist working on the Nasa TC4 observation campaign, said: 'Scientists have always appreciated knowing when an asteroid will make a close approach to and safely pass the Earth because they can make preparations to collect data to characterise and learn as much as possible about it.