Hit. The Dart spacecraft hit the asteroid Dimorphos. Its 500 kilos launched at 6 kilometers per second, 24 thousand kilometers per hour, have transferred all the energy to the space stone the size of the Colosseum, shifting its orbit.
The impact occurred 11 million kilometers from Earth, a safe distance equal to 28 times the distance from Earth to the Moon. For NASA it was a test: Dimorphos poses no risk for us, but if a dangerous asteroid gets too close to our planet, we now know that we have the ability to hit and deflect it.
Space, tonight the collision between the NASA probe and the asteroid: here’s how to look at it
by Elena Dusi
Dart made his way to his target unaided from Earth: guiding himself with his camera and the map of the stars recorded in his memory. He kept Dimorphos to the very end in the center of his eye called Draco. At the rate of one photo per second, the asteroid became larger and more defined as the distance got shorter.
Its irregular image gradually distinguished itself from that of the larger asteroid – the pyramid-like Didymos – around which Dimorphos orbits, a kilometer and a half away. Then, when Dimorphos occupied the entire field of vision, with the surface studded with boulders that made it look like a stuffed biscuit, the images stopped coming: the sign of the impact.
The Italian satellite LiciaCube, which traveled aboard Dimorphos until two weeks ago, has filmed the scene, but it will take a few days for photos of the plume of dust raised by Dart on the surface of the asteroid to reach Earth.
Dimorphos was chosen by NASA because it is distant – it poses no risk to the Earth – and because it is small enough to be moved on impact, but large enough not to pulverize. Small to be able to move but without demolishing it. Ground-based telescopes have measured the slight alteration of its orbit.
The mission cost NASA 330 million dollars. For the first time in reality, an asteroid was hit by an object thrown to Earth and diverted its path.