TechStuff Classic: Can we stop an asteroid from hitting Earth?

asteroid from hitting Earth? Yikes? Yeah, when you talk about existential threats and asteroid hitting Earth is way up there. We know that it will happen. The question is just when will it happen, not if when and what can we do to avoid that? Well, this episode, which we originally published on July eleven, two eleven, gets to the bottom of that. Chris Pallette and I take a look at some proposed solutions to this problem. Listen and enjoy.

We're gonna be talking about asteroids and preventing a collision with Earth and what sort of tech would be involved with that. And this comes courtesy of some Facebook requests and email requests. I can't believe that we had people send us Multiple people sent us this request which seems

really specific for more than one person. But hey, we're gonna do it, okay, And um, you know, if you have seen the documentary Armageddon, you remember that we shot Bruce Willis up into space um with Ben Affleck and some other folks like Steve bus Simmy to scare an asteroid out of the way, because Steve Busummy is a scary guy. Uh wait, I think I might be. I

think I might be a little off track. Oh well, anyway, the premise of the movie was that there was this enormous asteroid the size of Texas, which, by the way, not that guy, you do. Yeah, that that's that's a reference that goes over everyone's head because no one, none of our listeners have ever played the game Asteroids. What some of you have played Asteroids? And maybe so maybe maybe our our buddy Floyd the truck driver, he might have hopefully not while driving, well I hope not. Anyway,

we're getting off track already. So the whole, the whole premise of the movie is that there's this giant asteroid the size of Texas that's going to be flying at Earth, and so they come up with this idea where they scramble a bunch of uh minors essentially to shoot up into space, land on the asteroid, and plant a nuclear device on the asteroid that will blow it up to tiny little bits and save the Earth. And so we want to address this, um this first, So let's let's

get this all of the way. That would not work, That would that would be a bad thing. First of all, the power of such a device is hard to imagine. How would you create a nuclear device powerful enough to explode texas into tiny bits the equivalent of texas flying at you. Also, by the way, an asteroid that size would pretty much wipe out everybody. Um. You know, when we talk about asteroids that are are dangerous enough to

wipe out a city fifty yards that's big enough. A fifty yard asteroid, like an asteroid fifty yards across, we have enough power, enough enough force to destroy a city if it impacted the city. Um. Now, NASA classifies earth threatening asteroids as being a hundred and forty meters or larger. But then that conveniently is about the size that we can detect them. Well, it's uh. It's important to note

too that it's happened before. We have been hit with with many space objects in the past, and I assume to some small degree continue to do. So, Ye's something that we hear about in the news every day. But every single day the Earth is hit by by tiny little object. Granted we haven't been hit by a massive asteroid in a really long time, but meteorites hit the Earth every day. Sometimes they're so small that you know, they're almost undetectable, but it does happen the But yeah,

they've happen in the past. I mean, that's what wiped out the dinosaurs was an asteroid impact were possibly common impact, but it was a massive impact that that altered the Earth's climate, and dinosaurs did not have air conditioning, so they were pretty much doomed. Doomed. I figured it was their debaucherous lifestyle and it was unsustainable. Now you're thinking of Rome, right, you know, I get this confused a lot. Yeah, well, you know, if you've ever seen a t rex in

a toga never mind. So, so why would this plan not work with destroying an asteroid with a nuclear device. Let's assume that, for for argument's sake, that somehow you managed to find a nuclear device capable of breaking up a Texas size asteroid while it was hurtling towards Earth. And keep in mind this was this this asteroid was close to Earth by the time it blows up, Otherwise it's not nearly as dramatic an ending. Right, of course, you've gotta have it close enough to the Earth where

people are starting to really freak out. Oh and how long exactly did they have to prepare for this? It was like a couple of days or something like that. It was crazy short time period. We would know, Yeah, anything that's anything that that size, we would be able to spot between Mars and Jupiter, giving us years, literally years to prepare. It would not be a last minute thing.

And um, that's one of the myths that movies perpetuate is that you know, you have some uh, some some amateur astronomer out in the middle of nowhere just looking up and saying, that's weird that star wasn't there yesterday. And then and then that information slowly filters its way to some official source which immediately clamps down and keeps it all secret so that nobody knows that doom is on the way until it leaks to the media causing a panic. Yeah that we don't want to cause a panic.

It's definitely Hollywood related. So why would blowing up the asteroid not be a good idea. Well, that asteroids moving at a really fast speed and the nuclear warhead is not going to slow it down. Okay, so you've still got this this material moving at an incredible speed and the mass isn't gone. You haven't destroyed the mass. You've just spread it out some So instead of it being a one massive asteroid hitting the Earth, it's a whole

bunch of them hitting the Earth. And it's like the difference between getting hit by a slug and getting hit by um shotgun shot. You know, we just spread out the area of impact, is what you've done. This is mission control. We just wanted to say, oops, yeah, are bad so um so yeah, here's here's why this stuff would really work in the real world. All Right, We've

got lots of powerful telescopes pointing in all sorts of directions. Now, so the the the myths of the amateur astronomer who detects uh something the size the size that's in depicted an armageddon is really that's that's busted because it would be detected by much more powerful telescopes much earlier, and um that information would go to uh, it's kind of a clearing house for near Earth objects that could potentially

cause harm. It's called the Minor Planet Center. It's in Cambridge, Massachusetts. Now, the Minor Planet Center would then take the information that was sent to it, which usually would involve the size of the asteroid and it's it's shape of orbit around the Sun and whether that orbit could potentially uh collide with the Earth, send that information out to observatories all

across the planet. Now, these observatories would then train their telescopes onto the object to try and make their own calculations based upon their own their own perspective, to see if perhaps this would be a quote unquote interesting object. Now, in astronomical terms, interesting means holy crap, we're all going to die. That's the That's what they mean by interesting

as in potentially impact the Earth. Interesting. And that information would then be shared amongst those observatories, and the likelihood of a clamp down is really low, just because you have so many people who would be involved in this and have the information, and lots of them were gonna talk.

A lot of them we're gonna talk and say we got to prepare now, because if we don't, we're all going to die or a significant number of people are going to die, because if this asteroid hits a land mass, then it's gonna be like, depending on the size of the asteroid, it could be like the entire world's nuclear arsenal exploding in a single point. Um. If it hits the ocean, then it could generate a tsunami of unprecedented uh force that could wipe out an entire coast of

a of a continent. Um. So I mean this is serious business. Uh. Fortunately, we haven't discovered anything so far that would cause that much of a problem. But again, our ability to detect these objects is limited. Most of the objects that NASA concentrates on is anything that's the higher and forty meters or across or larger. And uh. The problem is that smaller objects could cause significant harm.

But finding those objects there is a lot trickier because space is big, really Yeah, and in relation to space, fifty yard across asteroid or is nothing. It's it's you know, you you it's it's impossible to exaggerate how tiny that is. Yeah, it's like a it's like a germ on a bug. And and and you happened to be like a blue whale that's kind of and even then that's not even close. Yeah, I can't get my mind around it. That's that's how

it is. We'd like to take a quick break from this existential crisis filled with anxiety and fear, to reflect for a moment on how lucky we are to have this sponsor. So all right, So nuking a an asteroid directly, as in trying to blow it up, is not a

feasible option. So let's let's assume for the moment that we have developed technology that helps us, that's improved our ability to detect asteroids to the point where any asteroid that could potentially cause significant harm to people on Earth, to life on Earth, that we have somehow managed to

to create the technology to detect it. Yeah, all right, and it's and it's important to do so because it is probable that we will be hit by something largish again at some point, Essentially, like it's worthwhile to develop this technology exactly. So, yeah, the the risk might be low,

but the impact would be huge. So you know, even taking a low risk perspective of it, the actual impact would be so enormous that it is a good argument, and a lot of people have made this argument to um to invest in technology to help prevent it from happening. So let's assume that we have improved technology so we can actually detect these asteroids from a pretty good distance.

Like I said, it might be years before they get here, or we're gonna need that time because we're gonna need that time to develop the actual vehicles that the tools that we're going to use in order to intercept that asteroid. So by intercepting it, what could we do to to avoid a collision. Well, the real key is deflecting the asteroid. You just have to move it a tiny bit, especially

the for there out you go. The further out you go, the tinier that that adjustment needs to be, because by the time it gets to the Earth it's going to be the distance is going to be much more enormous. You know. Just think about like you're walking to have a friend standing across from you across the football field, and you're both facing each other exactly. Now imagine that your friend just turns slightly a little bit to the

left and starts walking forward. Well, from a distance, it looks like there that your friend may actually meet up with you once they get all the way across the football field. But as they continue, you see that they're getting further and further away until they reach essentially a point parallel to you, and they are a good distance from you right there, further down the field, like further to the right or to the left, whichever way the

person turned. Um. That's kind of the idea here is that if you can catch an asteroid early enough and deflected just a couple of degrees, then you've solved the problem because it's going to miss the Earth by millions of miles. Else But how do you deflect it? Well, there's a lot of different options. Yeah, I read uh too specifically that seemed to be the options people are thinking of most like what's that? Um. One of them, ironically enough, was to use nuclear devices, Yes, but not

to destroy, but to nudge. Right. Yeah, The idea is being that you would you would detonate the device over the asteroid. This would actually, um cause a couple of things to happen, And it's you know, it's interesting that again that we're talking about something. You know, you might say, hey,

you just said nuking is bad. Well, in this case, what would happen is that you would uh create an uh A nuclear radiation would create this uh, this vaporizing energy and vaporize the surface or a section of the surface of the asteroid. Now that's going to cause that part of the surface to eject material into space. And you know, for a reaction action, there's an equal and opposite reaction, So that ejection from space is actually gonna as a pushing force on the asteroid. And it's tiny,

but that's all you need necessary. You know, that might be all you need to move that asteroid out of the pathway of the Earth. So yeah, um, you're just using it again to to give the asteroid a little push. Um. Actually, most of the the options I've seen are some variation on pushing the asteroid. It's just lots of different potential ways we could do that. Well, that's true. I did read uh Yeah, to be fair, I did read of the possibility of using an inert uh device, nothing that explodes,

but basically a bullet if you will, to shove. Yeah, using using kinetic force to push the asteroid out of the way. Yeah, that is another potential um solution, although it's it's again one of those that that has its own set of difficulties. But Yeah, that's that is what I've also heard where you're just using a kinetic force to to hap the asteroid out of the way. And

it's it's important to note that, UM. What we really can't stress how much detection and identifying the the object path how important that is because UM, there there's an effect called the Yarkowsky effect. Did you read about this, um, As the object gets close to the sun, closer to the Sun, UM. And I'm not talking about directly on a path too, but you know, as it gets closer and closer to the Sun in the center of our solar system, it's going to heat up. UM. And for

a larger object it doesn't matter so much. UM. But according uh to an article that I um than an article I read, the the Yarkovsky effect basically means that once the the object starts to heat up, the heat can affect its path. It can basically started to move in a slightly different direction. So you need to be able to we would need to be able to know exactly where the or as least as close enough to uh where the object is going to be, so that

we can accurately hit it with something. If we're going to try to use a brute force method of moving the the asteroid out of the way, and a lot of the attempts to move asteroids may depend upon sun, the sunlight and the Sun's power. Because um there are a lot of different options that would harness the power of the Sun in order to create a pulling effect

or pushing effect on the the asteroid. For example, there's one UM one possible technique where we would coat the asteroid with white and dark coating like paint or dust or whatever, and that would uh cause it to move because the Sun's energy would actually push against the asteroid. And if we coded the rights the correct side, not the right side, I mean there's no real right or left, but the correct side of the asteroid, it could push

the asteroid those couple of degrees. By the time it gets to where the Earth is, it's millions of miles away, and it's it's millions of miles off course from hitting the Earth. UM Similarly, there were suggestions that maybe we could create a solar sale that would attach we we would use a like a probe to attach a solar sale to an asteroid, and the solar sale would catch the Sun's energy and be propelled by the solar wind, essentially to pull the asteroid again outside of its pathway. Um.

That that's kind of a far fetched one, really. I mean, it's definitely a lot more challenging than say, coading an asteroid with a light colored material. Um. But then there's also the idea of using a net, an enormous net to encapsulate the the the asteroid, and the net would again act as almost like a solar sale. It would it would react again, you know, the sun. The Sun's energy would push against the net, which again would alter

the course of the asteroid. Um. Mirrors are another potential UH solution, where you you launch a device that is going to deploy mirrors around the asteroid to direct sunlight to specific points on the asteroid to again push it out of the way. Um. Well, everyone knows that asteroids are vain, so if you, you know, put the mirrors on the far side of the Earth, they'll go toward the mirrors and go, oh, my best side, I look good. Um.

But then there are a couple of other elements. There are a couple other ways of nudging an asteroid all the way that don't involve sunlight at all. UH. And one of them, and one of them's strapping a rocket to it. So essentially you have a UM, do we

have to land somebody on the asteroid. No, not necessarily, you'd have to have some sort of of remotely operated probe that could embed into the asteroid itself and then use um have enough fuel in it to be able to push as a rocket to push the asteroid out of the way of the pathway of collision. Now it doesn't have to push very hard, it doesn't have to

push for very long. Again, as long as you catch the asteroid early enough that we have to keep stressing that this is This is assuming that we capture, that we detect the asteroid and years and years and years in advance, and that we're able to react quickly enough so that by the time the probe reaches the asteroid, because you remember, this isn't gonna be overnight. It's gonna take time for the for whatever solution we deploy to

get to the asteroid. Like it maybe you know, we launched something and we don't know if it's gonna work for another two years or three years. I mean, it's kind of scary to think about, but that's true. So UM Yeah, you have to figure out a way where you have this this device, and it has to be able to carry enough fuel so that it can actually deploy properly. A lot of people suggest that this kind of approach would be best if it were already space born.

So in other words, we already had some sort of launching platform in space so that the uh, the individual probes would not need so much fuel to both escape the arts gravity and land on an asteroid and then propel it away. Um. That that does prose a problem. But then another one is the gravity tractor. Ah. Yes, and I when I looked up the gravity tractor, I had to check just a moment ago, and yes, someone has named their band gravity Tractor. Good for them, Yeah,

lead singer John Dear, nice, thank you. Um, but yeah, the gravity tractor is fascinating, um, because this is essentially using a different body and the gravity of another body and body that we would launch into space to pull the asteroid away without even I mean there's not the point here is not even a touch the asteroid. It's to get something near enough to it to affect um

the asteroids path with another gravitational field. Right, Because you gotta remember everything in the universe exerts a gravitational pull on everything else. It's just that that poll is dependent upon distance and mass and lots of other stuff. But they you know, so if you are able to put a massive enough object close enough to the asteroid, you could alter its pathway. There is there are some problems

with the gravity tractor, really yeah. One of them is that you have to figure out are a Well, you want the gravity tractor to pull the asteroid away from the path of collision. You don't want the asteroid to pull the gravity tractor into the path of collision. So so that means that you would have to have some sort of propulsion system aboard the gravity tractor to make little course corrections and continue to gently pull the asteroid

out of its pathway. Well, if you have propulsion, then there's the possibility that propulsion that you're going to when you fire your rockets to to give it a boost, that force may push against the asteroid, thus negating the gravity pull that you are exerting upon it. So essentially you're getting a net zero result because that you're you're pulling it out with gravity, but you're pushing on it

with your propulsion. System. So finding a way where you could create some sort of gravity tractor where the propulsion system would not actually push against the asteroid itself is would be part of the solution. Plus this would be really really expensive. It's a much more costly approach and not necessarily uh the most easy to implement compared to other approaches. So I don't know that this is necessarily

likely to happen. I mean, if if enough research goes into it where it proves that this is the most effective way, then sure I can see it happening, just because people would finally say, all right, well, you know, we have to invest in it, because we can't. We can't just play roulette all our existence. We have to prepare for this. UM. But I would imagine that we'd probably go with some other route before we tried this one. Yeah.

An article I read suggested that the the gravity tractor would have to be at least uh twenty tons in order to safely toe you know, effectively to I should say, not safely effectively to and an asteroid away from the Earth. UM. And I can't you know, I just imagine that's going to be very hard to get out of the Earth's orbit. I mean, you know, our gravity. I'm sorry to leave the gravitational field of the Earth to launch something that big into space. But you know, I'm not a rocket scientist,

so nor are you a brain surgeon. Now I'm not a rocket surgeon either, so um, well that's good. I can just imagine that going wrong. I hope you guys are enjoying this classic episode of tech stuff. I personally find it really inspirational to think about solutions to big problems, almost as inspiring as I find this next sponsor to be. Another potential, although it's far fetched, possibility of getting rid of an asteroid that um that's coming at you you

let robots eat it. Really Yeah, that's Robert Lamb actually wrote about this. He has a great article on the Our Our Discovery news site called top ten ways to stop an asteroid, and one of them is talking about using them robots that would actually essentially kind of chew up the asteroid and then shoot out the tiny bits of asteroid uh into space electromagnetically um and essentially disperse the asteroid while it's still really really really far away

from the Earth. Because keep in mind, if it's really far away on the Earth, then not all of that mass is going to hit the Earth the way it would in the beginning of UM the or or at the end of ARM again rather so, Yeah, these these robots, uh eating poop. They eat asteroids and they poop asteroid dust. I am. I wanted to go there, and I said, no, I'm not gonna say it. You're not gonna say they eating poop. Nope, But you did it for me. So I could see the look on your face and I

knew that you were thinking that. So I was like, I'm going to do it. UM, well, I wanted to recommend. Yeah, so this is this is definitely something that we need to think about. I mean, it's it's true that we need to think about invest in it. There are some talks about private companies actually investing in this UM sort of technology, this sort of approach UM, which is kind of cool that you know, it's not just not just depending upon governmental agencies that have lots of different you know,

things pulling on them. UM. I did read that UM scientists don't seem to believe that there's any thing likely to hit us in the next hundred years or so right at the earliest, well at least nothing that we can see, Yeah, exactly. So there's still the possibility that something smaller could hit and still cause massive damage. It's just not gonna necessarily cause global damage, but it could

cause catastrophic local damage, you know. Um. Yeah, there's some interesting organizations out there that are dedicated to trying to fix this problem. There's one called the B six one to Foundation, uh, and they their goal is to have a workable solution by So that's coming up pretty pretty soon. UM. If you guys want to learn more about the topic, well, I can recommend a couple of things and how stuff works. We actually have two articles that you go into more

detail about the stuff we've talked about. One is called could we really blow up an incoming asteroid with a nuclear bomb? And one is called could we stop an asteroid on a collision course towards the Earth? And also uh, there's a great program that aired on Discovery UM called Bad Universe, and it was it's hosted by Phil Plate,

the Bad Astronomer. Phil Plate, by the way, one of my favorite bloggers and scientists out there, because he's one of those scientists who really dedicates his work to explaining science to the layman. In terms that are easy, easy to understand. It makes science fun and exciting, and he does not shy away from topics like this, where you know, he's like, yeah, it'll kill you, so that's why I gotta fix it. So he's very matter of fact about it. Um,

really intelligent guy, very entertaining guy. So if you have not read his stuff or watched his show, I do recommend trying to catch that because it's he's a great guy. And he also has a really amusing Twitter feed, and he interacts with a lot of other uh Twitter Wisenheimer's out there, like Jonathan Colton, Paul and Storm, you know, um,

Will Wheaton. There's there's this kind of Twitter rottie that have have formed up and uh and so um he often will chat with those folks in interesting and entertaining ways. And he's and he shares a lot of really cool science news through his Twitter feed as well. I showed you that that amazing photo of the Space Shuttle Endeavor across the Sun. Yeah, yeah, that was that was courtesy of of Mr Phil Plate. So yeah, he's written extensively about this, and he's he's talked about it in his

blogs and on on on the show Bad Universe. Um, so I recommend that as well. And uh, well, I don't have any other potential solutions off the top of my head. Do you have anything else you want to add before we conclude? Not in particular? Now, well, then, um, I would suggest we all just take a moment to uh to to ridicule the documentary armagedon uh for its portrayal of how we would uh alter the course of a of an asteroid by blowing it up real good, uh Texas style. But you have to land a space

shuttle on it first. Yeah, and you have to sing the song I quoted at the beginning at some point, and uh, and Bruce Willis has to die. Oh spoiler alert. Yeah. Um, I was interested in though, that scientists are also talking about the possibility of of mining asteroids in a in an attempt to understand them better. Um yeah, I did

read that. Uh you know, although we may not necessarily be ready to to destroy one just yet, that scientists even alter its path, right right, Um, But scientists are considering the possibility if uh, you know, since they are tracking some asteroids that are coming near to Earth and near and again space is big, so near as a

relative term. Um that they're talking about the idea of visiting some near Earth asteroids with the possibility of mining, you know, taking some samples of the rocks that are there on the asteroid to get a better understanding of elements in the universe and bringing and back to Earth, which, uh, is a really cool idea. I don't I don't imagine

they would send people to do that. Um. So the idea of doing the complex calculation necessary to hit a moving object you know that's coming around, um, take samples and then return to Earth. That's that's really fascinating stuff. And that's not exactly the same topic, but I think it's a really cool application of science and hope that if they can do that that it will be fruitful

and we'll learn a lot from it. Yeah, and asteroid mining may actually lead to other things as well, like, for example, if we find an asteroid that has ice deposits on it, that could be a way of finding not just water, but actually generating oxygen for other space missions. Alright, guys, that wraps up this classic episode of tech stuff. I

hope you enjoyed that terrifying walk down memory Lane. It's not all scary We've got a lot of very smart people working on this problem, and there are a lot of potential solutions that could really be effective, just not in that Armageddon kind of way. But hey, if you guys want to join an arousing chorus of leaving on a jet plane, I'm right there with you, because I love my John Denver. If you guys have suggestions for

future episodes of tech Stuff, send me a message. You can email me at tech Stuff at how stuff works dot com, or drop me a line on Facebook or Twitter. The handle of both of those is text Stuff hs W. You should go to t public dot com slash tech stuff. Check out all the merchandise we have available on that page. Buy something for yourself. Every purchase goes to help the show,

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