NASA has successfully conducted its first planetary defence mission, sending a spacecraft smashing into an asteroid.

The mission aimed to change the speed and orbit of the 160-metre diameter asteroid, a technique scientists hope could one day be used for planetary defence.

NASA’s Double Asteroid Redirection Test spacecraft, or DART, collided with Dimorphos, an asteroid roughly the size of the Great Pyramid of Giza on Tuesday.

Now the real science begins, as scientists test the effects that impact had.

Today on Please Explain, Bianca Hall is joined by national science reporter Liam Mannix, to discuss NASA's epic planetary defence mission.

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