Could We Stop An Asteroid

The article discusses the threat of asteroids and the potential impact they could have on Earth. It addresses the need to detect and deflect asteroids that are on a collision course with our planet. The article also explores various methods of deflection, including using rockets, spacecraft, and laser beams.

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The Threat of Asteroids

We’ve all witnessed the beauty of a shooting star, but what would happen if an asteroid was on a collision course for Earth? Could we detect it ahead of time? And more importantly, could we stop it? Asteroid impacts are serious business. It’s widely accepted that the dinosaurs died out due to an asteroid impact, not because they had small brains as some theories suggest.

In my lifetime, people discovered a massive crater off Chicxulub, Mexico. This crater was so large that the asteroid that created it threw so much debris into the Earth’s sky that it was bigger in diameter than the Earth itself. This resulted in the Earth being surrounded by red hot rock for weeks at a time, cooking everything. Only the animals that lived in burrows and caves survived, leading to the evolution of species we see today.

The Impact of Asteroids

Asteroids are serious, most of them are very small. If you’re under 10 meters in diameter you hit the Earth’s atmosphere you burn up all. Big blue streak, green street, white streak and then humans make wishes upon you. However, if the asteroid starts to get bigger, starts to get into the twenty-five meters and the 45 meters in diameter then you get Meteor Crater Arizona. That would be like a city killer, or a county killer. And then when they get to be a 100 meters / 140 meters now you’re into a country killer, and then they get bigger than that and it’s a continent killer, much bigger than that and you’re taking out whole races of ancient species.

Detecting Asteroids

So, what if we found an asteroid that was headed our way, how would we find it? That’s a good question, well you can use telescopes. Skilled people can point the cameras at the sky and look for fast-moving objects. Objects that are crossing the Earth’s orbit, but we’re missing perhaps a hundred thousand of these things, of these county killers, city killers and country killers. So, what we want to do is build a spacecraft called The Sentinel, and as we say “it’s like looking for a charcoal briquette in the dark”, these things are hard to find. They are tiny compared to the vastness of space.

Deflecting Asteroids

But infrared light / heat bounces off them so what you will do – you are a satellite, you are a surveying spacecraft, you get your back to the Sun and look out from about the orbit of Venus. And try to find all these asteroids. And then you find one, what do you do? Do you run in circles screaming? No, No No, we’ve got to deflect it, just a little, just a tiny amount.

Asteroid might be going 10 km/s we want to change its speed about 2 mm/s. So ten kilometers, that’s ten times a thousand meters, that’s 10,000 meters. A millimeter that’s a thousandth of a meter so that you take the one over the thousand its a thousand times ten thousand, that’s 10 million. You want to change its speed a 10 millionth of its total. That’s not very much, but if you’re an asteroid that comes in at 10,000 tons / 100,000 tonnes, it does take quite a bit force to change it a 10 millionth of its speed.

Methods of Deflection

The easiest way is to get a rocket, just a big rocket, just go out there and smack into it. Except as an outer space so it just goes (silence) like that. Okay, that would change its speed a little, now notice everybody, what if it’s not just a rock? What if its a pile of rocks just loosely held together by primordial gravity? And so if you hit them they will just spread out and you will have a shower of rocks. That would be bad.

So, how about this? We will get a big spacecraft that is massive, a massive spacecraft will go out there and just get near to the asteroid. Just get near it, and then the mutual gravity of the you the asteroid and me the spacecraft will tug the asteroids just a little bit just a tiny amount or maybe get on the other side and tug this way. That might work but here’s the problem. We need a huge amount of fuel, for days and weeks and months and years. And what if it stops working, you can’t go out there and fix it.

Okay, how about this? The Laser Bees? A swarm of sunlight powered lasers, that are zapping the surface of the asteroid, for days, and weeks, and months, and years ZAP ZAP ZAP, so some asteroids, some rock is vaporized so the ejecta, or the stuff ejected has momentum just like rocket fuel, just like just like standing on a skateboard and playing catch with a bowling ball…the way you do. And so it would then cause the asteroid to change its speed. And so you send a swarm of these laser spacecraft, so that if one of them stops working you can use the other one. And you can have them come in from all different angles. And what if the asteroid is irregularly shaped (like this) you could beam it when the thing is smooth and then when there’s a pit or an inefficient place to be beaming you turn off, you wait for the asteroid to turn, then you turn it back on.


You see everybody, just because it’s unlikely, doesn’t mean it’s not a big deal. You know if it only happens once every few thousand years, well if it happens on my watch it would as the kids say “suck”. Okay, so we don’t want that to happen, we want to avoid that. Asteroids are serious business, but they’re exciting.

Got a burning question? Well be sure to subscribe asapscience, follow us on Twitter and Facebook, that’s what all the kids are doing. And if it’s an asteroid it may not be a burning question, it might be an impacting question, or even an ablating question.

Discussion Questions

  1. How do asteroids impact the Earth and what are the potential consequences?
  2. What methods do scientists use to detect asteroids and why is it challenging?
  3. How can asteroids be deflected from their collision course with Earth?
  4. What are the potential risks and limitations of using rockets or spacecraft to deflect asteroids?
  5. How do the Laser Bees work and what advantages do they have in deflection?
  6. What are the potential challenges of using Laser Bees to deflect irregularly shaped asteroids?
  7. Why is it important to invest in asteroid detection and deflection techniques?
  8. How can individuals stay informed and engaged in the efforts to prevent asteroid impacts on Earth?

Lesson Vocabulary

ThreatSomething that poses a risk or danger. – The hurricane is a potential threat to the coastal cities.

AsteroidsSmall rocky objects that orbit the sun, mostly found in the asteroid belt between Mars and Jupiter. – Scientists are studying asteroids to gain insights into the early formation of our solar system.

CollisionAn instance of two objects colliding with each other. – The car accident resulted in a severe collision between the two vehicles.

DetectTo discover or identify the presence or existence of something. – The security system can detect any unauthorized entry into the building.

StopTo cease the movement or operation of something. – They had to stop the construction work due to safety concerns.

ImpactsThe effects or consequences of an event or action. – The economic impacts of the pandemic have been significant.

CraterA large, bowl-shaped cavity on the surface of a planet or moon, typically caused by the impact of a meteorite. – The moon’s surface is covered with numerous craters from past impacts.

EvolutionThe gradual development and change of something over time. – The theory of evolution explains how species have diversified and adapted to their environments.

DetectingThe act of finding or discovering the presence of something. – The scientist is detecting the presence of a particular chemical in the water sample.

DeflectingThe act of changing the direction or path of something. – The magnetic field helps in deflecting charged particles from the Earth’s atmosphere.

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