Asteroid 2019 OK: The Little Doomsday

what are the ambiguous risks? Oh, you know we're talking about like you know, you're getting talking about like social media and how and how it's affecting the human condition or you know, certainly in our episodes on psychedelics, you know, we talked about some of the more ambiguous and even more concrete threats facing humanity and to what extent some commentators think that the psychedelic experience can prepare us for

those threats. Okay, so kind of vague possible psychic and cultural threats, right, yeah, less less threats like a huge rock hitting you. Right, because because we over good, what we're gonna be talking about the day is certainly the kind of threat that that a mushroom is not going to be able to help us with. Right, So we wanted to talk about an interesting, perhaps hair raising story

from recent Space News. So, just within the past couple of weeks, Earth had a very close encounter and almost perfectly timed intersection with the orbit of a fast moving object from outer space. And the creepy and fascinating thing about this is that this object came very close to Earth and we had almost no forewarning that it was coming. So what was this thing? Well, I actually first saw it when Robert shared an article about it on on

social media. That's right, Yeah, there we go, determining the topics of all conversation. Well, and the crazy thing about it is that, you know, as we've discussed in the show, and the the more extreme things get to know, the rise to the surface and social media and especially right now, it tends to be stuff related to politics. But then somehow, uh, this one story breached the surface. It may have helped that it had the word killer in the headline. So

this was an asteroid that is now officially called asteroid nineteen. Okay, and that doesn't mean it's okay, that's just a you know, that's the code assigned to it. I read it as asteroid two thousand, nineteen, Okay, it's kind of like that. So it was detected by astronomers in Brazil and the United States before being confirmed by NASA JPL and on July. It passed by Earth at a speed of about twenty four kilometers per second, which is like fifty four thousand

miles per hour. Pretty fast. And what we want to emphasize is it's already gone, okay, so we should emphasize that at the beginning, this asteroid represents zero threat to us on any meaningful time scale. It is passed, it's on its way to other things. And the reason we're talking about this is that I feel like this event is instructive. It shows the real life and death importance of astronomy in general and improving our capabilities for cataloging

near Earth objects more specifically. And it's also I think an event that really reveals the part of you that either leans towards the positive or the negative interpretation of things, you know, the glass half full half empty kind of thing, right, the near miss versus near hit. Yeah, and also reminded of the old adage. You know, I don't know if it's truly an adage, but the observation that you never

hear the one that has your name on it. You know, generally talking about say, you know, a bullet in a military, uh situation. It's like on the Sopranos, you know, you never know the one that's coming for you, right. But the thing is we are we are in the business right now of trying to know the ones that have our name on it, the the asteroids particularly that have

that that have Earth or possibly Earth printed on their side. Yeah, and it's always going to be a probabilistic thing when we're looking to far out, so you wouldn't know for sure, but you'd say, you know, we think there's a you know, zero point whatever percent chance this has Earth on its name, has Earth's name on it, or maybe has a chance right yet to be clear. And we'll get into some

of the statistics here in a bit. But there there are no asteroids out there right now that that Nassa or anyone else is saying this is a definite collision course. No no big ones, No big ones. So yeah, I mean, obviously they are ones that are going to imbact Us and with with with a little or no effect. But in terms of like really big problematic asteroids, the ones that are the ones that we know of, and it is a you know, just a segment of the ones that are out there. There are none that we are

like positive like, this is the one. This is the one we have to act on right now, right now. Yeah, but this twenty nineteen, Okay, asteroids. So first of all, the question we need to play the glass half full half empty thing with Was it big or was it small? Well, it was between we think about fifty seven and a hundred and thirty meters in diameter, which is a hundred and eighty seven to four hundred and twenty seven feet.

Is that big or is that small? Well, it depends on what you compare it to the object that struck the Earth sixty six million years ago, the impact that most likely played a major role in the extinction of the dinosaurs. That one was probably I've seen estimates of ten to fifteen kilometers across. I've seen that people say more recently, this might be an updated or more more precise figure that it was like fifteen or sixteen kilometers across.

That's obviously a lot bigger. We're we're talking this object that just went past us is a couple of orders of magnitude smaller than that. So we're not talking about like necessarily a full blown civilization buster. No no, no

extinction event level impact. Yeah. Unfortunately, astronomers believe that more than nine percent of objects in this extinction event size category category, the category of things on the scale of the asteroid that killed the dinosaurs, uh, things like that, more than nine percent in our orbital vicinity have already been disc covered and cataloged by NASA and other observers and space agencies because the bare ones are simply easier to spot, right exactly, And so for the biggest of

the biggest, we're pretty sure we know where they are, uh that, and that we would be able to predict if they're headed our way, which is good, right, But then again, you could compare it to something on the other side. So the Chelly bents Comedia, which exploded in the atmosphere over Russia in was only about twenty meters in diameter, just twenty And this meteor was not even large enough to reach the ground. It didn't hit the surface of the Earth like most smaller objects entering our

atmosphere from space. It exploded in the atmosphere and what's known as an air burst. And this this explosion injured over a thousand people. I think it was close to people. It damaged buildings, it collapsed roofs, it smashed windows in this big elliptical impact zone stretched out for dozens of kilometers um and and a lot of the damage and human injuries from this air blast were due to like blown out glass from windows hitting people. I should say.

The footage also, of course, was incredible and certainly certainly makes you feel like a primate when you watch it. You feel like an earth bound primate um that has no control over the great fiery mass that is just seared across the horizon. It's a it's a two thousand one of space Odyssey monolith kind of thing. Yeah, you're like, well, okay, should I worship that? Maybe? But so that one, the one that caused all that damage, was just twenty wide.

This this one that just passed us was somewhere between fifty seven and a hundred and thirty meters. Why that's a good bit bigger. It's somewhere between an extinction event level asteroid or object and you know, one of the smaller ones like we've seen with Cheli Bensk. In fact, the size of this thing that just passed us is probably roughly comparable to the size of something we're gonna talk about more in a bit, the meteor that exploded over Siberia in nineteen o eight and the event known

as the Tunguska in impact. And like I said, well, we'll come back to that later. But basically though, the issue is it depends on where it hits. Y. Yeah, the thing that just passed us. The point is that it poses no threat to us. It's already gone. But if it had hit Earth, that would be really scary on the off chance that it came anywhere near a populated area. And of course the location is important with

any of these. I mean, I've I've read arguments that the chicks a lube impact, Like if it had hit uh, if it had been a water impact as opposed to a land impact, Um, you know, it would have made some difference in what occurred. So that's that's going to be a factor no matter what scale you're talking about here. Absolutely, yeah, that that place a big role. Well, we'll talk more about that as we go on. So uh So we talked about the size, Another question is how close exactly

did it come to Earth? Because there are the simulations that you can watch online. You should look this up. Actually, that show like the orbital pathways of Earth and this asteroid and as they sort of approach each other, as the intersection of these two orbital pathways comes up, it'll zoom in further and further for you. And there it looks like they're just on a perfect collision course and then they just miss at the last second. Now, what what does that miss look like on distances that are

appreciable to us. The answer is it came within about seventy three thousand kilometers or about forty five thousand miles of Earth. So that sounds pretty far away, right, that's at least few trips to Disneyland. But if you stay zoomed out, like we were just talking about, looking at looking at this path on like an Earth orbit scale, the distance is something you can't even really see. It passed inside the orbit of the Moon, and that's pretty close.

Like it is. Essentially you could you could say it has passed within the realm of U, within the sphere of of human culture, you know, like we have been to the Moon and this thing has traversed the space betwixt the two. Yeah, and it wasn't even in the far side of the Moon circumference like in fact, twenty nineteen okay, came within less than twenty percent of the distance from the Earth to the Moon. It was pretty close.

According to a to a piece I was reading on vox by Kelsey Piper, on average, about zero point five percent of asteroids that come within this range of Earth actually hit us. So that's that's a nice thing to consider, right. That's on the other hand, the other ninety nine point five percent within this range still pass us by, like nineteen okay, did you know the vast majority are not going to hit Earth? So that's good, right, But we kind of must ask the question, what if an asteroid

of this size did hit Earth? What exactly would happen? Uh? So I was reading an article by Liam Mannox of the Sydney Morning Herald who interviewed the Swinburne University astronomer Dr Alan Duffy, and Duffy said that an object of this size would be what astronomers sometimes maybe maybe loqually call a city killer. So it's not of a size that would cause a mass extinction or potentially qualify as

like a planet killer. Its worst effects would probably be local in the area around where it hit, and if it had struck Earth. Duffy compared this hypothetical impact to

something like a large nuclear weapons strike. One of our listeners on the Facebook discussion module that Stuff to Build Your Mind discussion module Facebook group shared a like a map tool where you can input your city and then look at what would happen if various models of nuclear weaponry hit your city and determine like how far the danger the danger zone is, how you know, far the

the radiation radiation extends. It's a scary tool, yeah, but it also just really drives home that most of these these devices are very capable of destroying modern cities, or at least taking such a sizeable and crucial chunk out of them to effectively destroy it. And I mean so this impact would have actually been bigger than the real atomic weapons that we have seen deployed on cities in

human history. According to Duffy, this impact, if it had hit Earth, would have hit with over quote thirty times the energy of the atomic blast at Hiroshima. And so that you might be wondering, Okay, if you don't usually think about these things, how would it have that much energy? It's not a bomb, right, It's just a rock. Why would it act like a bomb that explodes? Um. So what you have to remember is that the the energy released upon an impact with Earth's surface is a product

of the mass and velocity of the falling object. Now, normally, when objects like a chunk of rock fall to the ground, they don't behave like a bomb because they're relatively light and they're relatively slow. So this, this asteroid, would be a falling object of a size and a speed that we never encounter in normal life in Earth's atmosphere. Something you know, maybe a hundred meters across, like a giant

boulder or a chunk of a mountainside. Things that big don't usually fall to begin with, I mean, except maybe like huge airplanes. Uh. And then it would be traveling at twenty four kilometers per second, which is more than twenty times the speed of your average shooting bullet. Yeah, exactly. And so once you multiply those things together, that mass and that velocity, and it also matters, of course the angle at which it enters the atmosphere hits the ground.

But once you build up these levels of kinetic energy, any normal falling object like a huge chunk of rock or metal as you would find in the case of an asteroid, essentially becomes a bomb upon impact. And this is a fact we've touched on in some of our more science fiction ety episodes where we've talked about about how if you simply had orbital superiority over a planet, this planet or another planet that had occupants, just by virtue of having orbit, uh an orbital position, you could

drop anything. You would not need to drop a bomb from that height. If you could drop just a big piece of metal or rock, et cetera, then you already you have a tremendous weapon at your disposal. And this is where we get the you know, the term rods from god kinetic energy kannetic kinetic energy weapons would just be a matter of just drop anything from up there and it can destroy like nothing else. Yeah, it's scary.

And now, on the other hand, uh, we want to remember throughout this episode to not be alarmist and not get people to worked up. Now, first of all, this asteroid, like we said, it already missed us. It's on its way. About things like this in general, it really does matter

where it hits. So fortunately in this scenario, the majority of Earth's humans are actually squeezed into a fairly small subsection of Earth's surface, So chances are that even if an asteroid like this were to hit Earth, it would probably strike in the ocean. Now that could have negative consequences depending on where it happens, but but definitely better than a hitting u like you know, land, yeah, populated

area especially yeah uh. And if it did strike on land, it would probably most likely hit in a rural, less populated area. Now, not like that would be okay, but that would be you know, obviously fewer casualties than it hitting one of these smaller subsections of Earth's surface where there are a lot of people. Now, small objects from space passed by Earth and inter Earth's atmosphere all the time. What's interesting about this asteroid was the combination of its

size and how close it passed. Apparently a few dozen smaller objects like less than twelve meters in diameter passed within the orbit of the Moon every year, and according to one article I was reading, objects of about the size of twenty nineteen okay, only passed by this close to Earth roughly once every ten years. So we just had like a decade event and that's generally our way of understanding these these these asteroids we generally talk about

like the frequency of their occurrence. Is this a once in a decade, Is this a once in a lifetime? Is this, you know, once in a thousand years or more? That's right, because all these things we think of across time scales in in terms of probability. Right, you know, things that are unlikely to happen any given year become near certainties at a certain time scale. Right. And of course, these devastating impacts of you know, of of you know, from prehistoric times and uh, you know, they tend to

leave of mark. You can tell that they occurred, and we can extrapolate the kind of damage that that resonated exactly right. So to come back to another thing we we mentioned earlier, we mentioned that this thing snuck up, right, we seemed to come out of nowhere. People astronomers did not detect it until just days before its arrival. And

that's ultimately the most sobering thing about it. Is not that that that asteroids like this exists, or that they that they they reached these sizes or or passed in this proximity, but that we just didn't see it coming, and then it was gone like that, just passed us in the night. Then we realized how close we came. So the question is why. There are a couple of

reasons here. One is that it was relatively small and faint. Obviously, it's easier to use our telescopes to pick up and track near Earth objects that are larger and reflect more light. Another reason is that it came generally from the direction of the Sun, which makes it harder to see because of the glare in the background. Another reason it was hard to pick up was that it was traveling very fast. It makes it harder to detect. Other asteroids recently passing

by Earth have been slower. According to an article I was reading by Alison Chew in the Washington Post, most of the recent asteroids passing by Earth have been between four and nineteen kilometers per second. Remember again, this one was booking at twenty four kilometers per second, which is very fast, which also, of course, potentially means that if it had hit Earth, the impact would have been more powerful because it's going faster. Next, the shape of its

orbit made it difficult to detect. Nineteen Okay had a very elliptical orbit, meaning it was not roughly circular like a lot of the orbit of a lot of things, most of the planets, it had an oblong oval shape. So this asteroid, as it travels around the Sun, sometimes it comes very close, like within the orbit of Venus, and other times it gets very far away, out beyond the orbit of Mars. This also made it more difficult

to detect. And so if you add all this up, you've got this small, fast moving object that's relatively faint out there orbiting the Sun, and then suddenly, within maybe just a couple of weeks before it passes us, it becomes bright enough to see, and then other people have to see it and confirm it. Uh, somebody's got to be looking at the right place at the right time in the first place to see it. It's not easy. Things like this really can just sneak up on us,

and scientists don't necessarily always have fore warning. So this kind of serves as a reminder that our orbital neighborhood is not a void. Space is not just avoid is full of rocks and comets and stuff, and that while our astronomers do a really admirable job cataloging near Earth objects with the tools available to them. Objects of really frightening size can still creep up on us in ways that give us only days or even hours of warning,

or maybe no warning at all. Speaking to the Sydney Morning Herald, Australian National University astronomer Dr Brad Tucker said that it is completely possible that objects of comparable size, objects about the size of twenty nineteen okay, passed by us like this and we never detect them at all. Sometimes they just go right by and no, no human is any the wiser. All right, well, and that's sobering. Note.

We're going to take a quick break, but when we come back, we will discuss what an asteroid of this size would do if it actually hit us. Thank alright,

we're back, all right. So we're talking about the idea of the asteroid that just recently passed the Earth within the past few weeks nineteen okay, which again zero risk to us now it's gone, you know, But we're thinking about what an asteroid of this size, you know, roughly this size would do if were to be you know, the zero point five percent of asteroids that come within

this range that actually do hit Earth. Uh, we know that an impact from a large enough asteroid can be devastating on a planetary scale, like space impacts have contributed to mass extinctions in Earth history, and of course we know that the main theory explaining the the kt extinction or the KPg extinction was a theory involving a space impact, and of course that this was the extinction event that killed the dinosaurs about sixty six million years ago. It's

the third greatest extinction event in Earth history. The basic details are probably familiar to you at this point, but a commeter asteroid some bulllied from space hit the Earth in what is now the Yucatan Peninsula was probably I've seen estimates, uh. I think maybe the older estimates are

that it was ten to fifteen kilometers in diameter. More recently, I think I've seen people saying sixteen kilometers in diameter is a huge object, you know, measured on a scale of miles or kilometers, And an object of this size impacting Earth at orbital speed is not just a collision. It is, as we were talking about earlier, a detonation.

It releases a blast of energy equivalent to millions of nuclear warheads all exploding at the same time, and things on this scale hitting the Earth are especially scary because they're not just threatening to organisms living in the local area right that they can have planet scale effects, like the leading theory about the cause of the KPg extinction

is that this impact happened. This bowled from space hit the Earth, and it threw up so much dust and debris into the atmosphere that it blocked out the sun for perhaps months, preventing photosynthesis, killing off huge numbers of plants and photosynthesizing organisms, which of course cut off food sources for larger animals. And more than three quarters of Earth species are believed to have been completely wiped out

in this event. But there's good news. Scientists now think that if there are asteroids of that size on any kind of likely collision course with Earth, we would very very likely already know about them. It's not a sure thing, but we would really probably know because, like I said, we've we've cataloged more than nine we think of asteroids that could be of this size in our orbital neighborhood.

And we're always trying to improve our near Earth object detection and mapping capabilities, And this is an astronomy priority of species level importance. Keep watching the skies. But objects on the scale of the one that just passed us. Remember it's not even close to as big as that one. But objects on this scale are trickier. They're more difficult to be sure about because they're smaller. We also have less confidence in our ability to detect them ahead of time.

So what would happen if an object roughly on the scale of twenty nineteen okay, were to hit the earth? Well, it turns out we actually have a pretty close analogy from twentieth century history, which we alluded to earlier, and that is the Tongue event. Robert. For my money, this is one of the most darkly fascinating events of the last few hundred years. I think, yeah, they're there, you know,

it's one of one of these stories. It's certainly it's given the fact that it did not decimate a major center of population, uh makes it something that doesn't feel, you know, googlesh to to look at. But it's it's it doesn't have this kind of mysterious quality to it. It's almost like it's like a warning shot from the gods. It is also strangely kind of a magnet for cranky theories.

It really attracts, you know, people who want to believe that like a sudden black hole or a bit of anti matter appeared and caused it, or that it was UFOs or some kind of science fiction, you know, like Tesla experiment or something. I've seen those various conspiracy theories and whatnot. I'm sorry for repeating them, because those things are not correct. I mean, we're positive this was a

space impact. So what happened, Well, on the morning of June thirtie, nineteen oh eight, okay, nineteen o eight, and checked from space, Probably some kind of asteroid entered Earth's atmosphere and possibly hit the ground, but more likely exploded in the air at an altitude of about five to ten kilometers over an area of eastern Siberia around the stony Tunguska River. And this is an area of extremely

sparsely populated wilderness. There's not a lot of people, not a lot of population density out there, and this explosion is hard for us to imagine. It annihilated roughly two thousand square kilometers of forest land, leaving trees flattened or stripped of all branches. The photos that exist of this damaged area look like a nuclear test. Site. The forest is just shredded and pancaked, and there actually were Despite how sparsely populated this area was, there were some contemporaneous

witnesses who were fairly close. And by fairly close, I mean within dozens of miles. Uh So, I want to read one contemporaneous account from a witness named S. B. Simonov, who lived in a place called Vanavara, which was about sixty kilometers south southeast from the epicenter of the blast side. Remember this is sixty kilometers away. Here's how his account goes. I was sitting on the porch of the house at the trading station of Vena Vara at breakfast time, and

looking towards the north. I had just raised my axe to hoop a cask, when suddenly, in the north, above vassili Iliatch own cools Tunguska Road, the sky split in two, and high above the forest, the whole northern part of the sky appeared to be covered with fire. At that moment, I felt great heat, as if my shirt had caught fire. This heat came from the north side. I wanted to pull off my shirt and throw it away, but at that moment there was a bang in the sky, and

a mighty crash was heard. I was thrown onto the ground about five and a half meters away from the porch, and for a moment I lost consciousness. My wife ran out and carried me into the hut. The crash was followed by noise like stones falling from the sky or guns firing. The earth trembled, and when I lay on the ground, I covered my head because I was afraid stones might hit it. At the moment when the sky opened, a hot wind, as from a cannon, blew past the

huts from the north. It left its mark on the ground in the form of little paths. It damaged onion plants. Later it turned out that many panes in the windows had been blown out, and the iron hasp in the door of the barn had been broken. When the fire appeared, I saw Kosolopov, who was working near the window of the house, sit down on the ground, seize his head with both hands, and then run into the hut sixty

kilometers away. And and and this was again this was like to what extent I mean today, if you saw that, you would your your mind would instantly turn to nuclear weapons, you know. But but there were no nuclear but there was nothing on the human scale that could, uh, they could explain what he was witnessing. I mean, you're you're left to, you know, astronomical explanations if you had privy to them. Otherwise it's just purely supernatural destruction, exactly. Well.

Some I have read reports that some of the native Siberian peoples of the region of the known as the Evenki tribes or the Tung people, believed that the Tunguska impact was the work of a god named Aga Dy who's the god of thunder and lightning. Though I've also seen ody described as these believe these creatures that were

like metal birds of thunder and lightning. Yeah. Other witnesses and generally describe having seen like a blue white streak in the sky, followed by what appeared to be this enormous fire consuming the whole sky, and then this gigantic column of black smoke and loud blasts and crashing noises

booming over the land. The air blast was picked up by meteorological equipment really far away, like more and six thousand kilometers away in England, and reportedly in the nights following the explosion, and I'm not sure this story is true, but this is just an anecdote repeated through history, may

may or may not be true. Supposedly, and the sky remained bright over parts of Europe and Asia in the following nights and uh and according to this anecdote, it was so bright that you could stand outside at night and read a newspaper by the light that was still glowing in the sky. The blast triggered fires that burned

trees tens of kilometers away. Amazingly, despite how destructive this blast was, I've read the most recent research on it has found evidence of only three reported human casualties from the impact. And this is apparently just sheer luck, you know, because it was out there where very few people live, in extremely sparse wilderness. If it had struck over Beijing or London, it would have been much like a city getting hit with a nuclear weapon and probably would have

killed millions. Yeah, and I mean of it, it it hid and major center of population even in I mean, it could have changed the course of history. I mean, it just it's it's impossible to really, I mean, I'm sure you can you can sort of like follow individual uh, you know, life stories and what non prefats There's been some speculation on this, but I mean it would it would have changed the course of history. It would have It would have killed so many people and impacted uh,

you know, places of of of power. It would have had an impact on on politics. I mean, this is it's it's it's almost hard to fathom the the different world we would live in had this thing impacted pretty much anywhere else. Right. Uh. Now, one thing we do know is that an object of the size is not Uh.

While it could have had worldwide events, like you're saying, like cultural impacts that far, it would not have been like the KPg extinction event size thing because it wouldn't have like thrown up sediment that completely blocked out the sun and like cut off photosynthesis. You know, it wouldn't be that big, right, Like if it hits St. Petersburg,

it would not have wiped out humanity. It would not have wiped out, you know, all members of the Russian Empire or anything to to that extent, but it would have severely it would have it would have killed countless people in that one city. Yeah, catastrophic local effects and

maybe some maybe some smaller global effects. Um. And so another question I guess is with strikes like this, these smaller ones, not like the you know, KPg event level thing, but with these smaller ones, has anybody studied what actually happens to nearby humans and other life forms when this type of impact occurs, Like if a Tungusca size object hits, what happens to you if you're nearby? I did find yes,

there is at least one study of this uh. It was published in Geophysical Research Letters in it's by rump Lewis and Atkinson. Is called Asteroid Impact of X and their Immediate Hazards for Human populations. And what the authors did here is they simulated the impacts of more than fifty thousand asteroid strikes at random locations on the surface of the Earth to gain insights on the average effects of human populations who would be nearby and so. Here

were a few of their main findings. One is that objects are less than maybe like sixty or seventy meters across tend not to hit the surface of the Earth, but rather always explode in the atmosphere. And this is not without risks like remember that all the damage caused by the Chelabinsk media which exploded in the sky, but it it tends to generate the air burst only, and an air bursts can still be powerful and dangerous. The main theory, of course about the Tunguska event is that

it was an air burst. It's exploded in the atmosphere and didn't have a chance to hit the ground, even though it was a good bit bigger. But for most sizes of asteroids, by far the greatest risk to humans is from what's known as wind blast. These are waves, you know, wave of hot compressed air exploding out of

the object. Uh. The second greatest risk after that is just straight thermal risk heat generated due to the impact, And then the third greatest risk in general was due to tsunamis, And the authors actually found that risk to human life from tsunamis is relatively lower than they expected, but it increases a lot as the object becomes larger than like two hundred or two hundred and fifty in diameter, And their estimates only include objects up to four hundred

meters in diameter, so effects could change dramatically as objects become bigger and bigger. Now, Robert, I think I think we should step back after what we've just been talking about. We should do in lot a reality check. We don't want to be alarmists, so to reiterate, the odds are in our favor here, at least on short time scales, because the vast majority of asteroids of this size don't come this close to Earth, maybe roughly one every ten years.

By that estimate we talked about earlier, only about zero point five percent of asteroid it's that pass within this range will actually hit Earth. And then even if one does hit Earth, most of the world's surfaces water, though of course there can be threats from an impact in water depending on where it happens. And then much of the land surface of Earth is sparsely populated, so on short time scales, the odds of a catastrophic impact on a city or something like that are very very low.

But it's one of those cases where the chance of a bad outcome on a short time scale may be low, but the consequences when that off chance does come to pass are devastating and on. Of course, the the other side of the coin is that on long enough time scales, these events go from extremely unlikely to near certainty. Yeah, one of the things I keep keep asking when I look at all these stats. It's like, Okay, am I

comfortable with those odds? But then if I'm comfortable with the odds, am I am I comfortable with the steaks? You know? Yeah? Totally uh. And it also raises, I guess a tangentially interesting question, at least to me, which is, like, how long have a time scale should we be concerned about? Like, if something is a civilization level threat but it's unlikely to happen, you know, more than once within the next ten thousand years, how much of our attention should it get?

Well that's how much should or how much will it? You know? I mean, well, yeah, those are very I mean exactly tend to be rather terrible at at weighing you know, our immediate situation with long term threats to to to the survival of the human race sort of the health of the planet. Yeah, you're exactly right about that.

I mean, obviously we're not even appropriately preparing for extremely likely to near certain climate related problems that are less than a hundred years away some or even you know, happening now or decades away. So maybe this question about longer time scales is moot just given like what our capabilities are, Like, maybe it doesn't even matter what we should be doing, because humans just can't make themselves do it.

But I don't want to be resigned or you know, I don't want to throw in the towel about that just because we haven't been good at it so far. No, because we the we have the tremendous ability to correct these errors. I mean, this has often brought up on the subject of climate change. Uh you know, well that's what I was just referring to. Yeah, I mean, but but specifically with climate change. Like, yes, we've got ourselves

into quite a mess, and that's that's bad. But the good side of it is we got ourselves into so much of this mess that just shows you the potential of human technology. Like, look at what we can do. Granted, we screwed things up here, but we imagine if we use that same level of energy and intensity towards a corrective measure. Yes, though I want to be clear that

so we're not misunderstood here. We are not advising people to hang their hat on like a potential like Holy Grail technology that will get rid of all the carbon or something like that. That is not a gamble that's worth playing with. I think they're talking about like other energy technology, other energy technologies, and also just like corrective

measures like and a willingness to change in that case. Yeah, absolutely, But I don't know, I mean, I I do think like this is a different kind of thing than climate change, because climate change is something that we're like, we're we're like near certain about some types of effects that are coming within a you know, compared to this a relatively short time scale. They're like almost definitely going to happen within decades or a hundred years or something, and the

effects will be catastrophic. So that's like you'd probably say that's actually a higher priority, but but this is a different priority, so that it's like a catastrophic tail risk. It's unlikely that we would get hit by an asteroid like this anytime soon, but if we did, it could be really bad, right of course. That The other obvious thing to point out is that asteroids have mostly, if not entirely and thankfully not been politicized. Oh yeah, so nobody is out there saying why aren't we why are

we charting the asteroids? Like look at the I mean they, I mean, you could easily imagine somebody taking up this is is there. They're they're horrible battle cry and saying, look how much we're spending on space exploration, Look how much we're spending on this, on on watching the movements of the asteroids, and look at these astronomical chances that anything is going to hit us. Well, the unfortunate fact about the politicization of science is that it does not

require both sides in order to happen. You can asymmetrically politicize and currently non political issue, you know, just by having one side get worked up about it, and then of course the process is irreversible. And so please don't do that with the planetary defense and stuff about, right, Yeah, hopefully, I think planetary defense should be something that we that everybody can agree on, and we should all like everybody should be able to agree, Yes, this is a this

is a good investment in our future. It's like having a lock on the door to your house. Yeah. But then again, the exact same thing should be true about alternative energy and climate change and stuff, and it's true not I mean, clearly, what is in our interest to de politicize does not correlate to what people actually do

de politicize. I think hopefully one I think one thing in our favor here is that, as we've discussed on the show, one of the problems with climate issues is that it's it's very difficult for most of us to wrap our hands heads around all that's happening in this vast chaotic system of atmosphere and uh in climate. You know, it's particularly when you're dealing with with larger periods of time, oh and asteroids more like an easy to identify villain. It's like it's like a rock thrown at your head.

Like we can instantly be like, yeah, like i'm here, that's there. That should not hit where I am, and like we can all agree that that that this this is a bad thing, that should be that the big should should be avoided at all costs and easier to process in the mind, it's an incoming projectile, and we've

we've evolved to deal with that kind of threat. That's a really good point, and I think it's absolutely, of course worth investing in planetary defense at multiple levels, by the way, probably most importantly right now, and expanding our surveying capabilities right to increase our ability to catalog and track near Earth objects, which we're already doing a pretty good job at with Earth based telescopes and all that, but expanding those capabilities it sounds like a very good

idea to me. And then I guess the next thing on top of that is something that maybe we'll talk about at the end of the episode, is what would we do if we did detect something? You know, pretty we did have fore warning, we're pretty sure something's on a collision course with Earth. Is there anything we can

actually do about it? Right? All right, well, let's take another break and when we come back, we'll discuss our general state of preparedness for small near Earth objects and then yeah, what what we would do if something did seem to have our name on it? Thank? Thank Alright, we're back. Okay, So Robert, we need to talk about what we would do if we got some bad news about a an asteroid uh coming down the pike in our direction? All right? Well, yeah, well first let's let's

let's touch again on our general state of preparedness. So, like we said earlier, of extinction, class near Earth objects and eos are are marked, and it works out in our favor because the bigger ones are easier to see. Exactly fortunate our ability to to track these things has certainly come a long way. Like I was reading about how in observations of the asteroid n XF eleven suggested that this half mile wide object would just simply hit

the Earth in. Only later did it turn out, via better orbit analysis that the Earth actually isn't in danger from this particular asteroid. So it was just you know, more or less taken off the list based on our current data. NASA has a sort of rogues gallery of potentially dangerous asteroids or UM, you know, also known as p h as fause potentially has dis asteroids, that's the

abbreviation UM. And these are ones that are predicted to you know, to make close passes, such as say feet on, which made a close pass in twenty seventeen, and we'll make a closer pass in but we're talking about a twenty seventeen distance of what, let's see, ten million, three d and twelve thousand and thirty four kilometers or six million, four hundred and seven thousand and six hundred one miles and then uh, the next pass, we're going to see it come in at two million, nine sixty four thousand

kilometers or one million, eight hundred forty one thousand miles, which is still again close enough to be of concern. But again this is just a to to really drive home the distances we're talking about here. So there are a number there are a number of potentially hazardous asteroids, but even the more hazardous ones have a pretty low

chance of hitting the Earth. One of the biggest known dangers out there right now, for example, is two thousand s g threety four, which has a one and eleven hundred chance of impact in one and again I come back to that question. You might are you might be cool with those odds, but are you cool with the steaks? It's again easier to spot the big civilization busters, and

that's where that nine tracking rate comes in. But according to the Planetary Society, which has a has a number of wonderful um uh educational resources on space, experty and astronomy, we're only tracking like twenty thousand out of a million smaller but potentially deadly pH s. So we need to improve our tracking capabilities right for these again, to deal with these potential city busters, especially, So I suppose the answer is that you know, we're doing better than we

ever have, but there's a lot of room for improvement and lots more room for certainty when the stakes are this high. And this is also a very important reason to always support and vote for political candidates and parties that value science, scientific consensus, and h and manifest that support for science in the form of policy and funding. Now, the next question is, okay, what if we what if we do spot one that is just coming way too close for comfort? What are we prepared to do about it?

And this is an area where various plans have been presented over the years, and it's really like it's one of these scenarios that that you really get the sense that a lot of you know, astronomers and science is really relish. The problem is a pure thought experiment, like what can you do to to deal with an asteroid that is on course to hit the Earth or getting way too close to the Earth for our comfort level? So you get Bruce Willis, Oh, no, I'm sorry, I

made that joke. You know. I was like, I'm gonna go this episode without referencing arm Agin, and then I just did it anyway. Yeah, well, I've never seen Armagin, so I can't I can't even chime in on that. I don't know if it's worth your time. But I've seen chronicles of Riddick and that had that had a dangerous sort of near Earth object like the Necromonger spaceship. As a comment, right, oh man, those those rat tail braids on Carl Urban's head, and that that is the

near Earth object that I'm most worried about. All right, So a near Earth object coming at the planet. What can you do? Well, all the all the proposed solutions tend to fall under one of two categories. Either you destroy the near Earth object, fragmenting it into smaller chunks, or you alter its trajectory. I am of the you know, I'm not an expert in this realm, but I'm of the opinion that one of the forks of the stile

emma is much better than the other. Well, blowing it up is certainly very you know, I think it's an ego inflate inflating option to be sure, you know, launch a nuke, get into that puppy and just make it go boom. Right. Of course, the thing is this fragments the larger ineo into smaller chunks that you know, hopefully if you're dealing with a small enough ineo, you know, you're you're breaking it up into chunks that will then just burn up in the atmosphere should you hit the atmosphere.

But you know it's also you could look at it another way and say, well, it's a bit like turning an incoming slug or an incoming bullet into an incoming blast of buckshot. Right. According according to Alan Duffy, one of the researchers we mentioned earlier, he was quoted in the Washington Post saying that this option of nuking it and blowing it into pieces, he says, quote, it makes for a great Hollywood film. The challenge with a nuke is that it may or may not work, but would

definitely make the asteroid radioactive. Okay, so radioactive buckshot? Ye coming I ship Now. The more popular ideas involve changing the ineo's trajectory, and these range from crashing another object into it so like croquet or Billard style, you know, to gently gently nudging it off course. This is generally known as the kinetic impact, but you could also use

nukes for this as well. It should be point out like if you were to use a nuclear device to deter to deflect an asteroid, you wouldn't have to like blow it up. You could just create an explosion in a close enough proximity to it to try and nudge it off course. Yeah, so you could, you know, of course you could have a kinetic impact or an explosion try to divert its course. Another often discussed solution is what's known as the gravity tractor. Oh yeah, I really

like this one. So this involves flying a probe out to meet the asteroid and then having the probe simply fly alongside it. And remember that gravity works both ways. It not only attracts smaller bodies to larger ones, it also attracts larger bodies to smaller ones. For example, in our Solar System, the planets actually do exert a small gravitational influence over the Sun, causing it to sort of wobble in place, and the same would be true here.

Over time, if you have a small spacecraft flying next to an asteroid, the asteroid would feel a slight gravitational tug toward the mutual center of gravity that shares with the probe flying alongside it, and this gravitational tug would slowly, over time nudge the asteroid off its trajectory and something about the solution is kind of beautiful to me, and I can tell from the way that many astrophysicists talk

about this they kind of feel the same way. I often see the gravity tractor described with the word elegant. I feel like it's kind of the Pixar solution because I can imagine it as a Pixar short the big grumpy asteroid that's on its way to destroy us, and we solve it not by launching a weapon at it, but by sending a robot friend. It gets there, it gets a manic Pixie gravity tractors, and and then it just over time, you know, it gradually steers off course

and chooses a new path in line. Now, the key to either of these, whether it's kinetic impact or or gravity tractor, if you're trying to divert the trajectory, the key is lead time. The earlier you detect a potential threat asteroid, the easier it is to divert. Kind of like if you imagine you're trying to knock off the aim of a gun. If it's at point blank range, this is a lot harder, you know, because the gun

can move around a lot and still hit you. If it's a very long range, an extremely tiny nudge will cause a miss right just because of the distance. You know, it goes wider and wider as it gets farther and farther away. Yeah, so it means that if you if you had advanced knowledge and you had the ability to send something out there to it some sort of probe. There are a number of more elegant solutions that present themselves that don't involve massive explosions and big kinetic strikes.

Uh So. Individual strategies involve everything from a fixing rocket boosters to to an object to one of my favorites, simply painting it white. Because consider if if an object were were darker, it would reflect something like the sunlight, but a white coat of paint. You see that number go up to about so altering the way photons of light interact with an ineos surface, either through paint another way that is sometimes there's been a suggested is through

solar sale shading. So move some sort of large solar sale device essentially a big space umbrella between the sun and the asteroid, or use lasers, etcetera. And this would allow you to mess with the Arkovsky effect. Now, the

Arkovsky effect, this is the NASA definition. Is it's name for a nineteenth century nineteenth century Russian engineer who first proposed the idea, and that is that a small, rocky space object would, over long periods of time be noticeably nudged in its orbit by the slight push created when it absorbs sunlight and then re emits that energy is heat, which is pretty which is pretty wonderful to think about. It's like you don't have to send out at a bomb or or a robot to mess with it, and

like strap rockets onto it. All you have to do is send more or less light and you can alter the trajectory of this asteroid. But again, all of these these options are highly dependent on having lots of lead time, knowing way way in advance that it could be coming our way. And this is yet again why the most important thing in all of these solutions is improving our survey and detection capabilities. I think we should come up with with an asteroid character right now that can be

our stand in villain. So when the asteroid, when the one appears that is a threat. We've got a ready made like character in our mythology to pair it up with, right, Yeah, you know, like, so you mentioned the Pixar movie you gotta have the grumpy asteroid that gets paired with the Manning Pixie space probe. Well, uh, you know, there are a few different ways you could go in that. In that in that area, I mean, obviously one turns to comics and you think of of say, oh, what's the

big Marvel guy, the planet guy Galactus? Galactus is a wonderful stand in for some sort of enormous cosmic threat. Does Galactus eat planets? He eats planets? Seems the other way around. Well, I mean it's like it's like a poison pill that our planet would eat. Well, I think the thing is, once Galactus gets to your planet, it's over. Uh you know, it's it doesn't really matter exactly how he you know, what happens. You just know you're doomed.

And and that's kind of the scenario with a significantly sized asteroid. But one thing I do keep coming back to with this topic, and I have over the years, it's like we're talking about an actual threat to the planet and efforts to mitigate that threat and to prevent any of any objects from hitting us. And it's like it is ultimately such a noble venture and again one that we can all get behind and all celebrate. And

really it kind of serves as as an example. I mean, it's it's almost like a perfectly romantic, uh simple problem to have and in many respects, like, yes, they're technological hurdles to overcome, but unlike so many more complicated problems in uh, in human events and even in the you know, the health of our planet, like, it's something with a clear cut threat and some some basic steps that we can continue to take to try and mitigate the danger. I agree. It's like it's like the one noble war.

It's a you know, a war. It's a fight for our lives, but without a human enemy. Right. Yeah. And and also the next time you hear a bit of space news that doesn't just completely like you know, fill you with wonder and excitement where you're like, oh, well, that's just I'm not particularly you know one over by that it doesn't like, you know, fill me with the

zeal for space. Think back to the fact that it's that's all a part of our ongoing attempt to better understand understand our our local and overall uh you know, galactic neighborhood. And by doing so, you know we're able to protect the planet from threats like this again, to protect ourselves against the wrath of Galactus or the wrath of act Yeah, all right, we're gonna call it right there. But as always, if you want to check out more episodes of Stuff to Blow Your Mind, head on over

to stuff to Blow your Mind dot com. And if you want to support the show, the best thing you can do is rate and review us wherever you have the power to do so, and make sure you have subscribed not only to this show but also Invention, which is the other podcast that Joe and I host, where each episode, one episode a week, we look at a different invention from human techno history, discuss where it came from, what came before, how do we possibly live before we had, say,

a toaster? And then how was life change forever afterwards? Huge thanks as always to our excellent audio producer Maya Cole. If you would like to get in touch with us with feedback on this episode or any other, to suggest a topic for the future, for just to say hello, you can email us at contact at stuff to Blow your Mind dot com. Stuff to Blow Your Mind is

a production of iHeart Radio's How Stuff Works. For more podcasts for my heart Radio, visit the iHeart Radio app, Apple podcasts, or wherever you listen to your favorite shows.