Meteor almost hits US Air Force base

The meteor exploded 43km in the air.
The meteor exploded 43km in the air. Photo credit: Getty

It's been revealed a meteor with the power of a "low-yield nuclear weapon" came within a whisker of obliterating a US Air Force base in Greenland in July.

NASA reported the meteor, but the news went under the radar until scientist Hans Kristensen of the Nuclear Information Project at the Federation of American Scientists mentioned it in a tweet.

The US military made no immediate mention of the space rock, which exploded 43km in the air above an early warning radar system at Thule Air Base, Greenland, on July 25.

"We're still here, so they correctly concluded it was not a Russian first strike," said Mr Kristensen. "There are nearly 2,000 nukes on alert, ready to launch."

The explosion had a force of 2.1kt - " sort of a very low-yield nuclear weapon level" Mr Kristensen told The Washington Examiner.

The object was travelling at more than 24km a second - Mach 74.

"Had it entered at a more perpendicular angle, it would have struck the earth with significantly greater force," Mr Kristensen said.

Once contacted by media, the Air Force confirmed the base was undamaged.

The meteor which exploded above Chelyabinsk in Russia in 2013 was estimated to be 500kt in strength - 30 times the bomb that dropped on Hiroshima.