- The pieces resulting from the explosion would be destroyed by the atmosphere, according to the study of the physicist Phill Lubin.
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| "An asteroid like that of the dinosaurs would end humanity," Lubin. |
In 1908, a meteoroid airburst flattened 80 million trees near the Podkamennaya Tunguska River (Siberia). An impact crater was never found, since, according to the story, the celestial body disintegrated at an altitude of 5 or 10 kilometers. What would have happened if the almost 100-meter-long rock had hit the surface of the Earth? Scientist Lubin is not willing to trust luck again and has devised a planetary defense system to deal with any dangerous asteroid or comet.
A physics professor at the University of California Santa Barbara, Philip Lubin, and co-investigator Alexander Cohen recently presented their new creation in the journal Advances in Space Research: PI, which stands for Pulverize It. Basically, it consists of using the technology to 'pulverize' the asteroid in question into smaller pieces that would then burn up in the Earth's atmosphere.
The difference: "as if a 500-kilogram piano was thrown at your head from a distance of one kilometer or 500 kilograms of foam balls fell on you from the same distance"
Paradoxically, his thesis rests on the idea of letting the Earth receive the impact of the celestial rock, instead of trying to divert its route as a large part of the scientific community had proposed until now.
The difference lies, in this case, in that your system would disassemble the threat into smaller pieces, mitigating the damage that it may cause. In fact, according to their study, these large "pieces" - the size of a conventional house - would be absorbed by the energy of the atmosphere without ever hitting the ground.
"In short intercept scenarios, asteroid fragments of a maximum of 10 meters in diameter allow the Earth's atmosphere to act as a 'beam discharge' where the fragments burn up in the atmosphere or burst in the air, with the main channel of energy entering spatially and temporally decorrelated shock waves," the study explains.
How to blow up the asteroid?
After theory comes to practice. And attacking a celestial object in full motion does not seem easy... To do this, researchers have developed an "impactor" that is not only kinetic but also explosive.
Through a system of penetrator rods - 10 to 30 cm in diameter and two to four meters long - placed in the path of the asteroid to "cut and cut" the threatening object, PI would succeed in fragmenting the nucleus of the asteroid or comet when he crashes into them at extreme speed.
The researchers explain the difference: imagine “a 500-kilogram piano being thrown at your head from a distance of one kilometer or having 500 kilograms of foam balls dropped on you from the same distance.” The balls might do some damage, but they definitely won't kill you.
His idea was awarded by NASA in the NIAC (Innovative Advanced Concepts) program, which promotes and supports visionary ideas that can transform future missions.
Just 10 days before the impact
Months or years in advance, a 'kinetic impactor' can be sent to redirect an asteroid. But what if this system fails? Or if we find out too late that an asteroid is approaching Earth? It is in this scenario that Lubin's plan becomes vitally important.
“The big advantage of this approach is that it allows for terminal defense in short alert times and target range mitigation when orbital drift is not feasible,” explains Lubin.
Based on their calculations, smaller targets, such as the Chelyabinsk meteor (2013-13 wounded), could be intercepted minutes before impact using smaller launchers similar to intercontinental ballistic missile interceptors. An asteroid like Tunguska's could be intercepted five hours before its impact. While targets that pose a more serious threat, such as Apophis (speculated to hit Earth in 2029), could be intercepted only 10 days before impact.
"Until now, humanity has been spared a large-scale catastrophe such as our previous inhabitants of the planet suffered, but relying on 'lucky' is a bad long-term strategy," Philip Lubin said in 2021.