Speaker 1: Hey, Welcome to Science Stuff, a production of iHeartRadio. Hoor
Speaker 1: Hey cham and today we're talking about asteroids. What exactly
Speaker 1: are they? Should we go out there and mind them
Speaker 1: or is one of them going to crash into Earth
Speaker 1: and wipe us out. We're going to be talking to
Speaker 1: one of the most famous astronomers on the planet about this,
Speaker 1: Who's going to step us through the nuances of how
Speaker 1: asteroids form, what it would be like to step on one,
Speaker 1: and what the most valuable resource in them actually is.
Speaker 1: So get your asteroids and gear as we tackle the
Speaker 1: meaty or topic of space rocks enjoying. Hey everyone. I
Speaker 1: don't know about you, but I like planet Earth and
Speaker 1: I'm not in a big hurry to leave it. But
Speaker 1: it does seem that at the rate we're going, we
Speaker 1: might run out of things here, which is why billionaires
Speaker 1: and space enthusiasts have proposed maybe goin shopping out there
Speaker 1: in the asteroid belt. I also like our planet enough
Speaker 1: that I don't want to see anything happen to it,
Speaker 1: like getting hit by an asteroid. So basically I had
Speaker 1: a lot of asteroid questions to answer them, I thought
Speaker 1: I'd reach out to one of the most well known
Speaker 1: astronomers on the planet. Doctor Phil Plait Doctor Plate, is
Speaker 1: the creator of the website Bad Astronomy, as well as
Speaker 1: the author of several books, including Death from Disguise, a
Speaker 1: fun survey of all the ways things from space can
Speaker 1: kill us, including asteroids.
Speaker 2: He also wrote Under.
Speaker 1: Alien Skies about what it would be like to visit
Speaker 1: other parts of the universe, like an asteroid. So I
Speaker 1: had three questions for doctor Plate. Number one, what exactly
Speaker 1: is an asteroid? It turns out there's a lot of
Speaker 1: people get wrong about that. Number two, is an asteroid
Speaker 1: going to hit the Earth and why it was out?
Speaker 1: And three should we mine the asteroid belt? It turns
Speaker 1: out there's more than just rocks and metals out there.
Speaker 1: We'll start with the first question, what exactly is an asteroid?
Speaker 1: Here's my conversation with doctor Phil Plate. Well, thank you
Speaker 1: doctor Plate for joining us.
Speaker 3: Oh my pleasure. It's nice to see you and hear you.
Speaker 3: I suppose hear you. Well.
Speaker 1: I think we're both not enough that everyone knows what
Speaker 1: we look like, or can know what we look like
Speaker 1: with a simple search.
Speaker 3: I'm not too hard to picture, you know, little aged, balding,
Speaker 3: bearded white guy.
Speaker 2: Yeah, you've seen me.
Speaker 1: Well, you famously read a book called Death from the
Speaker 1: Skies in which you talk about, among other things, the
Speaker 1: possibility of an asteroid hitting the Earth.
Speaker 2: We'll get into that, but.
Speaker 1: I guess maybe for people who are not familiar, what
Speaker 1: is technically an asteroid?
Speaker 3: Yeah, you know, this is one of those questions where
Speaker 3: it's like this is really easy to ask and super
Speaker 3: hard to answer. When you think of an asteroid, you
Speaker 3: probably think of a you know, big rock in space
Speaker 3: that's floating around orbiting the Sun. But it gets complicated.
Speaker 2: That's not the definition of it.
Speaker 3: Well, there's no real definition. There's not really a size
Speaker 3: on these things. The biggest ones are a few hundred
Speaker 3: kilometers across or miles if you're an American, but there's
Speaker 3: no sort of lower size limit to them. You could
Speaker 3: think of something a meter across, the size of a
Speaker 3: chair as an asteroid, and that's not wrong. But if
Speaker 3: it's the size of a grain of sand, I don't
Speaker 3: know what you would call that necessarily a meteoroid, but
Speaker 3: it's still kind of an asteroid. So that's what these
Speaker 3: things are. You know. I wouldn't call something the size
Speaker 3: of a grape an asteroid, but.
Speaker 2: It kind of is kind of that's what happens.
Speaker 3: You don't have a definition.
Speaker 2: It's a like a vibe. You go in by vibes.
Speaker 1: For the definition of asteroids, Yeah, yes, there is no
Speaker 1: clear definition of what an asteroid is. I mean, it
Speaker 1: basically means space rock, but not always. If the rock
Speaker 1: is mostly made of ice, then astronomers call it a
Speaker 1: or If the rocks are small enough, they call it
Speaker 1: space dust. And if the rock is on t way
Speaker 1: to Earth, they might call it a meteority. Now, the
Speaker 1: size of asteroids vary according to what scientists call an
Speaker 1: inverse law, meaning the bigger an asteroid is.
Speaker 2: The rarer it is.
Speaker 1: For example, really really big asteroids about one thousand kilometers wide.
Speaker 1: There's one it's called series asteroids about one hundred or
Speaker 1: more kilometers wide. There are about two hundred of them.
Speaker 1: But smaller asteroids there are a lot.
Speaker 3: As they get bigger, there are a fewer of them,
Speaker 3: which is just kind of how nature operates. And it
Speaker 3: turns out bigger than about one hundred meters you know,
Speaker 3: football field sized. There are probably a billion of them
Speaker 3: orbiting between Mars and Jupiter, which is a lot. But
Speaker 3: if you say how many are bigger than a meter across.
Speaker 3: I heave't no, it's hundreds of billions, trillions. I don't
Speaker 3: even know.
Speaker 1: There are a lot of asteroids out there. But before
Speaker 1: you get the idea that space is full of rocks
Speaker 1: flying all over the place, kind of like that asteroid
Speaker 1: field and solo flu, the Millennium falcon through and the
Speaker 1: Empire strikes back, you should know two things. First, space
Speaker 1: is big.
Speaker 3: And the thing is there are so many of them,
Speaker 3: and you think, my heavens Empire strikes back. You know,
Speaker 3: if I can quote what is now an.
Speaker 2: Ancient movie, let's not get into how the artful.
Speaker 3: Yeah, you have a space ship and it's going through
Speaker 3: an asteroid belt and they're asteroids everywhere, and it's like, no,
Speaker 3: it's not like that. In fact, when you look at
Speaker 3: how much space is between Mars and Jupiter, and it's
Speaker 3: you know, it's a several hundred million kilometers between them.
Speaker 3: And a friend of mine who studies asteroids actually told
Speaker 3: me this that if you take all of the one
Speaker 3: hundred meter sized asteroids a hundred meters, you know, that's decent,
Speaker 3: and you stand on one in the asteroid belt. If
Speaker 3: you were to spread them out evenly, you would not
Speaker 3: be able to see another asteroid with your naked eye. Whoa,
Speaker 3: they would all be so far away they'd be too
Speaker 3: faint to see. They're actually really far apart.
Speaker 1: Wow, it's pretty rare in the Solar System. It seems
Speaker 1: to run into one an asteroid.
Speaker 3: Yeah, and it just depends on what you mean, right, Yeah,
Speaker 3: there's zillions of them, so they're not rare, but they're
Speaker 3: so few and far between because of the just vast
Speaker 3: amount of space out there that you could go and
Speaker 3: travel to Jupiter and back thousands of times and never
Speaker 3: get even close enough to one to see.
Speaker 1: So there are hundreds of millions of asteroids out there,
Speaker 1: but space is so big you would rarely run into one,
Speaker 1: even in the area of the Solar System called the
Speaker 1: asteroid Belt. And the other thing is that even though
Speaker 1: there are huge asteroids out there and hundreds of millions
Speaker 1: of little asteroids, they actually don't add up too very much.
Speaker 1: Do you have a sense of how much asteroid mass
Speaker 1: is out there?
Speaker 3: The weird thing is if you add them all up together,
Speaker 3: you don't get a very big object. Even though there
Speaker 3: could be a trillion little ones. The biggest ones really
Speaker 3: eat up most of the space, and so you wind
Speaker 3: up getting something that's actually quite small. It's just a
Speaker 3: couple of thousand kilometers across what's smaller maybe than Earth's moon,
Speaker 3: or maybe the size of Earth's moon, something like that.
Speaker 3: Although there are lots of them, they don't add up
Speaker 3: too much.
Speaker 1: Interesting, and you're talking about all the asteroids in the
Speaker 1: asteroid belt.
Speaker 3: Yeah, and I could include the entire Solar System, although
Speaker 3: it gets more complicated if you go out past Neptune.
Speaker 3: There are these bodies out there that we call the
Speaker 3: Kuiper Belt and the ort Cloud, which is comets. There
Speaker 3: are objects that orbit the Sun beyond Neptune, and those
Speaker 3: get pretty big. I mean, you're talking about Pluto. There
Speaker 3: are probably a handful of objects roughly the size of Pluto,
Speaker 3: and so these are actually decent size. Those would add up, oh,
Speaker 3: I don't know, twice the volume, ten times the volume
Speaker 3: of the Moon. So you're still not talking about a planet.
Speaker 3: I don't think. You know, it's certainly not Jupiter or
Speaker 3: that sort of thing. You've got a lot of these things,
Speaker 3: but they're small.
Speaker 1: Oh, that's fascinating. It doesn't seem like a lot. Yeah,
Speaker 1: it's amazing, Okay, The last cool thing about asteroids before
Speaker 1: we get to the questions of whether we should mind
Speaker 1: them or whether one of them is going to hit
Speaker 1: the Earth and kill us all, is that asteroids are
Speaker 1: not as solid as some people would think. According to
Speaker 1: doctor Plate, they can be kind of crumply.
Speaker 3: Some of them are. And this gets weird. Oh, this
Speaker 3: gets so weird. This is a relatively new concept. Are
Speaker 3: there rubbel piles? So instead of being a solid object
Speaker 3: like a rock in your backyard, a chunk of rock,
Speaker 3: there are actually thousands or millions or billions of smaller rocks,
Speaker 3: tiny ones up to maybe the size of boulders, that
Speaker 3: are all held together by their very weak gravity. What
Speaker 3: and so it's like having a bag of rocks, but
Speaker 3: you remove the bag and what you're lift with is
Speaker 3: just the gravity holding them together. And a lot of
Speaker 3: the smaller ones, and we think the majority of smaller
Speaker 3: asteroids are these rubble piles. So that's what they look like.
Speaker 3: When you see pictures of them, you're like, yeah, that's
Speaker 3: actually not a solid surface, that is just a bunch
Speaker 3: of rocks.
Speaker 2: Well, what was happened? If you went there and he
Speaker 2: stood on this, would you think.
Speaker 3: Well, that's a good question. The thing is, these rocks,
Speaker 3: as we found, are very friable, which means they are
Speaker 3: incredibly fragile, and if you were to hold one in
Speaker 3: your hand, you could just crush it. There's very little
Speaker 3: structural strength to these things, and we found that out
Speaker 3: when a spacecraft, and I want to say it was
Speaker 3: Osiris Rex, went up to the asteroid and hit it
Speaker 3: at a very slow speed to collect material. It had
Speaker 3: a sample collector, and the idea was that it would
Speaker 3: go up to the asteroid and it would blow rocks
Speaker 3: off and stuff and collect them into this collector. It
Speaker 3: hit the asteroid and actually kept going. It penetrated down
Speaker 3: about a half a meter into the asteroid itself, which
Speaker 3: was a surprise, and they had to like break and
Speaker 3: reverse thrust and get it back out of there. They
Speaker 3: thought it might penetrate a little bit, but I think
Speaker 3: they were surprised by how much. So, Yeah, if you
Speaker 3: were to visit one of these things in a spaceship
Speaker 3: and say I'm going to jump from my ship and
Speaker 3: land on this asteroid feet first, you might just sink
Speaker 3: right into it, which would be embarrassing and potentially life threatening,
Speaker 3: So don't do it.
Speaker 1: So what you say, at least a lot of the
Speaker 1: what we think of as large ash asteroids out there
Speaker 1: are actually just kind of like crumbly cookies.
Speaker 3: Crumbly cookies, that's pretty good. It is true that a
Speaker 3: lot of the ones that get in near Earth that
Speaker 3: we have visited are like this. Some comets are like this.
Speaker 3: I think this is not at all how I was
Speaker 3: raised learning about asteroids.
Speaker 2: Yeah.
Speaker 1: Yeah, I feel like we've concluded that Star Wars has
Speaker 1: misled us for years unbelievably. Yes, so it's hard to
Speaker 1: run into an asteroid a large asteroid, and a lot
Speaker 1: of them are not sort of big solid rocks, the
Speaker 1: sort of crumbly cookies.
Speaker 3: Basically, the force is not worth it.
Speaker 1: Okay, so those are the basics of asteroids. Now I'll
Speaker 1: get to the big questions. Should we mind the asteroid belt?
Speaker 1: And is an asteroid gonna hit the Earth? It turns
Speaker 1: out that the answer to both of these questions, according
Speaker 1: to doctor Plate, is yes. When we come back, we're
Speaker 1: gonna venture out even further to examine how asteroids can
Speaker 1: kill us and how they can also save us.
Speaker 2: To stay with us, we'll.
Speaker 1: Be right back. Hey, we'll come back. We're talking about asteroids.
Speaker 1: Whether we should mind them and if one of them
Speaker 1: is going to hit the Earth and wipe us out.
Speaker 1: So far, we've talked about what an asteroid actually is
Speaker 1: and how many are out there now. Most of what
Speaker 1: we call asteroids, meaning rocks floating in space, come from
Speaker 1: the asteroid belt, which is the big ring between the
Speaker 1: orbits of Mars and Jupiter. So if you were to
Speaker 1: fly from Earth towards the edge of the Solar System,
Speaker 1: you'd hit the orbit of Mars, then the asteroid belt,
Speaker 1: then the orbit of Jupiter, Saturn, Urinus, and Neptune. And
Speaker 1: the reason the asteroid belt is there is pretty cool. Basically,
Speaker 1: you can blame Jupiter.
Speaker 3: So the early Solar System was the Sun, the young Sun,
Speaker 3: surrounded by this disk of material that's gas and dust
Speaker 3: and rock and stuff like that. These things started to accumulate.
Speaker 3: Grains would bump into each other and turn into pebbles.
Speaker 3: Pebbles bump into each other, turn into boulders, and eventually
Speaker 3: you would grow to get something like a planet. That's
Speaker 3: how our planets formed. But between Mars and Jupiter, Jupiter's
Speaker 3: gravity is very strong, and so any sort of object
Speaker 3: that would try to get big enough to form a planet.
Speaker 3: Jupiter's gravity would kind of swing it around, make it
Speaker 3: move faster, slam into other stuff in the asteroid belt,
Speaker 3: shatter it.
Speaker 1: So basically, the asteroid belt is the graveyard of the
Speaker 1: chaos caused by the huge gravity of Jupiter. Any planets
Speaker 1: that try to form there would get dragged by Jupiter
Speaker 1: and slammed into other rocks.
Speaker 2: And as we mentioned before, there are a lot.
Speaker 1: Of rocks in the asteroid belt, and sometimes those rocks
Speaker 1: can bump into each other and get nudge to fall
Speaker 1: in our direction, which raises the possibility that one of
Speaker 1: them could hit us. It wouldn't be the first time.
Speaker 1: Sixty five million years ago, an asteroid called the Chicchulub impactor,
Speaker 1: which was about fourteen kilometers wide, hit the Earth and
Speaker 1: caused so much mayhem that it killed fifty percent of
Speaker 1: all species on Earth, including the dinosaurs.
Speaker 2: Could it happen again?
Speaker 1: That was the next question I asked, Doctor Blade, Doctor Plade,
Speaker 1: is an asteroid going to hit the Earth? What's the
Speaker 1: likelihood of that happening? One hundred percent?
Speaker 3: One hitting us right now as we're talking? What there
Speaker 3: are thousands of hitting us right now? Well, I said,
Speaker 3: there's no lower limit to the size of an asteroid. Right,
Speaker 3: So if you consider something like a grain of sand
Speaker 3: an asteroid, there are fifty to one hundred tons of
Speaker 3: material that hits Earth every day. What so, zillions of
Speaker 3: these things are hitting Earth all the time, and you
Speaker 3: see them burning up as meteors shooting stars. If you
Speaker 3: call those asteroids, then we're getting hit all the time.
Speaker 3: If you say, oh, let's say something that's a meter across,
Speaker 3: then we get hit by something that size once a month,
Speaker 3: as we're speaking. One fell over Europe a few days ago,
Speaker 3: and a couple of nights ago, one came over Ohio
Speaker 3: and Pennsylvania was seen by thousands of people.
Speaker 2: You heard about that, Yeah, I saw the needs.
Speaker 3: Yeah, it was really bright. Yeah, I've seen the videos.
Speaker 3: It's pretty cool. We get hit by those on timescales
Speaker 3: of a month or so, and the bigger they are,
Speaker 3: the more rare they are.
Speaker 1: What picker Plate is saying is that just like the
Speaker 1: sizes of asteroids out in space, follow an inverse law,
Speaker 1: so that the asteroids that happened to hit the Earth,
Speaker 1: small asteroids hit Earth all the time, but as they
Speaker 1: get bigger, they get rarer and rarer. One of the
Speaker 1: biggest ones to hit US in recent years with the
Speaker 1: Cheliabinsk meteor event, which you can find video of if
Speaker 1: you search for it online.
Speaker 3: Actually, so when you talk about something like the chel
Speaker 3: Yabinsk impact, which was in Russia in twenty thirteen, that
Speaker 3: was nineteen meters across, so you're talking to something the
Speaker 3: size of a house, big house. Those are much more rare.
Speaker 3: Those you're talking about every few decades or century. If
Speaker 3: one is fifty meters across and gets closer than that,
Speaker 3: it's not great. You don't want that, but it's not
Speaker 3: classified as potentially hazardous. It's still if it hits Earth,
Speaker 3: it'll blow up like a nuclear weapon. I mean, you're
Speaker 3: still talking about a megaton or more explosion. That's bad,
Speaker 3: but it's not a global catastrophe.
Speaker 1: Okay, but at around one hundred and footy meters that
Speaker 1: could be a global catastrophe, Yeah.
Speaker 3: I think regional. So you're talking about if one hit
Speaker 3: in the middle of the US, it would be catastrophic
Speaker 3: for US, but not necessarily for you know, India or
Speaker 3: something like that, although it's not great and certainly economically
Speaker 3: you know, if you hit a country that is economically
Speaker 3: critical to the rest of the world.
Speaker 2: That's bad.
Speaker 3: I mean, we saw what happened when like a terrorist
Speaker 3: attack can cripple the economy of a country and bring
Speaker 3: about a global recession. So you don't want these things
Speaker 3: hitting over New York City, Moscow, you know, anything like that.
Speaker 3: That would be very, very bad.
Speaker 1: So's if a one hundred footy meter asteroids hit is
Speaker 1: it would be about how many nuclear weapons?
Speaker 3: Oh golly, so something like two hundred megatons, so multiple
Speaker 3: times the largest nuclear weapon ever dropped. But it's not radioactive,
Speaker 3: so at least you know, yay, no fallout. Hooray.
Speaker 2: It's still bad, Okay, quick recap here.
Speaker 1: Earth is hit by asteroids all the time, but most
Speaker 1: of the time they're small and they end up burning
Speaker 1: up when they hit all that air in the atmosphere.
Speaker 1: That's what a shooting star is. When the asteroids start
Speaker 1: getting about fifty to one hundred and forty meters wide,
Speaker 1: that's when they can do a lot of damage.
Speaker 2: They could wipe by.
Speaker 1: The city and maybe cause a global crisis, but it
Speaker 1: wouldn't end the human race. And luckily that size of
Speaker 1: asteroid only hits Earth statistically every one hundred years or so.
Speaker 1: Now you might be wondering, what about the big ones,
Speaker 1: you know, like the one that took out the dinosaurs,
Speaker 1: that are like several kilometers wide.
Speaker 2: Those would be really bad.
Speaker 1: But actually scientists are not too worried about those because
Speaker 1: remember the inverse law of asteroids says, there aren't that
Speaker 1: many of them out there.
Speaker 3: We know there are no large asteroids big enough to
Speaker 3: be catastrophic globally, like an extinction level event. There's none
Speaker 3: that can get near us for at least the next century.
Speaker 3: It just gets hard to predict farther in the future
Speaker 3: because we don't know their orbits perfectly. But you know,
Speaker 3: something that's a global like like out of a movie
Speaker 3: armagedd and deep impact, something like that. If you remember
Speaker 3: those movies from thirty years ago, Now those are extraordinarily rare.
Speaker 3: Those are like every you know, tens of millions of years,
Speaker 3: like dinosaur killer impacts. Those are extremely rare.
Speaker 1: And in fact, there is an office at NASA called
Speaker 1: the Center for Near Earth Object Studies where the main
Speaker 1: job of the scientists there is to keep track of
Speaker 1: all the big asteroids in the Solar System and make
Speaker 1: sure we're not in a collision course with them. And
Speaker 1: according to their calculations.
Speaker 2: We're good for now.
Speaker 1: Now, does that mean we're totally safe? Not quite. Remember,
Speaker 1: those smaller asteroids in the fifty to a few hundred
Speaker 1: meters wide range can still come out of nowhere and
Speaker 1: do a lot of damage. But there is good news.
Speaker 1: According to doctor Plate, the good.
Speaker 3: News is we can do something about them. The first
Speaker 3: thing we have to do is find them, and we
Speaker 3: are building observatories now. The Vera Ruben Observatory takes huge
Speaker 3: images of the sky and looks for things that change
Speaker 3: from night to night. So an asteroid is, you know,
Speaker 3: in one spot, and the next night it's in the
Speaker 3: next spot. Reuben will see it. And in its first
Speaker 3: night it observed two thousand asteroids and so it's going
Speaker 3: to do this every night. So it's going to map
Speaker 3: out zillions of these things, and that's good because you
Speaker 3: want to know if one's coming toward us, or if
Speaker 3: it's orbit it's going to intersect ours in twenty years
Speaker 3: or something like that. Next thing you have to do
Speaker 3: is push it out of the way. You know, you
Speaker 3: don't necessarily want a nuke it because that's illegal and
Speaker 3: that may not do the trick. Well, is it illegal, Yeah,
Speaker 3: it's actually, the Outer Space Treaty, which was signed by
Speaker 3: a lot of nations in the sixties, makes it illegal
Speaker 3: to test nuclear weapons or detonate them in space, but
Speaker 3: in general, like blowing up a nuke and space is
Speaker 3: illegal and it's a bad idea. But on the other hand,
Speaker 3: NASA has just tested a few years ago in twenty two,
Speaker 3: twenty twenty two, to spacecraft into an asteroid. Ditamos was
Speaker 3: the name of the asteroid, a few hundred meters across.
Speaker 3: It has a moon called Dimorphos, which is one hundred
Speaker 3: and seventy meters across, and they slammed this dishwasher size
Speaker 3: spacecraft into it called DART, which was the Double Asteroid
Speaker 3: Redirection Test DART. DART. It hit the Moon at high
Speaker 3: speed and the idea was the impact would change the
Speaker 3: orbit of the Moon. And then this thing hit it
Speaker 3: and the period of that object changed by half an hour,
Speaker 3: which means we significantly changed the orbit of that asteroid.
Speaker 3: And that's good because that means that if you have
Speaker 3: enough time, like ten years lead time, you can build
Speaker 3: a rocket, send a probe to it, slam it, and
Speaker 3: then hopefully move it enough that over the next few
Speaker 3: years you've pushed its orbit enough that it misses the
Speaker 3: Earth with a dishwasher something like that. So really the
Speaker 3: key here, the absolute key here, is finding them early.
Speaker 3: And if you have twenty years before you think this
Speaker 3: thing's going to hit us, that is plenty of time
Speaker 3: to get to work and try to do something about
Speaker 3: getting it to move out of the way.
Speaker 2: So we do have a system in case that happens.
Speaker 3: Oh, I don't know if I'd glorify it by calling
Speaker 3: it a system. We have rockets and we've done this.
Speaker 3: We hit an asteroid in two thousand and five. There
Speaker 3: was a mission called Deep Impact and that hit an
Speaker 3: asteroid to see what would happen. And then we hit
Speaker 3: dimorphos a few years ago, and that's really it. But
Speaker 3: we're getting better at this all the time. In thirty years,
Speaker 3: hopefully we'll have learned enough about how to do this
Speaker 3: that if anything's coming our way, we'll be able to
Speaker 3: whack it and stop it. You're not trying to shatter
Speaker 3: it necessarily, you're just trying to change its trajectory.
Speaker 2: I see, I see.
Speaker 1: You don't want to stop the asteroid. You just wind
Speaker 1: to nudget out of the way.
Speaker 3: Yeah, gently persuade it maybe you should go.
Speaker 1: Over there hit Mars part is looking pretty good. Yeah,
Speaker 1: but I guess the take home message is that we
Speaker 1: have the ability and we have actually hit an asteroid
Speaker 1: that was out there flying and been able to just
Speaker 1: its trajectory.
Speaker 2: Yeah.
Speaker 3: I mean, that's great, fantastic news. I was really excited
Speaker 3: and I'll tell you relieved in that mission work when
Speaker 3: dart work, because it shows we can do it.
Speaker 2: Oh, fascinating.
Speaker 3: Yeah, it's just all relatively new knowledge. It's pretty cool.
Speaker 2: Okay.
Speaker 1: Few for those of you worried we were going to
Speaker 1: go extinct because of an asteroid hitting us, you can
Speaker 1: rest a little easier knowing that NASA has our backs
Speaker 1: at least against asteroids now, assuming something else doesn't do us,
Speaker 1: and then the big question becomes, how do we survive
Speaker 1: in the long term. It's possible that in the future
Speaker 1: we might run out of resource this year on Earth,
Speaker 1: and in that case, maybe asteroids can save us. There
Speaker 1: are a ton of asteroids out there, but things that
Speaker 1: we could potentially mine to bring back to Earth.
Speaker 2: But is that really feasible?
Speaker 1: Can we or should we mine the asteroid belt while
Speaker 1: we come back. I'll ask doctor Plate this question, and
Speaker 1: I think you might be surprised by the answer, so
Speaker 1: stay with us. We'll be right back. Hey, welcome back.
Speaker 1: We're talking about asteroids and pew. So far, we've learned
Speaker 1: that while the Earth is getting hit by small asteroids
Speaker 1: all the time, the likelihood of a big one coming
Speaker 1: and ending the human race anytime soon is fairly small.
Speaker 1: NASA and other space agencies around the world are keeping
Speaker 1: track of all the big asteroids in our Solar system,
Speaker 1: and even if a medium size one comes our way,
Speaker 1: we are getting better at reaching them and deflecting them. Now,
Speaker 1: the question is good asteroids actually be good for us?
Speaker 1: A lot of people have noticed that asteroids in the
Speaker 1: asteroid belt are full of materials that we meet here
Speaker 1: on Earth, and so a possible is for us to
Speaker 1: go out there and mine them. But is that a
Speaker 1: good idea? Should we send a spacecraft out there to
Speaker 1: check out the metals and minerals and those floating space rocks.
Speaker 1: Actually it furs out we already have.
Speaker 3: There's a current mission NASA launched called Psyche, which is
Speaker 3: on its way. The asteroid's name is Psyche. It's this
Speaker 3: big asteroid. It's one of the biggest ones, and we
Speaker 3: think it's mostly metal. And when we say metal, we
Speaker 3: mean iron, nickel, and mostly silicon, and then a lot
Speaker 3: of lesser ones titanium, tungsten, aluminum, Platinum, for example, is
Speaker 3: very valuable on Earth and it's used in electronics. It's
Speaker 3: very important metal for a lot of reasons. Palladium is
Speaker 3: another one. And it's not like these are abundant in asteroids,
Speaker 3: but they are out there. And so if you could
Speaker 3: take an asteroid and grind it up and extract these metals,
Speaker 3: you could then sell them on Earth and make a
Speaker 3: lot of money.
Speaker 1: Yes, you could technically mine asteroids and bring back their
Speaker 1: precious metals and sell them for a lot of money.
Speaker 2: So why don't we do it?
Speaker 1: I mean, sending a spacecraft to an asteroid is hard,
Speaker 1: but we've done it before. In fact, we've managed to
Speaker 1: get to flying asteroids several times. In the nineteen eighties,
Speaker 1: we sent fly spacecraft from three space agencies around the
Speaker 1: world to get a close look at hay Least comment.
Speaker 1: Since then, there have been about a dozen more missions
Speaker 1: that were sent to either fly by or actually land
Speaker 1: on comets or asteroids.
Speaker 2: But here's the thing.
Speaker 1: Getting to an asteroid to mine it is not the
Speaker 1: main problem. The real problem is bringing back what you mind.
Speaker 3: The big step is you then bring these things back
Speaker 3: to Earth. But bring it back to Earth it's not straightforward.
Speaker 3: You have something that's moving eight kilometers a second. If
Speaker 3: it's coming from deep space, it could be doing twice
Speaker 3: that fast. You have to slow this thing down and
Speaker 3: then somehow get it to the surface of the Earth
Speaker 3: in quantities that are usable. Right, if I'd drop a
Speaker 3: pound of platinum on the Earth, that's not really going
Speaker 3: to help. And you can just drop that from orbit,
Speaker 3: let it hit. It'll actually lose a lot of it.
Speaker 3: You could encase it in concrete or something whatever, let
Speaker 3: that burn off as it goes through the atmosphere. But now,
Speaker 3: if you're talking about one hundred tons of something, how
Speaker 3: do you get that to the surface.
Speaker 1: That's hard without basically creating a giant asteroid that will
Speaker 1: kill people on Earth.
Speaker 3: Yeah, you could build some sort of machinery that would
Speaker 3: slow these things down and drop them for more of it,
Speaker 3: but that's also very expensive, and to do this at
Speaker 3: scale where you're talking about you know, a building weighs
Speaker 3: tens of thousands of tons, so you need a lot
Speaker 3: of this material to build a rocket or to provide
Speaker 3: for the electronics industry or whatever. And right now it's
Speaker 3: just cheaper to keep doing this on Earth. Some day
Speaker 3: it might be easier to do this. We're just not
Speaker 3: there yet.
Speaker 2: That's right.
Speaker 1: Getting things from space to Earth is hard, or at
Speaker 1: least it's easy. But the hard part is having what
Speaker 1: did drop from faith Land in one piece. And even
Speaker 1: if you do manage to figure out how to, say,
Speaker 1: bring all those precious metals from asteroids to Earth, there
Speaker 1: could be other things that can happen that you didn't expect.
Speaker 3: There are other problems like crashing the market if you
Speaker 3: suddenly introduce a vast amount of material into the market.
Speaker 3: You know, the reason these things are expensive is because
Speaker 3: they are rare, and if you bring in a lot,
Speaker 3: there's more than one hundred tons of gold out there,
Speaker 3: but if you bring in a lot, it could actually
Speaker 3: damage the market. This, I can't stress this enough, is
Speaker 3: super super hard to do. We do not have the
Speaker 3: technology in place to do this. We have the technology
Speaker 3: where we can start looking at it and investigating it
Speaker 3: and doing this step by step. But right now, if
Speaker 3: you wanted to mine an asteroid, I think you're looking decades.
Speaker 3: I don't know how many to at least, but it's
Speaker 3: going to be a while. I may be wrong.
Speaker 1: So mining the asteroid belt for materials to bring back
Speaker 1: to birth is a bit of a hard sell. Or
Speaker 1: at least, you'd have to be really, really really desperate
Speaker 1: to make it worth all that money and development and
Speaker 1: risk to do it. But according to doctor Playd, there
Speaker 1: is one other reason we might want to mine the
Speaker 1: asteroid belt that is not about bringing stuff back to Earth,
Speaker 1: and that is for space exploration.
Speaker 3: If we want to build a space station on Earth,
Speaker 3: we have to build it down here, all the pieces,
Speaker 3: and then launch each piece into space and put it together.
Speaker 3: And that takes a long time. It costs a lot
Speaker 3: of money. The space station International Space Station was one
Speaker 3: hundred billion dollars and took ten years to complete. Something
Speaker 3: like that. The rocket launches are expensive. Takes a lot
Speaker 3: of energy to move those things out of Earth's gravity
Speaker 3: into orbit or off the surface. If you mind an asteroid,
Speaker 3: it's out there in space already. Oh and if you
Speaker 3: can figure out a way of processing it, smelting it
Speaker 3: and processing it in a way that you can use
Speaker 3: it to build structures, that is a lot, lot, lot
Speaker 3: easier than trying to lift everything off of Earth. And
Speaker 3: so this is something that people looked into them.
Speaker 2: I see, it's like it's possible.
Speaker 3: Yeah. I don't think there's anything physically or in an
Speaker 3: engineering sense impossible about any of this. You can imagine
Speaker 3: building a factory around an asteroid, using it, having it
Speaker 3: spin for centrifugal force, which is like gravity, and that
Speaker 3: you can use to separate out metals.
Speaker 2: I see.
Speaker 1: Okay, so let me see if I can recap so
Speaker 1: the idea of going to an asteroid mining it to
Speaker 1: bring back material like rare earth metals technically possible, but
Speaker 1: maybe not worth it.
Speaker 3: Questionably profitable, Yeah.
Speaker 2: Questionably profitable, I mean maybe just not right now. I see.
Speaker 1: But then there's sort of the other reason why we
Speaker 1: might mind the asteroid belt, which is for space exploration,
Speaker 1: Like if we wanted to, we could use it as
Speaker 1: a source of metals to build spacecraft and space stations
Speaker 1: and there. It's not so much a business consideration, it's
Speaker 1: just like if we want to do it or not.
Speaker 3: Yeah, I mean it's a sort of government level idea. Yeah,
Speaker 3: if you wanted to explore the outer planets, if you
Speaker 3: want to put humans out in space on Mars, for example,
Speaker 3: where some of these materials are scarce. Then yeah, going
Speaker 3: to the asteroid belt and figuring out how to do
Speaker 3: all this is not the worst idea.
Speaker 2: In that case. Maybe it's the cheaper option.
Speaker 3: Rather than lifting it from Earth. Yeah, because right now
Speaker 3: it still costs a lot of money per kilogram to
Speaker 3: just send air, water, food to people living on the
Speaker 3: Moon or Mars. If you could start in space already,
Speaker 3: it's vastly easier. You're getting rid of some majority of
Speaker 3: the cost of just launching something off Earth is so
Speaker 3: expensive and hard. If you're starting in space, it's way easier,
Speaker 3: and so it's a lot simpler technologically, and it's a
Speaker 3: lot cheaper, a lot less expensive.
Speaker 1: So the asteroid belt could become like the wild West
Speaker 1: of the space frontier. And here's the interesting thing. Most
Speaker 1: people assume, like I did, that the most valuable materials
Speaker 1: in the asteroid belt that we would want to mine
Speaker 1: are the metals and the like iron or copper. But
Speaker 1: actually the most important raw element in them is wetter.
Speaker 3: This wasn't known until relatively recently, a few decades ago,
Speaker 3: that asteroids can have a lot of water in them. Oh,
Speaker 3: what series for example, has a mountain on it that
Speaker 3: seems to be salty water from the interior that oozed
Speaker 3: out and froze in place, and it's a mesa. It's
Speaker 3: like this big flat topped mountain. It's huge, and it's
Speaker 3: made of dirty ice, basically dirty salt water ice. Whoa.
Speaker 3: So these things do have water, and you need water.
Speaker 3: Water is the most useful thing you can have in space.
Speaker 3: You drink it. We need that to live. You can
Speaker 3: break it down and make oxygen to breathe. Water is
Speaker 3: h two Oh, it's hydrogen and oxygen together. You can
Speaker 3: recombine these to make hydrogen peroxide, which in its pure form,
Speaker 3: not like the stuff you buy at the drug store,
Speaker 3: which is like three percent.
Speaker 2: You can diyur hairt space.
Speaker 3: Yeah. Yeah, it's like you know, it's three percent hydrogen
Speaker 3: peroxide and the rest of its water, and it's more
Speaker 3: pure form. It's like ninety percent hydrogen peroxide. It burns
Speaker 3: and it becomes a really good fuel. So you can
Speaker 3: drink it, you can breathe it, and you can move
Speaker 3: around with it. So water is it, that's what you want.
Speaker 3: It's actually the single most important thing if you want
Speaker 3: to have a permanent presence in space. Water is the
Speaker 3: most important thing besides you know, food, but even more
Speaker 3: than food, because again with water you can make air and.
Speaker 2: Fuel right right, the grow food, you need water as well.
Speaker 3: Yeah, humans need a lot of water just to survive
Speaker 3: because of not just our direct needs but also our
Speaker 3: needs like growing plants and protection from radiation. Water is
Speaker 3: great at absorbing radiation, so you can encase your ship
Speaker 3: in a tank of water and protect it from solar
Speaker 3: flares and such. So it's all around. It's just like
Speaker 3: the most useful thing ever in.
Speaker 1: Space, right, and you need it to shower if you
Speaker 1: were so inclined to shower in space, Yeah, that would
Speaker 1: be a good.
Speaker 3: Idea too, although who knows, you know, by then we'll
Speaker 3: have sonic showers like in Star Trek. Who knows it's
Speaker 3: out there. There's lots of their comments that are mostly
Speaker 3: water asteroids. There are moons of Jupiter and Saturn that
Speaker 3: are mostly water. Those are harder to get through than asteroids.
Speaker 3: But still there's a lot out there plenty for everybody.
Speaker 1: Yes, it turns out the real question we should be
Speaker 1: asking it's not whether we should mine the asteroid belt,
Speaker 1: but whether we should drink it. Hey, this puts a
Speaker 1: whole new spin on the phrase meteor shower. All right,
Speaker 1: Hopefully this all gives you a good sense of what's
Speaker 1: out there sprinkled in our solar system that could hit
Speaker 1: us or potentially save us as we keep traveling through
Speaker 1: the vastness of space. Thanks for joining us. See you
Speaker 1: next time.
Speaker 2: You've been listening to Science Stuff.
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