Bam! NASA spacecraft crashes into asteroid in defence test

Planetary defense experts prefer nudging a threatening asteroid out of the way, rather than blowing it up.

A NASA spacecraft rammed an asteroid at blistering speed on Monday in an unprecedented dress rehearsal for the day a killer rock menaces Earth.

The galactic slam occurred at a harmless asteroid 7 million miles (11.3 million kilometres) away, with the spacecraft named Dart plowing into the space rock at 14,000 mph (22,500 kph).

Scientists expected the impact to carve out a crater, hurl streams of rocks and dirt into space and, most importantly, alter the asteroid's orbit.

“We have impact!” Mission Control's Elena Adams announced, jumping up and down and thrusting her arms skyward.

Telescopes around the world and in space aimed at the same point in the sky to capture the spectacle.

Though the impact was immediately obvious — Dart's radio signal abruptly ceased — it will take as long as a couple of months to determine how much the asteroid's path was changed.

The USD 325 million mission was the first attempt to shift the position of an asteroid or any other natural object in space.