Photo provided by NASA on October 11, 2022 showing the asteroid Dimorphos as seen by the Dart mission craft seconds before impact (NASA/Jons Hopkins APL/Handout)
“It’s not Hollywood” but NASA: The US space agency announced on Tuesday that it had managed to deflect an asteroid from its orbit by projecting a ship the size of a large refrigerator against its surface in late September.
An unprecedented test mission worthy of a science fiction novel that should enable humanity to learn to protect itself from a possible future threat.
The Dart mission ship had deliberately crashed into the asteroid Dimorphos, the satellite of a larger asteroid called Didymos. The NASA device managed to move it by reducing its orbit by 32 minutes, space agency chief Bill Nelson said at a news conference.
It is “a defining moment for planetary defense and a defining moment for humanity,” he welcomed, pleased that his agency’s expectations had been exceeded.
It would already be “considered a huge success if it (the craft) only shortened the orbit by about 10 minutes, but it actually reduced it by 32 minutes,” he added. With this mission, “Nasa has proven that we are serious about defending the planet,” he said.
Dimorphos, about 11 million kilometers from Earth at the time of the impact, has a diameter of about 160 meters and poses no threat to our planet.
It has so far sailed around Didymos in 11 hours 55 minutes, a period that has been shortened to 11 hours 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 whatever the universe can throw at us,” he says.
If the goal remained relatively modest compared to the disaster scenarios of sci-fi movies like “Armageddon”, this unprecedented mission of “planetary defense”, called Dart (dart, in English), is the first to test such a technique. This will allow NASA to train in case an asteroid threatens to hit Earth one day.
“If we find in the future that an asteroid is in danger of hitting Earth and is large enough to cause damage, it will be a relief to conduct this successful test,” Bill Nelson told Reuters.
– Egg shape –
To determine how much the asteroid’s orbit has changed, scientists were required to analyze data from ground-based telescopes in Chile, South Africa and the United States.
Description of NASA’s DART rocket probe, which crashed on a small asteroid to change its orbit, a test to anticipate a possible future collision between Earth and an asteroid (AFP/)
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 built-in nanosatellite for the LICIACube mission — showed a huge cloud of dust around Dimorphos, stretching for thousands of miles.
Then the James Webb and Hubble telescopes, the most powerful space observatories, revealed detailed images of the impact of NASA’s spacecraft, especially the movement of ejecta – the material being ripped 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 thus to measure the exact effect that this technique – called kinetic impact – can have on them.
Images of Dimorphos taken shortly before the impact show that the surface is gray and rocky and ovoid.
The mission revealed that the asteroid looked more like an amalgam of large rocks connected by their mutual gravitational pull than a solid mass.
The kamikaze ship had been traveling in California for ten months since takeoff.
Images provided by the European Space Agency on September 29, 2022 showing the impact (d) of NASA’s Dart spacecraft against the asteroid Dimorphos taken by the Webb and Hubble telescopes ( ESA/WEBB / Handout)
Nearly 30,000 asteroids of all shapes and sizes have been cataloged near Earth.
Today, none of these known asteroids threaten our planet for the next 100 years. Except they haven’t all been listed yet.
According to the scientists, almost all those of a kilometer or more have been spotted. But they estimate they only know about 40% of asteroids 140 meters or more — capable of devastating an entire region.