NASA has succeeded in its bet. His ship, sent into space at the end of September, managed to hit an asteroid last night to deflect it from its trajectory. A test mission which aims to know how to react in the event of a future threat to “protect humanity”.
“It’s Not Hollywood” but NASA: the American space agency announced on Tuesday that it had succeeded in deflecting an asteroid from its trajectory by projecting, at the end of September, a vessel the size of a large refrigerator against its surface.
An unprecedented test mission worthy of a science fiction novel, which should allow humanity to learn how to protect itself from a possible future threat.
The Dart mission ship had deliberately crashed into the asteroid Dimorphos, which is the satellite of a larger asteroid named Didymos. The NASA device managed to move it by reducing its orbit by 32 minutes, said the head of the space agency, Bill Nelson, during a press conference.
This is “a watershed moment for planetary defense and a watershed moment for humanity”, he greeted, congratulating himself that the expectations of his agency had been exceeded. It would have already been “considered a huge success if it (the craft) had only reduced orbit by about 10 minutes. But it actually reduced it by 32 minutes”, he added. With this assignment, “Nasa has proven that we are serious as defenders of the planet”he said.
Dimorphos, located some 11 million kilometers from Earth at the time of impact, is about 160 meters in diameter and poses no danger to our planet.
It has so far circumnavigated Didymos in 11 hours and 55 minutes, a period shortened to 11 hours and 23 minutes, Nelson said.
“It looks like a movie script. But it’s not Hollywood (…). This mission shows that NASA is trying to be ready for anything the universe could throw at us”did he declare.
If the objective remained relatively modest compared to the disaster scenarios of science fiction films like “Armageddon”, this unprecedented mission of “planetary defense”, named Dart (dart, in English), is the first to test such a technique. It allows NASA to train in case an asteroid threatens to hit Earth one day.
“In the future, if we find out that an asteroid is threatening to hit the Earth, and that it would be big enough to do damage, it will be a relief to have conducted this successful test”Bill Nelson told AFP.
To establish how much the asteroid’s trajectory has been altered, it took scientists to analyze data from ground-based telescopes in Chile, South Africa and the United States. The latter observed the variation in brightness when the small asteroid passes in front of and behind the large one.
Soon after the collision, early images — taken by ground-based telescopes and the onboard nano-satellite for the LICIACube mission — showed a vast dust cloud around Dimorphos, stretching for thousands of kilometres.
Then the James Webb and Hubble telescopes, the most powerful space observatories, revealed detailed views of the impact of NASA’s spacecraft, showing in particular the movement of ejecta – the material torn from the star.
All this should make it possible to better understand the composition of Dimorphos, representative of a population of fairly common asteroids, and therefore to measure the exact effect that this technique – called kinetic impact – can have on them.
Images of Dimorphos, taken shortly before impact, show its surface to be gray and rocky and egg-shaped.
The mission revealed that the asteroid was more like an amalgam of large rocks linked by their mutual gravity than a solid mass.
The kamikaze ship had traveled for ten months since its takeoff, in California.
Nearly 30,000 asteroids of all sizes have been cataloged in the vicinity of Earth.
Today, none of these known asteroids threaten our planet for the next 100 years. Except that they are not yet all identified.
Those of a kilometer or more have almost all been spotted, according to the scientists. But they estimate that they only know about 40% of asteroids measuring 140 meters or more — those capable of devastating an entire region.