NASA hit an asteroid to deflect it, a first for humanity

Confirmed impact: a NASA ship deliberately crashed on Monday September 26 on an asteroid in order to deviate its trajectory, during an unprecedented test mission which should allow humanity to learn how to protect itself from a potential future threat.

The ship, smaller than a car, rushed at a speed of more than 20,000 km / h on its target, reached at the scheduled time (23:14 GMT). Nasa teams, gathered at the Mission Control Center in Maryland, United States, exploded with joy at the moment of the collision.

A few minutes before, the asteroid Dimorphos, located about 11 million kilometers from Earth, has gradually grown on the spectacular images broadcast live by the ship. We could clearly distinguish the pebbles on its gray surface, just before the images stop at the moment of the explosion. “We have embarked on a new era, where we potentially have the ability to shield ourselves from a dangerous asteroid impact,” said Lori Glaze, director of planetary sciences at NASA.

A few days to wait to confirm that the trajectory has indeed been diverted

Dimorphos is about 160 meters in diameter and poses no danger to our planet. It is actually the satellite of a larger asteroid, Didymos, which it has so far circumnavigated in 11 hours and 55 minutes. NASA seeks to reduce the orbit of Dimorphos by 10 minutes, that is to say to bring it closer to Didymos.

It will take a few days or weeks before scientists can confirm that the trajectory of the asteroid has indeed been altered. They will do this thanks to telescopes on Earth, which will observe the variation in brightness as the small asteroid passes in front and behind the large one.

NASA’s DART mission to deflect an asteroid / AFP

This mission of “planetary defense”, named Dart (Double asteroid redirection test, and “dart” in English), is the first to test such a technique. It allows NASA to train in case an asteroid threatens to crash into Earth one day.