House-sized asteroid ‘narrowly’ misses Earth

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Image: '2012 TC4' missed Earth by about 27,000 miles. Pic: NASA

By Russell Hope, News Reporter

An asteroid the size of a large house passed by Earth early on Thursday morning at a distance of about 27,000 miles (44,000km).

NASA has estimated that "2012 TC4" is 15m to 30m long (45ft to 100ft) – and in space terms, the asteroid narrowly missed our planet.

Ahead of its approach, scientists had stressed there was no risk of collision from the asteroid.

Mike Kelly, who leads the agency's project to track it, said: "We've now been observing TC4 for two months, so we have very accurate position information on it, which in turn allows very precise calculations of its orbit."

Its closest point of contact with earth was predicted to be over Antarctica at 7.40am UK time.

A small asteroid will safely fly by Earth on Oct 12. Our network of observatories & scientists will test tracking it https://t.co/8ISXusz06U pic.twitter.com/yafgR5LTE1

— NASA (@NASA) 11 October 2017

The asteroid had a one in 750 chance of crashing into Earth – placing it at number 13 on the list of objects posing even a remote risk of collision.

As its name suggests, 2012 TC4 was first discovered five years ago, and was spotted most recently in July by the European Space Agency and the European Southern Observatory.

It is roughly the same size as the meteor that caused widespread damage when it exploded in the atmosphere over Chelyabinsk in central Russia in 2013.

That blast, which had 30 times the kinetic energy of the atomic bomb dropped on Hiroshima, left more than 1,200 people injured and blew out windows in approximately 5,000 buildings.

TC4 is being used as a test for a global asteroid pre-warning system – supported by a network of observatories, universities and laboratories around the world – to see if such rocks can be accurately tracked.

"For us this is a test case," said Detlef Koschny of the European Space Agency's Near-Earth Object programme.

"We are practising for a real serious case," he added.

TC4, which orbits the sun every 609 days and will return to Earth in 2050 and 2079, is one of thousands of asteroids with a known location.

However, the whereabouts of millions more remain unknown.