DART was bang on target

The asteroid-deflecting DART mission worked with incredible accuracy

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AIthough no known asteroid poses a threat to Earth for at least the next century, the database we've built up of near-Earth asteroids is not yet complete for smaller bodies that could still cause devastation on a regional scale.

Several methods have been proposed to protect Earth from asteroids on a collision course, including blowing them up with a nuclear weapon and using a 'gravity tractor', a large spacecraft whose gravity pulls the asteroid so it misses our planet. The strategy identified as the highest priority to develop and test, however, is kinetic impact. In simple terms: fly a spacecraft at high speed into the asteroid so that it is nudged onto a different trajectory.