Watch incredible moment Nasa crashes fridge-sized satellite into moving asteroid

Watch: Moment Nasa's DART spacecraft smashes into asteroid

A pioneering NASA spacecraft has made science fiction a reality - or, at least, that’s the theory.

In the early hours of the morning, the Double Asteroid Redirection Test (DART) spacecraft successfully crashed into a small asteroid as part of a planetary protection test mission.

While the asteroid – named Dimorphos – posed no threat to Earth, the aim of the mission was to demonstrate that dangerous incoming rocks can be deflected by deliberately smashing into them.

“IMPACT SUCCESS!” Nasa tweeted after its spacecraft collided with the 170-metre wide (560ft) asteroid at about 00:20 UK time on Tuesday.

The US space agency’s staff cheered and clapped in a video shared online as the spacecraft successfully smashed into Dimorphos, which is the size of a football stadium.

“And we have impact. A triumph for humanity in the name of planetary defence,” a member of Nasa’s team said in a video recorded in the control room as the collision took place.

The idea is familiar from Hollywood blockbusters such as Armageddon, but marks humanity’s first attempt to change the path of a moon or other celestial body.

It’s the first step towards a real solution if an asteroid is hurtling towards Earth - a mission to knock potential doomsday asteroids onto less-threatening flight paths.

The theory is that the fridge-sized DART spacecraft - travelling faster than a bullet - will change its orbit.

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The spacecraft rammed the moonlet Didymos B, which orbits around a larger asteroid Didymos A, travelling at around 3.7 miles per second.

NASA scientists will now monitor to see what effect it has on the 530ft rock’s flight path.

It took 10 months for Dart to come close to Dimorphos after launching last November on SpaceX’s Falcon 9 rocket.

Two weeks ago, the spacecraft took its first pictures of Didymos system, from 20 million miles away.

The collision was recorded by a briefcase-sized satellite known as the Light Italian CubeSat for Imaging of Asteroids (LICIACube), which was provided by the Italian Space Agency.

DART needed to self-navigate to impact successfully with Dimorphos without any human intervention.

There are currently somewhere around 27,000 asteroids in near-Earth orbit.

Rocks that are 140 metres (460ft) and larger in size and come nearer than 4.7 million miles (7.5 million km) during orbit are classed as potentially hazardous asteroids (PHAs).

Watch: Launch of DART spacecraft lights up night sky