We independently assess all our recommendations. Purchases through our links may earn us a commission.
In this article:
- The short answer: probably.
- The good news is astronomers can now track asteroids and estimate if (and when) they might collide with our planet with high accuracy.
- There are a few different scenarios for how the world could deal with an asteroid, ranging from nudging it off course to blowing it up.
- Even if none of those methods work and the asteroid hits us, our odds of survival are pretty decent, depending on how big it is and where it lands.
Let’s admit it: It’s pretty scary that in our advanced age the answer to the question “can humans survive a killer asteroid” is maybe, it’s not a solid yes.
Scientists have been scrambling to come up with a plan if an asteroid is found on a collision course with Earth. Fortunately, unlike what happened in the movie Don’t Look Up, our scientists and governments are shelling out the resources needed to give us a fighting chance if we ever found an asteroid on course to hit Earth.
Before we get into the specifics, I know how scary it can be to think about, so I’ll give it to you straight: We do have a chance to survive. In fact, unlike other natural disasters like hurricanes, typhoons, earthquakes, tornadoes, and volcanic eruptions, asteroid impacts are probably one of the rarest natural disasters there are.
With that said, here are some of the ways we could survive a killer asteroid. And what our chances of survival are if an asteroid did hit Earth. Hopefully, you’ll be able to sleep better at night after reading this article.
Asteroid Hunt
I just want to say something quickly, no matter what method for deflecting or destroying asteroids we talk about, all of them are useless if we can’t see the asteroid in advance since most of the methods would take years of preparation and execution.
To see those asteroids in advance, scientists are equipped with ground-based telescopes as well as space-based telescopes to scan the solar system and beyond for any moving objects that might be asteroids. With some math, each asteroid is also analyzed to find out its orbit and trajectory and how long it will take to reach Earth.
The good news is, with more and more funding being put into asteroid hunting and with how fast technology is being developed, NASA and other space agencies now have the ability to find more and more of these killer rocks long before they reach Earth.
In fact, asteroid hunting has gotten so good that we can now predict the orbits of above 90% of asteroids that have the possibility of hitting us. That means we have a pretty good idea of which ones might be a threat to us and can take steps to avoid them.
4 Ways to Avoid an Asteroid Apocalypse
As of now, there are several things we can do to avoid an asteroid collision with Earth. Some of these strategies include:
Gravity Tractors/Space Tugs
If we have more than 20 years to prepare, one way to deflect an asteroid is to use a spacecraft called a gravity tractor (or a space tug). The gravity tractor would fly alongside the asteroid and use its own gravity to slowly but surely pull the asteroid off its original course.
I hear you asking, “What about if the asteroid is absolutely massive?” Well, larger asteroids will require more time for a small spacecraft’s gravity to tug it off course, which is why we would need at least 20 years to pull this one off.
This method is considered one of the most gentle ways to deflect an asteroid and doesn’t have any of the risks that come with other suggestions, like using nuclear weapons. Nor does the spacecraft need to crash into the asteroid so we might even save some money by being able to reuse it on future deadly asteroids.
This technology is actually currently in development already at companies like Tesla and Exolaunch. However, the goal is not to steer asteroids off orbit, but to clean up space junk.
Kinetic Impactors
Let’s say we only have a couple of years to prepare so the gravity tractor is out of the question. In this scenario, the best way to deflect an asteroid would be with a kinetic impactor. This is a spacecraft that’s designed to crash into the asteroid and change its trajectory by using the momentum of the impact.
While it might not seem like much, a kinetic impactor would be able to deflect a small asteroid about the size of a car enough to avoid a collision if it’s traveling at over 15,000 miles per hour!
If the kinetic impactor were bigger and traveling at a much faster velocity, it could shove asteroids much quicker, and could even be used to deflect larger asteroids. But, in a realistic scenario, a large asteroid wouldn’t change its trajectory enough with just a kinetic impactor. Instead, it could slow the larger asteroid down enough to buy time for other solutions.
Solar Sails
If we have more than a few decades to prepare, then another way to deflect an asteroid would be by using something called solar sails.
These are large sheets of reflective material that would use the power of light to propel a spacecraft attached to it. Think of it as a normal sail on a ship sailing by sea.
Yes, you read that right. Light can propel objects in space. Light particles have momentum, and in the vacuum of space where few other forces aside from a little gravity are present, the momentum from light particles is enough to push a solar sail.
It could theoretically push a spacecraft as fast as 18,600 miles per second, which is faster than what a conventional rocket-powered spacecraft can achieve! This is due to the constant acceleration as long as there’s light hitting the sail.
Now, we can use solar sails to deflect an asteroid in two ways. The first is by using a solar sail to propel a kinetic impactor since a solar sail is theoretically faster than rockets. The faster velocity brought by the solar sail will result in a more effective impact on the asteroid.
The second is by wrapping or tethering an asteroid with a solar sail. We could do this in a way that the asteroid will either change its trajectory or slow down.
Nuclear Bombs
If all else failed or we had no time to prepare, nuking the asteroid would be our best hope. Nukes are our most powerful weapons and I’m sure they’re the first thing that comes to mind when most people think about a hypothetical asteroid about to hit Earth. I mean, it’s also what we’ve always seen in movies.
It’s not just the method with the most sense, it’s also probably the most efficient. While other methods require decades of planning and building, the nuclear option can be set in action in just a couple of years, maybe even almost instantly if the asteroid is near enough for existing nukes.
While bombing an asteroid is theoretically one of the most efficient options, it’s also probably going to be the messiest one. Remember: these weapons can pulverize entire cities. It’ll do the same thing to an asteroid. That means we’ll avoid the massive impact of a huge asteroid, but the Earth could still be peppered by a shower of asteroid fragments.
For nukes to be safe, they should only be used in situations where the asteroid is far enough that it only needs to be blown off course, not pulverized.
What Are Our Chances of Survival if an Asteroid Hit Us?
Let’s say our worst fears have happened. All of our deflection methods have failed and a giant rock is hurtling towards us, ready to hit in a matter of days or hours. What are our chances of survival?
It depends. How big is the asteroid? How fast is it moving? Where will it hit?
These three factors can determine our chances of surviving an asteroid hitting us. Let’s say that the asteroid in question has enough mass and velocity that it would hit Earth with enough force to create a crater similar to its size.
In that case, life as we know it is pretty much done for. The asteroid will wipe out most of life on Earth. Some would survive the mass extinction event, but those survivors will live the rest of their lives adapting to a new and strange world.
If it hits land, our chances of survival are relatively high. But if it hits the ocean, that’s a different story. The ocean would absorb most of the asteroid’s energy causing not only earthquakes and volcanic eruptions, but also tsunamis large enough to submerge entire nations underwater. By the time the ocean settles back down, most of us will have drowned already.
While all of this sounds terrible, most of these aren’t enough to kill all life on Earth. That ability is reserved for asteroids larger than 60 miles (96 kilometers) in diameter.
Smaller asteroids of about 1-5 miles can render a lot of species extinct, but they wouldn’t cause human extinction. But, even an asteroid as small as 0.6 miles (1 kilometer) can trigger a mini ice age, make the climate significantly colder. And no, that wouldn’t cancel out with the current global warming trend we’re dealing with. Any change in our global climate will destabilize our ecosystems and make life on earth harder.
While all of these scenarios are technically possible, the most likely one is that we’ll wake up to find a (relatively) small number of lives will be lost, economies would collapse, and it would take us a couple of years or decades to establish a new normal. All that is to say: it would be a massive disaster, but it wouldn’t be the end of the world.
What do you think? Are you convinced that we are capable of stopping a killer asteroid? Maybe you have some ideas of your own on avoiding an asteroid apocalypse? Let us know in the comments below!
