The tabletop experiment, as NASA referred to it at the time, was designed to test if an asteroid that was discovered approximately six months before it was expected to strike the Earth might be stopped in its tracks. It turned out that no technology at the moment, not even nuclear weapons, could stop it. In the experiment, Germany, the Czech Republic, and Austria were all destroyed when the asteroid ultimately dropped in Europe.
Nothing really noteworthy has occurred on this front since then. The Double Asteroid Redirection Test (DART) spacecraft will collide with the asteroid Dimorphos on September 26. At that point, we will be able to determine if the notion that a hard impact may alter an asteroid’s course is true.
The key factor is how much ahead notice we get, even if DART is a success. Keep in mind that NASA’s research showed that not even six months are sufficient to organize a response and avert a probable extinction-level disaster.
But there must be methods we can do it if only someone could come up with them. Fortunately, someone accomplished it earlier this year, and NASA acknowledged the value of the concept by awarding them an Innovative Advanced Concepts (NIAC) grant.
This person’s name is Philip Lubin, and the idea he’s putting out is called PI – Terminal Defense for Humanity. Philip Lubin is from the University of California, Santa Barbara. Or, to quote the researcher, “a feasible and effective technique of planetary defense that allows for incredibly short mitigation time scales if necessary.”
An “array of tiny hypervelocity kinetic penetrators that smash and dismantle an asteroid or small comet” is the basis for the concept. We’ll now refer to them as space bullets since “tiny hypervelocity kinetic penetrators” sounds a little too scholarly.
These asteroids are intended to be shattered to pieces by these space weapons rather than being gently nudged away. They might be sent into orbit or anywhere else is necessary by using SpaceX’s Falcon Heavy and Starship or NASA’s own Space Launch System (SLS).
Space missiles and their launchers might be set up in advance on Earth or even up there on the Moon. Specialized stations would be continually scanning for threats from space, supplementing the infrastructure that is already in place on Earth.
Although Lubin doesn’t specify the size or composition of the bullets, he does say that they will be inexpensive, highly effective, and created using already-available tools and materials. Most critically, they must be effective against both dangers that are known to exist in advance and asteroids that slip past all sky-gazing eyes and approach us within hours or less of being identified.
The bullets would ultimately fragment the asteroid into pieces that would likely miss Earth when fired at far-off targets.
The ones that have been spotted nearby will likewise be neutralized, but in order for the same thing to happen to their remnants, our atmosphere must intervene and play a role as well, burning the pieces before they reach the surface. According to Lubin, these projectiles might produce pieces with a maximum diameter of 10 meters (33 feet), which the atmosphere should easily burn.
The “multi-hundred-meter diameter class” of asteroids, according to our source, would be an easy target for these space bullets since, even if they weren’t able to entirely neutralize the danger, they would still greatly lessen the repercussions of the collision.
The scientist who came up with this as-yet unrealized concept even conducted some math to see how a space bullet might impact its target. He discovered that they would be effective even against an asteroid that was discovered just five hours before impact and had a diameter of 50 meters (164 feet)—roughly half the size of the one that erupted over Tunguska in 1908. Even two minutes of an intercept before impact would be sufficient in the event of an asteroid less than half that size.
When it comes to bigger asteroids, a rock with a diameter of one kilometer (0.62-miles) may also be stopped if we see it 60 days before it decimates significant portions of our world.
The concept is still in its infancy, and more effort must be done before it might produce anything genuinely concrete. But if an asteroid doesn’t wipe us out in the next decades, we could become the first species that we are aware of that can defend itself from extinction.