NASA’s Double Asteroid Redirection Test (DART) spacecraft smashed into an asteroid deliberately, on September 2022, altering the rock’s trajectory through space. Scientists have deconstructed the collision. DART, which was the size of a big car, collided with the asteroid called Dimorphos. The impact caused the asteroid’s orbit around another space rock to shrink — Dimorphos now completes an orbit 33 minutes faster than before the impact, researchers reported in Nature. This means that if a dangerous asteroid were ever detected heading for Earth, a mission to smash into it would probably be able to divert it away from the planet.
NASA’s goal was to alter Dimorphos’s orbit enough for astronomers to spot the changes by monitoring the brightness of the pair over time using ground-based telescopes. Neither asteroid is, or will ever be, a threat to Earth.The impact ejected at least one million kilograms of rock from Dimorphos’s 4.3-billion-kilogram mass. The debris formed a tail that stretched for tens of thousands of kilometres behind the asteroid. Various telescopes watched over weeks as the tail shifted and evolved under the pressure of the Sun’s rays; the Hubble Space Telescope even detected a second tail, which had disappeared by 18 days after the impact. Dimorphos is 151 metres wide and orbits the larger asteroid Didymos.