Dart mission: why is Nasa crashing a spacecraft into an asteroid?

The SpaceX Falcon 9 rocket with the Double Asteroid Redirection Test, or Dart, spacecraft onboard Photograph: REX/Shutterstock

The SpaceX Falcon 9 rocket with the Double Asteroid Redirection Test, or Dart, spacecraft onboard Photograph: REX/Shutterstock

source https://www.theguardian.com/science/2021/nov/24/dart-mission-why-is-nasa-crashing-a-spacecraft-into-an-asteroid