The impact of the NASA mission that changed the course of an asteroid

Calculations carried out by NASA, the American space agency, estimate the number of near-Earth asteroids at 25,000. Occasionally, one of them lands on the planet. On February 15, 2013, a rock measuring 18 meters in diameter hit the city of Chelyabinsk, Russia. The event generated a shock wave that injured 1,200 people and caused material damage worth US$30 million. In the coming years, it is certain that, to a lesser or greater degree, new collisions will happen. A possible impact is predicted to occur between 2048 and 2057, when asteroid VK184 passes through Earth orbit. Fortunately, there is no prediction of a repeat of the tragedy of 66 million years ago, when a meteorite 10 kilometers in diameter plummeted over Mexico’s Yucatan Peninsula — overnight, three-quarters of all species of animals and plants were wiped out, including dinosaurs. Given all this, a feat accomplished by NASA a few days ago can be considered, in fact, extraordinary. Thanks to the unprecedented operation, humanity will now be able to sleep a little more peacefully.

On Monday 26, a spacecraft sent by the agency ten months ago crashed into the small asteroid Dimorphos. With only 163 meters, it is part of the Didymos system, the name of another much larger celestial body, 780 meters in diameter. Neither of them is dangerous. In fact, the scientists’ goal was to test the ability to hit a target 11 million kilometers away and cause a change in the original orbit. Streamed live on NASA’s YouTube channel, the impact was watched by millions of people. The grandiose spectacle has gone down in history, but its real effectiveness will only be known for a while – the exact date has not been set – when NASA will know whether the asteroid’s path has been altered, as predicted, by 1%. Only that? Yes, a small change of direction would be enough to prove that it is possible, with current technology, to deflect threats that are about to collide with Earth.

In the last decade, NASA has been increasing investments in the exploration of Mars. At the same time, but without the same visibility, he created a cell to study mechanisms capable of reducing the risk that an asteroid collision would bring to the planet. It is concluded that hitting celestial objects would be the most appropriate strategy, and the analysis of the tests carried out a few days ago will bring definitive answers to the challenge. In 2016, the space agency released a document stating that it monitored 244 near-Earth cosmic objects. In the future, it may be the case to ram them to remove the possibility that they will hit us. Monitoring tools are being improved. In 2026, NASA plans to put the NEO Surveyor telescope into orbit, whose infrared camera system will scan the cosmos for twelve years in search of objects that put the planet at risk.

The fear of a deadly impact is present in pop culture. In 1998, two films, Armageddon and Deep Impact, addressed the attempt by humans to prevent a meteor from ending everything, something more or less similar to what NASA has now done. Last year, Don’t Look Up, from Netflix, showed the story of two astronomers who unsuccessfully try to convince people that the approach of a comet will destroy the Earth. In the end, the planet is devastated by the impact. Thanks to the advance of science, however, tragedies like this will become increasingly distant, on the opposite side of denialism.

Published in VEJA of October 5, 2022, issue #2809