A NASA spacecraft is about to commit suicide. If everything goes as planned, it’ll ram into an asteroid on Monday afternoon. Astronomers will keep an eye on the asteroid to see how the impact affects its orbit around a larger companion asteroid.

The mission is known as DART. It’s an early step in the effort to develop ways to protect Earth from asteroids or comets that might be on a collision course with our planet. An impacting spacecraft might deflect such a body just enough to miss us.

The target is Dimorphos, which is about 525 feet in diameter. It orbits Didymos, which is about half a mile across. DART will hit the little moon head on. A small companion spacecraft will snap pictures from a safe distance.

The system isn’t a threat to Earth. But it passes close enough that it’s easy to reach. And the sizes of the two bodies provide a good test of just what an impact can do. It should cause a small but measurable change in the orbit of Dimorphos. Astronomers will monitor the system for months to measure the size of that change. That will tell us how effective such an impact might be against a true danger.

Another spacecraft is scheduled to fly past the system in late 2026. It’ll take pictures to see how the collision changed the smaller asteroid. The images should reveal the layers inside it, telling us more about its history — a bonus from a mission to test a way to protect Earth from cosmic missiles.
 

Script by Damond Benningfield

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