As in the cinema, a scientific study affirms that destroying an asteroid before it impacts the Earth is “the most efficient method” to get rid of it.
Over 19,000 near-Earth asteroids drift through our Solar System. To prevent them from crashing on Earth (and annihilating us like dinosaurs), a scientific team has just demonstrated that destroying them in flight with a nuclear explosion is the surest way to make them harmless. Easier said than done, however.
Hollywood was right: detonating a meteor in flight is still the safest way to make it harmless
Armageddon in 1998 with Bruce Willis, Deep Impact three months earlier with Elijah Wood (it was the disaster theme of the year), or even the misunderstood Meteor, released in 1979 with Sean Connery in the lead role … cinema loves to scare us with falling meteors. And as the cinema also loves the big show, these poor pieces of rock circulating in the wrong place, at the wrong time always end at the last second annihilated by nuclear explosions. If this were to happen in reality, however, the disaster scenario would not be avoided, as a large-scale impact simulation demonstrated this year.
According to a very serious team of American researchers, unrelated to Hollywood, this would actually be the best possible method to make them harmless. They recently published a study in the scientific journal Astronautics Act. Today, the only solution that NASA is working on is a “soft” method to divert dangerous NEOs before their impact with the Earth. It is preparing with its DART mission a probe intended to change the trajectory of the asteroid Didymus (which is not threatening). But this solution is only valid if there is a sufficient warning period, of the order of several years, the time to build and launch the probe. There is currently no science fiction “planetary defense system” able to knock out an asteroid on a whim in a few hours.
Researchers have developed software that finds the best configuration to detonate meteors
American researchers, from Johns Hopkins University of Physics and various astronomical laboratories, call their method the “disturbance” of asteroids, a euphemism which actually means to explode it into a thousand pieces. They simulated the behavior of various meteors subjected to nuclear explosions of about one megaton, then analyzed the dispersion of their fragments. ” If we have, say 10 years of lead time, which is possible given the detection capabilities, a kinetic impactor could handle a wide variety of threats of varying sizes ”, explains Patrick K. King, the study’s lead author.
By placing the “kinetic impactor” (the nuclear bomb, if you prefer) in the right orbit, at the right speed and at the right time, nuclear explosives outperform just about any existing solution, researchers say. They are now able to determine these criteria with precision, thanks to physical models integrated into the software that they have programmed specifically for the needs of their study.
According to their method, by fragmenting the meteor as uniformly as possible, about 99% of the debris resulting from the explosion would miss the planet. They would then join the 80 to 100 tons of perfectly harmless asteroid fragments, which burn in the atmosphere (the famous shooting stars) or fall to the surface each day, generally in very small pieces highly prized by geologists.
Source : Acta Astronautica / Science Direct