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How can a small nudge make an asteroid miss Earth?

An asteroid does not necessarily need to be shattered to change where it will go. NASA's DART spacecraft struck Dimorphos in 2022 and changed its orbit around another asteroid, providing a real test of a deliberate push. Turning that result into a defense of Earth also raises questions about warning time and how differently shaped or structured asteroids respond.

5–7 min

Questions you could explore

  • How did the DART mission measure a change in Dimorphos's motion after impact?
  • Why does warning time matter when a small change in velocity is meant to prevent a future collision?

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