Asteroid explosion ‘near ground’ in France is giving scientists sleepless nights. Here’s why

An asteroid that entered over France and exploded at quite a low altitude has uncovered a new impact risk that Earth’s planetary defences might not be ready to fight. Asteroid 2023 CX1 burst into a fireball after disintegrating in the sky at an altitude of around 28 kilometres. According to a research that looked into the asteroid explosion, the asteroid did not start breaking apart after entering, and instead had a single explosion, releasing much of its energy at a very low height. Meteorites and other space rocks that enter Earth start disintegrating as soon as they hit the atmosphere, breaking apart in smaller chunks, thus releasing their energy slowly. But asteroid 2023 CX1 remained intact for a longer duration and only exploded after it came pretty close to the ground. NASA’s Ames Research Centre calcualted that the meteor released a dynamic pressure of 4 MPa. A zone of high overpressures was created because of this, which was around four times bigger than expected for an asteroid of this size. Also Read: Asteroid KY26 smaller and faster than expected, new challenge for Japan’s Hayabusa2

This finding presents a scenario that has never been explored before in planetary defence. According to the study, if in future an asteroid similar to 2023 CX1 was to hit Earth, and undergoes a similar burst, then it could cause a significant damage at the ground level. This means that people working to secure the planet from asteroids and comets have a new problem on their hands. They now need to rethink what is considered a “safe” small impact in the future. The problem turns even bigger if a bigger piece of space rock were to hit Earth. If it behaves like 2023 CX1, it could wreak havoc. In the absence of multiple detonations in its trajectory, a single large blow occurs near the ground, making it act like a bomb, Auriane Egal, who conducted the research at the University of Western Ontario in Canada, said. Also Read: Watch: Did China shoot down a meteor with a missile? Scientists doubt Friday’s fireball came from space

She added that if a bigger asteroid entered Earth, the shock to the surface of our atmosphere would be significantly stronger. “This kind of fragmentation is more dangerous,” Egal continued. “If you have a larger asteroid, its effects are going to be amplified. Maybe we need to evacuate a larger area near the predicted impact location.” Explaining why 2023 CX1 behaved in this manner, Egal said it belings to a parent rock in the inner asteroid belt where many collisions likely “toughened” it up. “We have multiple shock veins in the meteorite that are witnesses [to] lots of impacts,” she said. This is why it held strong until the last minute.