Mankind’s first attempt to deflect an asteroid has succeeded, as those responsible for the DART mission led by the US space agency (NASA) confirmed on Tuesday. The small robotic probe that struck Dimorpho about 11 million kilometers from Earth managed to significantly change its course, several scientists of the project assured at a press conference held in Washington on Tuesday.
“The team has confirmed that Dimorpho’s orbit has shortened by 32 minutes,” said NASA Administrator Bill Nelson. “This is a pivotal moment for the defense of the planet and a pivotal moment for humanity,” he added. Giorgio Saccoccia, President of the Italian Space Agency, which contributed the LICIACube satellite that recorded the before and after of the collision, stated: “This international project is something to be proud of.” dangerous asteroids,” he added.
On September 27, the DART probe – the size of a refrigerator and with a mass of about 600 kilograms – struck Dimorpho, an asteroid about 10 million times its size. It was the first dress rehearsal for NASA’s Planetary Protection Office to learn how to deflect future 450-foot-diameter asteroids that could destroy an entire city if they hit our planet.
The mission was a resounding success as it managed to slow down Dimorfo significantly. This 160 meter diameter body was chosen because it orbits like a moon around Didymus, another 780 meter diameter asteroid. Under normal conditions, Dimorpho completed one orbit around its companion every 11 hours and 55 minutes. After DART hit its target head-on and at about 14,000 miles per hour, DART cut that time by 32 minutes. With that, Dimorfo also got closer to his brother by about 35 meters. Last year, the science team determined that if DART shortened Dimorph’s orbit by 73 seconds or more, the mission would already be a success, although the hope was to slow it by about 10 minutes.
Tom Statler, NASA’s DART chief scientist, said the team will continue to work to learn more about the asteroid’s composition and impact impact to begin development of an Earth-wide planetary defense system.
Currently, 95% of all asteroids with a diameter of more than one kilometer have been discovered; capable of causing a planetary catastrophe similar to that which led to the extinction of the dinosaurs 66 million years ago. Bodies over 140 meters like Dimorfo are much more worrying because only 40% have been found. In 2017, NASA decided to spend around 325 million euros to make the DART mission a reality. With this, they wanted to perfect the current computer models so that in the future humanity could deal with dangerous rocks by hitting them with a custom-made probe.
This small probe’s collision happened on September 27 and was tracked almost directly from Earth. The last images sent by the DART cameras before hitting Dimorfo showed that its surface was very irregular and rocky. This seemed to indicate that this body is what astrophysicists call a “rubble pile”; a low-density mass of rocks and dust. This implied that despite its small size, the impact would kick up a cloud of material that could be observed by dozens of ground-based telescopes tracking the shock’s evolution. It was like this.
like a comet
Two days after the impact, the SOAR telescope in Chile pointed to Dimorfo and confirmed that the impact had turned it into some kind of comet. The dust trail kicked up by the impact formed a tail about 10,000 kilometers long, confirming that the asteroid is very sparse.
René Duffard, researcher at the Andalusian Institute of Astrophysics and DART research associate, explains: “Dimorfo is like a pool of balls held together by gravity.” a liquid behaves like a solid stone. That’s why this huge line formed,” he elaborates. According to the observations of the scientific team, this tail consists only of dust, without traces of water, which distinguishes it from those of comets.
The success of DART is the first step towards a planetary protection system. The data collected by the probe and its companion LICIACube, a small satellite that witnessed the moments before and after the impact, as well as all observations from ground-based telescopes, will help perfect the models that simulate possible impacts depending on the type of impact Asteroid.
In 2026, the European Space Agency’s Hera probe will arrive in the Dimorpho Didimus system to accurately measure the mass, composition and internal structure of these two asteroids and perform a detailed three-dimensional reconstruction of the crater left behind by DART. The next step would be to already have a reliable model that can determine what type of probe could deflect a future threatening asteroid based on its size and mass and the time available before it hits Earth. In 2026, the US plans to launch the NEO telescope, which will create a catalog of asteroids and comets over 140 meters in diameter. This instrument will have infrared vision that will make it possible to detect bodies approaching from the direction of the sun, which is difficult to locate with conventional telescopes.
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