NASA's DART mission successfully smashes spacecraft into asteroid

NASA's Double Asteroid Redirection Test (DART) spacecraft prior to impact at the Didymos binary asteroid system showed in this undated illustration handout. © NASA/Johns Hopkins via Reuters

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

The galactic grand slam occurred at a harmless asteroid 7 million miles (9.6 million kilometres) away, with the spacecraft named Dart plowing into the small space rock at 14,000 mph (22,500 kph).