Deep Impact and Armageddon in real life. NASA announced Tuesday it had managed to deflect an asteroid from its orbit by smashing a golf car-sized spacecraft into its surface during an unprecedented test mission in late September, which should allow humanity to learn , to protect themselves from an asteroid possible future threat.
The Dart mission ship had intentionally rammed into its target, the asteroid Dimorphos, which is the satellite of a larger asteroid called Didymos. The NASA device managed to move it by shortening its orbit by 32 minutes, Space Agency chief Bill Nelson said during a news conference. It is “a defining moment for the defense of the planet and a defining moment for humanity,” he said.
Orbit reduction three greater than expected
It would have been “considered a great success if it (the vehicle) shortened the orbit by only about 10 minutes.” But he actually cut it by 32 minutes,” he added. With this mission, “Nasa has proven that we mean business as defenders of the planet,” he said.
Dimorphos, which was about 11 million kilometers from Earth at the time of the impact, is about 160 meters in diameter and poses no threat to our planet. It has orbited Didymos so far in 11 hours and 55 minutes, one in 11 hours and 23 minutes shortened time, Nelson said. “It looks like a script for a movie. But it’s not Hollywood (…). This mission shows that NASA is trying to be prepared for anything the universe might throw at us,” he said.
If the goal remained relatively modest compared to the disaster scenarios of sci-fi movies, this unprecedented “planet defense” mission dubbed Dart is the first to test such a technique. This allows NASA to train if one day an asteroid threatens to hit Earth.
Observation by Hubble and James Webb
Confirming that the asteroid’s trajectory had indeed been altered had to wait for scientists to analyze data from ground-based telescopes. The latter observed the variation in brightness as the small asteroid passes in front of and behind the large one.
Shortly after the collision, early images – taken by ground-based telescopes and the onboard nanosatellite for the LICIACube mission – showed a huge dust cloud surrounding Dimorphos, stretching thousands of kilometers.
Then the James Webb and Hubble telescopes, the most powerful space observatories, showed detailed views of NASA’s spacecraft impact, specifically showing the movement of ejecta — the material ripped away from the star.
All of this should make it possible to better understand the composition of Dimorphos, which are representative of a population of fairly common asteroids, and therefore to measure the precise effect that this technique – called kinetic impact – can have on them.
egg shape
Images of Dimorphos taken just before impact show that its surface is gray, rocky, and ovoid. Knowing these details is important in case humanity is ever forced to collide with an object approaching Earth. The ship had been ten months since its launch in California.
Nearly 30,000 asteroids of all sizes have been cataloged near Earth (they are called NEOs, meaning their orbits intersect that of our planet). Today none of these known asteroids threaten our planet for the next 100 years. Except that not all of them are listed yet. Almost all of the animals have been sighted from a kilometer or more, according to the scientists. But they estimate they only know about 40% of asteroids 140 meters or larger in size – the ones that can devastate an entire region.