Asteroids

This BBC podcast is supported by ads outside the UK.

What's going on, California?

It's Bluff here.

You know what's better than a relaxing day at the beach?

A relaxing day at the beach with SpinQuest.com, America's number one social casino, with over a thousand slots and table games available to the comfort of your own phone, with instant cash prize redemptions, and new users get a $30 coin package for only 10 bucks.

That's SPINQUEST.com.

I'll see you there.

SpinQuest is a free-to-play social social casino.

Voidwear Prohibited.

Visit spinQuest.com for more details.

Want to stop engine problems before they start?

Pick up a can of C-Foam Motor Treatment.

SeaFoam helps engines start easier, run smoother, and last longer.

Trusted by millions every day, C-Foam is safe and easy to use in any engine.

Just pour it in your fuel tank.

Make the proven choice with C-Foam.

Available everywhere.

Automotive products are sold.

Safe home.

Hey there, it's Ryan Seacress for Safeway.

Feel good and look good this summer with savings on your personal care favorites and earn four times points.

Now through September 9th, shop in-store or online for items like Dollar Shave Club Razors, Hydro Silk Razors, and Edge Shave Gel.

Plus some favorite brands like Tampax Pearl, Depend, and Poise to earn four times points to use for later discounts on groceries or gas.

Hurry in before these deals are gone.

Offer end September 9th.

Restrictions apply.

Offers may vary.

Visit Safeway.com for more details.

You're about to listen to the Infinite Monkey Cage.

Episodes will be released on Wednesdays, wherever you get your podcasts.

If you're in the UK, the full series is available right now.

First on BBC Sounds.

Hello, I'm Brian Cox.

I'm Robin Inks, and this is the Infinite Monkey Cage.

Now, my favourite is 624 Hector, while Brian's favourite, I believe, is 4179 Tutalia.

Go on, what are you talking about?

I am talking about

anyone know what that is?

Oh, there we go.

What do you reckon?

Because Brian, you haven't got a clue, have you?

It is the arcade game Asteroids.

Now, I was not intending to do the noises.

We were going to use a recording.

But it turns out, Atari are very litigious, even with their games from 1979.

So I've had to end up becoming like a cheap version of Michael Winslow from Police Academy.

It's genuinely true.

We were told the BBC cannot afford the licensing fee of the beeps.

So I literally,

when we were writing, I just went, what, we can't afford the bew, bew, boo, bo-coo, bo-coo, and they went, that'll do.

So, yeah, asteroid, my favorite, by the way, my favourite asteroid is 18610 or 18610, Arthur Dent.

That is such a guy.

Arthur Dent.

Three and a half kilometres in diameter, middle of the asteroid, belt, dressing gown.

He's a 85 Bieber box one, which is like a twin asteroid going around themselves.

Yeah.

So, what are we going to be asking today?

Well, today we're asking what are asteroids, what is their composition and history of formation, and what can we learn from them about the history and formation of the solar system as a whole.

And of course, we'll also be talking about whether they will be the ultimate death of civilization, possibly within two to three years.

That's because the BBC said that people listen to shows more often if there is a greater sense of jeopardy.

So that's not scientifically accurate.

It's just for the nature of storytelling and it's also for any fans of Armageddon, obviously.

Again, we were going to have a bit of Aerosmith there.

I'm going to play.

They're very litigious as well.

So the best we can.

Loving an elevator!

Litigant in Armageddon.

I'll admit, it's not the one in Armageddon, but I think it's better, Loving the Elevator.

I don't like their ballads.

Well, to guide us through the asteroid belt, we're joined by a professor of planetary science, an astrophysicist, and perhaps most importantly of all, a Time Lords companion.

And they are.

Hi, I'm Alan Fitzsimmons.

I'm professor of astronomy at Queen's University Belfast.

And my day job is studying asteroids and other things orbiting the sun out there beyond the Earth-Moon system.

And over the years, I've looked at and discovered asteroids that come close to a planet.

And I'm kind of thinking that if there's a silver lining to an asteroid impact, it would be that we'd never again hear the phrase X, formerly known as Twitter.

So true.

So I'm Professor Sarah Russell, and I am from the Natural History Museum here in London, where I study meteorites.

So most meteorites come from asteroids, so they're the objects that Alan studies when they're floating in space, when they've landed on Earth.

And I think the silver lining to having an asteroid crash into the Earth would be loads of new meteorites for us to study.

I'm John Bishop, I'm a comedian.

I used to play a computer game called Asteroids, and I'm a big Aerosmith fan.

And I think if there's a silver lining of an asteroid hitting Hair, it'll mean that we never have to watch another film where an American who's got a dubious personal life going on somehow saves us from an asteroid hitting the earth.

That's an extra!

So, let's start off with, we will start with the definition, which is what is an asteroid?

Because I think people think of so many, you know, when you think of asteroids and meteorites, and we think of meteoroids, and we think of shooting stars, and we think, and I think people get very confused by all this thing.

So, what is the definition of an asteroid?

Well, an asteroid is really anything that's smaller than a planet made of rock orbiting the Sun.

Now, that means we can go from the largest asteroid, which is the asteroid Ceres, that's 933 kilometers in diameter out there between Mars and Jupiter, all the way down to about something about a meter across.

Anything smaller than a metre across, if you can't put your arms around it, it's probably not an asteroid anymore.

It's just a boulder or meteoroid or something like that.

We've got over a million of these objects now discovered by astronomers all between

those two planets.

So most of them are quite far away and because of their size they're quite small.

So the word asteroid comes from star-like and it's because even with a decent telescope the asteroids just appear as points of light.

You can't see any details on them.

It's only with the largest telescopes we have on Earth that you can see anything else than just a star-like object.

So Sarah, are all the asteroids in the asteroid belt?

No, they're not.

So most of them are in the asteroid belt, but some of them are closer to Jupiter, and some come into the innermost part of the solar system.

So there's this whole group of objects called the near-earth objects, and these are the ones that we have our eye on as potential impactors to the Earth.

And they can potentially make meteorites.

So a meteorite is any extraterrestrial natural object that falls onto the surface of the Earth or another planet.

And are there any further out than Jupiter?

Yeah.

The further out you go, you get to something called the snow line, where things get colder as you go further away from the Sun.

So they become more and more icy, and then they sort of morph into this other kind of body called the Kalperbelt objects, which sometimes come into the innermost part of the solar system as comets that we can see with the tails.

So where's the edge?

If I said to you, where is the edge?

Where's the edge of the solar system?

How far do you have to go before you say we're no longer in the solar system?

Yeah, probably about a tenth of the the way to the nearest star, but we have what's called the Oort cloud.

And knowing that structure of the solar system from where the asteroids are in the inner solar system out to the cometary region, that's how we

decipher what's happened to our solar system over the four and a half billion years.

We used to think that the solar system was kind of regular.

You had all the eight major planets and Pluto in kind of

fairly regular orbits and then a lot of flotsum and jetsum.

But it turns out that by looking at that flotsum and jetsum, particularly the asteroids, we now now understand that the early solar system was mad, basically.

The planets were going everywhere.

Jupiter moved in, Jupiter moved out, Saturn moved in with with

Jupiter a bit of a lobstick that moved out.

And all of those processes through the the gravitational pulls of the planets went into sculpt the solar system as we see it today.

Well Sarah, you mentioned the the asteroid belt.

Now is it

is it a belt?

Is it like a sphere around Saturn?

Is it thin?

Is the asteroid belt everywhere?

Because can you fly past it, basically?

Yeah, well, it's shaped like a doughnut.

But even though, you know, when you watch kind of Star Trek and stuff, when you go through an asteroid belt, everybody's like getting kicked around by these rocks.

It's not really like that.

It happened to me and Doctor Who.

Very shaky.

Yeah, but actually, even though there's a belt of rocks, they're actually millions of miles apart.

So, several, like lots of spacecraft have been through it, no problem at all.

But then we've got the Oort cloud, which is not a belt, it's a cloud.

So, why is the Oort cloud a cloud, which is basically more spherical?

And the asteroid belt and everything else flat?

Well, there's two reasons for that.

First of all, when the objects in the Oort cloud, which there are probably both asteroids and comets out there, when that was created, it was created by Jupiter and other planets, throwing material out there in the the early days of the solar system.

And amazingly, once they get out there, they're traveling so slowly they can be affected by the gravitational field of the Milky Way galaxy as a whole.

And that spreads them out into more of this spherical cloud surrounding the solar system as a whole.

But that's a long way out.

And to be honest, it's so far out we've never seen it.

So we're kind of taking what we measure in the inner solar system and projecting what it's like out there.

It does raise the question, doesn't it, John?

Like, we've never seen it.

I don't know.

But it's a big

structure.

I listen to this podcast, and the amount of times you have people on talking about stuff that no one's ever seen,

to be honest with you.

It's the most made-up podcast

in the world.

Oh, I don't know if you hear some of the ones about economics, you might find out.

So, Sarah, how do we infer that there's this giant structure?

As you said, the tenth of the way up to the nearest star.

How do you infer that?

Yeah, so occasionally, objects from this Oort cloud come into the innermost part of the solar system.

They can have quite an eccentric, chaotic orbit.

And when they come into the innermost part of the solar system, we can see them as comets.

And then when we look at the trajectory to see where it's come from, we realize it's come from way out of the solar system.

But just an answer to John, I would say

the great thing about asteroids and meteorites, which are mostly from asteroids, is that they are a part of astronomy that you can actually see and hold and measure in the lab.

So

it's a very sort of

we can visit the natural history museum, John.

So when you say you can hold them, like from your experience, what was the first one you ever picked up and what did that feel like?

I was at university and I had just been to a lecture about meteorites and was told this was four and a half billion years old and it absolutely blew my mind that I was got a chance to hold something that was older than the Earth and not only that but they contain tiny grains inside them that are older than our whole solar system that they formed in stars that were ancestors to our solar system.

I just wanted to ask Sari you gave a very specific number there, a date.

So you said these things that we find on the ground here that we have in the Natural History Museum are some of them are older than the Earth, and there are grains in there that are older in the solar system.

How do we know?

These are very, very tiny grains inside meteorites.

They're only.

You can't actually see them, and we're still not sure.

You can see them, actually, Robin,

if you have an electron microscope.

So, yeah, they definitely do exist, and they have isotopic compositions that match what you would expect a red giant to produce or a supernova to produce.

So, they have compositions that are just way beyond what we find in our average solar system.

So you see a small grain and it has essentially the composition of an exploded star.

Exactly.

Not a form.

Oh, you explain it so much, Prada Brunt.

No, I do.

Exactly.

And how do we put the date on these things?

So we can measure the age of the meteorite really accurately and we date them by looking at radioactive isotopes inside them.

And when I think of how many people seem to have a problem with understanding the length of the life of the universe or indeed of the existence of the solar system, there is something, isn't there, in having something tactile and having something that you can hold?

A lot of astronomy is kind of very kind of conceptual and it can be quite difficult to grasp, but if you have something that you can literally grasp in your hand and think this came from space, I think that's very powerful.

How many fall to the earth every year?

It's relatively common, isn't it?

Good shit.

We've got a lot of them.

We've got about 70,000 in our collections around the world.

About a dozen or so are reported every year, but there's a load more than that that fall that are not collected.

What would be the common size of something that actually lands on Earth?

Well, the vast majority of material that lands on Earth is actually in the form of dust.

So every time you see a shooting star, that's a tiny

sand-like particle that's coming through our atmosphere and just burns up.

And we think that about 40,000 tons of material every year comes to Earth that way.

So the Earth is still growing every year.

it gets bigger because it's getting all of this extraterrestrial material.

But the larger ones, long ones that are big enough to pick up, that happens only a few times a year.

The number of samples you've got at the Natural History Museum.

And there must be times where you break someone's heart.

There must be times when you go, I think that must be from next door's patio.

And you're obviously not getting on with your neighbours, they're throwing things, they're getting the cat out of the garden or whatever.

I can't tell you how often I've had that conversation.

So we get loads of people all the time who think they've found a meteorite.

And yes, sometimes it is like half a brick that obviously their neighbours have thrown, tossed over the fence or whatever.

The worst or most heartbreaking times for me is when people come and say, you know, this has been in our family for generations.

My great-great-grandfather's a lot of people.

This is like the anti-gold shop.

Yeah, it's awful.

But yeah, the real meteorites don't happen very often.

So one fell in the UK in 2021 and that was the first one for 30 years.

So it doesn't happen very often.

Was that the one in no which was one the Cotswolds?

Yes, exactly.

That was Winchcombe.

Made a dent in someone's drive, didn't it?

It did.

And scattered all over the land, but it was in lockdown.

So all the pieces.

Well, why did it get such a silly name?

What's the name?

Well, it's called Winchcombe, so all meteorites.

Just give the name of the town.

The BBC.

The BBC.

John, you know, how often I go to Cotswold, the BBC would like to apologise to everybody.

John's agent went, we've cancelled the gig in Winchcombe and also Cheltenham and Gloucester.

Just to be safe, John, just to be safe.

Meteorites are always named after the place where they land.

They're always named after the place that they land.

So they're like wombles, they have geographical names always.

Could I just ask, you know, when you look at.

I never realised that about wombles.

Oh, I love it in a series where I really learned something.

You know, when you look at them, is there anything within the structure of meteorites that is not identifiable as anything relatable on Earth?

It has all the same elements as on Earth.

So the periodic table is the same everywhere.

So it has the same elements, but they can combine together to make different minerals because they formed at different pressures and temperatures.

So they often contain minerals that we don't find on the surface of the Earth.

And also, they tend to contain a lot more metals.

And

that's not because they have a lot of metals, it's because the surface of the Earth doesn't have enough metal because it's all sunk to form the Earth's core.

Alan, what can the composition of these objects tell us?

Why are we so interested in them scientifically?

Well, the important thing for asteroids out there in space is that when we look at the asteroid belt, there is what we call a compositional gradient.

That if we look at asteroids in the belt closest to Mars, they are pretty stony.

If you pick up a stony meteorite, one of Sarah's stony meteorites and compare it with a rock from Earth, it's not that dissimilar.

It feels a little bit heavier because, as Sarah said, it has more metals in it.

But you've got to have a practised eye to actually tell the difference, as we've heard.

But as you go further out in the asteroid belt, as you approach the planet Jupiter, we find that their makeup changes.

We see that they have progressively a lot more lighter elements, such as carbon, in them, and so they progressively become darker.

And that's telling us something about the structure of the planetary system in its first days of formation.

That nearer the Sun, we had very generally denser elements because all the heat from the newly born Sun was actually driving away the lighter atoms.

But as you go further out in the solar system, you managed to retain more of those lighter elements.

So you get a much clearer idea of the primordial composition of the material from which our solar system formed.

And that's that's pretty important when we want to go back in time and find out exactly what was the process by which our solar system came into being and what was here at that time.

So, actually, seeing these different types of asteroids and linking them to the types of meteorites that Sarah studies is actually really, really important.

It gives us this global picture of the current structure of our solar system and what it was like back then at the solar system formation.

And what are the specific questions?

We're going to talk about these two missions that you're both involved in, which are going to asteroids.

So, what are the very specific questions you ask?

When you're planning a mission, you say, Right, we're going to go to that region or that particular asteroid.

What are the questions that you want to answer?

Well, a lot of the time it can be linked to that formation and origin process.

If we're going to an asteroid, how did that asteroid get there?

And how can we explain its structure and its composition, given what we think we know about the history of the solar system?

So to give an example, the asteroid that

recently had samples returned from it, asteroid Bennu,

and Servas part of that analysis team, that's an asteroid with a lot of carbon in it.

So we believe that that asteroid originated further out in the solar system.

And so it's given us a much clearer idea of what the material, what material was there when it wasn't affected from being too near the sun?

Could you talk about the OSIRIS mission a little bit?

Because it's quite an ambitious thing to do, isn't it?

To go to an asteroid, get some stuff, and bring it back.

Yeah, it's been an amazing mission, Brian.

So, this is a NASA mission that launched in 2016.

It went to visit asteroid Bennu, which, as Alan said, is a carbon-rich asteroid.

And Bennu is only 500 meters across, so it doesn't have very much gravity or anything.

So, it's basically the spacecraft was kind of flying with Bennu rather than in orbit around it.

And it spent some time going around Bennu, getting lots and lots of data.

And then it did this maneuver called the touch-and-go maneuver, where this arm came out into the surface, grabbed some of the rubble on the surface of the asteroid, and then brought it back to Earth.

So it came back to Earth in September 2023.

Who picks where to grab?

Because we've all grabbed in the wrong place.

Speak for yourself, John.

It's the first time we've directly had a cancellation in the show, isn't it?

But seriously, you know, if you were to say, just grab a beach,

you could grab something worthless or something.

Well, you were thinking of those grabber things, aren't you?

Yeah, that's what we know.

I thought, you know, in the end, it came back with a soft toy.

I've been hoping it was going to get that bottle of wine with the tenor wraps around it.

There was an amazing amount of debate in the team to decide where to actually sample.

So engineers always want to go to like the safest possible place and the scientists want to go to the most exciting place and then they have to find something.

But within that 500 meters of mass.

Yeah.

What's so different about that small space?

Well,

we got there, we were amazed.

So first of all, we thought that the surface was all going to be sort of powder, like

the astronauts walking on the moon walk on this sort of very fine-grained powder.

But actually, it was full of boulders and it was full of craters,

and there were darker bits, and there were lighter bits, and there were like these big veins of white stuff going through it.

So, there was loads of interesting stuff going on.

It was also what we call an active asteroid.

So, every so often, some stuff would spurt out of the center of it and just go into space.

So,

it was a really interesting asteroid.

Did you know what the white stuff was?

Was that part of the grab?

We do have some white stuff that we have grabbed, yeah.

So not every sentence as this is going to sound as scientific as it is.

Someone's just tearing it off.

It sounds like we're talking about washing powder, doesn't it?

What is it?

What is it?

It's not classé drugs.

What is it, actually?

Not class A drugs.

Oh, sorry.

No, no, no, that's fine.

Because I can imagine it's, you know, you're going to get bored.

You've got a lot of waiting around, isn't there?

You've got to keep the energy up.

And that's another cancellation on the show.

I wasn't expecting two in a row quite so fast.

Yeah, so the white stuff, we realized quite quickly there was a lot of this material called carbonate, which is a rock that forms

under the action of water.

So the cliffs of Dover are made of carbonate material.

But one of the surprises when we got the material back is there's another white mineral in there, a phosphate mineral, so we're still trying to work out what that means.

But it also probably formed through the action of water.

And one of the most beautiful things about this mission, which is like all space missions, is that it discovers things that you didn't expect or didn't predict.

So, when Osiris Rex went down to do its grabbing,

what they found out had happened afterwards was that

when the sampling mechanism went down to touch the surface, it didn't stop.

It just went straight through as if it wasn't there.

And if it hadn't been pre-programmed to fire its thrusters, the whole spacecraft could have just buried itself in the asteroid.

But that actually tells us something about the structure of this asteroid.

It tells us it's very porous and it's almost, well, what we call a rubble pile asteroid, in that it's composed of little bits of smaller asteroid that really are very weakly held together.

And you better be careful if you want to put on a space suit and jump onto an asteroid, because you could end up just going straight through it and out the other way.

This is really strange, because you're painting a picture of of this, as you said, a rubble pile.

How do you get liquid water in a pile of rubble?

Because it wasn't always a rubble pile, so we think it was it was it had a parent asteroid, or maybe more than one parent,

probably out in the outermost part of the solar system or beyond Jupiter originally.

And there there could have been liquid water, so it wouldn't have been quite so porous.

But then that got disrupted and

probably was hit by something and then re-accreted into this loose.

It's Bretzky, baby, and I don't know why they let me on the radio, but I do know you're in California, which means you can play on spinquest.com with over a thousand slots and table games absolutely free and with the ability to win real cash prizes with instant redemptions.

Your first $30 coin package is only $10 today.

Hurry up, spinquest.com.

SpinQuest is a free-to-play social casino.

Voidwear prohibited.

Visit SpinQuest.com for more details.

Want to stop engine problems before they start?

Pick up a can of C-Foam Motor Treatment.

C-Foam helps engines start easier, run smoother, and last longer.

Trusted by millions every day, C-Foam is safe and easy to use in any engine.

Just pour it in your fuel tank.

Make the proven choice with C-Foam.

Available everywhere.

Automotive products are sold.

Safe home.

My story goes, drug addiction.

I ended up getting clean.

Okay.

And so throughout that process of getting clean, I started volunteering for the state prison and carrying the message of recovery.

You know, you meet a lot of people, right?

And convicts need a chance too.

And so giving these guys a chance was an opportunity for me.

They absolutely have turned their life around and made a difference.

Season two of Beyond the Moon, a Ditch Witch podcast, is streaming now on your favorite podcast platform.

Subscribe or download and listen today.

Hey there, it's Ryan Seacrest for Safeway.

Feel good and look good this summer with savings on your personal care favorites and earn four times points.

Now through September 9th, shop in-store or online for items like Dollar Shave Club Razors, Hydro Silk Razors, and Edge Shave Gel.

Plus, some favorite brands like Tampa's Pearl, Depend, and Poise to earn four times points to use for later discounts on groceries or gas.

Hurry in before these deals are gone.

Offer on September 9th.

Restrictions apply.

Offers may vary.

Visit safeway.com for more details.

Sprubble pile.

People have hypothesized that the asteroids could be a stepping stone to further space travel because if you could land on one, there'd be enough water resource to be able to take off.

Or is that just science fiction?

Yeah, no, that's absolutely not science fiction.

So,

yeah, one of the aims of the Aceris-Rex mission was to investigate asteroids for use as a potential resource.

And although it doesn't have liquid water anymore, it still has water trapped in its minerals.

So it's mostly made of a clay mineral.

So it's basically like a mud, and it's got about 10% water in it.

So that's something that you could use as a gas station if you're going through space and you needed to stuff.

Did you say mud, clay-like mud?

Yeah.

So you could take a kiln as well.

And once you were all

in a little vase to take home.

So I was always under the impression until I started looking at the asteroids that the water is a rarity in space.

But what it seems to be that it's it's everywhere except

where we've been looking on Mars and people.

Those dowsers weren't as good as we'd hoped they'd be sent up, were they?

Yeah, absolutely.

So H2O is two of the most common elements in the universe.

But yeah, Mars has kind of dried out though, unfortunately.

Well this brings us to future missions, and also maybe you could talk a bit about the DART mission, because Robin was talking about Armageddon moving asteroids that they're coming towards the Earth.

Well, DART was the

first experimental test of a technology we might use to deflect threatening asteroids in the future.

Really, instead of darts, maybe it should have been called billiards, because we know that if you hit something with something else,

that something else will move.

The whole point of DART was seeing: Could we deflect an asteroid to change its path?

Now, we could try that with an asteroid just orbiting by itself around the Sun.

But then you've got a problem about measuring exactly how much did you move it.

It's much easier, it turns out, if you move the moon of an asteroid

that's going around it, because then you can actually see how that moon's orbit changes.

And also, you don't have the problem of maybe knocking the main asteroid onto a collision course with the Earth.

All you do is change the orbit of the Moon, which is a good thing.

If the big thing that we're worried about is an asteroid hitting the Earth and everyone accepts that that's what killed out the dinosaurs, did that asteroid strike change Earth's orbit?

It may have done, but at such a small level it would have been immeasurable.

All the effects of the dinosaur killer 66 million years ago were really on the surface of the Earth.

The Earth as a planet didn't really notice.

It was the poor things living on the surface of the planet that actually did notice.

You know,

they didn't have a very good day of it, to be completely honest.

Now,

but the important thing is, of course, dinosaurs didn't have a space program.

We do.

So that's why DART was launched by NASA to do this first test of could we move a small, even a small 160-meter diameter asteroid.

And by gun, they moved it.

It was a fantastic situation.

Just to set

the stage, so 160-metre asteroid coming in at the right angle.

What kind of a threat would that be?

Okay, well, let's play that favourite game then.

Let's have the

asteroid have a projected impact point of, say, BBC in London.

You work for the Daily Telegraph, yeah.

So you lose the BBC,

you lose London,

and you lose the home counties.

Really?

That would be.

Interesting to notice it had an effect there.

Didn't care about Berber.

The BBC, didn't care about London.

Berkshire.

Tumbridge.

Oh.

So that's a massive reduction in the sale of Gillettes.

And that's the strangest.

The good news is Winch comes safe.

And that's the strangest thing about these movies and TV shows about asteroids heading towards the Earth.

The asteroid that participated in the extinction of the dinosaurs was only 10 kilometers across, and it had global consequences.

We believe the threshold for global consequences is an asteroid only one kilometer across.

And because these things are traveling so fast, it's the kinetic energy of the asteroid.

Imagine something the size of a small mountain moving at 15 kilometers per second, 10 miles per second.

What happens basically is that when it hits the ground, it gouges out a crater on the Earth's surface, and all that material that used to be on the Earth's surface is thrown up into the stratosphere and immediately starts global cooling, disrupting the food chain.

And the last simulations I saw that was that if we had a one-kilometre asteroid hit the Earth,

then it's a possible mortality rate of 25% of the Earth's population within one year because of just farming is not happening anymore.

So that's the bad news.

That's lifted the rumour.

There's good news.

The good news is we've pretty much found all of those one kilometre and larger asteroids over the past 20 or 30 years through dedicated astronomical surveys, and they're not coming towards us for at least the next hundred years.

So we don't have to worry about it.

100, 200, 300 meters would be devastating for a city or a country, a region.

So of those,

how many do we do we think we have?

There's a number of ways to calculate this number using the telescopic surveys we've been doing over the past 20 or 30 years.

And both of those techniques really converged on the same number that

for the

going down to about, say, 120 meters across, because you do the calculations and it turns out that if you're smaller than 120 meters, you might or might not make it to the Earth's surface, depending on the composition of the asteroid and its structure.

Above 120 meters, no, it's going to make it to the ground and make a crater.

And

out of those, we've probably found about a quarter of them so far.

Has anyone staked a claim to the mineral wealth that's out there?

Well, that is, Sarah.

I mean, that is a a a big question, isn't it?

Which is I presume that private money is now kind of gets more and more interested the moment that you start talking about minerals,

about phosphates and all of those things.

And that is one of the big questions, isn't it, in terms of when do we get that who owns what in space?

Yeah, absolutely.

So there are billionaires now kind of planning their next big adventure of mining asteroids, and I think at the moment it's pretty much find us, keep us, but obviously that's going to have to change.

So we're going to have to really kind of rethink our ideas about who owns what in space.

So, at the moment, the laws are governed by the Outer Space Treaty, which was from 1967.

So, it's way out of date and really predates all of our explorations.

I'm not doing at the moment.

I love the fact that there's an outer space treaty before space 1999 was even on the telly.

In terms of

the mineral wealth, because it sounds like a lot of trouble to go to to do some mining.

So what are we talking about out there?

You know, as you said, it's very difficult to get out there.

What turn this?

Well, it's interesting.

NASA last year launched a mission called Psyche, which is going to an asteroid called Psyche.

They didn't think much about it.

But it's the largest metal-rich asteroid we know about in the asteroid belt.

And I think the estimate is that if you could take all the metal out and somehow get it back to Earth, it's, what is it, it's $100 trillion or something?

Ridiculously silly number.

It's more than the BBC license fee.

Oh, yet again, the undercover telegraph agent

pipes up with his agenda.

On a serious note, I mean, it is science fiction mining an asteroid.

So you're talking about metal on an asteroid.

The initial plans for using the resources in the asteroid belt go back to what we talked about previously, which is water, because when you take water, you can make rocket fuel out of it.

And the idea is that if you're going to explore and exploit the solar system, one of the problems is taking the fuel with you.

If you can create your own fuel for your engines out in the asteroid belt, then things do become a lot cheaper.

So it is initially this idea before we get into bringing back all the lithium perhaps and the rare earth elements that we might need for you know the future technologies.

Well well you said the word there, that's perhaps a bigger question.

You said the word exploit.

Is it right that we as what we know to be the only beings in the universe have the right to go and exploit or change the balance of it?

I don't know.

What do you think, John?

Welcome to the moral maze.

No, it's just that we've not been that great at looking after where we live.

Are we making life better?

We just go into space so that we have more stuff because we don't need more stuff.

I think, in fact, one of the things I would bring out is a rule that says no one's allowed to invent anything for the next five years whilst we all learn how to use the stuff.

I mean, but it is what I was thinking all the way through: is that bit where you people in Yorkshire, Nottingham, and Derbyshire, and other places going, yeah, we had all the mines closed in the 1980s because they weren't financially viable.

So now they're mining in the solar system.

Yeah,

I just wanted to ask, we've run out of time, but I just wanted to ask very briefly about the HERA mission because you've got a lot of badges that all say HERA.

So

what does that mission?

And perhaps just a very brief summary of the future missions that the HERA mission is the follow-up to the DART mission because the DART mission moved this small asteroid moon but in the process destroyed itself.

So all our views of what actually happened there came from our Earth-bound telescopes and the Hubble Space Telescope and so on back then.

And we really want to know how did that asteroid move, what happened to that asteroid.

So if we have to use this technology in the future

then we'll have a better idea of what's going to happen.

So here is the follow-up and it will launch in October this year.

It's an an ESA mission.

And rather than going directly there at high velocity, like the DART mission did, it's going to take just over two years to rendezvous with the binary asteroid.

And it's going to spend at least six months there flying alongside, measuring exactly what happened to that moon.

Even

basically, what shape is it now?

All our simulations imply that what the moon will see when we get there isn't quite the moon we saw from Dart because we gave it a pretty big wallop.

And while it's there, by the way, it will release two little CubeSats.

There'll be three spacecraft there.

It will arrive at the system in January 2027.

We're going to have six months of amazing images, finished by both here and at least one of the CubeSats landing.

on those asteroids and themselves.

So it's going to be great fun.

And then beyond that, we've got a whole bunch of other missions, of course.

We have a Japanese mission, the Hayabusa 2 mission, which has already returned

a small sample of the near-Earth asteroid to Earth, and it's en route to another two near-Earth asteroids.

OSIRIS-REx, oh this is brilliant, OSIRIS-REx is now called Osiris-Apex

because in 2004 astronomers discovered an asteroid called Apophis, which is named after the god of chaos.

Because we know that this fairly sizable asteroid, it's over 250 meters across, is going to regularly approach our planet.

And the next approach will be on Friday the 13th

of April 2029, when it's going to be so close that you can go outside in a clear, dark sky in England and watch it fly past the Earth with your eyes as a faint star.

And Osiris Apex will be pretty much there at that time.

And a couple of days later, we'll rendezvous with the asteroid to find out exactly what that close approach to the Earth did to Epophis.

The Earth's gravity will change the orbit of Epophis dramatically.

We also think it's going to change its spin, the way it's spinning as well, and it may even move stuff around the surface.

So, this is just an amazing mission.

And there's a whole bunch of other stuff because what we've understood from all the asteroid missions we've done up to now, again, is that every time we go there, we find something

new, something unexpected that we didn't expect.

And we think that's going to continue for many years to come.

I love that test, the fact that it's Friday the 13th.

That's almost the way of whittling down the team, isn't it?

Oh, not Friday the 13th.

That'll be unlucky.

You're out of the science group.

Sorry.

Yeah, and there's just so many exciting things coming up as well.

So, as well as all the missions that Alan was talking about, my favorite upcoming mission is

the Japanese mission called MMX, which is going to visit the moon of Mars called Phobos, which might be an asteroid, or it might not be we don't we don't know what it is so that's going to be really exciting it's going to bring a bit of that back to earth in a few years time I always felt I'm sure like other people did that asteroids were an accidental bit of rock rubbish in space you know they were just in the way on the way to all the planets and and I just think now that they are themselves a whole world that I or a whole system that I knew nothing about a whole science that I think is exciting well that's it again that's exactly exactly what we hope: is that you look at things and you go, wow, that's that each thing has such an intriguing life and

intriguing existence.

Anyway, we asked the audience as well a question, and we wanted to know: if Earth needs to be saved from an asteroid, who would be in your crack team to save civilization?

I've got here my wife.

She's always right, so no one would dare argue.

And her glares are powerful enough to change an asteroid's trajectory.

Thank you, Donald.

Who would be one support in charge of saving the the earth?

Anyone except the dinosaurs?

Bad track record.

Freddy Flint off a few beers and a bat.

Ian McKellen, as we would want the asteroids to pass.

Wait, weren't you just playing Ian McKellen's husband?

I was playing Ian McKellen's husband, yes.

I he he was uh he was mother goose, I was daddy goose.

That sounds worse when you say it out loud.

But that's effectively what happened.

That was your thing.

It wasn't a play, he just kept on calling me that.

Oh, I don't like this one.

Brian, because I would love to see him in a little spandex suit.

I'll tell you what, if you go on to OnlyFans, it's quite expensive, but you find him there.

Right, I've got Dwayne Johnson, as there isn't a celebrity named after its natural nemesis paper, the rock would at least guarantee a draw.

God, that's a long gag, isn't it?

Rishi Sonak, he knows all about missing targets.

This one says, My mum, she writes a good letter of complaint, but I don't see that would help, would it?

Again, very radio 4.

I will write a very strongly worded letter to this asteroid.

More Brian Coxes, Brian Cox, because he could smile sweetly at it and it would coyly avoid hitting him.

Professor Brian Cox all naked and stuff.

Well, that's all we have to do.

There we are.

Thank you.

Thank you very much to our panel.

Professor Alan Simmons, Professor Sarah Russell, and honorary Gallifrean, John Bishop.

Over the last few series, some of you might have noticed that as the series go by, there seems to be an increase in murderous intent in the subject matter, including, in fact, how to do the perfect murder quite recently.

So now, in fact, we're going to continue with that.

Next week, what we're going to do is we're going to learn about poison and how to do it.

Which I'm really sure, I'm not sure we should do that or not.

That's going to be very carefully handled.

It will be very, very carefully handled.

So we are going to leave you to think about next week's episode of Poison while you're enjoying the warm milk that your partner brings to you every evening.

Tastes of almonds, I don't know why.

Thank you, darling.

Good night.

In the infinite monkey cage without your trousers.

In the infinite monkey cage.

Now nice again.

Hello, Russell Russell Kane here.

I used to love British history.

Be proud of it.

Henry VIII, Queen Victoria, massive fan of stand-up comedians.

Obviously, Bill Hicks, Richard Pryor.

That has become much more challenging, for I am the host of BBC Radio 4's Evil Genius, the show where we take heroes and villains from history and try to work out were they evil or genius.

Do not catch up on BBC Sounds by searching Evil Genius if you don't want to see your heroes destroyed.

But if, like me, you quite enjoy it, have a little search.

Listen to Evil Genius with me, Russell Cain.

Go to BBC Sounds and have your world destroyed.

Want to stop engine problems before they start?

Pick up a can of C-Foam Motor Treatment.

C-Foam helps engines start easier, run smoother, and last longer.

Trusted by millions every day, C-Foam is safe and easy to use in any engine.

Just pour it in your fuel tank.

Make the proven choice with C-Foam.

Available everywhere, automotive products are sold.

Seafoam!