It's Confirmed: The DART Mission Successfully Deflected An Asteroid From Its Trajectory
A shoebox-sized satellite, called LICIACube, released by the DART a few days ago, passed about 55 km from the asteroid to take images of the impact visible in the upper right.< /p>
NASA succeeded in deflecting an asteroid from its trajectory by launching a spacecraft against its surface at the end of September during an unprecedented test mission which should allow humanity learn how to protect yourself from a possible future threat.
Image captured by the Hubble telescope of the impact of the DART probe with the asteroid Dimorphos.
The DART probe had deliberately struck its target, the asteroid Dimorphos, which is the satellite of a larger asteroid named Didymos. The NASA spacecraft managed to move it, reducing its orbit by 32 minutes, space agency chief Bill Nelson told a press conference.
This is a watershed moment for planetary defense and a watershed moment for humanity, he hailed.
It would already have been considered a huge success if it [the ship] had only reduced orbit by about 10 minutes. But he actually cut it by 32 minutes, he added. With this mission, NASA has proven that we are serious as defenders of the planet, he said.
The asteroid Didymos (upper left) and its satellite, Dimorphos, about 2.5 minutes before the impact of DART with the latter. The image was taken by the DRACO imager at a distance of 920 kilometers.
Dimorphos, located some 11 million kilometers from Earth at the time of impact, is approximately 160 meters in diameter and poses no danger to our planet.
If the goal remains relatively modest compared to the disaster scenarios of science fiction films like Armageddon, this unprecedented planetary defense mission, 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.
To confirm that the asteroid's trajectory had indeed been altered, it took 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.
Rapidly after the collision, the first images – taken by telescopes on the ground and by the nanosatellite embarked for the LICIACube mission – had shown a vast cloud of dust around Dimorphos, extending for thousands of kilometers.
Then the James Webb and Hubble telescopes, the most powerful space observatories, revealed the detailed views of the NASA spacecraft's impact, 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 that its surface is gray and rocky and has an egg shape.
The last complete image of the asteroid Dimorphos taken by the DART probe's DRACO imager about 12 kilometers from the asteroid and 2 seconds before impact. The image shows an area of the asteroid 31 meters in diameter.
Knowing these details is important in case humanity is ever forced to crash into an object approaching Earth.
The spacecraft had traveled for 10 months since its liftoff in California.
Nearly 30,000 asteroids of all sizes have been cataloged in the vicinity of the Earth (they are called near-Earth cruisers, that is, their orbit crosses that of our planet).
Today Today, none of these known asteroids threaten our planet for the next 100 years. Except that they have not yet all been identified.
Those of a kilometer or more have almost all been spotted, according to scientists. But they estimate they only know about 40% of asteroids measuring 140 meters and larger – those capable of devastating an entire region.