Speaker 1: Welcome Stuff to Blow Your Mind, a production of I
Speaker 1: Heart Radios How Stuff Works. Hey, you welcome to Stuff
Speaker 1: to Blow your Mind. My name is Robert Lamb and
Speaker 1: I'm Joe McCormick. You know, we've been talking a lot
Speaker 1: recently about you know, some perhaps more ambiguous risks to humanity,
Speaker 1: but but not so much the ambiguity in this episode. Wait,
Speaker 1: what are the ambiguous risks? Oh, you know we're talking
Speaker 1: about like you know, you're getting talking about like social
Speaker 1: media and how and how it's affecting the human condition
Speaker 1: or you know, certainly in our episodes on psychedelics, you know,
Speaker 1: we talked about some of the more ambiguous and even
Speaker 1: more concrete threats facing humanity and to what extent some
Speaker 1: commentators think that the psychedelic experience can prepare us for
Speaker 1: those threats. Okay, so kind of vague possible psychic and
Speaker 1: cultural threats, right, yeah, less less threats like a huge
Speaker 1: rock hitting you. Right, because because we over good, what
Speaker 1: we're gonna be talking about the day is certainly the
Speaker 1: kind of threat that that a mushroom is not going
Speaker 1: to be able to help us with. Right, So we
Speaker 1: wanted to talk about an interesting, perhaps hair raising story
Speaker 1: from recent Space News. So, just within the past couple
Speaker 1: of weeks, Earth had a very close encounter and almost
Speaker 1: perfectly timed intersection with the orbit of a fast moving
Speaker 1: object from outer space. And the creepy and fascinating thing
Speaker 1: about this is that this object came very close to
Speaker 1: Earth and we had almost no forewarning that it was coming.
Speaker 1: So what was this thing? Well, I actually first saw
Speaker 1: it when Robert shared an article about it on on
Speaker 1: social media. That's right, Yeah, there we go, determining the
Speaker 1: topics of all conversation. Well, and the crazy thing about
Speaker 1: it is that, you know, as we've discussed in the show,
Speaker 1: and the the more extreme things get to know, the rise
Speaker 1: to the surface and social media and especially right now,
Speaker 1: it tends to be stuff related to politics. But then somehow, uh,
Speaker 1: this one story breached the surface. It may have helped
Speaker 1: that it had the word killer in the headline. So
Speaker 1: this was an asteroid that is now officially called asteroid nineteen. Okay,
Speaker 1: and that doesn't mean it's okay, that's just a you know,
Speaker 1: that's the code assigned to it. I read it as
Speaker 1: asteroid two thousand, nineteen, Okay, it's kind of like that.
Speaker 1: So it was detected by astronomers in Brazil and the
Speaker 1: United States before being confirmed by NASA JPL and on July.
Speaker 1: It passed by Earth at a speed of about twenty
Speaker 1: four kilometers per second, which is like fifty four thousand
Speaker 1: miles per hour. Pretty fast. And what we want to
Speaker 1: emphasize is it's already gone, okay, so we should emphasize
Speaker 1: that at the beginning, this asteroid represents zero threat to
Speaker 1: us on any meaningful time scale. It is passed, it's
Speaker 1: on its way to other things. And the reason we're
Speaker 1: talking about this is that I feel like this event
Speaker 1: is instructive. It shows the real life and death importance
Speaker 1: of astronomy in general and improving our capabilities for cataloging
Speaker 1: near Earth objects more specifically. And it's also I think
Speaker 1: an event that really reveals the part of you that
Speaker 1: either leans towards the positive or the negative interpretation of things,
Speaker 1: you know, the glass half full half empty kind of thing, right,
Speaker 1: the near miss versus near hit. Yeah, and also reminded
Speaker 1: of the old adage. You know, I don't know if
Speaker 1: it's truly an adage, but the observation that you never
Speaker 1: hear the one that has your name on it. You know,
Speaker 1: generally talking about say, you know, a bullet in a military,
Speaker 1: uh situation. It's like on the Sopranos, you know, you
Speaker 1: never know the one that's coming for you, right. But
Speaker 1: the thing is we are we are in the business
Speaker 1: right now of trying to know the ones that have
Speaker 1: our name on it, the the asteroids particularly that have
Speaker 1: that that have Earth or possibly Earth printed on their side. Yeah,
Speaker 1: and it's always going to be a probabilistic thing when
Speaker 1: we're looking to far out, so you wouldn't know for sure,
Speaker 1: but you'd say, you know, we think there's a you know,
Speaker 1: zero point whatever percent chance this has Earth on its name,
Speaker 1: has Earth's name on it, or maybe has a chance
Speaker 1: right yet to be clear. And we'll get into some
Speaker 1: of the statistics here in a bit. But there there
Speaker 1: are no asteroids out there right now that that Nassa
Speaker 1: or anyone else is saying this is a definite collision course.
Speaker 1: No no big ones, No big ones. So yeah, I mean,
Speaker 1: obviously they are ones that are going to imbact Us
Speaker 1: and with with with a little or no effect. But
Speaker 1: in terms of like really big problematic asteroids, the ones
Speaker 1: that are the ones that we know of, and it
Speaker 1: is a you know, just a segment of the ones
Speaker 1: that are out there. There are none that we are
Speaker 1: like positive like, this is the one. This is the
Speaker 1: one we have to act on right now, right now. Yeah,
Speaker 1: but this twenty nineteen, Okay, asteroids. So first of all,
Speaker 1: the question we need to play the glass half full
Speaker 1: half empty thing with Was it big or was it small? Well,
Speaker 1: it was between we think about fifty seven and a
Speaker 1: hundred and thirty meters in diameter, which is a hundred
Speaker 1: and eighty seven to four hundred and twenty seven feet.
Speaker 1: Is that big or is that small? Well, it depends
Speaker 1: on what you compare it to the object that struck
Speaker 1: the Earth sixty six million years ago, the impact that
Speaker 1: most likely played a major role in the extinction of
Speaker 1: the dinosaurs. That one was probably I've seen estimates of
Speaker 1: ten to fifteen kilometers across. I've seen that people say
Speaker 1: more recently, this might be an updated or more more
Speaker 1: precise figure that it was like fifteen or sixteen kilometers across.
Speaker 1: That's obviously a lot bigger. We're we're talking this object
Speaker 1: that just went past us is a couple of orders
Speaker 1: of magnitude smaller than that. So we're not talking about
Speaker 1: like necessarily a full blown civilization buster. No no, no
Speaker 1: extinction event level impact. Yeah. Unfortunately, astronomers believe that more
Speaker 1: than nine percent of objects in this extinction event size
Speaker 1: category category, the category of things on the scale of
Speaker 1: the asteroid that killed the dinosaurs, uh, things like that,
Speaker 1: more than nine percent in our orbital vicinity have already
Speaker 1: been disc covered and cataloged by NASA and other observers
Speaker 1: and space agencies because the bare ones are simply easier
Speaker 1: to spot, right exactly, And so for the biggest of
Speaker 1: the biggest, we're pretty sure we know where they are,
Speaker 1: uh that, and that we would be able to predict
Speaker 1: if they're headed our way, which is good, right, But
Speaker 1: then again, you could compare it to something on the
Speaker 1: other side. So the Chelly bents Comedia, which exploded in
Speaker 1: the atmosphere over Russia in was only about twenty meters
Speaker 1: in diameter, just twenty And this meteor was not even
Speaker 1: large enough to reach the ground. It didn't hit the
Speaker 1: surface of the Earth like most smaller objects entering our
Speaker 1: atmosphere from space. It exploded in the atmosphere and what's
Speaker 1: known as an air burst. And this this explosion injured
Speaker 1: over a thousand people. I think it was close to people.
Speaker 1: It damaged buildings, it collapsed roofs, it smashed windows in
Speaker 1: this big elliptical impact zone stretched out for dozens of
Speaker 1: kilometers um and and a lot of the damage and
Speaker 1: human injuries from this air blast were due to like
Speaker 1: blown out glass from windows hitting people. I should say.
Speaker 1: The footage also, of course, was incredible and certainly certainly
Speaker 1: makes you feel like a primate when you watch it.
Speaker 1: You feel like an earth bound primate um that has
Speaker 1: no control over the great fiery mass that is just
Speaker 1: seared across the horizon. It's a it's a two thousand
Speaker 1: one of space Odyssey monolith kind of thing. Yeah, you're like, well, okay,
Speaker 1: should I worship that? Maybe? But so that one, the
Speaker 1: one that caused all that damage, was just twenty wide.
Speaker 1: This this one that just passed us was somewhere between
Speaker 1: fifty seven and a hundred and thirty meters. Why that's
Speaker 1: a good bit bigger. It's somewhere between an extinction event
Speaker 1: level asteroid or object and you know, one of the
Speaker 1: smaller ones like we've seen with Cheli Bensk. In fact,
Speaker 1: the size of this thing that just passed us is
Speaker 1: probably roughly comparable to the size of something we're gonna
Speaker 1: talk about more in a bit, the meteor that exploded
Speaker 1: over Siberia in nineteen o eight and the event known
Speaker 1: as the Tunguska in impact. And like I said, well,
Speaker 1: we'll come back to that later. But basically though, the
Speaker 1: issue is it depends on where it hits. Y. Yeah,
Speaker 1: the thing that just passed us. The point is that
Speaker 1: it poses no threat to us. It's already gone. But
Speaker 1: if it had hit Earth, that would be really scary
Speaker 1: on the off chance that it came anywhere near a
Speaker 1: populated area. And of course the location is important with
Speaker 1: any of these. I mean, I've I've read arguments that
Speaker 1: the chicks a lube impact, Like if it had hit uh,
Speaker 1: if it had been a water impact as opposed to
Speaker 1: a land impact, Um, you know, it would have made
Speaker 1: some difference in what occurred. So that's that's going to
Speaker 1: be a factor no matter what scale you're talking about here. Absolutely, yeah,
Speaker 1: that that place a big role. Well, we'll talk more
Speaker 1: about that as we go on. So uh So we
Speaker 1: talked about the size, Another question is how close exactly
Speaker 1: did it come to Earth? Because there are the simulations
Speaker 1: that you can watch online. You should look this up. Actually,
Speaker 1: that show like the orbital pathways of Earth and this
Speaker 1: asteroid and as they sort of approach each other, as
Speaker 1: the intersection of these two orbital pathways comes up, it'll
Speaker 1: zoom in further and further for you. And there it
Speaker 1: looks like they're just on a perfect collision course and
Speaker 1: then they just miss at the last second. Now, what
Speaker 1: what does that miss look like on distances that are
Speaker 1: appreciable to us. The answer is it came within about
Speaker 1: seventy three thousand kilometers or about forty five thousand miles
Speaker 1: of Earth. So that sounds pretty far away, right, that's
Speaker 1: at least few trips to Disneyland. But if you stay
Speaker 1: zoomed out, like we were just talking about, looking at
Speaker 1: looking at this path on like an Earth orbit scale,
Speaker 1: the distance is something you can't even really see. It
Speaker 1: passed inside the orbit of the Moon, and that's pretty close.
Speaker 1: Like it is. Essentially you could you could say it
Speaker 1: has passed within the realm of U, within the sphere
Speaker 1: of of human culture, you know, like we have been
Speaker 1: to the Moon and this thing has traversed the space
Speaker 1: betwixt the two. Yeah, and it wasn't even in the
Speaker 1: far side of the Moon circumference like in fact, twenty
Speaker 1: nineteen okay, came within less than twenty percent of the
Speaker 1: distance from the Earth to the Moon. It was pretty close.
Speaker 1: According to a to a piece I was reading on
Speaker 1: vox by Kelsey Piper, on average, about zero point five
Speaker 1: percent of asteroids that come within this range of Earth
Speaker 1: actually hit us. So that's that's a nice thing to consider, right.
Speaker 1: That's on the other hand, the other ninety nine point
Speaker 1: five percent within this range still pass us by, like
Speaker 1: nineteen okay, did you know the vast majority are not
Speaker 1: going to hit Earth? So that's good, right, But we
Speaker 1: kind of must ask the question, what if an asteroid
Speaker 1: of this size did hit Earth? What exactly would happen? Uh?
Speaker 1: So I was reading an article by Liam Mannox of
Speaker 1: the Sydney Morning Herald who interviewed the Swinburne University astronomer
Speaker 1: Dr Alan Duffy, and Duffy said that an object of
Speaker 1: this size would be what astronomers sometimes maybe maybe loqually
Speaker 1: call a city killer. So it's not of a size
Speaker 1: that would cause a mass extinction or potentially qualify as
Speaker 1: like a planet killer. Its worst effects would probably be
Speaker 1: local in the area around where it hit, and if
Speaker 1: it had struck Earth. Duffy compared this hypothetical impact to
Speaker 1: something like a large nuclear weapons strike. One of our
Speaker 1: listeners on the Facebook discussion module that Stuff to Build
Speaker 1: Your Mind discussion module Facebook group shared a like a
Speaker 1: map tool where you can input your city and then
Speaker 1: look at what would happen if various models of nuclear
Speaker 1: weaponry hit your city and determine like how far the
Speaker 1: danger the danger zone is, how you know, far the
Speaker 1: the radiation radiation extends. It's a scary tool, yeah, but
Speaker 1: it also just really drives home that most of these
Speaker 1: these devices are very capable of destroying modern cities, or
Speaker 1: at least taking such a sizeable and crucial chunk out
Speaker 1: of them to effectively destroy it. And I mean so
Speaker 1: this impact would have actually been bigger than the real
Speaker 1: atomic weapons that we have seen deployed on cities in
Speaker 1: human history. According to Duffy, this impact, if it had
Speaker 1: hit Earth, would have hit with over quote thirty times
Speaker 1: the energy of the atomic blast at Hiroshima. And so
Speaker 1: that you might be wondering, Okay, if you don't usually
Speaker 1: think about these things, how would it have that much energy?
Speaker 1: It's not a bomb, right, It's just a rock. Why
Speaker 1: would it act like a bomb that explodes? Um. So
Speaker 1: what you have to remember is that the the energy
Speaker 1: released upon an impact with Earth's surface is a product
Speaker 1: of the mass and velocity of the falling object. Now, normally,
Speaker 1: when objects like a chunk of rock fall to the ground,
Speaker 1: they don't behave like a bomb because they're relatively light
Speaker 1: and they're relatively slow. So this, this asteroid, would be
Speaker 1: a falling object of a size and a speed that
Speaker 1: we never encounter in normal life in Earth's atmosphere. Something
Speaker 1: you know, maybe a hundred meters across, like a giant
Speaker 1: boulder or a chunk of a mountainside. Things that big
Speaker 1: don't usually fall to begin with, I mean, except maybe
Speaker 1: like huge airplanes. Uh. And then it would be traveling
Speaker 1: at twenty four kilometers per second, which is more than
Speaker 1: twenty times the speed of your average shooting bullet. Yeah, exactly.
Speaker 1: And so once you multiply those things together, that mass
Speaker 1: and that velocity, and it also matters, of course the
Speaker 1: angle at which it enters the atmosphere hits the ground.
Speaker 1: But once you build up these levels of kinetic energy,
Speaker 1: any normal falling object like a huge chunk of rock
Speaker 1: or metal as you would find in the case of
Speaker 1: an asteroid, essentially becomes a bomb upon impact. And this
Speaker 1: is a fact we've touched on in some of our
Speaker 1: more science fiction ety episodes where we've talked about about
Speaker 1: how if you simply had orbital superiority over a planet,
Speaker 1: this planet or another planet that had occupants, just by
Speaker 1: virtue of having orbit, uh an orbital position, you could
Speaker 1: drop anything. You would not need to drop a bomb
Speaker 1: from that height. If you could drop just a big
Speaker 1: piece of metal or rock, et cetera, then you already
Speaker 1: you have a tremendous weapon at your disposal. And this
Speaker 1: is where we get the you know, the term rods
Speaker 1: from god kinetic energy kannetic kinetic energy weapons would just
Speaker 1: be a matter of just drop anything from up there
Speaker 1: and it can destroy like nothing else. Yeah, it's scary.
Speaker 1: And now, on the other hand, uh, we want to
Speaker 1: remember throughout this episode to not be alarmist and not
Speaker 1: get people to worked up. Now, first of all, this asteroid,
Speaker 1: like we said, it already missed us. It's on its way.
Speaker 1: About things like this in general, it really does matter
Speaker 1: where it hits. So fortunately in this scenario, the majority
Speaker 1: of Earth's humans are actually squeezed into a fairly small
Speaker 1: subsection of Earth's surface, So chances are that even if
Speaker 1: an asteroid like this were to hit Earth, it would
Speaker 1: probably strike in the ocean. Now that could have negative
Speaker 1: consequences depending on where it happens, but but definitely better
Speaker 1: than a hitting u like you know, land, yeah, populated
Speaker 1: area especially yeah uh. And if it did strike on land,
Speaker 1: it would probably most likely hit in a rural, less
Speaker 1: populated area. Now, not like that would be okay, but
Speaker 1: that would be you know, obviously fewer casualties than it
Speaker 1: hitting one of these smaller subsections of Earth's surface where
Speaker 1: there are a lot of people. Now, small objects from
Speaker 1: space passed by Earth and inter Earth's atmosphere all the time.
Speaker 1: What's interesting about this asteroid was the combination of its
Speaker 1: size and how close it passed. Apparently a few dozen
Speaker 1: smaller objects like less than twelve meters in diameter passed
Speaker 1: within the orbit of the Moon every year, and according
Speaker 1: to one article I was reading, objects of about the
Speaker 1: size of twenty nineteen okay, only passed by this close
Speaker 1: to Earth roughly once every ten years. So we just
Speaker 1: had like a decade event and that's generally our way
Speaker 1: of understanding these these these asteroids we generally talk about
Speaker 1: like the frequency of their occurrence. Is this a once
Speaker 1: in a decade, Is this a once in a lifetime?
Speaker 1: Is this, you know, once in a thousand years or more?
Speaker 1: That's right, because all these things we think of across
Speaker 1: time scales in in terms of probability. Right, you know,
Speaker 1: things that are unlikely to happen any given year become
Speaker 1: near certainties at a certain time scale. Right. And of course,
Speaker 1: these devastating impacts of you know, of of you know,
Speaker 1: from prehistoric times and uh, you know, they tend to
Speaker 1: leave of mark. You can tell that they occurred, and
Speaker 1: we can extrapolate the kind of damage that that resonated
Speaker 1: exactly right. So to come back to another thing we
Speaker 1: we mentioned earlier, we mentioned that this thing snuck up, right,
Speaker 1: we seemed to come out of nowhere. People astronomers did
Speaker 1: not detect it until just days before its arrival. And
Speaker 1: that's ultimately the most sobering thing about it. Is not
Speaker 1: that that that asteroids like this exists, or that they
Speaker 1: that they they reached these sizes or or passed in
Speaker 1: this proximity, but that we just didn't see it coming,
Speaker 1: and then it was gone like that, just passed us
Speaker 1: in the night. Then we realized how close we came.
Speaker 1: So the question is why. There are a couple of
Speaker 1: reasons here. One is that it was relatively small and faint. Obviously,
Speaker 1: it's easier to use our telescopes to pick up and
Speaker 1: track near Earth objects that are larger and reflect more light.
Speaker 1: Another reason is that it came generally from the direction
Speaker 1: of the Sun, which makes it harder to see because
Speaker 1: of the glare in the background. Another reason it was
Speaker 1: hard to pick up was that it was traveling very fast.
Speaker 1: It makes it harder to detect. Other asteroids recently passing
Speaker 1: by Earth have been slower. According to an article I
Speaker 1: was reading by Alison Chew in the Washington Post, most
Speaker 1: of the recent asteroids passing by Earth have been between
Speaker 1: four and nineteen kilometers per second. Remember again, this one
Speaker 1: was booking at twenty four kilometers per second, which is
Speaker 1: very fast, which also, of course, potentially means that if
Speaker 1: it had hit Earth, the impact would have been more
Speaker 1: powerful because it's going faster. Next, the shape of its
Speaker 1: orbit made it difficult to detect. Nineteen Okay had a
Speaker 1: very elliptical orbit, meaning it was not roughly circular like
Speaker 1: a lot of the orbit of a lot of things,
Speaker 1: most of the planets, it had an oblong oval shape.
Speaker 1: So this asteroid, as it travels around the Sun, sometimes
Speaker 1: it comes very close, like within the orbit of Venus,
Speaker 1: and other times it gets very far away, out beyond
Speaker 1: the orbit of Mars. This also made it more difficult
Speaker 1: to detect. And so if you add all this up,
Speaker 1: you've got this small, fast moving object that's relatively faint
Speaker 1: out there orbiting the Sun, and then suddenly, within maybe
Speaker 1: just a couple of weeks before it passes us, it
Speaker 1: becomes bright enough to see, and then other people have
Speaker 1: to see it and confirm it. Uh, somebody's got to
Speaker 1: be looking at the right place at the right time
Speaker 1: in the first place to see it. It's not easy.
Speaker 1: Things like this really can just sneak up on us,
Speaker 1: and scientists don't necessarily always have fore warning. So this
Speaker 1: kind of serves as a reminder that our orbital neighborhood
Speaker 1: is not a void. Space is not just avoid is
Speaker 1: full of rocks and comets and stuff, and that while
Speaker 1: our astronomers do a really admirable job cataloging near Earth
Speaker 1: objects with the tools available to them. Objects of really
Speaker 1: frightening size can still creep up on us in ways
Speaker 1: that give us only days or even hours of warning,
Speaker 1: or maybe no warning at all. Speaking to the Sydney
Speaker 1: Morning Herald, Australian National University astronomer Dr Brad Tucker said
Speaker 1: that it is completely possible that objects of comparable size,
Speaker 1: objects about the size of twenty nineteen okay, passed by
Speaker 1: us like this and we never detect them at all.
Speaker 1: Sometimes they just go right by and no, no human
Speaker 1: is any the wiser. All right, well, and that's sobering. Note.
Speaker 1: We're going to take a quick break, but when we
Speaker 1: come back, we will discuss what an asteroid of this
Speaker 1: size would do if it actually hit us. Thank alright,
Speaker 1: we're back, all right. So we're talking about the idea
Speaker 1: of the asteroid that just recently passed the Earth within
Speaker 1: the past few weeks nineteen okay, which again zero risk
Speaker 1: to us now it's gone, you know, But we're thinking
Speaker 1: about what an asteroid of this size, you know, roughly
Speaker 1: this size would do if were to be you know,
Speaker 1: the zero point five percent of asteroids that come within
Speaker 1: this range that actually do hit Earth. Uh, we know
Speaker 1: that an impact from a large enough asteroid can be
Speaker 1: devastating on a planetary scale, like space impacts have contributed
Speaker 1: to mass extinctions in Earth history, and of course we
Speaker 1: know that the main theory explaining the the kt extinction
Speaker 1: or the KPg extinction was a theory involving a space impact,
Speaker 1: and of course that this was the extinction event that
Speaker 1: killed the dinosaurs about sixty six million years ago. It's
Speaker 1: the third greatest extinction event in Earth history. The basic
Speaker 1: details are probably familiar to you at this point, but
Speaker 1: a commeter asteroid some bulllied from space hit the Earth
Speaker 1: in what is now the Yucatan Peninsula was probably I've
Speaker 1: seen estimates, uh. I think maybe the older estimates are
Speaker 1: that it was ten to fifteen kilometers in diameter. More recently,
Speaker 1: I think I've seen people saying sixteen kilometers in diameter
Speaker 1: is a huge object, you know, measured on a scale
Speaker 1: of miles or kilometers, And an object of this size
Speaker 1: impacting Earth at orbital speed is not just a collision.
Speaker 1: It is, as we were talking about earlier, a detonation.
Speaker 1: It releases a blast of energy equivalent to millions of
Speaker 1: nuclear warheads all exploding at the same time, and things
Speaker 1: on this scale hitting the Earth are especially scary because
Speaker 1: they're not just threatening to organisms living in the local
Speaker 1: area right that they can have planet scale effects, like
Speaker 1: the leading theory about the cause of the KPg extinction
Speaker 1: is that this impact happened. This bowled from space hit
Speaker 1: the Earth, and it threw up so much dust and
Speaker 1: debris into the atmosphere that it blocked out the sun
Speaker 1: for perhaps months, preventing photosynthesis, killing off huge numbers of
Speaker 1: plants and photosynthesizing organisms, which of course cut off food
Speaker 1: sources for larger animals. And more than three quarters of
Speaker 1: Earth species are believed to have been completely wiped out
Speaker 1: in this event. But there's good news. Scientists now think
Speaker 1: that if there are asteroids of that size on any
Speaker 1: kind of likely collision course with Earth, we would very
Speaker 1: very likely already know about them. It's not a sure thing,
Speaker 1: but we would really probably know because, like I said,
Speaker 1: we've we've cataloged more than nine we think of asteroids
Speaker 1: that could be of this size in our orbital neighborhood.
Speaker 1: And we're always trying to improve our near Earth object
Speaker 1: detection and mapping capabilities, And this is an astronomy priority
Speaker 1: of species level importance. Keep watching the skies. But objects
Speaker 1: on the scale of the one that just passed us.
Speaker 1: Remember it's not even close to as big as that one.
Speaker 1: But objects on this scale are trickier. They're more difficult
Speaker 1: to be sure about because they're smaller. We also have
Speaker 1: less confidence in our ability to detect them ahead of time.
Speaker 1: So what would happen if an object roughly on the
Speaker 1: scale of twenty nineteen okay, were to hit the earth? Well,
Speaker 1: it turns out we actually have a pretty close analogy
Speaker 1: from twentieth century history, which we alluded to earlier, and
Speaker 1: that is the Tongue event. Robert. For my money, this
Speaker 1: is one of the most darkly fascinating events of the
Speaker 1: last few hundred years. I think, yeah, they're there, you know,
Speaker 1: it's one of one of these stories. It's certainly it's
Speaker 1: given the fact that it did not decimate a major
Speaker 1: center of population, uh makes it something that doesn't feel,
Speaker 1: you know, googlesh to to look at. But it's it's
Speaker 1: it doesn't have this kind of mysterious quality to it.
Speaker 1: It's almost like it's like a warning shot from the gods.
Speaker 1: It is also strangely kind of a magnet for cranky theories.
Speaker 1: It really attracts, you know, people who want to believe
Speaker 1: that like a sudden black hole or a bit of
Speaker 1: anti matter appeared and caused it, or that it was
Speaker 1: UFOs or some kind of science fiction, you know, like
Speaker 1: Tesla experiment or something. I've seen those various conspiracy theories
Speaker 1: and whatnot. I'm sorry for repeating them, because those things
Speaker 1: are not correct. I mean, we're positive this was a
Speaker 1: space impact. So what happened, Well, on the morning of
Speaker 1: June thirtie, nineteen oh eight, okay, nineteen o eight, and
Speaker 1: checked from space, Probably some kind of asteroid entered Earth's
Speaker 1: atmosphere and possibly hit the ground, but more likely exploded
Speaker 1: in the air at an altitude of about five to
Speaker 1: ten kilometers over an area of eastern Siberia around the
Speaker 1: stony Tunguska River. And this is an area of extremely
Speaker 1: sparsely populated wilderness. There's not a lot of people, not
Speaker 1: a lot of population density out there, and this explosion
Speaker 1: is hard for us to imagine. It annihilated roughly two
Speaker 1: thousand square kilometers of forest land, leaving trees flattened or
Speaker 1: stripped of all branches. The photos that exist of this
Speaker 1: damaged area look like a nuclear test. Site. The forest
Speaker 1: is just shredded and pancaked, and there actually were Despite
Speaker 1: how sparsely populated this area was, there were some contemporaneous
Speaker 1: witnesses who were fairly close. And by fairly close, I
Speaker 1: mean within dozens of miles. Uh So, I want to
Speaker 1: read one contemporaneous account from a witness named S. B. Simonov,
Speaker 1: who lived in a place called Vanavara, which was about
Speaker 1: sixty kilometers south southeast from the epicenter of the blast side.
Speaker 1: Remember this is sixty kilometers away. Here's how his account goes.
Speaker 1: I was sitting on the porch of the house at
Speaker 1: the trading station of Vena Vara at breakfast time, and
Speaker 1: looking towards the north. I had just raised my axe
Speaker 1: to hoop a cask, when suddenly, in the north, above
Speaker 1: vassili Iliatch own cools Tunguska Road, the sky split in two,
Speaker 1: and high above the forest, the whole northern part of
Speaker 1: the sky appeared to be covered with fire. At that moment,
Speaker 1: I felt great heat, as if my shirt had caught fire.
Speaker 1: This heat came from the north side. I wanted to
Speaker 1: pull off my shirt and throw it away, but at
Speaker 1: that moment there was a bang in the sky, and
Speaker 1: a mighty crash was heard. I was thrown onto the
Speaker 1: ground about five and a half meters away from the porch,
Speaker 1: and for a moment I lost consciousness. My wife ran
Speaker 1: out and carried me into the hut. The crash was
Speaker 1: followed by noise like stones falling from the sky or
Speaker 1: guns firing. The earth trembled, and when I lay on
Speaker 1: the ground, I covered my head because I was afraid
Speaker 1: stones might hit it. At the moment when the sky opened,
Speaker 1: a hot wind, as from a cannon, blew past the
Speaker 1: huts from the north. It left its mark on the
Speaker 1: ground in the form of little paths. It damaged onion plants.
Speaker 1: Later it turned out that many panes in the windows
Speaker 1: had been blown out, and the iron hasp in the
Speaker 1: door of the barn had been broken. When the fire appeared,
Speaker 1: I saw Kosolopov, who was working near the window of
Speaker 1: the house, sit down on the ground, seize his head
Speaker 1: with both hands, and then run into the hut sixty
Speaker 1: kilometers away. And and and this was again this was
Speaker 1: like to what extent I mean today, if you saw that,
Speaker 1: you would your your mind would instantly turn to nuclear weapons,
Speaker 1: you know. But but there were no nuclear but there
Speaker 1: was nothing on the human scale that could, uh, they
Speaker 1: could explain what he was witnessing. I mean, you're you're
Speaker 1: left to, you know, astronomical explanations if you had privy
Speaker 1: to them. Otherwise it's just purely supernatural destruction, exactly. Well.
Speaker 1: Some I have read reports that some of the native
Speaker 1: Siberian peoples of the region of the known as the
Speaker 1: Evenki tribes or the Tung people, believed that the Tunguska
Speaker 1: impact was the work of a god named Aga Dy
Speaker 1: who's the god of thunder and lightning. Though I've also
Speaker 1: seen ody described as these believe these creatures that were
Speaker 1: like metal birds of thunder and lightning. Yeah. Other witnesses
Speaker 1: and generally describe having seen like a blue white streak
Speaker 1: in the sky, followed by what appeared to be this
Speaker 1: enormous fire consuming the whole sky, and then this gigantic
Speaker 1: column of black smoke and loud blasts and crashing noises
Speaker 1: booming over the land. The air blast was picked up
Speaker 1: by meteorological equipment really far away, like more and six
Speaker 1: thousand kilometers away in England, and reportedly in the nights
Speaker 1: following the explosion, and I'm not sure this story is true,
Speaker 1: but this is just an anecdote repeated through history, may
Speaker 1: may or may not be true. Supposedly, and the sky
Speaker 1: remained bright over parts of Europe and Asia in the
Speaker 1: following nights and uh and according to this anecdote, it
Speaker 1: was so bright that you could stand outside at night
Speaker 1: and read a newspaper by the light that was still
Speaker 1: glowing in the sky. The blast triggered fires that burned
Speaker 1: trees tens of kilometers away. Amazingly, despite how destructive this
Speaker 1: blast was, I've read the most recent research on it
Speaker 1: has found evidence of only three reported human casualties from
Speaker 1: the impact. And this is apparently just sheer luck, you know,
Speaker 1: because it was out there where very few people live,
Speaker 1: in extremely sparse wilderness. If it had struck over Beijing
Speaker 1: or London, it would have been much like a city
Speaker 1: getting hit with a nuclear weapon and probably would have
Speaker 1: killed millions. Yeah, and I mean of it, it it hid
Speaker 1: and major center of population even in I mean, it
Speaker 1: could have changed the course of history. I mean, it
Speaker 1: just it's it's impossible to really, I mean, I'm sure
Speaker 1: you can you can sort of like follow individual uh,
Speaker 1: you know, life stories and what non prefats There's been
Speaker 1: some speculation on this, but I mean it would it
Speaker 1: would have changed the course of history. It would have
Speaker 1: It would have killed so many people and impacted uh,
Speaker 1: you know, places of of of power. It would have
Speaker 1: had an impact on on politics. I mean, this is
Speaker 1: it's it's it's almost hard to fathom the the different
Speaker 1: world we would live in had this thing impacted pretty
Speaker 1: much anywhere else. Right. Uh. Now, one thing we do
Speaker 1: know is that an object of the size is not Uh.
Speaker 1: While it could have had worldwide events, like you're saying,
Speaker 1: like cultural impacts that far, it would not have been
Speaker 1: like the KPg extinction event size thing because it wouldn't
Speaker 1: have like thrown up sediment that completely blocked out the
Speaker 1: sun and like cut off photosynthesis. You know, it wouldn't
Speaker 1: be that big, right, Like if it hits St. Petersburg,
Speaker 1: it would not have wiped out humanity. It would not
Speaker 1: have wiped out, you know, all members of the Russian
Speaker 1: Empire or anything to to that extent, but it would
Speaker 1: have severely it would have it would have killed countless
Speaker 1: people in that one city. Yeah, catastrophic local effects and
Speaker 1: maybe some maybe some smaller global effects. Um. And so
Speaker 1: another question I guess is with strikes like this, these
Speaker 1: smaller ones, not like the you know, KPg event level thing,
Speaker 1: but with these smaller ones, has anybody studied what actually
Speaker 1: happens to nearby humans and other life forms when this
Speaker 1: type of impact occurs, Like if a Tungusca size object hits,
Speaker 1: what happens to you if you're nearby? I did find yes,
Speaker 1: there is at least one study of this uh. It
Speaker 1: was published in Geophysical Research Letters in it's by rump
Speaker 1: Lewis and Atkinson. Is called Asteroid Impact of X and
Speaker 1: their Immediate Hazards for Human populations. And what the authors
Speaker 1: did here is they simulated the impacts of more than
Speaker 1: fifty thousand asteroid strikes at random locations on the surface
Speaker 1: of the Earth to gain insights on the average effects
Speaker 1: of human populations who would be nearby and so. Here
Speaker 1: were a few of their main findings. One is that
Speaker 1: objects are less than maybe like sixty or seventy meters
Speaker 1: across tend not to hit the surface of the Earth,
Speaker 1: but rather always explode in the atmosphere. And this is
Speaker 1: not without risks like remember that all the damage caused
Speaker 1: by the Chelabinsk media which exploded in the sky, but
Speaker 1: it it tends to generate the air burst only, and
Speaker 1: an air bursts can still be powerful and dangerous. The
Speaker 1: main theory, of course about the Tunguska event is that
Speaker 1: it was an air burst. It's exploded in the atmosphere
Speaker 1: and didn't have a chance to hit the ground, even
Speaker 1: though it was a good bit bigger. But for most
Speaker 1: sizes of asteroids, by far the greatest risk to humans
Speaker 1: is from what's known as wind blast. These are waves,
Speaker 1: you know, wave of hot compressed air exploding out of
Speaker 1: the object. Uh. The second greatest risk after that is
Speaker 1: just straight thermal risk heat generated due to the impact,
Speaker 1: And then the third greatest risk in general was due
Speaker 1: to tsunamis, And the authors actually found that risk to
Speaker 1: human life from tsunamis is relatively lower than they expected,
Speaker 1: but it increases a lot as the object becomes larger
Speaker 1: than like two hundred or two hundred and fifty in diameter,
Speaker 1: And their estimates only include objects up to four hundred
Speaker 1: meters in diameter, so effects could change dramatically as objects
Speaker 1: become bigger and bigger. Now, Robert, I think I think
Speaker 1: we should step back after what we've just been talking about.
Speaker 1: We should do in lot a reality check. We don't
Speaker 1: want to be alarmists, so to reiterate, the odds are
Speaker 1: in our favor here, at least on short time scales,
Speaker 1: because the vast majority of asteroids of this size don't
Speaker 1: come this close to Earth, maybe roughly one every ten years.
Speaker 1: By that estimate we talked about earlier, only about zero
Speaker 1: point five percent of asteroid it's that pass within this
Speaker 1: range will actually hit Earth. And then even if one
Speaker 1: does hit Earth, most of the world's surfaces water, though
Speaker 1: of course there can be threats from an impact in
Speaker 1: water depending on where it happens. And then much of
Speaker 1: the land surface of Earth is sparsely populated, so on
Speaker 1: short time scales, the odds of a catastrophic impact on
Speaker 1: a city or something like that are very very low.
Speaker 1: But it's one of those cases where the chance of
Speaker 1: a bad outcome on a short time scale may be low,
Speaker 1: but the consequences when that off chance does come to
Speaker 1: pass are devastating and on. Of course, the the other
Speaker 1: side of the coin is that on long enough time scales,
Speaker 1: these events go from extremely unlikely to near certainty. Yeah,
Speaker 1: one of the things I keep keep asking when I
Speaker 1: look at all these stats. It's like, Okay, am I
Speaker 1: comfortable with those odds? But then if I'm comfortable with
Speaker 1: the odds, am I am I comfortable with the steaks?
Speaker 1: You know? Yeah? Totally uh. And it also raises, I
Speaker 1: guess a tangentially interesting question, at least to me, which is, like,
Speaker 1: how long have a time scale should we be concerned about? Like,
Speaker 1: if something is a civilization level threat but it's unlikely
Speaker 1: to happen, you know, more than once within the next
Speaker 1: ten thousand years, how much of our attention should it get?
Speaker 1: Well that's how much should or how much will it?
Speaker 1: You know? I mean, well, yeah, those are very I
Speaker 1: mean exactly tend to be rather terrible at at weighing
Speaker 1: you know, our immediate situation with long term threats to
Speaker 1: to to the survival of the human race sort of
Speaker 1: the health of the planet. Yeah, you're exactly right about that.
Speaker 1: I mean, obviously we're not even appropriately preparing for extremely
Speaker 1: likely to near certain climate related problems that are less
Speaker 1: than a hundred years away some or even you know,
Speaker 1: happening now or decades away. So maybe this question about
Speaker 1: longer time scales is moot just given like what our
Speaker 1: capabilities are, Like, maybe it doesn't even matter what we
Speaker 1: should be doing, because humans just can't make themselves do it.
Speaker 1: But I don't want to be resigned or you know,
Speaker 1: I don't want to throw in the towel about that
Speaker 1: just because we haven't been good at it so far. No,
Speaker 1: because we the we have the tremendous ability to correct
Speaker 1: these errors. I mean, this has often brought up on
Speaker 1: the subject of climate change. Uh you know, well that's
Speaker 1: what I was just referring to. Yeah, I mean, but
Speaker 1: but specifically with climate change. Like, yes, we've got ourselves
Speaker 1: into quite a mess, and that's that's bad. But the
Speaker 1: good side of it is we got ourselves into so
Speaker 1: much of this mess that just shows you the potential
Speaker 1: of human technology. Like, look at what we can do. Granted,
Speaker 1: we screwed things up here, but we imagine if we
Speaker 1: use that same level of energy and intensity towards a
Speaker 1: corrective measure. Yes, though I want to be clear that
Speaker 1: so we're not misunderstood here. We are not advising people
Speaker 1: to hang their hat on like a potential like Holy
Speaker 1: Grail technology that will get rid of all the carbon
Speaker 1: or something like that. That is not a gamble that's
Speaker 1: worth playing with. I think they're talking about like other
Speaker 1: energy technology, other energy technologies, and also just like corrective
Speaker 1: measures like and a willingness to change in that case. Yeah, absolutely,
Speaker 1: But I don't know, I mean, I I do think
Speaker 1: like this is a different kind of thing than climate change,
Speaker 1: because climate change is something that we're like, we're we're
Speaker 1: like near certain about some types of effects that are
Speaker 1: coming within a you know, compared to this a relatively
Speaker 1: short time scale. They're like almost definitely going to happen
Speaker 1: within decades or a hundred years or something, and the
Speaker 1: effects will be catastrophic. So that's like you'd probably say
Speaker 1: that's actually a higher priority, but but this is a
Speaker 1: different priority, so that it's like a catastrophic tail risk.
Speaker 1: It's unlikely that we would get hit by an asteroid
Speaker 1: like this anytime soon, but if we did, it could
Speaker 1: be really bad, right of course. That The other obvious
Speaker 1: thing to point out is that asteroids have mostly, if
Speaker 1: not entirely and thankfully not been politicized. Oh yeah, so
Speaker 1: nobody is out there saying why aren't we why are
Speaker 1: we charting the asteroids? Like look at the I mean they,
Speaker 1: I mean, you could easily imagine somebody taking up this
Speaker 1: is is there. They're they're horrible battle cry and saying,
Speaker 1: look how much we're spending on space exploration, Look how
Speaker 1: much we're spending on this, on on watching the movements
Speaker 1: of the asteroids, and look at these astronomical chances that
Speaker 1: anything is going to hit us. Well, the unfortunate fact
Speaker 1: about the politicization of science is that it does not
Speaker 1: require both sides in order to happen. You can asymmetrically
Speaker 1: politicize and currently non political issue, you know, just by
Speaker 1: having one side get worked up about it, and then
Speaker 1: of course the process is irreversible. And so please don't
Speaker 1: do that with the planetary defense and stuff about, right, Yeah, hopefully,
Speaker 1: I think planetary defense should be something that we that
Speaker 1: everybody can agree on, and we should all like everybody
Speaker 1: should be able to agree, Yes, this is a this
Speaker 1: is a good investment in our future. It's like having
Speaker 1: a lock on the door to your house. Yeah. But
Speaker 1: then again, the exact same thing should be true about
Speaker 1: alternative energy and climate change and stuff, and it's true
Speaker 1: not I mean, clearly, what is in our interest to
Speaker 1: de politicize does not correlate to what people actually do
Speaker 1: de politicize. I think hopefully one I think one thing
Speaker 1: in our favor here is that, as we've discussed on
Speaker 1: the show, one of the problems with climate issues is
Speaker 1: that it's it's very difficult for most of us to
Speaker 1: wrap our hands heads around all that's happening in this
Speaker 1: vast chaotic system of atmosphere and uh in climate. You know,
Speaker 1: it's particularly when you're dealing with with larger periods of time,
Speaker 1: oh and asteroids more like an easy to identify villain.
Speaker 1: It's like it's like a rock thrown at your head.
Speaker 1: Like we can instantly be like, yeah, like i'm here,
Speaker 1: that's there. That should not hit where I am, and
Speaker 1: like we can all agree that that that this this
Speaker 1: is a bad thing, that should be that the big
Speaker 1: should should be avoided at all costs and easier to
Speaker 1: process in the mind, it's an incoming projectile, and we've
Speaker 1: we've evolved to deal with that kind of threat. That's
Speaker 1: a really good point, and I think it's absolutely, of
Speaker 1: course worth investing in planetary defense at multiple levels, by
Speaker 1: the way, probably most importantly right now, and expanding our
Speaker 1: surveying capabilities right to increase our ability to catalog and
Speaker 1: track near Earth objects, which we're already doing a pretty
Speaker 1: good job at with Earth based telescopes and all that,
Speaker 1: but expanding those capabilities it sounds like a very good
Speaker 1: idea to me. And then I guess the next thing
Speaker 1: on top of that is something that maybe we'll talk
Speaker 1: about at the end of the episode, is what would
Speaker 1: we do if we did detect something? You know, pretty
Speaker 1: we did have fore warning, we're pretty sure something's on
Speaker 1: a collision course with Earth. Is there anything we can
Speaker 1: actually do about it? Right? All right, well, let's take
Speaker 1: another break and when we come back, we'll discuss our
Speaker 1: general state of preparedness for small near Earth objects and
Speaker 1: then yeah, what what we would do if something did
Speaker 1: seem to have our name on it? Thank? Thank Alright,
Speaker 1: we're back. Okay, So Robert, we need to talk about
Speaker 1: what we would do if we got some bad news
Speaker 1: about a an asteroid uh coming down the pike in
Speaker 1: our direction? All right? Well, yeah, well first let's let's
Speaker 1: let's touch again on our general state of preparedness. So,
Speaker 1: like we said earlier, of extinction, class near Earth objects
Speaker 1: and eos are are marked, and it works out in
Speaker 1: our favor because the bigger ones are easier to see.
Speaker 1: Exactly fortunate our ability to to track these things has
Speaker 1: certainly come a long way. Like I was reading about
Speaker 1: how in observations of the asteroid n XF eleven suggested
Speaker 1: that this half mile wide object would just simply hit
Speaker 1: the Earth in. Only later did it turn out, via
Speaker 1: better orbit analysis that the Earth actually isn't in danger
Speaker 1: from this particular asteroid. So it was just you know,
Speaker 1: more or less taken off the list based on our
Speaker 1: current data. NASA has a sort of rogues gallery of
Speaker 1: potentially dangerous asteroids or UM, you know, also known as
Speaker 1: p h as fause potentially has dis asteroids, that's the
Speaker 1: abbreviation UM. And these are ones that are predicted to
Speaker 1: you know, to make close passes, such as say feet on,
Speaker 1: which made a close pass in twenty seventeen, and we'll
Speaker 1: make a closer pass in but we're talking about a
Speaker 1: twenty seventeen distance of what, let's see, ten million, three
Speaker 1: d and twelve thousand and thirty four kilometers or six million,
Speaker 1: four hundred and seven thousand and six hundred one miles
Speaker 1: and then uh, the next pass, we're going to see
Speaker 1: it come in at two million, nine sixty four thousand
Speaker 1: kilometers or one million, eight hundred forty one thousand miles,
Speaker 1: which is still again close enough to be of concern.
Speaker 1: But again this is just a to to really drive
Speaker 1: home the distances we're talking about here. So there are
Speaker 1: a number there are a number of potentially hazardous asteroids,
Speaker 1: but even the more hazardous ones have a pretty low
Speaker 1: chance of hitting the Earth. One of the biggest known
Speaker 1: dangers out there right now, for example, is two thousand
Speaker 1: s g threety four, which has a one and eleven
Speaker 1: hundred chance of impact in one and again I come
Speaker 1: back to that question. You might are you might be
Speaker 1: cool with those odds, but are you cool with the steaks?
Speaker 1: It's again easier to spot the big civilization busters, and
Speaker 1: that's where that nine tracking rate comes in. But according
Speaker 1: to the Planetary Society, which has a has a number
Speaker 1: of wonderful um uh educational resources on space, experty and astronomy,
Speaker 1: we're only tracking like twenty thousand out of a million
Speaker 1: smaller but potentially deadly pH s. So we need to
Speaker 1: improve our tracking capabilities right for these again, to deal
Speaker 1: with these potential city busters, especially, So I suppose the
Speaker 1: answer is that you know, we're doing better than we
Speaker 1: ever have, but there's a lot of room for improvement
Speaker 1: and lots more room for certainty when the stakes are
Speaker 1: this high. And this is also a very important reason
Speaker 1: to always support and vote for political candidates and parties
Speaker 1: that value science, scientific consensus, and h and manifest that
Speaker 1: support for science in the form of policy and funding. Now,
Speaker 1: the next question is, okay, what if we what if
Speaker 1: we do spot one that is just coming way too
Speaker 1: close for comfort? What are we prepared to do about it?
Speaker 1: And this is an area where various plans have been
Speaker 1: presented over the years, and it's really like it's one
Speaker 1: of these scenarios that that you really get the sense
Speaker 1: that a lot of you know, astronomers and science is
Speaker 1: really relish. The problem is a pure thought experiment, like
Speaker 1: what can you do to to deal with an asteroid
Speaker 1: that is on course to hit the Earth or getting
Speaker 1: way too close to the Earth for our comfort level?
Speaker 1: So you get Bruce Willis, Oh, no, I'm sorry, I
Speaker 1: made that joke. You know. I was like, I'm gonna
Speaker 1: go this episode without referencing arm Agin, and then I
Speaker 1: just did it anyway. Yeah, well, I've never seen Armagin,
Speaker 1: so I can't I can't even chime in on that.
Speaker 1: I don't know if it's worth your time. But I've
Speaker 1: seen chronicles of Riddick and that had that had a
Speaker 1: dangerous sort of near Earth object like the Necromonger spaceship.
Speaker 1: As a comment, right, oh man, those those rat tail
Speaker 1: braids on Carl Urban's head, and that that is the
Speaker 1: near Earth object that I'm most worried about. All right,
Speaker 1: So a near Earth object coming at the planet. What
Speaker 1: can you do? Well, all the all the proposed solutions
Speaker 1: tend to fall under one of two categories. Either you
Speaker 1: destroy the near Earth object, fragmenting it into smaller chunks,
Speaker 1: or you alter its trajectory. I am of the you know,
Speaker 1: I'm not an expert in this realm, but I'm of
Speaker 1: the opinion that one of the forks of the stile
Speaker 1: emma is much better than the other. Well, blowing it
Speaker 1: up is certainly very you know, I think it's an
Speaker 1: ego inflate inflating option to be sure, you know, launch
Speaker 1: a nuke, get into that puppy and just make it
Speaker 1: go boom. Right. Of course, the thing is this fragments
Speaker 1: the larger ineo into smaller chunks that you know, hopefully
Speaker 1: if you're dealing with a small enough ineo, you know,
Speaker 1: you're you're breaking it up into chunks that will then
Speaker 1: just burn up in the atmosphere should you hit the atmosphere.
Speaker 1: But you know it's also you could look at it
Speaker 1: another way and say, well, it's a bit like turning
Speaker 1: an incoming slug or an incoming bullet into an incoming
Speaker 1: blast of buckshot. Right. According according to Alan Duffy, one
Speaker 1: of the researchers we mentioned earlier, he was quoted in
Speaker 1: the Washington Post saying that this option of nuking it
Speaker 1: and blowing it into pieces, he says, quote, it makes
Speaker 1: for a great Hollywood film. The challenge with a nuke
Speaker 1: is that it may or may not work, but would
Speaker 1: definitely make the asteroid radioactive. Okay, so radioactive buckshot? Ye
Speaker 1: coming I ship Now. The more popular ideas involve changing
Speaker 1: the ineo's trajectory, and these range from crashing another object
Speaker 1: into it so like croquet or Billard style, you know,
Speaker 1: to gently gently nudging it off course. This is generally
Speaker 1: known as the kinetic impact, but you could also use
Speaker 1: nukes for this as well. It should be point out
Speaker 1: like if you were to use a nuclear device to
Speaker 1: deter to deflect an asteroid, you wouldn't have to like
Speaker 1: blow it up. You could just create an explosion in
Speaker 1: a close enough proximity to it to try and nudge
Speaker 1: it off course. Yeah, so you could, you know, of
Speaker 1: course you could have a kinetic impact or an explosion
Speaker 1: try to divert its course. Another often discussed solution is
Speaker 1: what's known as the gravity tractor. Oh yeah, I really
Speaker 1: like this one. So this involves flying a probe out
Speaker 1: to meet the asteroid and then having the probe simply
Speaker 1: fly alongside it. And remember that gravity works both ways.
Speaker 1: It not only attracts smaller bodies to larger ones, it
Speaker 1: also attracts larger bodies to smaller ones. For example, in
Speaker 1: our Solar System, the planets actually do exert a small
Speaker 1: gravitational influence over the Sun, causing it to sort of
Speaker 1: wobble in place, and the same would be true here.
Speaker 1: Over time, if you have a small spacecraft flying next
Speaker 1: to an asteroid, the asteroid would feel a slight gravitational
Speaker 1: tug toward the mutual center of gravity that shares with
Speaker 1: the probe flying alongside it, and this gravitational tug would slowly,
Speaker 1: over time nudge the asteroid off its trajectory and something
Speaker 1: about the solution is kind of beautiful to me, and
Speaker 1: I can tell from the way that many astrophysicists talk
Speaker 1: about this they kind of feel the same way. I
Speaker 1: often see the gravity tractor described with the word elegant.
Speaker 1: I feel like it's kind of the Pixar solution because
Speaker 1: I can imagine it as a Pixar short the big
Speaker 1: grumpy asteroid that's on its way to destroy us, and
Speaker 1: we solve it not by launching a weapon at it,
Speaker 1: but by sending a robot friend. It gets there, it
Speaker 1: gets a manic Pixie gravity tractors, and and then it
Speaker 1: just over time, you know, it gradually steers off course
Speaker 1: and chooses a new path in line. Now, the key
Speaker 1: to either of these, whether it's kinetic impact or or
Speaker 1: gravity tractor, if you're trying to divert the trajectory, the
Speaker 1: key is lead time. The earlier you detect a potential
Speaker 1: threat asteroid, the easier it is to divert. Kind of
Speaker 1: like if you imagine you're trying to knock off the
Speaker 1: aim of a gun. If it's at point blank range,
Speaker 1: this is a lot harder, you know, because the gun
Speaker 1: can move around a lot and still hit you. If
Speaker 1: it's a very long range, an extremely tiny nudge will
Speaker 1: cause a miss right just because of the distance. You know,
Speaker 1: it goes wider and wider as it gets farther and
Speaker 1: farther away. Yeah, so it means that if you if
Speaker 1: you had advanced knowledge and you had the ability to
Speaker 1: send something out there to it some sort of probe.
Speaker 1: There are a number of more elegant solutions that present
Speaker 1: themselves that don't involve massive explosions and big kinetic strikes.
Speaker 1: Uh So. Individual strategies involve everything from a fixing rocket
Speaker 1: boosters to to an object to one of my favorites,
Speaker 1: simply painting it white. Because consider if if an object
Speaker 1: were were darker, it would reflect something like the sunlight,
Speaker 1: but a white coat of paint. You see that number
Speaker 1: go up to about so altering the way photons of
Speaker 1: light interact with an ineos surface, either through paint another
Speaker 1: way that is sometimes there's been a suggested is through
Speaker 1: solar sale shading. So move some sort of large solar
Speaker 1: sale device essentially a big space umbrella between the sun
Speaker 1: and the asteroid, or use lasers, etcetera. And this would
Speaker 1: allow you to mess with the Arkovsky effect. Now, the
Speaker 1: Arkovsky effect, this is the NASA definition. Is it's name
Speaker 1: for a nineteenth century nineteenth century Russian engineer who first
Speaker 1: proposed the idea, and that is that a small, rocky
Speaker 1: space object would, over long periods of time be noticeably
Speaker 1: nudged in its orbit by the slight push created when
Speaker 1: it absorbs sunlight and then re emits that energy is heat,
Speaker 1: which is pretty which is pretty wonderful to think about.
Speaker 1: It's like you don't have to send out at a
Speaker 1: bomb or or a robot to mess with it, and
Speaker 1: like strap rockets onto it. All you have to do
Speaker 1: is send more or less light and you can alter
Speaker 1: the trajectory of this asteroid. But again, all of these
Speaker 1: these options are highly dependent on having lots of lead time,
Speaker 1: knowing way way in advance that it could be coming
Speaker 1: our way. And this is yet again why the most
Speaker 1: important thing in all of these solutions is improving our
Speaker 1: survey and detection capabilities. I think we should come up
Speaker 1: with with an asteroid character right now that can be
Speaker 1: our stand in villain. So when the asteroid, when the
Speaker 1: one appears that is a threat. We've got a ready
Speaker 1: made like character in our mythology to pair it up with, right, Yeah,
Speaker 1: you know, like, so you mentioned the Pixar movie you
Speaker 1: gotta have the grumpy asteroid that gets paired with the
Speaker 1: Manning Pixie space probe. Well, uh, you know, there are
Speaker 1: a few different ways you could go in that. In
Speaker 1: that in that area, I mean, obviously one turns to
Speaker 1: comics and you think of of say, oh, what's the
Speaker 1: big Marvel guy, the planet guy Galactus? Galactus is a
Speaker 1: wonderful stand in for some sort of enormous cosmic threat.
Speaker 1: Does Galactus eat planets? He eats planets? Seems the other
Speaker 1: way around. Well, I mean it's like it's like a
Speaker 1: poison pill that our planet would eat. Well, I think
Speaker 1: the thing is, once Galactus gets to your planet, it's over.
Speaker 1: Uh you know, it's it doesn't really matter exactly how
Speaker 1: he you know, what happens. You just know you're doomed.
Speaker 1: And and that's kind of the scenario with a significantly
Speaker 1: sized asteroid. But one thing I do keep coming back
Speaker 1: to with this topic, and I have over the years,
Speaker 1: it's like we're talking about an actual threat to the
Speaker 1: planet and efforts to mitigate that threat and to prevent
Speaker 1: any of any objects from hitting us. And it's like
Speaker 1: it is ultimately such a noble venture and again one
Speaker 1: that we can all get behind and all celebrate. And
Speaker 1: really it kind of serves as as an example. I mean,
Speaker 1: it's it's almost like a perfectly romantic, uh simple problem
Speaker 1: to have and in many respects, like, yes, they're technological
Speaker 1: hurdles to overcome, but unlike so many more complicated problems
Speaker 1: in uh, in human events and even in the you know,
Speaker 1: the health of our planet, like, it's something with a
Speaker 1: clear cut threat and some some basic steps that we
Speaker 1: can continue to take to try and mitigate the danger.
Speaker 1: I agree. It's like it's like the one noble war.
Speaker 1: It's a you know, a war. It's a fight for
Speaker 1: our lives, but without a human enemy. Right. Yeah. And
Speaker 1: and also the next time you hear a bit of
Speaker 1: space news that doesn't just completely like you know, fill
Speaker 1: you with wonder and excitement where you're like, oh, well,
Speaker 1: that's just I'm not particularly you know one over by
Speaker 1: that it doesn't like, you know, fill me with the
Speaker 1: zeal for space. Think back to the fact that it's
Speaker 1: that's all a part of our ongoing attempt to better
Speaker 1: understand understand our our local and overall uh you know,
Speaker 1: galactic neighborhood. And by doing so, you know we're able
Speaker 1: to protect the planet from threats like this again, to
Speaker 1: protect ourselves against the wrath of Galactus or the wrath
Speaker 1: of act Yeah, all right, we're gonna call it right there.
Speaker 1: But as always, if you want to check out more
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Speaker 1: each episode, one episode a week, we look at a
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Speaker 1: what came before, how do we possibly live before we had, say,
Speaker 1: a toaster? And then how was life change forever afterwards?
Speaker 1: Huge thanks as always to our excellent audio producer Maya Cole.
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Speaker 1: a topic for the future, for just to say hello,
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