NASA reveals nuclear-armed asteroid-busting HAMMER project

Bruce Willis and Ben Affleck in Armageddon.
Bruce Willis and Ben Affleck in Armageddon. Photo credit: Buena Vista Pictures

NASA is getting ready to take down an asteroid, Bruce Willis-style.

The US space agency has revealed plans for a new spacecraft called HAMMER, which stands for Hypervelocity Asteroid Mitigation Mission for Emergency Response.

A fleet of HAMMER craft, each weighing 8.8 tonnes, would be directed at any incoming asteroid deemed a threat to humanity.

If the asteroid is big enough, the HAMMERs will be armed with nuclear weapons, BuzzFeed News reported.

"If the asteroid is small enough, and we detect it early enough, we can do it with the impactor," said physicist David Dearborn of the Lawrence Livermore National Laboratory.

"The impactor is not as flexible as the nuclear option when we really want to change the speed of the body in a hurry."

The biggest threat appears to be an asteroid called Bennu, which physicists estimate has a one-in-2700 chance of slamming into the Earth on September 21, 2135. Bennu is travelling at 101,000km/h, and is almost 500m across.

It's not big enough to wipe out life as we know it, but could cause "immense suffering and death", astronomer Dante Lauretta of the Lunar and Planetary Laboratory at the University of Arizona said in 2015.

The HAMMER team estimate the energy unleashed if Bennu hit Earth would be 23 times bigger than a biggest hydrogen bomb ever exploded.

Dr Lauretta is heading a mission to send a probe to Bennu in 2023, and bring back samples for study.

In December an asteroid no one had ever seen before whizzed past Earth. 'Oumuamua, as it was dubbed, came from interstellar space, and astronomers didn't see it until it had already passed us by.

No cost has been attached to the HAMMER project.