March 25, 2026 • 34 mins
Do asteroids have precious metals we can mine? Or is one of them going to hit us and make us go extinct first?
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Speaker 1 (00:01):
Hey, Welcome to Science Stuff, a production of iHeartRadio. Hoor
Hey cham and today we're talking about asteroids. What exactly
are they? Should we go out there and mind them
or is one of them going to crash into Earth
and wipe us out. We're going to be talking to
one of the most famous astronomers on the planet about this,
Who's going to step us through the nuances of how
(00:24):
asteroids form, what it would be like to step on one,
and what the most valuable resource in them actually is.
So get your asteroids and gear as we tackle the
meaty or topic of space rocks enjoying. Hey everyone. I
(00:45):
don't know about you, but I like planet Earth and
I'm not in a big hurry to leave it. But
it does seem that at the rate we're going, we
might run out of things here, which is why billionaires
and space enthusiasts have proposed maybe goin shopping out there
in the asteroid belt. I also like our planet enough
that I don't want to see anything happen to it,
(01:07):
like getting hit by an asteroid. So basically I had
a lot of asteroid questions to answer them, I thought
I'd reach out to one of the most well known
astronomers on the planet. Doctor Phil Plait Doctor Plate, is
the creator of the website Bad Astronomy, as well as
the author of several books, including Death from Disguise, a
(01:29):
fun survey of all the ways things from space can
kill us, including asteroids.
Speaker 2 (01:37):
He also wrote Under.
Speaker 1 (01:38):
Alien Skies about what it would be like to visit
other parts of the universe, like an asteroid. So I
had three questions for doctor Plate. Number one, what exactly
is an asteroid? It turns out there's a lot of
people get wrong about that. Number two, is an asteroid
going to hit the Earth and why it was out?
(01:59):
And three should we mine the asteroid belt? It turns
out there's more than just rocks and metals out there.
We'll start with the first question, what exactly is an asteroid?
Here's my conversation with doctor Phil Plate. Well, thank you
doctor Plate for joining us.
Speaker 3 (02:18):
Oh my pleasure. It's nice to see you and hear you.
I suppose hear you. Well.
Speaker 1 (02:23):
I think we're both not enough that everyone knows what
we look like, or can know what we look like
with a simple search.
Speaker 3 (02:28):
I'm not too hard to picture, you know, little aged, balding,
bearded white guy.
Speaker 2 (02:31):
Yeah, you've seen me.
Speaker 1 (02:33):
Well, you famously read a book called Death from the
Skies in which you talk about, among other things, the
possibility of an asteroid hitting the Earth.
Speaker 2 (02:41):
We'll get into that, but.
Speaker 1 (02:43):
I guess maybe for people who are not familiar, what
is technically an asteroid?
Speaker 3 (02:48):
Yeah, you know, this is one of those questions where
it's like this is really easy to ask and super
hard to answer. When you think of an asteroid, you
probably think of a you know, big rock in space
that's floating around orbiting the Sun. But it gets complicated.
Speaker 2 (03:02):
That's not the definition of it.
Speaker 3 (03:04):
Well, there's no real definition. There's not really a size
on these things. The biggest ones are a few hundred
kilometers across or miles if you're an American, but there's
no sort of lower size limit to them. You could
think of something a meter across, the size of a
chair as an asteroid, and that's not wrong. But if
(03:24):
it's the size of a grain of sand, I don't
know what you would call that necessarily a meteoroid, but
it's still kind of an asteroid. So that's what these
things are. You know. I wouldn't call something the size
of a grape an asteroid, but.
Speaker 2 (03:37):
It kind of is kind of that's what happens.
Speaker 3 (03:39):
You don't have a definition.
Speaker 2 (03:40):
It's a like a vibe. You go in by vibes.
Speaker 1 (03:43):
For the definition of asteroids, Yeah, yes, there is no
clear definition of what an asteroid is. I mean, it
basically means space rock, but not always. If the rock
is mostly made of ice, then astronomers call it a
or If the rocks are small enough, they call it
space dust. And if the rock is on t way
(04:05):
to Earth, they might call it a meteority. Now, the
size of asteroids vary according to what scientists call an
inverse law, meaning the bigger an asteroid is.
Speaker 2 (04:16):
The rarer it is.
Speaker 1 (04:18):
For example, really really big asteroids about one thousand kilometers wide.
There's one it's called series asteroids about one hundred or
more kilometers wide. There are about two hundred of them.
But smaller asteroids there are a lot.
Speaker 3 (04:37):
As they get bigger, there are a fewer of them,
which is just kind of how nature operates. And it
turns out bigger than about one hundred meters you know,
football field sized. There are probably a billion of them
orbiting between Mars and Jupiter, which is a lot. But
if you say how many are bigger than a meter across.
I heave't no, it's hundreds of billions, trillions. I don't
even know.
Speaker 1 (04:58):
There are a lot of asteroids out there. But before
you get the idea that space is full of rocks
flying all over the place, kind of like that asteroid
field and solo flu, the Millennium falcon through and the
Empire strikes back, you should know two things. First, space
is big.
Speaker 3 (05:17):
And the thing is there are so many of them,
and you think, my heavens Empire strikes back. You know,
if I can quote what is now an.
Speaker 2 (05:23):
Ancient movie, let's not get into how the artful.
Speaker 3 (05:27):
Yeah, you have a space ship and it's going through
an asteroid belt and they're asteroids everywhere, and it's like, no,
it's not like that. In fact, when you look at
how much space is between Mars and Jupiter, and it's
you know, it's a several hundred million kilometers between them.
And a friend of mine who studies asteroids actually told
me this that if you take all of the one
hundred meter sized asteroids a hundred meters, you know, that's decent,
(05:49):
and you stand on one in the asteroid belt. If
you were to spread them out evenly, you would not
be able to see another asteroid with your naked eye. Whoa,
they would all be so far away they'd be too
faint to see. They're actually really far apart.
Speaker 1 (06:04):
Wow, it's pretty rare in the Solar System. It seems
to run into one an asteroid.
Speaker 3 (06:08):
Yeah, and it just depends on what you mean, right, Yeah,
there's zillions of them, so they're not rare, but they're
so few and far between because of the just vast
amount of space out there that you could go and
travel to Jupiter and back thousands of times and never
get even close enough to one to see.
Speaker 1 (06:26):
So there are hundreds of millions of asteroids out there,
but space is so big you would rarely run into one,
even in the area of the Solar System called the
asteroid Belt. And the other thing is that even though
there are huge asteroids out there and hundreds of millions
of little asteroids, they actually don't add up too very much.
(06:49):
Do you have a sense of how much asteroid mass
is out there?
Speaker 3 (06:52):
The weird thing is if you add them all up together,
you don't get a very big object. Even though there
could be a trillion little ones. The biggest ones really
eat up most of the space, and so you wind
up getting something that's actually quite small. It's just a
couple of thousand kilometers across what's smaller maybe than Earth's moon,
or maybe the size of Earth's moon, something like that.
(07:13):
Although there are lots of them, they don't add up
too much.
Speaker 1 (07:15):
Interesting, and you're talking about all the asteroids in the
asteroid belt.
Speaker 3 (07:19):
Yeah, and I could include the entire Solar System, although
it gets more complicated if you go out past Neptune.
There are these bodies out there that we call the
Kuiper Belt and the ort Cloud, which is comets. There
are objects that orbit the Sun beyond Neptune, and those
get pretty big. I mean, you're talking about Pluto. There
are probably a handful of objects roughly the size of Pluto,
(07:40):
and so these are actually decent size. Those would add up, oh,
I don't know, twice the volume, ten times the volume
of the Moon. So you're still not talking about a planet.
I don't think. You know, it's certainly not Jupiter or
that sort of thing. You've got a lot of these things,
but they're small.
Speaker 1 (07:55):
Oh, that's fascinating. It doesn't seem like a lot. Yeah,
it's amazing, Okay, The last cool thing about asteroids before
we get to the questions of whether we should mind
them or whether one of them is going to hit
the Earth and kill us all, is that asteroids are
not as solid as some people would think. According to
doctor Plate, they can be kind of crumply.
Speaker 3 (08:16):
Some of them are. And this gets weird. Oh, this
gets so weird. This is a relatively new concept. Are
there rubbel piles? So instead of being a solid object
like a rock in your backyard, a chunk of rock,
there are actually thousands or millions or billions of smaller rocks,
tiny ones up to maybe the size of boulders, that
(08:37):
are all held together by their very weak gravity. What
and so it's like having a bag of rocks, but
you remove the bag and what you're lift with is
just the gravity holding them together. And a lot of
the smaller ones, and we think the majority of smaller
asteroids are these rubble piles. So that's what they look like.
When you see pictures of them, you're like, yeah, that's
actually not a solid surface, that is just a bunch
(08:58):
of rocks.
Speaker 2 (09:00):
Well, what was happened? If you went there and he
stood on this, would you think.
Speaker 3 (09:04):
Well, that's a good question. The thing is, these rocks,
as we found, are very friable, which means they are
incredibly fragile, and if you were to hold one in
your hand, you could just crush it. There's very little
structural strength to these things, and we found that out
when a spacecraft, and I want to say it was
Osiris Rex, went up to the asteroid and hit it
(09:25):
at a very slow speed to collect material. It had
a sample collector, and the idea was that it would
go up to the asteroid and it would blow rocks
off and stuff and collect them into this collector. It
hit the asteroid and actually kept going. It penetrated down
about a half a meter into the asteroid itself, which
(09:46):
was a surprise, and they had to like break and
reverse thrust and get it back out of there. They
thought it might penetrate a little bit, but I think
they were surprised by how much. So, Yeah, if you
were to visit one of these things in a spaceship
and say I'm going to jump from my ship and
land on this asteroid feet first, you might just sink
right into it, which would be embarrassing and potentially life threatening,
(10:09):
So don't do it.
Speaker 1 (10:11):
So what you say, at least a lot of the
what we think of as large ash asteroids out there
are actually just kind of like crumbly cookies.
Speaker 3 (10:19):
Crumbly cookies, that's pretty good. It is true that a
lot of the ones that get in near Earth that
we have visited are like this. Some comets are like this.
I think this is not at all how I was
raised learning about asteroids.
Speaker 2 (10:33):
Yeah.
Speaker 1 (10:34):
Yeah, I feel like we've concluded that Star Wars has
misled us for years unbelievably. Yes, so it's hard to
run into an asteroid a large asteroid, and a lot
of them are not sort of big solid rocks, the
sort of crumbly cookies.
Speaker 3 (10:52):
Basically, the force is not worth it.
Speaker 1 (10:56):
Okay, so those are the basics of asteroids. Now I'll
get to the big questions. Should we mind the asteroid belt?
And is an asteroid gonna hit the Earth? It turns
out that the answer to both of these questions, according
to doctor Plate, is yes. When we come back, we're
(11:17):
gonna venture out even further to examine how asteroids can
kill us and how they can also save us.
Speaker 2 (11:24):
To stay with us, we'll.
Speaker 1 (11:25):
Be right back. Hey, we'll come back. We're talking about asteroids.
(11:46):
Whether we should mind them and if one of them
is going to hit the Earth and wipe us out.
So far, we've talked about what an asteroid actually is
and how many are out there now. Most of what
we call asteroids, meaning rocks floating in space, come from
the asteroid belt, which is the big ring between the
orbits of Mars and Jupiter. So if you were to
(12:08):
fly from Earth towards the edge of the Solar System,
you'd hit the orbit of Mars, then the asteroid belt,
then the orbit of Jupiter, Saturn, Urinus, and Neptune. And
the reason the asteroid belt is there is pretty cool. Basically,
you can blame Jupiter.
Speaker 3 (12:27):
So the early Solar System was the Sun, the young Sun,
surrounded by this disk of material that's gas and dust
and rock and stuff like that. These things started to accumulate.
Grains would bump into each other and turn into pebbles.
Pebbles bump into each other, turn into boulders, and eventually
you would grow to get something like a planet. That's
how our planets formed. But between Mars and Jupiter, Jupiter's
(12:50):
gravity is very strong, and so any sort of object
that would try to get big enough to form a planet.
Jupiter's gravity would kind of swing it around, make it
move faster, slam into other stuff in the asteroid belt,
shatter it.
Speaker 1 (13:02):
So basically, the asteroid belt is the graveyard of the
chaos caused by the huge gravity of Jupiter. Any planets
that try to form there would get dragged by Jupiter
and slammed into other rocks.
Speaker 2 (13:16):
And as we mentioned before, there are a lot.
Speaker 1 (13:18):
Of rocks in the asteroid belt, and sometimes those rocks
can bump into each other and get nudge to fall
in our direction, which raises the possibility that one of
them could hit us. It wouldn't be the first time.
Sixty five million years ago, an asteroid called the Chicchulub impactor,
which was about fourteen kilometers wide, hit the Earth and
(13:40):
caused so much mayhem that it killed fifty percent of
all species on Earth, including the dinosaurs.
Speaker 2 (13:48):
Could it happen again?
Speaker 1 (13:50):
That was the next question I asked, Doctor Blade, Doctor Plade,
is an asteroid going to hit the Earth? What's the
likelihood of that happening? One hundred percent?
Speaker 3 (14:00):
One hitting us right now as we're talking? What there
are thousands of hitting us right now? Well, I said,
there's no lower limit to the size of an asteroid. Right,
So if you consider something like a grain of sand
an asteroid, there are fifty to one hundred tons of
material that hits Earth every day. What so, zillions of
these things are hitting Earth all the time, and you
see them burning up as meteors shooting stars. If you
(14:22):
call those asteroids, then we're getting hit all the time.
If you say, oh, let's say something that's a meter across,
then we get hit by something that size once a month,
as we're speaking. One fell over Europe a few days ago,
and a couple of nights ago, one came over Ohio
and Pennsylvania was seen by thousands of people.
Speaker 2 (14:41):
You heard about that, Yeah, I saw the needs.
Speaker 3 (14:44):
Yeah, it was really bright. Yeah, I've seen the videos.
It's pretty cool. We get hit by those on timescales
of a month or so, and the bigger they are,
the more rare they are.
Speaker 1 (14:53):
What picker Plate is saying is that just like the
sizes of asteroids out in space, follow an inverse law,
so that the asteroids that happened to hit the Earth,
small asteroids hit Earth all the time, but as they
get bigger, they get rarer and rarer. One of the
biggest ones to hit US in recent years with the
Cheliabinsk meteor event, which you can find video of if
(15:16):
you search for it online.
Speaker 3 (15:18):
Actually, so when you talk about something like the chel
Yabinsk impact, which was in Russia in twenty thirteen, that
was nineteen meters across, so you're talking to something the
(15:38):
size of a house, big house. Those are much more rare.
Those you're talking about every few decades or century. If
one is fifty meters across and gets closer than that,
it's not great. You don't want that, but it's not
classified as potentially hazardous. It's still if it hits Earth,
it'll blow up like a nuclear weapon. I mean, you're
still talking about a megaton or more explosion. That's bad,
(16:00):
but it's not a global catastrophe.
Speaker 1 (16:02):
Okay, but at around one hundred and footy meters that
could be a global catastrophe, Yeah.
Speaker 3 (16:07):
I think regional. So you're talking about if one hit
in the middle of the US, it would be catastrophic
for US, but not necessarily for you know, India or
something like that, although it's not great and certainly economically
you know, if you hit a country that is economically
critical to the rest of the world.
Speaker 2 (16:23):
That's bad.
Speaker 3 (16:23):
I mean, we saw what happened when like a terrorist
attack can cripple the economy of a country and bring
about a global recession. So you don't want these things
hitting over New York City, Moscow, you know, anything like that.
That would be very, very bad.
Speaker 1 (16:37):
So's if a one hundred footy meter asteroids hit is
it would be about how many nuclear weapons?
Speaker 3 (16:42):
Oh golly, so something like two hundred megatons, so multiple
times the largest nuclear weapon ever dropped. But it's not radioactive,
so at least you know, yay, no fallout. Hooray.
Speaker 2 (16:57):
It's still bad, Okay, quick recap here.
Speaker 1 (17:00):
Earth is hit by asteroids all the time, but most
of the time they're small and they end up burning
up when they hit all that air in the atmosphere.
That's what a shooting star is. When the asteroids start
getting about fifty to one hundred and forty meters wide,
that's when they can do a lot of damage.
Speaker 2 (17:19):
They could wipe by.
Speaker 1 (17:20):
The city and maybe cause a global crisis, but it
wouldn't end the human race. And luckily that size of
asteroid only hits Earth statistically every one hundred years or so.
Now you might be wondering, what about the big ones,
you know, like the one that took out the dinosaurs,
that are like several kilometers wide.
Speaker 2 (17:40):
Those would be really bad.
Speaker 1 (17:42):
But actually scientists are not too worried about those because
remember the inverse law of asteroids says, there aren't that
many of them out there.
Speaker 3 (17:53):
We know there are no large asteroids big enough to
be catastrophic globally, like an extinction level event. There's none
that can get near us for at least the next century.
It just gets hard to predict farther in the future
because we don't know their orbits perfectly. But you know,
something that's a global like like out of a movie
armagedd and deep impact, something like that. If you remember
those movies from thirty years ago, Now those are extraordinarily rare.
(18:17):
Those are like every you know, tens of millions of years,
like dinosaur killer impacts. Those are extremely rare.
Speaker 1 (18:23):
And in fact, there is an office at NASA called
the Center for Near Earth Object Studies where the main
job of the scientists there is to keep track of
all the big asteroids in the Solar System and make
sure we're not in a collision course with them. And
according to their calculations.
Speaker 2 (18:40):
We're good for now.
Speaker 1 (18:43):
Now, does that mean we're totally safe? Not quite. Remember,
those smaller asteroids in the fifty to a few hundred
meters wide range can still come out of nowhere and
do a lot of damage. But there is good news.
According to doctor Plate, the good.
Speaker 3 (19:01):
News is we can do something about them. The first
thing we have to do is find them, and we
are building observatories now. The Vera Ruben Observatory takes huge
images of the sky and looks for things that change
from night to night. So an asteroid is, you know,
in one spot, and the next night it's in the
next spot. Reuben will see it. And in its first
night it observed two thousand asteroids and so it's going
to do this every night. So it's going to map
(19:22):
out zillions of these things, and that's good because you
want to know if one's coming toward us, or if
it's orbit it's going to intersect ours in twenty years
or something like that. Next thing you have to do
is push it out of the way. You know, you
don't necessarily want a nuke it because that's illegal and
that may not do the trick. Well, is it illegal, Yeah,
it's actually, the Outer Space Treaty, which was signed by
(19:43):
a lot of nations in the sixties, makes it illegal
to test nuclear weapons or detonate them in space, but
in general, like blowing up a nuke and space is
illegal and it's a bad idea. But on the other hand,
NASA has just tested a few years ago in twenty two,
twenty twenty two, to spacecraft into an asteroid. Ditamos was
the name of the asteroid, a few hundred meters across.
(20:05):
It has a moon called Dimorphos, which is one hundred
and seventy meters across, and they slammed this dishwasher size
spacecraft into it called DART, which was the Double Asteroid
Redirection Test DART. DART. It hit the Moon at high
speed and the idea was the impact would change the
orbit of the Moon. And then this thing hit it
(20:26):
and the period of that object changed by half an hour,
which means we significantly changed the orbit of that asteroid.
And that's good because that means that if you have
enough time, like ten years lead time, you can build
a rocket, send a probe to it, slam it, and
then hopefully move it enough that over the next few
years you've pushed its orbit enough that it misses the
(20:46):
Earth with a dishwasher something like that. So really the
key here, the absolute key here, is finding them early.
And if you have twenty years before you think this
thing's going to hit us, that is plenty of time
to get to work and try to do something about
getting it to move out of the way.
Speaker 2 (21:03):
So we do have a system in case that happens.
Speaker 3 (21:06):
Oh, I don't know if I'd glorify it by calling
it a system. We have rockets and we've done this.
We hit an asteroid in two thousand and five. There
was a mission called Deep Impact and that hit an
asteroid to see what would happen. And then we hit
dimorphos a few years ago, and that's really it. But
we're getting better at this all the time. In thirty years,
(21:27):
hopefully we'll have learned enough about how to do this
that if anything's coming our way, we'll be able to
whack it and stop it. You're not trying to shatter
it necessarily, you're just trying to change its trajectory.
Speaker 2 (21:38):
I see, I see.
Speaker 1 (21:39):
You don't want to stop the asteroid. You just wind
to nudget out of the way.
Speaker 3 (21:42):
Yeah, gently persuade it maybe you should go.
Speaker 1 (21:45):
Over there hit Mars part is looking pretty good. Yeah,
but I guess the take home message is that we
have the ability and we have actually hit an asteroid
that was out there flying and been able to just
its trajectory.
Speaker 2 (21:58):
Yeah.
Speaker 3 (21:59):
I mean, that's great, fantastic news. I was really excited
and I'll tell you relieved in that mission work when
dart work, because it shows we can do it.
Speaker 2 (22:07):
Oh, fascinating.
Speaker 3 (22:08):
Yeah, it's just all relatively new knowledge. It's pretty cool.
Speaker 2 (22:12):
Okay.
Speaker 1 (22:13):
Few for those of you worried we were going to
go extinct because of an asteroid hitting us, you can
rest a little easier knowing that NASA has our backs
at least against asteroids now, assuming something else doesn't do us,
and then the big question becomes, how do we survive
in the long term. It's possible that in the future
(22:33):
we might run out of resource this year on Earth,
and in that case, maybe asteroids can save us. There
are a ton of asteroids out there, but things that
we could potentially mine to bring back to Earth.
Speaker 2 (22:46):
But is that really feasible?
Speaker 1 (22:48):
Can we or should we mine the asteroid belt while
we come back. I'll ask doctor Plate this question, and
I think you might be surprised by the answer, so
stay with us. We'll be right back. Hey, welcome back.
(23:20):
We're talking about asteroids and pew. So far, we've learned
that while the Earth is getting hit by small asteroids
all the time, the likelihood of a big one coming
and ending the human race anytime soon is fairly small.
NASA and other space agencies around the world are keeping
track of all the big asteroids in our Solar system,
(23:40):
and even if a medium size one comes our way,
we are getting better at reaching them and deflecting them. Now,
the question is good asteroids actually be good for us?
A lot of people have noticed that asteroids in the
asteroid belt are full of materials that we meet here
on Earth, and so a possible is for us to
(24:01):
go out there and mine them. But is that a
good idea? Should we send a spacecraft out there to
check out the metals and minerals and those floating space rocks.
Actually it furs out we already have.
Speaker 3 (24:17):
There's a current mission NASA launched called Psyche, which is
on its way. The asteroid's name is Psyche. It's this
big asteroid. It's one of the biggest ones, and we
think it's mostly metal. And when we say metal, we
mean iron, nickel, and mostly silicon, and then a lot
of lesser ones titanium, tungsten, aluminum, Platinum, for example, is
(24:38):
very valuable on Earth and it's used in electronics. It's
very important metal for a lot of reasons. Palladium is
another one. And it's not like these are abundant in asteroids,
but they are out there. And so if you could
take an asteroid and grind it up and extract these metals,
you could then sell them on Earth and make a
lot of money.
Speaker 1 (24:56):
Yes, you could technically mine asteroids and bring back their
precious metals and sell them for a lot of money.
Speaker 2 (25:03):
So why don't we do it?
Speaker 1 (25:05):
I mean, sending a spacecraft to an asteroid is hard,
but we've done it before. In fact, we've managed to
get to flying asteroids several times. In the nineteen eighties,
we sent fly spacecraft from three space agencies around the
world to get a close look at hay Least comment.
Since then, there have been about a dozen more missions
(25:25):
that were sent to either fly by or actually land
on comets or asteroids.
Speaker 2 (25:31):
But here's the thing.
Speaker 1 (25:32):
Getting to an asteroid to mine it is not the
main problem. The real problem is bringing back what you mind.
Speaker 3 (25:42):
The big step is you then bring these things back
to Earth. But bring it back to Earth it's not straightforward.
You have something that's moving eight kilometers a second. If
it's coming from deep space, it could be doing twice
that fast. You have to slow this thing down and
then somehow get it to the surface of the Earth
in quantities that are usable. Right, if I'd drop a
pound of platinum on the Earth, that's not really going
(26:02):
to help. And you can just drop that from orbit,
let it hit. It'll actually lose a lot of it.
You could encase it in concrete or something whatever, let
that burn off as it goes through the atmosphere. But now,
if you're talking about one hundred tons of something, how
do you get that to the surface.
Speaker 1 (26:16):
That's hard without basically creating a giant asteroid that will
kill people on Earth.
Speaker 3 (26:21):
Yeah, you could build some sort of machinery that would
slow these things down and drop them for more of it,
but that's also very expensive, and to do this at
scale where you're talking about you know, a building weighs
tens of thousands of tons, so you need a lot
of this material to build a rocket or to provide
for the electronics industry or whatever. And right now it's
(26:43):
just cheaper to keep doing this on Earth. Some day
it might be easier to do this. We're just not
there yet.
Speaker 2 (26:51):
That's right.
Speaker 1 (26:51):
Getting things from space to Earth is hard, or at
least it's easy. But the hard part is having what
did drop from faith Land in one piece. And even
if you do manage to figure out how to, say,
bring all those precious metals from asteroids to Earth, there
could be other things that can happen that you didn't expect.
Speaker 3 (27:12):
There are other problems like crashing the market if you
suddenly introduce a vast amount of material into the market.
You know, the reason these things are expensive is because
they are rare, and if you bring in a lot,
there's more than one hundred tons of gold out there,
but if you bring in a lot, it could actually
damage the market. This, I can't stress this enough, is
super super hard to do. We do not have the
technology in place to do this. We have the technology
(27:35):
where we can start looking at it and investigating it
and doing this step by step. But right now, if
you wanted to mine an asteroid, I think you're looking decades.
I don't know how many to at least, but it's
going to be a while. I may be wrong.
Speaker 1 (27:50):
So mining the asteroid belt for materials to bring back
to birth is a bit of a hard sell. Or
at least, you'd have to be really, really really desperate
to make it worth all that money and development and
risk to do it. But according to doctor Playd, there
is one other reason we might want to mine the
(28:10):
asteroid belt that is not about bringing stuff back to Earth,
and that is for space exploration.
Speaker 3 (28:20):
If we want to build a space station on Earth,
we have to build it down here, all the pieces,
and then launch each piece into space and put it together.
And that takes a long time. It costs a lot
of money. The space station International Space Station was one
hundred billion dollars and took ten years to complete. Something
like that. The rocket launches are expensive. Takes a lot
of energy to move those things out of Earth's gravity
(28:40):
into orbit or off the surface. If you mind an asteroid,
it's out there in space already. Oh and if you
can figure out a way of processing it, smelting it
and processing it in a way that you can use
it to build structures, that is a lot, lot, lot
easier than trying to lift everything off of Earth. And
so this is something that people looked into them.
Speaker 2 (29:00):
I see, it's like it's possible.
Speaker 3 (29:03):
Yeah. I don't think there's anything physically or in an
engineering sense impossible about any of this. You can imagine
building a factory around an asteroid, using it, having it
spin for centrifugal force, which is like gravity, and that
you can use to separate out metals.
Speaker 2 (29:18):
I see.
Speaker 1 (29:19):
Okay, so let me see if I can recap so
the idea of going to an asteroid mining it to
bring back material like rare earth metals technically possible, but
maybe not worth it.
Speaker 3 (29:30):
Questionably profitable, Yeah.
Speaker 2 (29:32):
Questionably profitable, I mean maybe just not right now. I see.
Speaker 1 (29:37):
But then there's sort of the other reason why we
might mind the asteroid belt, which is for space exploration,
Like if we wanted to, we could use it as
a source of metals to build spacecraft and space stations
and there. It's not so much a business consideration, it's
just like if we want to do it or not.
Speaker 3 (29:54):
Yeah, I mean it's a sort of government level idea. Yeah,
if you wanted to explore the outer planets, if you
want to put humans out in space on Mars, for example,
where some of these materials are scarce. Then yeah, going
to the asteroid belt and figuring out how to do
all this is not the worst idea.
Speaker 2 (30:12):
In that case. Maybe it's the cheaper option.
Speaker 3 (30:14):
Rather than lifting it from Earth. Yeah, because right now
it still costs a lot of money per kilogram to
just send air, water, food to people living on the
Moon or Mars. If you could start in space already,
it's vastly easier. You're getting rid of some majority of
the cost of just launching something off Earth is so
(30:36):
expensive and hard. If you're starting in space, it's way easier,
and so it's a lot simpler technologically, and it's a
lot cheaper, a lot less expensive.
Speaker 1 (30:44):
So the asteroid belt could become like the wild West
of the space frontier. And here's the interesting thing. Most
people assume, like I did, that the most valuable materials
in the asteroid belt that we would want to mine
are the metals and the like iron or copper. But
actually the most important raw element in them is wetter.
Speaker 3 (31:09):
This wasn't known until relatively recently, a few decades ago,
that asteroids can have a lot of water in them. Oh,
what series for example, has a mountain on it that
seems to be salty water from the interior that oozed
out and froze in place, and it's a mesa. It's
like this big flat topped mountain. It's huge, and it's
(31:30):
made of dirty ice, basically dirty salt water ice. Whoa.
So these things do have water, and you need water.
Water is the most useful thing you can have in space.
You drink it. We need that to live. You can
break it down and make oxygen to breathe. Water is
h two Oh, it's hydrogen and oxygen together. You can
recombine these to make hydrogen peroxide, which in its pure form,
(31:51):
not like the stuff you buy at the drug store,
which is like three percent.
Speaker 2 (31:54):
You can diyur hairt space.
Speaker 3 (31:56):
Yeah. Yeah, it's like you know, it's three percent hydrogen
peroxide and the rest of its water, and it's more
pure form. It's like ninety percent hydrogen peroxide. It burns
and it becomes a really good fuel. So you can
drink it, you can breathe it, and you can move
around with it. So water is it, that's what you want.
It's actually the single most important thing if you want
to have a permanent presence in space. Water is the
(32:17):
most important thing besides you know, food, but even more
than food, because again with water you can make air and.
Speaker 2 (32:24):
Fuel right right, the grow food, you need water as well.
Speaker 3 (32:27):
Yeah, humans need a lot of water just to survive
because of not just our direct needs but also our
needs like growing plants and protection from radiation. Water is
great at absorbing radiation, so you can encase your ship
in a tank of water and protect it from solar
flares and such. So it's all around. It's just like
the most useful thing ever in.
Speaker 1 (32:46):
Space, right, and you need it to shower if you
were so inclined to shower in space, Yeah, that would
be a good.
Speaker 3 (32:52):
Idea too, although who knows, you know, by then we'll
have sonic showers like in Star Trek. Who knows it's
out there. There's lots of their comments that are mostly
water asteroids. There are moons of Jupiter and Saturn that
are mostly water. Those are harder to get through than asteroids.
But still there's a lot out there plenty for everybody.
Speaker 1 (33:11):
Yes, it turns out the real question we should be
asking it's not whether we should mine the asteroid belt,
but whether we should drink it. Hey, this puts a
whole new spin on the phrase meteor shower. All right,
Hopefully this all gives you a good sense of what's
out there sprinkled in our solar system that could hit
us or potentially save us as we keep traveling through
(33:35):
the vastness of space. Thanks for joining us. See you
next time.
Speaker 2 (33:44):
You've been listening to Science Stuff.
Speaker 1 (33:45):
Production of iHeartRadio written and produced by me or Hey
Cham edited by Rose Seguda, Executive producer Jerry Rowland, an
audio engineer and mixer Casey Peckron, and you can follow
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the name of your favorite platform. Be sure to subscribe
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(34:06):
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take a second and leave us a review on Apple Podcasts, Spotify,
(34:27):
or wherever you listen to the podcast.
Speaker 2 (34:29):
Thanks a lot,
Hey, Welcome to Science Stuff, a production of iHeartRadio. Hoor
Hey cham and today we're talking about asteroids. What exactly
are they? Should we go out there and mind them
or is one of them going to crash into Earth
and wipe us out. We're going to be talking to
one of the most famous astronomers on the planet about this,
Who's going to step us through the nuances of how
(00:24):
asteroids form, what it would be like to step on one,
and what the most valuable resource in them actually is.
So get your asteroids and gear as we tackle the
meaty or topic of space rocks enjoying. Hey everyone. I
(00:45):
don't know about you, but I like planet Earth and
I'm not in a big hurry to leave it. But
it does seem that at the rate we're going, we
might run out of things here, which is why billionaires
and space enthusiasts have proposed maybe goin shopping out there
in the asteroid belt. I also like our planet enough
that I don't want to see anything happen to it,
(01:07):
like getting hit by an asteroid. So basically I had
a lot of asteroid questions to answer them, I thought
I'd reach out to one of the most well known
astronomers on the planet. Doctor Phil Plait Doctor Plate, is
the creator of the website Bad Astronomy, as well as
the author of several books, including Death from Disguise, a
(01:29):
fun survey of all the ways things from space can
kill us, including asteroids.
Speaker 2 (01:37):
He also wrote Under.
Speaker 1 (01:38):
Alien Skies about what it would be like to visit
other parts of the universe, like an asteroid. So I
had three questions for doctor Plate. Number one, what exactly
is an asteroid? It turns out there's a lot of
people get wrong about that. Number two, is an asteroid
going to hit the Earth and why it was out?
(01:59):
And three should we mine the asteroid belt? It turns
out there's more than just rocks and metals out there.
We'll start with the first question, what exactly is an asteroid?
Here's my conversation with doctor Phil Plate. Well, thank you
doctor Plate for joining us.
Speaker 3 (02:18):
Oh my pleasure. It's nice to see you and hear you.
I suppose hear you. Well.
Speaker 1 (02:23):
I think we're both not enough that everyone knows what
we look like, or can know what we look like
with a simple search.
Speaker 3 (02:28):
I'm not too hard to picture, you know, little aged, balding,
bearded white guy.
Speaker 2 (02:31):
Yeah, you've seen me.
Speaker 1 (02:33):
Well, you famously read a book called Death from the
Skies in which you talk about, among other things, the
possibility of an asteroid hitting the Earth.
Speaker 2 (02:41):
We'll get into that, but.
Speaker 1 (02:43):
I guess maybe for people who are not familiar, what
is technically an asteroid?
Speaker 3 (02:48):
Yeah, you know, this is one of those questions where
it's like this is really easy to ask and super
hard to answer. When you think of an asteroid, you
probably think of a you know, big rock in space
that's floating around orbiting the Sun. But it gets complicated.
Speaker 2 (03:02):
That's not the definition of it.
Speaker 3 (03:04):
Well, there's no real definition. There's not really a size
on these things. The biggest ones are a few hundred
kilometers across or miles if you're an American, but there's
no sort of lower size limit to them. You could
think of something a meter across, the size of a
chair as an asteroid, and that's not wrong. But if
(03:24):
it's the size of a grain of sand, I don't
know what you would call that necessarily a meteoroid, but
it's still kind of an asteroid. So that's what these
things are. You know. I wouldn't call something the size
of a grape an asteroid, but.
Speaker 2 (03:37):
It kind of is kind of that's what happens.
Speaker 3 (03:39):
You don't have a definition.
Speaker 2 (03:40):
It's a like a vibe. You go in by vibes.
Speaker 1 (03:43):
For the definition of asteroids, Yeah, yes, there is no
clear definition of what an asteroid is. I mean, it
basically means space rock, but not always. If the rock
is mostly made of ice, then astronomers call it a
or If the rocks are small enough, they call it
space dust. And if the rock is on t way
(04:05):
to Earth, they might call it a meteority. Now, the
size of asteroids vary according to what scientists call an
inverse law, meaning the bigger an asteroid is.
Speaker 2 (04:16):
The rarer it is.
Speaker 1 (04:18):
For example, really really big asteroids about one thousand kilometers wide.
There's one it's called series asteroids about one hundred or
more kilometers wide. There are about two hundred of them.
But smaller asteroids there are a lot.
Speaker 3 (04:37):
As they get bigger, there are a fewer of them,
which is just kind of how nature operates. And it
turns out bigger than about one hundred meters you know,
football field sized. There are probably a billion of them
orbiting between Mars and Jupiter, which is a lot. But
if you say how many are bigger than a meter across.
I heave't no, it's hundreds of billions, trillions. I don't
even know.
Speaker 1 (04:58):
There are a lot of asteroids out there. But before
you get the idea that space is full of rocks
flying all over the place, kind of like that asteroid
field and solo flu, the Millennium falcon through and the
Empire strikes back, you should know two things. First, space
is big.
Speaker 3 (05:17):
And the thing is there are so many of them,
and you think, my heavens Empire strikes back. You know,
if I can quote what is now an.
Speaker 2 (05:23):
Ancient movie, let's not get into how the artful.
Speaker 3 (05:27):
Yeah, you have a space ship and it's going through
an asteroid belt and they're asteroids everywhere, and it's like, no,
it's not like that. In fact, when you look at
how much space is between Mars and Jupiter, and it's
you know, it's a several hundred million kilometers between them.
And a friend of mine who studies asteroids actually told
me this that if you take all of the one
hundred meter sized asteroids a hundred meters, you know, that's decent,
(05:49):
and you stand on one in the asteroid belt. If
you were to spread them out evenly, you would not
be able to see another asteroid with your naked eye. Whoa,
they would all be so far away they'd be too
faint to see. They're actually really far apart.
Speaker 1 (06:04):
Wow, it's pretty rare in the Solar System. It seems
to run into one an asteroid.
Speaker 3 (06:08):
Yeah, and it just depends on what you mean, right, Yeah,
there's zillions of them, so they're not rare, but they're
so few and far between because of the just vast
amount of space out there that you could go and
travel to Jupiter and back thousands of times and never
get even close enough to one to see.
Speaker 1 (06:26):
So there are hundreds of millions of asteroids out there,
but space is so big you would rarely run into one,
even in the area of the Solar System called the
asteroid Belt. And the other thing is that even though
there are huge asteroids out there and hundreds of millions
of little asteroids, they actually don't add up too very much.
(06:49):
Do you have a sense of how much asteroid mass
is out there?
Speaker 3 (06:52):
The weird thing is if you add them all up together,
you don't get a very big object. Even though there
could be a trillion little ones. The biggest ones really
eat up most of the space, and so you wind
up getting something that's actually quite small. It's just a
couple of thousand kilometers across what's smaller maybe than Earth's moon,
or maybe the size of Earth's moon, something like that.
(07:13):
Although there are lots of them, they don't add up
too much.
Speaker 1 (07:15):
Interesting, and you're talking about all the asteroids in the
asteroid belt.
Speaker 3 (07:19):
Yeah, and I could include the entire Solar System, although
it gets more complicated if you go out past Neptune.
There are these bodies out there that we call the
Kuiper Belt and the ort Cloud, which is comets. There
are objects that orbit the Sun beyond Neptune, and those
get pretty big. I mean, you're talking about Pluto. There
are probably a handful of objects roughly the size of Pluto,
(07:40):
and so these are actually decent size. Those would add up, oh,
I don't know, twice the volume, ten times the volume
of the Moon. So you're still not talking about a planet.
I don't think. You know, it's certainly not Jupiter or
that sort of thing. You've got a lot of these things,
but they're small.
Speaker 1 (07:55):
Oh, that's fascinating. It doesn't seem like a lot. Yeah,
it's amazing, Okay, The last cool thing about asteroids before
we get to the questions of whether we should mind
them or whether one of them is going to hit
the Earth and kill us all, is that asteroids are
not as solid as some people would think. According to
doctor Plate, they can be kind of crumply.
Speaker 3 (08:16):
Some of them are. And this gets weird. Oh, this
gets so weird. This is a relatively new concept. Are
there rubbel piles? So instead of being a solid object
like a rock in your backyard, a chunk of rock,
there are actually thousands or millions or billions of smaller rocks,
tiny ones up to maybe the size of boulders, that
(08:37):
are all held together by their very weak gravity. What
and so it's like having a bag of rocks, but
you remove the bag and what you're lift with is
just the gravity holding them together. And a lot of
the smaller ones, and we think the majority of smaller
asteroids are these rubble piles. So that's what they look like.
When you see pictures of them, you're like, yeah, that's
actually not a solid surface, that is just a bunch
(08:58):
of rocks.
Speaker 2 (09:00):
Well, what was happened? If you went there and he
stood on this, would you think.
Speaker 3 (09:04):
Well, that's a good question. The thing is, these rocks,
as we found, are very friable, which means they are
incredibly fragile, and if you were to hold one in
your hand, you could just crush it. There's very little
structural strength to these things, and we found that out
when a spacecraft, and I want to say it was
Osiris Rex, went up to the asteroid and hit it
(09:25):
at a very slow speed to collect material. It had
a sample collector, and the idea was that it would
go up to the asteroid and it would blow rocks
off and stuff and collect them into this collector. It
hit the asteroid and actually kept going. It penetrated down
about a half a meter into the asteroid itself, which
(09:46):
was a surprise, and they had to like break and
reverse thrust and get it back out of there. They
thought it might penetrate a little bit, but I think
they were surprised by how much. So, Yeah, if you
were to visit one of these things in a spaceship
and say I'm going to jump from my ship and
land on this asteroid feet first, you might just sink
right into it, which would be embarrassing and potentially life threatening,
(10:09):
So don't do it.
Speaker 1 (10:11):
So what you say, at least a lot of the
what we think of as large ash asteroids out there
are actually just kind of like crumbly cookies.
Speaker 3 (10:19):
Crumbly cookies, that's pretty good. It is true that a
lot of the ones that get in near Earth that
we have visited are like this. Some comets are like this.
I think this is not at all how I was
raised learning about asteroids.
Speaker 2 (10:33):
Yeah.
Speaker 1 (10:34):
Yeah, I feel like we've concluded that Star Wars has
misled us for years unbelievably. Yes, so it's hard to
run into an asteroid a large asteroid, and a lot
of them are not sort of big solid rocks, the
sort of crumbly cookies.
Speaker 3 (10:52):
Basically, the force is not worth it.
Speaker 1 (10:56):
Okay, so those are the basics of asteroids. Now I'll
get to the big questions. Should we mind the asteroid belt?
And is an asteroid gonna hit the Earth? It turns
out that the answer to both of these questions, according
to doctor Plate, is yes. When we come back, we're
(11:17):
gonna venture out even further to examine how asteroids can
kill us and how they can also save us.
Speaker 2 (11:24):
To stay with us, we'll.
Speaker 1 (11:25):
Be right back. Hey, we'll come back. We're talking about asteroids.
(11:46):
Whether we should mind them and if one of them
is going to hit the Earth and wipe us out.
So far, we've talked about what an asteroid actually is
and how many are out there now. Most of what
we call asteroids, meaning rocks floating in space, come from
the asteroid belt, which is the big ring between the
orbits of Mars and Jupiter. So if you were to
(12:08):
fly from Earth towards the edge of the Solar System,
you'd hit the orbit of Mars, then the asteroid belt,
then the orbit of Jupiter, Saturn, Urinus, and Neptune. And
the reason the asteroid belt is there is pretty cool. Basically,
you can blame Jupiter.
Speaker 3 (12:27):
So the early Solar System was the Sun, the young Sun,
surrounded by this disk of material that's gas and dust
and rock and stuff like that. These things started to accumulate.
Grains would bump into each other and turn into pebbles.
Pebbles bump into each other, turn into boulders, and eventually
you would grow to get something like a planet. That's
how our planets formed. But between Mars and Jupiter, Jupiter's
(12:50):
gravity is very strong, and so any sort of object
that would try to get big enough to form a planet.
Jupiter's gravity would kind of swing it around, make it
move faster, slam into other stuff in the asteroid belt,
shatter it.
Speaker 1 (13:02):
So basically, the asteroid belt is the graveyard of the
chaos caused by the huge gravity of Jupiter. Any planets
that try to form there would get dragged by Jupiter
and slammed into other rocks.
Speaker 2 (13:16):
And as we mentioned before, there are a lot.
Speaker 1 (13:18):
Of rocks in the asteroid belt, and sometimes those rocks
can bump into each other and get nudge to fall
in our direction, which raises the possibility that one of
them could hit us. It wouldn't be the first time.
Sixty five million years ago, an asteroid called the Chicchulub impactor,
which was about fourteen kilometers wide, hit the Earth and
(13:40):
caused so much mayhem that it killed fifty percent of
all species on Earth, including the dinosaurs.
Speaker 2 (13:48):
Could it happen again?
Speaker 1 (13:50):
That was the next question I asked, Doctor Blade, Doctor Plade,
is an asteroid going to hit the Earth? What's the
likelihood of that happening? One hundred percent?
Speaker 3 (14:00):
One hitting us right now as we're talking? What there
are thousands of hitting us right now? Well, I said,
there's no lower limit to the size of an asteroid. Right,
So if you consider something like a grain of sand
an asteroid, there are fifty to one hundred tons of
material that hits Earth every day. What so, zillions of
these things are hitting Earth all the time, and you
see them burning up as meteors shooting stars. If you
(14:22):
call those asteroids, then we're getting hit all the time.
If you say, oh, let's say something that's a meter across,
then we get hit by something that size once a month,
as we're speaking. One fell over Europe a few days ago,
and a couple of nights ago, one came over Ohio
and Pennsylvania was seen by thousands of people.
Speaker 2 (14:41):
You heard about that, Yeah, I saw the needs.
Speaker 3 (14:44):
Yeah, it was really bright. Yeah, I've seen the videos.
It's pretty cool. We get hit by those on timescales
of a month or so, and the bigger they are,
the more rare they are.
Speaker 1 (14:53):
What picker Plate is saying is that just like the
sizes of asteroids out in space, follow an inverse law,
so that the asteroids that happened to hit the Earth,
small asteroids hit Earth all the time, but as they
get bigger, they get rarer and rarer. One of the
biggest ones to hit US in recent years with the
Cheliabinsk meteor event, which you can find video of if
(15:16):
you search for it online.
Speaker 3 (15:18):
Actually, so when you talk about something like the chel
Yabinsk impact, which was in Russia in twenty thirteen, that
was nineteen meters across, so you're talking to something the
(15:38):
size of a house, big house. Those are much more rare.
Those you're talking about every few decades or century. If
one is fifty meters across and gets closer than that,
it's not great. You don't want that, but it's not
classified as potentially hazardous. It's still if it hits Earth,
it'll blow up like a nuclear weapon. I mean, you're
still talking about a megaton or more explosion. That's bad,
(16:00):
but it's not a global catastrophe.
Speaker 1 (16:02):
Okay, but at around one hundred and footy meters that
could be a global catastrophe, Yeah.
Speaker 3 (16:07):
I think regional. So you're talking about if one hit
in the middle of the US, it would be catastrophic
for US, but not necessarily for you know, India or
something like that, although it's not great and certainly economically
you know, if you hit a country that is economically
critical to the rest of the world.
Speaker 2 (16:23):
That's bad.
Speaker 3 (16:23):
I mean, we saw what happened when like a terrorist
attack can cripple the economy of a country and bring
about a global recession. So you don't want these things
hitting over New York City, Moscow, you know, anything like that.
That would be very, very bad.
Speaker 1 (16:37):
So's if a one hundred footy meter asteroids hit is
it would be about how many nuclear weapons?
Speaker 3 (16:42):
Oh golly, so something like two hundred megatons, so multiple
times the largest nuclear weapon ever dropped. But it's not radioactive,
so at least you know, yay, no fallout. Hooray.
Speaker 2 (16:57):
It's still bad, Okay, quick recap here.
Speaker 1 (17:00):
Earth is hit by asteroids all the time, but most
of the time they're small and they end up burning
up when they hit all that air in the atmosphere.
That's what a shooting star is. When the asteroids start
getting about fifty to one hundred and forty meters wide,
that's when they can do a lot of damage.
Speaker 2 (17:19):
They could wipe by.
Speaker 1 (17:20):
The city and maybe cause a global crisis, but it
wouldn't end the human race. And luckily that size of
asteroid only hits Earth statistically every one hundred years or so.
Now you might be wondering, what about the big ones,
you know, like the one that took out the dinosaurs,
that are like several kilometers wide.
Speaker 2 (17:40):
Those would be really bad.
Speaker 1 (17:42):
But actually scientists are not too worried about those because
remember the inverse law of asteroids says, there aren't that
many of them out there.
Speaker 3 (17:53):
We know there are no large asteroids big enough to
be catastrophic globally, like an extinction level event. There's none
that can get near us for at least the next century.
It just gets hard to predict farther in the future
because we don't know their orbits perfectly. But you know,
something that's a global like like out of a movie
armagedd and deep impact, something like that. If you remember
those movies from thirty years ago, Now those are extraordinarily rare.
(18:17):
Those are like every you know, tens of millions of years,
like dinosaur killer impacts. Those are extremely rare.
Speaker 1 (18:23):
And in fact, there is an office at NASA called
the Center for Near Earth Object Studies where the main
job of the scientists there is to keep track of
all the big asteroids in the Solar System and make
sure we're not in a collision course with them. And
according to their calculations.
Speaker 2 (18:40):
We're good for now.
Speaker 1 (18:43):
Now, does that mean we're totally safe? Not quite. Remember,
those smaller asteroids in the fifty to a few hundred
meters wide range can still come out of nowhere and
do a lot of damage. But there is good news.
According to doctor Plate, the good.
Speaker 3 (19:01):
News is we can do something about them. The first
thing we have to do is find them, and we
are building observatories now. The Vera Ruben Observatory takes huge
images of the sky and looks for things that change
from night to night. So an asteroid is, you know,
in one spot, and the next night it's in the
next spot. Reuben will see it. And in its first
night it observed two thousand asteroids and so it's going
to do this every night. So it's going to map
(19:22):
out zillions of these things, and that's good because you
want to know if one's coming toward us, or if
it's orbit it's going to intersect ours in twenty years
or something like that. Next thing you have to do
is push it out of the way. You know, you
don't necessarily want a nuke it because that's illegal and
that may not do the trick. Well, is it illegal, Yeah,
it's actually, the Outer Space Treaty, which was signed by
(19:43):
a lot of nations in the sixties, makes it illegal
to test nuclear weapons or detonate them in space, but
in general, like blowing up a nuke and space is
illegal and it's a bad idea. But on the other hand,
NASA has just tested a few years ago in twenty two,
twenty twenty two, to spacecraft into an asteroid. Ditamos was
the name of the asteroid, a few hundred meters across.
(20:05):
It has a moon called Dimorphos, which is one hundred
and seventy meters across, and they slammed this dishwasher size
spacecraft into it called DART, which was the Double Asteroid
Redirection Test DART. DART. It hit the Moon at high
speed and the idea was the impact would change the
orbit of the Moon. And then this thing hit it
(20:26):
and the period of that object changed by half an hour,
which means we significantly changed the orbit of that asteroid.
And that's good because that means that if you have
enough time, like ten years lead time, you can build
a rocket, send a probe to it, slam it, and
then hopefully move it enough that over the next few
years you've pushed its orbit enough that it misses the
(20:46):
Earth with a dishwasher something like that. So really the
key here, the absolute key here, is finding them early.
And if you have twenty years before you think this
thing's going to hit us, that is plenty of time
to get to work and try to do something about
getting it to move out of the way.
Speaker 2 (21:03):
So we do have a system in case that happens.
Speaker 3 (21:06):
Oh, I don't know if I'd glorify it by calling
it a system. We have rockets and we've done this.
We hit an asteroid in two thousand and five. There
was a mission called Deep Impact and that hit an
asteroid to see what would happen. And then we hit
dimorphos a few years ago, and that's really it. But
we're getting better at this all the time. In thirty years,
(21:27):
hopefully we'll have learned enough about how to do this
that if anything's coming our way, we'll be able to
whack it and stop it. You're not trying to shatter
it necessarily, you're just trying to change its trajectory.
Speaker 2 (21:38):
I see, I see.
Speaker 1 (21:39):
You don't want to stop the asteroid. You just wind
to nudget out of the way.
Speaker 3 (21:42):
Yeah, gently persuade it maybe you should go.
Speaker 1 (21:45):
Over there hit Mars part is looking pretty good. Yeah,
but I guess the take home message is that we
have the ability and we have actually hit an asteroid
that was out there flying and been able to just
its trajectory.
Speaker 2 (21:58):
Yeah.
Speaker 3 (21:59):
I mean, that's great, fantastic news. I was really excited
and I'll tell you relieved in that mission work when
dart work, because it shows we can do it.
Speaker 2 (22:07):
Oh, fascinating.
Speaker 3 (22:08):
Yeah, it's just all relatively new knowledge. It's pretty cool.
Speaker 2 (22:12):
Okay.
Speaker 1 (22:13):
Few for those of you worried we were going to
go extinct because of an asteroid hitting us, you can
rest a little easier knowing that NASA has our backs
at least against asteroids now, assuming something else doesn't do us,
and then the big question becomes, how do we survive
in the long term. It's possible that in the future
(22:33):
we might run out of resource this year on Earth,
and in that case, maybe asteroids can save us. There
are a ton of asteroids out there, but things that
we could potentially mine to bring back to Earth.
Speaker 2 (22:46):
But is that really feasible?
Speaker 1 (22:48):
Can we or should we mine the asteroid belt while
we come back. I'll ask doctor Plate this question, and
I think you might be surprised by the answer, so
stay with us. We'll be right back. Hey, welcome back.
(23:20):
We're talking about asteroids and pew. So far, we've learned
that while the Earth is getting hit by small asteroids
all the time, the likelihood of a big one coming
and ending the human race anytime soon is fairly small.
NASA and other space agencies around the world are keeping
track of all the big asteroids in our Solar system,
(23:40):
and even if a medium size one comes our way,
we are getting better at reaching them and deflecting them. Now,
the question is good asteroids actually be good for us?
A lot of people have noticed that asteroids in the
asteroid belt are full of materials that we meet here
on Earth, and so a possible is for us to
(24:01):
go out there and mine them. But is that a
good idea? Should we send a spacecraft out there to
check out the metals and minerals and those floating space rocks.
Actually it furs out we already have.
Speaker 3 (24:17):
There's a current mission NASA launched called Psyche, which is
on its way. The asteroid's name is Psyche. It's this
big asteroid. It's one of the biggest ones, and we
think it's mostly metal. And when we say metal, we
mean iron, nickel, and mostly silicon, and then a lot
of lesser ones titanium, tungsten, aluminum, Platinum, for example, is
(24:38):
very valuable on Earth and it's used in electronics. It's
very important metal for a lot of reasons. Palladium is
another one. And it's not like these are abundant in asteroids,
but they are out there. And so if you could
take an asteroid and grind it up and extract these metals,
you could then sell them on Earth and make a
lot of money.
Speaker 1 (24:56):
Yes, you could technically mine asteroids and bring back their
precious metals and sell them for a lot of money.
Speaker 2 (25:03):
So why don't we do it?
Speaker 1 (25:05):
I mean, sending a spacecraft to an asteroid is hard,
but we've done it before. In fact, we've managed to
get to flying asteroids several times. In the nineteen eighties,
we sent fly spacecraft from three space agencies around the
world to get a close look at hay Least comment.
Since then, there have been about a dozen more missions
(25:25):
that were sent to either fly by or actually land
on comets or asteroids.
Speaker 2 (25:31):
But here's the thing.
Speaker 1 (25:32):
Getting to an asteroid to mine it is not the
main problem. The real problem is bringing back what you mind.
Speaker 3 (25:42):
The big step is you then bring these things back
to Earth. But bring it back to Earth it's not straightforward.
You have something that's moving eight kilometers a second. If
it's coming from deep space, it could be doing twice
that fast. You have to slow this thing down and
then somehow get it to the surface of the Earth
in quantities that are usable. Right, if I'd drop a
pound of platinum on the Earth, that's not really going
(26:02):
to help. And you can just drop that from orbit,
let it hit. It'll actually lose a lot of it.
You could encase it in concrete or something whatever, let
that burn off as it goes through the atmosphere. But now,
if you're talking about one hundred tons of something, how
do you get that to the surface.
Speaker 1 (26:16):
That's hard without basically creating a giant asteroid that will
kill people on Earth.
Speaker 3 (26:21):
Yeah, you could build some sort of machinery that would
slow these things down and drop them for more of it,
but that's also very expensive, and to do this at
scale where you're talking about you know, a building weighs
tens of thousands of tons, so you need a lot
of this material to build a rocket or to provide
for the electronics industry or whatever. And right now it's
(26:43):
just cheaper to keep doing this on Earth. Some day
it might be easier to do this. We're just not
there yet.
Speaker 2 (26:51):
That's right.
Speaker 1 (26:51):
Getting things from space to Earth is hard, or at
least it's easy. But the hard part is having what
did drop from faith Land in one piece. And even
if you do manage to figure out how to, say,
bring all those precious metals from asteroids to Earth, there
could be other things that can happen that you didn't expect.
Speaker 3 (27:12):
There are other problems like crashing the market if you
suddenly introduce a vast amount of material into the market.
You know, the reason these things are expensive is because
they are rare, and if you bring in a lot,
there's more than one hundred tons of gold out there,
but if you bring in a lot, it could actually
damage the market. This, I can't stress this enough, is
super super hard to do. We do not have the
technology in place to do this. We have the technology
(27:35):
where we can start looking at it and investigating it
and doing this step by step. But right now, if
you wanted to mine an asteroid, I think you're looking decades.
I don't know how many to at least, but it's
going to be a while. I may be wrong.
Speaker 1 (27:50):
So mining the asteroid belt for materials to bring back
to birth is a bit of a hard sell. Or
at least, you'd have to be really, really really desperate
to make it worth all that money and development and
risk to do it. But according to doctor Playd, there
is one other reason we might want to mine the
(28:10):
asteroid belt that is not about bringing stuff back to Earth,
and that is for space exploration.
Speaker 3 (28:20):
If we want to build a space station on Earth,
we have to build it down here, all the pieces,
and then launch each piece into space and put it together.
And that takes a long time. It costs a lot
of money. The space station International Space Station was one
hundred billion dollars and took ten years to complete. Something
like that. The rocket launches are expensive. Takes a lot
of energy to move those things out of Earth's gravity
(28:40):
into orbit or off the surface. If you mind an asteroid,
it's out there in space already. Oh and if you
can figure out a way of processing it, smelting it
and processing it in a way that you can use
it to build structures, that is a lot, lot, lot
easier than trying to lift everything off of Earth. And
so this is something that people looked into them.
Speaker 2 (29:00):
I see, it's like it's possible.
Speaker 3 (29:03):
Yeah. I don't think there's anything physically or in an
engineering sense impossible about any of this. You can imagine
building a factory around an asteroid, using it, having it
spin for centrifugal force, which is like gravity, and that
you can use to separate out metals.
Speaker 2 (29:18):
I see.
Speaker 1 (29:19):
Okay, so let me see if I can recap so
the idea of going to an asteroid mining it to
bring back material like rare earth metals technically possible, but
maybe not worth it.
Speaker 3 (29:30):
Questionably profitable, Yeah.
Speaker 2 (29:32):
Questionably profitable, I mean maybe just not right now. I see.
Speaker 1 (29:37):
But then there's sort of the other reason why we
might mind the asteroid belt, which is for space exploration,
Like if we wanted to, we could use it as
a source of metals to build spacecraft and space stations
and there. It's not so much a business consideration, it's
just like if we want to do it or not.
Speaker 3 (29:54):
Yeah, I mean it's a sort of government level idea. Yeah,
if you wanted to explore the outer planets, if you
want to put humans out in space on Mars, for example,
where some of these materials are scarce. Then yeah, going
to the asteroid belt and figuring out how to do
all this is not the worst idea.
Speaker 2 (30:12):
In that case. Maybe it's the cheaper option.
Speaker 3 (30:14):
Rather than lifting it from Earth. Yeah, because right now
it still costs a lot of money per kilogram to
just send air, water, food to people living on the
Moon or Mars. If you could start in space already,
it's vastly easier. You're getting rid of some majority of
the cost of just launching something off Earth is so
(30:36):
expensive and hard. If you're starting in space, it's way easier,
and so it's a lot simpler technologically, and it's a
lot cheaper, a lot less expensive.
Speaker 1 (30:44):
So the asteroid belt could become like the wild West
of the space frontier. And here's the interesting thing. Most
people assume, like I did, that the most valuable materials
in the asteroid belt that we would want to mine
are the metals and the like iron or copper. But
actually the most important raw element in them is wetter.
Speaker 3 (31:09):
This wasn't known until relatively recently, a few decades ago,
that asteroids can have a lot of water in them. Oh,
what series for example, has a mountain on it that
seems to be salty water from the interior that oozed
out and froze in place, and it's a mesa. It's
like this big flat topped mountain. It's huge, and it's
(31:30):
made of dirty ice, basically dirty salt water ice. Whoa.
So these things do have water, and you need water.
Water is the most useful thing you can have in space.
You drink it. We need that to live. You can
break it down and make oxygen to breathe. Water is
h two Oh, it's hydrogen and oxygen together. You can
recombine these to make hydrogen peroxide, which in its pure form,
(31:51):
not like the stuff you buy at the drug store,
which is like three percent.
Speaker 2 (31:54):
You can diyur hairt space.
Speaker 3 (31:56):
Yeah. Yeah, it's like you know, it's three percent hydrogen
peroxide and the rest of its water, and it's more
pure form. It's like ninety percent hydrogen peroxide. It burns
and it becomes a really good fuel. So you can
drink it, you can breathe it, and you can move
around with it. So water is it, that's what you want.
It's actually the single most important thing if you want
to have a permanent presence in space. Water is the
(32:17):
most important thing besides you know, food, but even more
than food, because again with water you can make air and.
Speaker 2 (32:24):
Fuel right right, the grow food, you need water as well.
Speaker 3 (32:27):
Yeah, humans need a lot of water just to survive
because of not just our direct needs but also our
needs like growing plants and protection from radiation. Water is
great at absorbing radiation, so you can encase your ship
in a tank of water and protect it from solar
flares and such. So it's all around. It's just like
the most useful thing ever in.
Speaker 1 (32:46):
Space, right, and you need it to shower if you
were so inclined to shower in space, Yeah, that would
be a good.
Speaker 3 (32:52):
Idea too, although who knows, you know, by then we'll
have sonic showers like in Star Trek. Who knows it's
out there. There's lots of their comments that are mostly
water asteroids. There are moons of Jupiter and Saturn that
are mostly water. Those are harder to get through than asteroids.
But still there's a lot out there plenty for everybody.
Speaker 1 (33:11):
Yes, it turns out the real question we should be
asking it's not whether we should mine the asteroid belt,
but whether we should drink it. Hey, this puts a
whole new spin on the phrase meteor shower. All right,
Hopefully this all gives you a good sense of what's
out there sprinkled in our solar system that could hit
us or potentially save us as we keep traveling through
(33:35):
the vastness of space. Thanks for joining us. See you
next time.
Speaker 2 (33:44):
You've been listening to Science Stuff.
Speaker 1 (33:45):
Production of iHeartRadio written and produced by me or Hey
Cham edited by Rose Seguda, Executive producer Jerry Rowland, an
audio engineer and mixer Casey Peckron, and you can follow
me on social media to search for PhD comics and
the name of your favorite platform. Be sure to subscribe
to Sign Stuff on the iHeartRadio app, Apple Podcasts, or
(34:06):
wherever you get your podcasts, and please tell your friends
we'll be back next Wednesday with another episode. Hey, please
take a second and leave us a review on Apple Podcasts, Spotify,
(34:27):
or wherever you listen to the podcast.
Speaker 2 (34:29):
Thanks a lot,
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