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.
