Earth was teeming with life, but everything changed in a single day: what is known as the K–T Event, the asteroid impact that caused the extinction of the dinosaurs and 70% of all living organisms on our planet.
A 10-kilometer-wide asteroid struck the Yucatán Peninsula in Mexico. It generated an explosion equivalent to 3,000 times the power of all the nuclear bombs currently in existence. It is impossible to imagine. Rock melted and was blasted into the atmosphere like wax, only to fall back down thousands of kilometers away. The skies darkened from dust and smoke produced by global fires.
An apocalyptic scenario—and for the dinosaurs, it truly was the apocalypse.
Today is International Asteroid Day, a day dedicated to reminding us that we live on a planet, in a solar system, inside a galaxy, and that every now and then we should look up at the stars and make sure everything is alright.
Now let's provide some historical context. In 2014, Brian May, legendary guitarist of Queen, Russell Schweickart, Apollo 9 astronaut, Grig Richters, filmmaker and activist, and Danica Remy, president of the B612 Foundation (a non-profit organization that develops planetary defence strategies), presented the "100X Declaration," a petition calling for our ability to detect, map, and track asteroid orbits to improve by at least one hundred times over the following ten years.
But why June 30th? Once again, we need to talk a little history.
On June 30, 1908, in Siberia, an asteroid between 60 and 80 meters in diameter collided with Earth and exploded in the atmosphere about 8 kilometers above the ground. The resulting explosion devastated everything within a radius of 600 kilometers. It was an explosion comparable to 1,000 times the bomb that leveled Hiroshima.
Thankfully, this event occurred over the skies of Siberia, a sparsely populated region, and there were relatively few casualties. But imagine what would have happened if it had struck a city. How would history have changed if this meteorite had hit London, Berlin, or Rome? This is one of the most fascinating "what ifs" in history.
Now, I don't think I need to tell anyone that if a meteorite were to hit Earth the way one did 66 million years ago, things would not go very well for us. So, dear readers, let's talk about how to prevent that.
Those who have seen the movie Don't Look Up have probably already understood the kinds of problems astrophysicists face when it comes to planetary defense.
The first challenge, perhaps the least obvious one, is that we must identify these threats. How many asteroids are there in our Solar System? What are their orbits, and what influences them? It is estimated that we know only between 20 and 30 percent of our Solar System, and the farther we move from Earth, the smaller these objects (asteroids and comets) become, and the lower that percentage gets.
Secondly, we need to develop technologies and infrastructure capable of deflecting asteroids. Unlike what happens in the movie Armageddon, destroying an asteroid makes little sense because we would simply fragment it into many smaller pieces with a thousand different trajectories that could still strike Earth.
Deflecting asteroids makes much more sense. Think about it: an object millions of kilometers away that experiences even a slight change in its trajectory—just a single degree—can end up on a completely different path.
This brings me back to what I was saying earlier: we need to develop new technologies and infrastructure.
What do I mean by infrastructure? Imagine two similar scenarios with one simple difference. An asteroid is on a collision course with Earth. In the first case, we launch a rocket from Earth on a mission to deflect the asteroid. In the second case, we launch it from a space base.
In the first case, we have much less time. What I mean is that we must wait for the rocket to intercept the object before we can attempt to deflect it. If we had space bases already operating throughout the Solar System, interception times would be drastically reduced. And if, in the worst-case scenario, our first intervention failed, we would still have time to devise a second response, perhaps launched from another space base.
As for technology, there is not much to say. If we want to place space bases in space—not orbiting our planet, but perhaps orbiting other planets—we will inevitably need to develop far more sophisticated rocket technologies.
Secondly, we must develop and test asteroid-deflection technologies. Astrophysicists working in this field have proposed many methods, but only one has been tested.
In 2022, NASA attempted to alter the trajectory of a binary asteroid system, Dimorphos and Didymos (they were not on a collision course with Earth; the test was conducted simply to see whether the method would work). What did NASA do? In simple terms, it launched a spacecraft into Dimorphos, and the kinetic force of the impact alone was enough to change the orbit of the asteroid system.
Other methods have been theorized but never tested. One is the Gravity Tractor, which uses the gravitational pull of another object to alter an asteroid's trajectory. Another concept, developed by the ESA (European Space Agency), is the Ion Beam Shepherd: a spacecraft directs a continuous stream of ions toward the asteroid, slowly pushing it off course.
All of these technologies still need to be developed and tested in space. For now, they are only ink on paper.
Finally, we must address the elephants in the room, and there are mainly two.
The first is that no country possesses the resources necessary to carry out planetary defense on its own. Cooperation among all the nations of the world is therefore absolutely essential—not only in the scientific field, but also in the economic and industrial sectors, which have always been a major source of disagreement between states.
The second elephant in the room concerns suspicion. If a single power were able to independently develop technologies capable of deflecting asteroids, those same technologies could easily be used to turn an asteroid into a weapon. After all, if you can move an asteroid away from Earth, you can also direct it toward Earth—and perhaps toward a specific country.
If you remember how this article began, in 1908 a meteorite exploded over Siberia. Imagine what would have happened if it had fallen on London, Paris, or Moscow.
For this reason, planetary defense must be approached in terms of Humanity, not nations; in terms of cooperation, not competition. Perhaps that will prove impossible. Or perhaps it will mark the beginning of a new era for humankind.
Federico Kock-Kramer is an Italian volunteer who writes about the World Asteroid Day.






