What would happen if an asteroid threatened to hit Earth, causing a global cataclysm? NASA has revealed the international alert system which would make it possible to warn the population and avoid catastrophe.
The collision between Earth and a large asteroid causing a global catastrophe makes for an enticing scenario for a science fiction film. And yet, the threat posed by these space travelers is taken very seriously by NASA. The American space agency continuously monitors asteroids and their trajectories to avoid being caught off guard if one of them ventures a little too close to our planet.
While dinosaurs were probably surprised when the sky fell on their heads 66 million years ago, space agencies are doing everything they can to ensure that we don't suffer the same fate as them. The consequences of such an impact could be disastrous depending on the size of the asteroid, leading to tsunamis, earthquakes or even a cloud of ash in the atmosphere, which would plunge the Earth into the heart of a freezing winter for many years. . Rest assured, at present none of these space objects present an imminent danger to our planet. However, the United Nations has created a network called the International Asteroid Warning Network (IAWN) which coordinates their monitoring on a global scale. Recently, NASA revealed the international alert procedure that would be followed in the event of detection of a dangerous asteroid by this network.
Imagining that an object of this type that has been under the radar for all this time is spotted and presents a serious threat, two scenarios would be considered. If the asteroid threatened the United States, NASA would first warn the White House, which would then be responsible for warning the population. In the event that the threat is of international magnitude, the IAWN would notify the United Nations Office for Outer Space Affairs which would put in place a planetary defense plan.
The whole challenge in the event of an alert is to spot the asteroid early enough to be able to act in time. According to Geo magazine, NASA would need a period of 10 years before the collision to have time to put in place a device adapted to the situation. With a margin of 10 years, NASA plans to divert the asteroid's trajectory to avoid collision. A conclusive test has already been carried out with the DART mission which deflected the asteroid Bennu in 2022 by crushing a probe on its surface. On the other hand, for a more imminent threat where it would be impossible to change the object's trajectory in time, one would have to consider destroying the asteroid with a nuclear bomb, but this alternative would be very risky for Earth, due to the impacts of fragments...
