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Hello! And welcome you have downloaded

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the podcast version of Inside Science

0:53

first broadcast on the twenty First

0:55

of March. Twenty Twenty Four. This.

0:58

Week our focus is the widest

1:00

aperture out there are solar system

1:02

and beyond. Because I'm pleased to

1:04

say we're joined by Chris Lintott

1:06

professor of Astrophysics at the University

1:08

of Oxford, Gresham Professor of Astronomy

1:10

probably best known to many of

1:12

our listeners as a presenter of

1:14

the Sky at Night or two

1:16

radio purists you don't dabble in

1:18

Tv is that bloke off the

1:20

monkey cage astronomy specials. You can

1:22

answer any question about space at

1:24

Welcome to Inside. So as Chris.

1:26

Thinks it's it's good to be not argued start

1:28

know it's been around long enough. It's it's an

1:30

honorary radio program. Or yeah, yeah, you know what?

1:32

Yes for you've got the budgets of a radio

1:34

program. Right? And something I bought. Your

1:37

with me for the next half hour

1:39

for a good rummage through both the

1:41

history and the very latest discoveries in

1:43

a space themed show. Shall I tell

1:45

you what we got coming out? Yeah,

1:47

sure! We zooming in on Saturn's moon,

1:49

Titan to solve the mystery of what

1:51

created the massive genes that cover almost

1:53

a fifth of it surface to. Dial

1:55

or Love Titan. It's my favorite place.

1:58

rk and our moon,

2:00

talky of moons, commodity or communally

2:03

owned companion. We raise an eyebrow

2:05

at efforts to mine it. A

2:07

bit of space politics maybe. Yep, yep.

2:10

And we'll also be looking at twin

2:12

stars. They're born in the same cosmic

2:14

nursery and they ought to be identical.

2:16

We'll be hearing why some pairs aren't.

2:18

This just came out this morning. I was reading

2:20

this on the train, so it's good that that's

2:23

come up. Great, it's hot off the press. So

2:26

these topics are all within the scope

2:28

of your latest book and you've chosen

2:30

to write about the happy accidents that

2:32

help us discover so much about space

2:34

and what we know about it. It's

2:36

called Our Accidental Universe.

2:39

What grabbed you about the stories?

2:41

I think the thing that unites them and

2:43

it is really a set of stories of

2:45

discovery is that they're all fun. And

2:47

I think one of the things I really wanted to write

2:50

about was that discovering things in

2:52

the universe is a lot more fun than

2:54

I think we often talk about. We're often

2:56

quite serious when we talk about this. There's

2:58

the moment of revelation where we suddenly understood

3:00

the deep mysteries of the universe. Or there's

3:02

a film shot of people sitting

3:04

around a table worrying about an asteroid. And

3:06

actually a lot of astronomy is arguing with

3:08

friends, being confused, not knowing what the thing

3:10

that's appeared in the image that you've got

3:12

from the Hubble Space Telescope is. And so

3:14

I wanted to tell those stories. And as

3:16

I dug deeper, you discover that all

3:18

over the place that the best

3:20

discoveries, the most important discoveries, come from

3:22

the most interesting people having fun. And

3:24

so really that was the thing that

3:26

unites the book that talks about the

3:29

distant universe, nearby asteroids, things traveling through

3:31

the solar system. And as you said

3:33

Saturn, it's just this sense of

3:35

being surprised by the universe as a way of

3:38

understanding the cosmos. I

3:40

wanted to talk to you about what

3:44

we think about when we think about

3:46

a telescope, because so

3:49

much of what I think about

3:51

as the tool that helps us discover

3:53

stuff in space is essentially a tube

3:55

and you look down one end of

3:58

it. But there's also... a

4:00

lot that you can tell by listening to

4:02

space. Oh,

4:09

that's very high-tech listening to space. That's

4:11

actually a sound I recognise from a

4:13

space probe called Cassini that flew around

4:16

the Saturn system. And just

4:18

before it plunged to its doom, it

4:20

was studying plasma waves, so waves in Saturn's

4:23

atmosphere, caused by interactions with a small moon

4:25

called Enceladus that maybe we'll get to in

4:27

effect. And what you're hearing there is sort

4:29

of an audio representation of those waves. But

4:31

you're right, we get data in all sorts

4:34

of ways. So we can still look through

4:36

telescopes, though these days we tend to use

4:38

cameras because they can add

4:40

up light. They can take images over many

4:42

hours instead of your eyeball, which is processing

4:45

all the time. We can also use radio

4:47

telescopes. We can detect x-rays. And actually now

4:49

in astronomy, we can detect ripples in space

4:51

and particles. So we use all of this

4:53

information to try and understand what's

4:56

going on in this quite confusing cosmos we

4:58

find ourselves in. Your book

5:00

is full of characters. And one of

5:02

the ones I think your favourite is

5:04

a guy called Reba, who was for

5:07

a while the only radio astronomer. Can

5:09

you tell me a bit more about

5:11

him? Yeah, he was a radio engineer working in Chicago

5:13

in the 30s and early 1940s. And he'd heard some

5:19

star noise on the radio from a

5:22

previous astronomer called Karl Jansky,

5:24

who was also a distracted radio engineer who'd

5:26

worked out that you his antennae were picking

5:29

up signals from space or or founds from

5:31

space, I suppose. And Reba wanted to investigate

5:33

these, wrote to Jansky and said, Can I

5:35

have a job with you? And Jansky essentially

5:38

said, No, my bosses would rather I studied

5:40

interference and things on Earth. He

5:42

wrote to all the astronomers in the country

5:44

at the time in the US and was told that

5:46

this was not proper science and that astronomers use telescopes,

5:49

as you said, and looked through them and mapped the

5:51

sky. And so he built

5:53

the world's first radio telescope in his back

5:55

garden in Wheaton, which is in about 50

5:57

miles outside Chicago, he'd get to work. during

6:00

the day, he'd come back, he'd remove the

6:02

washing that his mother tended to hang on

6:04

the radio telescope, and then overnight he would

6:06

map the Milky Way. And he

6:08

was the person who discovered our galaxy. The Milky

6:11

Way is a spiral galaxy. He found radio emission

6:13

coming from its centre, which we now know is

6:15

associated with a black hole. And

6:17

essentially no one took him seriously. He tried

6:19

to publish these results and he was basically

6:21

pursued by the establishment, despite

6:24

the fact he'd invented this means of

6:26

doing radio astronomy. And radio

6:28

astronomy you can do during the day

6:30

because it doesn't need the darkness. You

6:32

can. He had, as well as

6:34

having a day job, which was problematic,

6:36

he also realised that cars

6:38

of the time, their starter motors, emitted radio

6:41

waves. And so he needed to wait for

6:43

everyone else to stop driving around. And he

6:45

eventually got a job after the war, as

6:47

radio astronomy took off in this

6:49

country with Jodrell Bank and elsewhere. He did

6:51

get a job thinking about new radio telescopes,

6:53

but decided he'd rather be his own man,

6:56

move to Hawaii and then Tasmania, and essentially

6:58

spent the rest of his life building his

7:00

own telescopes. At one point he

7:02

did try to get hold of an ICBM,

7:05

a missile, to fly above the telescope and

7:07

alter the Earth's atmosphere, but

7:09

was refused permission, probably for the best. I

7:12

think he's a really interesting example of

7:14

what happens when you're trying to go

7:16

against the establishment. So to kind of

7:18

move things forward in a way that

7:21

creates a new picture or something incredibly

7:23

new. There's a lot of pushback. That's

7:25

right. And he also invented his own theory. So

7:27

he also was very rude about astronomers like me

7:29

who believe in such theories, such as the Big

7:31

Bang. And so he spent a lot of his

7:34

time trying to prove his own cosmological theories, but it

7:36

doesn't take away from his invention

7:38

of radio astronomy as a science. And lots

7:41

of what we do now, he would have

7:43

recognised using telescopes to map the sky. And

7:46

so radio astronomy is in the book as a big

7:49

example of a surprise. None of the

7:51

astronomers of the time at places like

7:53

Yerkes, the big national well-funded observatories,

7:55

were wondering about how to use radio to

7:57

look at the cosmos. It all came from...

7:59

people trying to understand how to use

8:02

radio to communicate. I just want

8:04

to read in your book, I

8:07

mean, you've mentioned Reba made up

8:09

his own series. He didn't believe in the Big

8:11

Bang. And he

8:14

thought of astronomers like you who

8:16

followed the cosmological status quo as

8:19

doing so not out of malice

8:21

or corruption, but simply due to

8:23

narrow-minded incompetence. See, I think that's quite generous. I've

8:25

definitely been called a lot worse, but I like that. And

8:28

it gives you a bit of a flavor of the man,

8:30

I think. He also discovered

8:32

Tasmanian parrots are right clawed and built his

8:34

own electric car in the 70s. So he's

8:36

clearly a forward thinker. Now,

8:39

when space missions are

8:42

decided to try and

8:44

explore the solar system, one

8:47

of the pools when deciding a destination is

8:50

the tantalizing prospect of finding life

8:52

off this planet. And the

8:54

European Space Agency currently has a mission

8:56

called JUICE. And that's to

8:58

Europa, right? Yeah, one of the moons

9:01

of Jupiter, one of the big moons of

9:03

Jupiter, with an ocean underneath a water ice

9:06

surface. This is going to

9:08

orbit Europa and give us more

9:10

data about whether there's possible life

9:12

there. Yeah, it will fly by. And really,

9:14

it's looking for habitats for life. So we

9:16

know, we think, that like many of the

9:18

moons in the outer solar system, Europa has

9:20

an ocean within it. But we don't know

9:22

how deep the ocean is. So therefore, we

9:24

don't know how big it is. We don't

9:26

know how long-lived it is. And those are

9:28

the questions that JUICE, and then there's an

9:31

American mission launching later this year called Europa

9:33

Clipper that will go into orbit around Europa.

9:35

Those two missions will sort of map the

9:37

geography. Of course, the place in the solar

9:39

system where we've got a bit further already

9:41

is Saturn's moon Enceladus, which is

9:43

a tiny thing. It's about the size of the British Isles. And

9:46

because it's being squeezed by Saturn's gravity

9:48

as it orbits, then it's got a

9:50

liquid ocean in the center. And

9:53

we know that it's a salty ocean. And

9:55

salt means that there must be an ocean floor. So

9:58

that's the place where I think we've got the... Best

10:00

habitat for nice and. The.

10:03

Ocean of In Salad Us was discovered

10:05

by accident by the Cassini probe which

10:07

was supposed to be looking at Saturn

10:09

and it's magnificent. rings and maybe some

10:11

of the large amounts flew past and

10:13

Xeloda, Son and one of the team

10:15

led by Michelle doctor year Imperial College

10:17

down the road discovered that there was

10:19

some disturbance in the magnetic field. dissuaded

10:21

the team to get back. Took pictures

10:23

are discovered there are fountains of water

10:25

shooting into space from the South Pole.

10:27

It's a it's an absolutely amazing discoveries

10:29

made completely by accident. Or they just

10:32

pointed the camera accident in my place.

10:34

Will that when they went back I knew

10:36

something odd was happening around the moon. So

10:38

they look to the moon and they followed

10:40

over the South Pole. I I think sometimes

10:42

maps if that first fly by had been

10:44

over the North Pole. weather isn't Morticia Dame

10:46

Spice Cassini may never have gone back to

10:48

insult us. say we might not know that

10:50

as this place where who knows their a

10:52

squid or bacteria or at least the potential

10:54

for life swimming around dumber and. Not just

10:56

more sense as he will. Test. Fizzy water

10:58

yet say I said it was salty

11:00

but guess is also and it's sort

11:02

of about the fish. You get off

11:04

a decent bottle of champagne to see

11:06

Fisa rather wonderful analogy that one of

11:08

the scientists gave me say say and

11:10

that means that there's chemistry happening down

11:12

there so it's beginning to look like

11:14

the kind of dynamic place where we

11:16

think on earth my my of got

11:18

started in the deep ocean around and

11:20

and volcanic vents or something like that

11:22

sites and some of this as I

11:24

think the most intriguing place and it

11:26

has the advantage. That you can

11:28

get back there if we send a probe

11:31

back and you can sample the water by

11:33

flying for it. So one day soon I

11:35

hope we'll send a chemistry set essentially to

11:37

go in and collect. Some of the city

11:39

will turn and might. My personal idea is

11:41

that we should fund this mission by bring

11:43

it back and Selling is the most expensive

11:45

mineral water ever obtained. I think people would

11:47

buy that. I think they would you

11:50

say subsidize their the science with sent

11:52

by selling the that's. Right? Yeah yeah you're

11:54

doing you're You're very rare and sell it and

11:56

mortar with Amy and by it's are included to

11:58

school to have health and. I'm sure

12:00

if. You were ideas as a flogging

12:03

men who reported to believe and

12:05

as I'm. Typing. Quite

12:07

nicely with one of today's stories,

12:09

Because taking resources from heavenly bodies

12:11

and bringing them back to earth

12:14

could be big business in the

12:16

future, and an isotope with helium

12:18

Helium three is one such commodity.

12:20

Seattle based Startup Interludes has recently

12:22

announced that it intends to harvest

12:25

this gas from our own main.

12:27

Now I called Sarah Russell, cosmic

12:29

Mineralogist at the Natural History Museum

12:31

in London to find out what

12:34

Helium Three even is. So.

12:36

Helium three is one neutron

12:38

with to protons so it's

12:40

the baby siblings of helium

12:42

for which is as you

12:44

protons and to neutrons and

12:47

which is much more abundant

12:49

so Helium three isn't that

12:51

much rarer isotope of the

12:53

to. A guy and

12:55

helium for is the one we

12:57

know with helium that guys in

12:59

party blades exactly most of those

13:01

stuff and possibly insists his helium

13:03

for so. Helium three is

13:05

it is it to. We use it

13:07

for anything. It doesn't even exist on

13:09

us. It doesn't exist on earth but

13:11

it's very very ras. I must say

13:13

Helium three on earth is the helium

13:16

three that the Earth was born with

13:18

which is not very much at all

13:20

plus a little bit that was formed

13:22

during things like ten nuclear testing said

13:24

the some human and pull into their

13:26

as well. but it does have some

13:28

uses say some cool it down to

13:30

very very low temperatures plus the absolute

13:32

zero up. For that reason it's used

13:34

in quantum. Computers to a cool

13:36

the components of them. it's also

13:38

used and medical imaging fit presumably

13:41

only in small amounts and quite

13:43

expensive, exactly. is incredibly expensive and

13:45

only use and very small amounts.

13:47

So there's little on us that

13:49

there's more of it on the

13:52

moon. Cell count. Yes, yes. So

13:54

in some ways the earth and

13:56

the moon are very similar to

13:58

a chemically to each other, but

14:00

there are some. really. the difference

14:02

is one of them is that

14:05

the earth has got an atmosphere

14:07

on has a magnetic fields and

14:09

that shields it from all sorts

14:11

of cosmic rays. the Saw in

14:13

space and in particular the earth.

14:16

Solar Winds produces this stream of

14:18

items into space and these hit

14:20

the surface of the moon ah

14:22

on implants into the rock. So

14:24

the Solar Winds includes hydrogen and

14:26

helium, including helium three as well.

14:29

Okay, so this. Company that's announce

14:31

that they're putting sixteen million towards

14:33

getting helium three off. The mean:

14:35

how would they go about extracting

14:37

it? So they've made their own

14:39

special instruments that's like going to

14:42

put on the moon to try

14:44

to strip the helium out so

14:46

that the big problem with Helium

14:48

three on the moon is that

14:50

although the sun is kind of

14:52

spray painting the entire surface of

14:55

the moon with helium three, it

14:57

says so in a super super

14:59

thin layer. That a mates

15:01

and sake or less. So it's an

15:03

incredibly thin layer across the surface of

15:06

the moon. And so us.

15:08

The extra thing that from the rock

15:10

is going to be really really difficult

15:12

to have the process. It's huge amounts

15:14

of broke and in the end zone

15:16

he gets tiny amounts of helium three

15:18

outfits and return it to us and

15:20

then return. It's worth yes, Says a

15:22

lot of difficult steps in this whole

15:24

process. that feels like an awful lot

15:26

of effort. Sara Yes, Wouldn't it be

15:28

easier just to make kids on Earth?

15:31

Can you make it on us? Well,

15:33

it has been made on earth by

15:35

humans during and nuclear weapons tests. but.

15:37

I guess I also make the whole live other stuff

15:39

as well. That you might not or

15:41

once assuming. Ah, that's

15:43

they do manage to

15:45

successfully and via Bleed

15:47

Mine. Helium. Three from the

15:49

moon. And bring. It back. How

15:52

significant could that be? So. Industry

15:55

What could change it would be.

15:57

a real sort of milestones because

16:00

it would be the first time

16:03

that we have exploited material from

16:05

space commercially. So it throws up

16:07

an awful lot of legal and

16:10

ethical issues but it

16:12

would be a massive massive deal and

16:14

yeah so the companies think

16:16

that if they manage to get the helium-3

16:18

back to earth it might potentially

16:21

open up new ways of

16:23

using helium-3 so it might inspire

16:25

new industries to form that can

16:27

use this new resource. Like what?

16:30

Well the sort of great dream

16:32

of helium-3 has always been to

16:34

use it for nuclear fusion so

16:37

this is something that's been talked about

16:39

for decades and decades but so far

16:42

we haven't been able to make

16:45

nuclear fusion work and even if we did

16:47

then I'm not sure that helium-3 would be

16:49

the best type of fuel for it so

16:51

that dream is still quite a long

16:53

way away. Lovely point there from

16:55

Sarah Russell. This is Inside Science and

16:57

I'm Marnie Chesterton. Today I'm joined in

16:59

studio by Astro Physicist and presenter Professor

17:01

Chris Lintott. Chris, it feels daft to

17:04

even point out what a source of

17:06

wonder the moon has been to us

17:08

all. Where does that leave mining

17:10

the moon? Well I think you

17:12

heard it there as Sarah was finishing that

17:14

interview which is that it's

17:17

very strange to talk about using moon for

17:19

commercial purposes. I think those of us who

17:21

want to see more space exploration have been

17:23

used to cheerleading this stuff because it's a

17:25

reason to get companies to pay to go back

17:27

to the moon you know we'll go we'll all

17:29

go helium-3 mining that would be great even if

17:32

the economics works out this is strip mining the

17:34

moon and the moon should the

17:36

UN say belong to all of us

17:38

it's in space so I think we've

17:40

got some serious problems to work out

17:42

about who gets to exploit what. It's

17:45

this weird catch-ready too. Friends of mine are talking

17:47

about putting a radio telescope on the far side

17:49

of the moon shielded from all the noise of

17:52

Earth but the technology that's making it cheap enough

17:54

that we might be able to do that is

17:56

also causing noise around the moon so we're struggling

17:58

we may only have a of years

18:00

to use the far side of the

18:02

Moon before it becomes as commercial as

18:04

the rest of low Earth orbit and

18:07

near Earth space. So I think we

18:09

need to think hard about why we're

18:11

using celestial bodies and who

18:14

gets to make those decisions. I'm

18:17

also not sure about some of the stuff we've

18:19

already littered the Moon with. So

18:22

you know 96 bags of poo and

18:24

an old camera. That's true, some interesting

18:26

art as well, some tardigrades crashed. There's

18:28

all sorts of things there but those

18:31

are small scale. This would be large

18:33

scale. Thanks Chris. We started off

18:35

talking about one of Saturn's moons and

18:37

now let's move to its largest, Titan,

18:39

which is bigger than Mercury. But that's

18:41

not the only thing that makes it

18:43

special. It's the only

18:45

known Moon with an atmosphere which

18:48

means it has wind and rain,

18:50

lakes and oceans. It also has

18:52

these mysterious giant dunes, about 100

18:54

meters high. So that's on a

18:56

par with the tallest ones here

18:58

on Earth which I believe are

19:00

in the United Arab Emirates where

19:03

the film Dune was recently shot.

19:05

But how did the ones on Titan get there?

19:08

That's always been a bit of a mystery. Over

19:11

at Southwest Research Institute in Boulder,

19:13

Colorado, planetary scientist Bill Bopka has

19:15

a new theory and I asked

19:17

him first to describe these dunes.

19:20

Think about your coffee you have in the

19:22

morning and now imagine sort of giant

19:24

mountains of coffee grounds that exist on Titan.

19:27

And some of these might be the order

19:29

of like 100 meters high. They're very large

19:32

and they cover about 17% of

19:34

the entire surface of Titan. So it's

19:37

a lot of stuff spread over this

19:39

really large area on this Moon. Okay

19:42

so I've got a mental picture

19:44

of Middle Eastern desert but

19:46

I'm just trying to make all the dunes a bit

19:48

darker so the colour of coffee grounds. Do you know

19:50

what they're made of? Are they sand? Well

19:53

this is the big mystery. Okay so

19:55

for a long time we thought they

19:58

might be organics that formed high-end. the

20:00

atmosphere. The current thinking was that

20:02

when the sun interacts with Titan's

20:04

atmosphere, it makes small little organic

20:06

particles, little carbon rich particles that

20:08

eventually fall out of the atmosphere.

20:11

And then the problem is, is the things that fall in

20:13

the atmosphere are too small, so they have to grow to

20:15

much larger sizes on the surface. Eventually

20:17

they would break free of the ground ice, and

20:20

then the wind would blow them around. And what happens

20:22

is that in order to get dunes, you have to

20:24

have the wind sort of blow you, and you jump

20:26

a little bit, and then when you strike the surface

20:28

again, you knock off over dune particles, within

20:30

undergo these little hops. And these hops are

20:32

called saltation. But the trick is, how can

20:34

the atmosphere make the particles that are the

20:37

right size for Titan's dunes? Okay,

20:39

and can it?

20:42

Well, they need to be about 200 microns

20:44

in size. That's about 0.2 millimeters.

20:47

This doesn't sound like very much, but that's a

20:49

very big particle to make in the atmosphere. And

20:51

making it on the ground, no one really understands

20:54

how you can make it on the ground. So

20:56

that's a problem. The other thing is they've looked

20:58

at particles not identical to Titan's dune particles, but

21:00

they've looked at particles in the laboratory that they

21:02

think might be like Titan's dune particles, and they

21:05

find that they're very weak, and they're very easy

21:07

to break apart. You need something that's stronger than

21:09

that, so we may need a different hypothesis. Okay,

21:12

and this is where you come in with a

21:14

different theory. That's right. So one

21:16

other thing that's always sort of interested me

21:19

is comets and comet particles. And these objects

21:21

are not only fairly strong, but they have

21:23

about the right sizes to saltate on Titan's

21:25

atmosphere. The question is, when it's a hypothesis

21:27

to make sense, is that where could you

21:29

get this huge amount of comet material? Where

21:31

could it come from? That's a lot of comets, yeah,

21:33

I was going to say. It's a lot

21:36

of comets, right? We probably can't get them just

21:38

from comets passing by. If you

21:40

go beyond Titan, so even more distant

21:42

from Saturn's orbit, what you find is

21:44

you eventually get to the realm of

21:46

where there's objects that look a lot

21:48

like big comets, or sometimes what we

21:50

call Kuiperball objects. And these are called

21:52

the irregular satellites. Some go

21:54

clockwise around, others go counterclockwise around.

21:57

We think that early on solar system history, a

22:00

lot of these objects were actually captured from

22:02

the processes that were happening at that time.

22:05

And because they were captured in these

22:07

strange orbits, they like to collide. And

22:09

so collusally, they're hitting each other and

22:11

they're breaking themselves down. And

22:13

when you look at the numbers on this, you can

22:15

get a lot of small particles that are created here.

22:18

And then what happens is that they

22:20

start to evolve inward towards Saturn by

22:23

interaction with solar radiation forces. And many of

22:25

those particles go to Titan. So

22:28

it could be on the end, Titan's

22:30

particles are actually from ground up of

22:32

regular satellites of Saturn. Is

22:34

there any way of testing whether you're right? NASA's

22:37

Dragonfly mission. This mission is

22:40

going to be launched in 2028. It

22:42

will get there in 2032. And

22:44

they have a special device which is called a mass

22:46

spectrometer that they're going to use

22:48

to analyze the molecules and the rest that

22:50

exist on the surface. And they're actually going

22:52

to fly into the dunes. And so using

22:54

that instrument, it's very possible we'll be able

22:57

to tell whether my hypothesis is right or

22:59

whether the existing hypothesis is right. If

23:01

you're right, when would you get an

23:03

answer? Probably 2032, when Dragonfly goes

23:05

there, or at

23:07

least a little bit afterwards. They're going to be

23:10

landing on Titan. And then eventually they're going

23:12

to fly into the dunes. And I think the

23:14

dune passage will probably happen, let's say,

23:16

within a year or so about landing on the surface. I

23:19

guess I keep your fingers crossed. And

23:22

yeah, we'll have you back on in a

23:24

decade. I

23:26

would greatly enjoy coming back. And we

23:28

can see if I'm right or wrong. And you guys

23:31

can be the judge. Bill Bocker there.

23:33

Professor Chris Lintott is with me in

23:35

the studio. Chris, what I love about

23:37

this is the timing. So Bill wanted

23:39

to flag this theory now so that

23:41

the next NASA mission flies with the

23:43

right equipment in order to test it.

23:46

Yeah, this next mission is, I think, the

23:48

coolest that we've flown in a long while.

23:51

It's called Dragonfly, good name. Great name. And

23:53

it's essentially a little chemistry lab attached to

23:55

a robocopter. So it can hop around the

23:57

surface of Titan, land in many different places.

24:00

We've been to Titan once already with the

24:02

Huygens probe, but Huygens touchdown lasted for half

24:04

an hour Gave us one picture and sampled

24:06

one place. Dragonfly is going to be a

24:09

proper mission of exploration And it probably

24:11

can test this it may be able to

24:13

tell us if those dunes are made of

24:15

distant comet stuff Or whether they're something a

24:17

bit more local and and it's just I

24:19

mean you go online look at the video

24:22

of it It's just cool. I can just

24:24

this is radio but a huge smile on

24:26

Chris's face right now. This is clearly exciting

24:28

Yeah, I think it's this sense of exploration

24:30

of Titan is a world.

24:32

It's a place that has different landscapes It

24:35

has oceans it has rivers It has strange

24:37

islands that appear and disappear which may

24:39

be something to do with bubbles in

24:41

the oceans It's got polar regions and the

24:43

idea of hopping around and exploring a new

24:45

world. That's really exciting Now

24:48

moving on all over the universe.

24:50

There are stars that originate from

24:53

the same molecular clouds That travel

24:55

together as a pair and should

24:57

be identical. They're called twin stars

25:00

But researchers in Australia recently

25:02

found something very odd something

25:04

that might have significant consequences

25:07

beyond the stars themselves What's

25:09

going on? I

25:11

spoke to Yoon Seung Ting from

25:13

the Australian National University Twin

25:16

stars are the star that were

25:18

born together And

25:20

they're also of the same mass.

25:23

So that should be identical

25:25

to each other And

25:27

what we did in the study is to

25:29

use the twin star to try to figure

25:32

out if one of the twins are

25:34

More odd than the other because

25:36

we know that by nature that

25:38

should be identical So if there's

25:40

anything strange in one star, we

25:43

know that it's by nurture not

25:45

the nature Oh, love

25:47

it. So exactly the same as twin

25:49

studies in in epidemiology

25:51

in genetics You're

25:53

looking for nature versus nurture but in

25:56

the cosmos Yes,

25:58

exactly got twin stars,

26:01

I mean how far away would they be

26:03

orbiting from each other? Yeah,

26:05

so they can be quite far away. So we are

26:07

talking about 10,000 to a million times the

26:11

distance of the Earth to

26:14

the Sun. So they are quite far apart,

26:16

but of course by a cosmic standard it's

26:18

not that far. Yeah, the space is

26:20

vast. So we study

26:22

91 pairs of twin

26:24

stars and we find that about

26:27

8% of them do

26:29

show chemical peculiarity, meaning that

26:31

out of the 91 pairs,

26:33

7 pairs of

26:35

twins do not look exactly the same. And

26:38

we dug deeper into the differences between

26:40

the two stars and confirmed

26:43

that some of them might have

26:45

created a planet or

26:47

some planetary material to change

26:49

the composition of the stars.

26:52

So they're born identical and

26:55

then one of the

26:57

pair starts swallowing planets? One

27:00

of the stars of the pair has

27:02

swallowed a planet. Looking at the

27:04

Earth and the Sun, the Earth

27:06

has more heavy elements than

27:08

the Sun, more iron

27:10

than carbon compared to the Sun. So

27:13

if the Earth were to drop into

27:15

the Sun, that will

27:17

elevate the iron to carbon

27:19

ratio a little bit. And this is

27:22

also what we detect from these

27:24

seven pairs of twins. So one

27:26

of them seems to have slightly

27:28

elevated heavy elements from

27:31

which we can tell that they must have engulfed

27:34

some planets. Can I just

27:36

check at this point, given that this

27:39

is about stars swallowing up

27:41

Earth-like planets, that's unlikely to happen

27:43

with our solar system, right? It could

27:46

happen. I was talking to

27:48

a theorist yesterday on the

27:51

stability of the solar system. It could

27:54

be the solar system in the past

27:56

has more than eight planets and

27:58

some of them might be by the

28:00

Sun. But this is still like

28:02

happening on a timescale of billions

28:04

of years. So when we talk

28:07

about either the solar system

28:09

is stable or not, we are

28:11

really talking about in the long timescale.

28:14

And therefore for the human race,

28:16

if we know the current solar

28:18

system is stable, it will

28:20

still be stable for the

28:22

human timescale, it should be like forever. This

28:26

is some quite clever research, you

28:28

know, looking at stars and working out

28:30

what they must have eaten and

28:33

noticing the difference between it

28:35

and its twin. Why

28:38

does it matter? What does it tell us about the universe?

28:40

So I think at the grander level,

28:42

it will give us a better appreciation

28:45

of how star and

28:47

planet are interact, right?

28:50

Because not too long ago, the

28:52

only planetary system that we know

28:54

is the solar system. But because

28:57

of modern day technology, we

28:59

can look into the planetary system outside

29:01

the solar system. But not only that,

29:03

like now we can even study some

29:06

of the fate of this planet.

29:08

So it really gives us a

29:11

perspective of ourselves and our position

29:13

in the universe. Joon

29:16

Seung Ting, talking about how studying

29:18

these very far off twin star

29:20

systems gives us insights into our

29:22

own solar system. Chris Lintock,

29:24

for people who don't care about anything

29:26

that happens outside our own planet, does

29:28

any of this matter? Well, I

29:31

think it matters if you care about

29:33

our existence here. One of the things

29:35

I took from this study is it's

29:37

telling us that these solar systems aren't

29:39

stable, that planets have been pingy around

29:41

and into the star, even when the

29:43

stars are mature. We thought that was

29:45

something that happened when stars were young,

29:47

but once you reach a nice stable

29:49

maturity, planetary systems shouldn't do this. And

29:51

so then you can ask the question,

29:53

will this happen here? Yeah, that's what

29:55

I did. Yeah. And we're

29:57

not sure, right? But also, I think it's

29:59

another way in which perhaps our solar system

30:01

is slightly unusual or at least we don't

30:03

live in one of these unstable systems so

30:06

it helps us understand our place in the

30:08

cosmos and it helps us understand and appreciate

30:10

maybe the planet that we're sitting on. Isn't

30:13

there that that threat, may you

30:15

live an interesting time? Yeah you definitely

30:17

don't want to live in an interesting solar

30:19

system, a nice boring one, stable planetary orbits,

30:22

less useful for physicists maybe but

30:24

we should stay here. There

30:26

was a time when people were predicting that

30:29

our solar system should be unstable and

30:31

that was disturbing but we now think that

30:34

we live in a peculiarly stable solar system

30:36

that the planets are interacting

30:38

with each other through gravity in such a way

30:40

that they they more or less are likely to

30:42

stay in their nice orbits and we get a

30:44

nice temperate earth to exist on for the

30:47

next few billion years or so. Now Radio

30:49

4 doesn't make a habit of

30:51

plugging rival podcasts but you have

30:53

one that fills a niche that

30:55

we haven't got to yet. Stargazing

30:57

with your dog. Is

30:59

your dog into astronomy? Well sort of.

31:02

I've always been a fan of lazy astronomy

31:04

of just going out and looking up and

31:06

I found having a quiet Mr. Max the

31:09

dog that I found myself outside most east things

31:12

looking at the sky and so I thought we'd

31:14

take some people with us on our walks and

31:16

experience what I see which is the sky and

31:18

a little bit of what Mr. Max sees which

31:21

is mostly whatever's on the ground and probably edible.

31:23

Let's have a little clip of you out with Max. Hello

31:26

and welcome to Dog Stars for Friday the

31:28

25th of... Hello Max. There's

31:31

an event happening in the next 10 days that I'm really excited

31:33

about which is the annual Perseid

31:35

meteor shower where we

31:37

get shooting stars. What's good

31:40

about this year is that the

31:42

moon for those peak nights is

31:44

out the way. Hello and welcome from Mr.

31:46

Max and I to... Don't leave it! Welcome.

31:50

If you haven't seen the space station it's fat.

31:53

It's just this bright star that travels across

31:56

the sky and then after a while it's

31:58

like somebody turns on a door... which

32:01

vanishes. It's quite disturbing

32:03

if you're thinking about the astronauts that are on board. Have

32:05

you found any more? No,

32:07

that's a dandelion. Okay,

32:10

you investigate that. That seems fine. Oh my god,

32:12

a whole lot of bread. No, no,

32:14

no. No, it's not the bread. That's

32:17

great. I love it. That's

32:20

pretty much my life at the minute. So, yeah. So

32:23

that's you and Rescue Lurch Max.

32:25

Yes, indeed. So dog-spouse wherever you

32:27

get your podcasts. Am I allowed

32:29

to plug it? Yes, sure, why

32:31

not? Chris,

32:34

will you stay with us for more

32:36

accidental science for the podcast version of

32:38

Inside Science? Of course, yes. Because I

32:40

want to talk about the possible alien

32:43

signal picked up by the Parkes Telescope

32:45

in 2020. Okay. Now,

32:47

because this is the podcast version of

32:49

Inside Science, we don't have to stick

32:52

to strict timings. And I've still got

32:54

Chris Lintock with me in the studio.

32:56

We can wang on for as long

32:58

as we like. Good stuff. So

33:01

in your book, you talk

33:03

about this strange alien signal

33:06

that the Parkes Telescope discovered.

33:09

Tell me about the Parkes Telescope and tell me

33:11

about the story. So the Parkes

33:13

Telescope, people will know as

33:15

the dish, which relayed

33:18

some of the Apollo landing footage back down

33:20

to Earth, but it's a working radio telescope.

33:22

It's sort of Australia's jodral bank. That's

33:25

probably offended everyone at Parkes and Jodrol, but nevermind.

33:27

You get the idea. It's a big radio telescope.

33:29

It does all sorts of sorts of science, but

33:31

it's particularly good at finding things that change in

33:33

the sky. And it's had a couple of adventures

33:35

that I talked about in the book. One was

33:38

something that the astronomers call peritons,

33:40

which are bursts of radio waves

33:43

that seem to come from all over the

33:45

sky. They're very mysterious and they couldn't be

33:47

seen by any other telescope. But, you

33:49

know, a bit of Australian pride. It's very good

33:51

at this. They thought, well, maybe our telescope is

33:53

just better at seeing these things until Somebody

33:56

made a crucial discovery, which is that they discovered

33:58

that these things, these peritons, Since

34:00

when you turn up around

34:02

lunchtime and. Whatever creating

34:05

radio waves in the universe doesn't know

34:07

about lumps time on earth we hope.

34:09

Ah as for a little bit more

34:11

investigation and see a help from a

34:13

citizen scientists to a retired engineer who

34:15

read some of the papers have recognized

34:17

the signals stand out. The door on

34:19

the microwave in the visitors center was

34:21

broken and so if you if you

34:23

impatient and opens the door before the

34:25

my wife went pings created a parrot

34:27

on and he had this is what's

34:29

known as a terrestrial signal study Also

34:31

illustrates how hard the job of radio

34:33

astronomers us we. Have to filter through

34:35

this noise and around the same

34:37

time. I'm they were

34:39

also during ah what we call Saturday

34:42

So actually you looking for signals that

34:44

might indicate the presence of Amy and

34:46

license? This has got easier in recent

34:49

years because we can look at stars

34:51

when we know that they were planets

34:53

and they looked at proximal center I

34:56

the nearest star to the sun. And

34:58

to their surprise they saw a signal.

35:00

I saw what appeared to be a.

35:03

Radio source attached to a moving as if

35:05

it was attached to a planet around the

35:08

star which they only saw when they pointed

35:10

the telescope at the stars say it was

35:12

there for for a few weeks When they

35:14

went back. Was. I found in the

35:16

data they went back it seem to have disappeared

35:18

but still very exciting and this was a product

35:20

called Breakthrough. Listen say that the. Things

35:23

could be Lc once and.

35:26

It. Leaked into the press that they might be

35:28

looking at aliens. The bills memory good about

35:30

same when we don't know I had the

35:32

for a while we have this candid at

35:34

signal from her near was planet that seem

35:36

to perhaps the at a signal of the

35:38

kind we'd expect from intention isis. It turns

35:40

out once they. Knew what they do look

35:42

like. They went and found it. All. over the

35:44

sky and some student quite know

35:46

when it was but it was

35:48

certainly something local it was a

35:50

malfunctioning not quite a mike wife

35:52

this died but satellite or something

35:54

like that sites know aliens i'm

35:56

and plenty of lunch but it

35:58

does illustrate that capable of looking

36:00

for signs of intelligence and I think

36:03

we're getting better at using telescopes like

36:06

parks to do their normal science but

36:08

at the same time listen along and

36:10

hope to be surprised. Okay

36:12

so one day one of the surprises is

36:14

going to be something that... I will

36:17

come on the Inside Science podcast and tell you the

36:19

moment it happens. Excellent! It's

36:22

a date. But for

36:24

now Chris Lin's our author of

36:27

Our Accidental Universe stories

36:29

of discovery from asteroids to aliens. Thank

36:31

you so much for coming on the

36:33

Inside Science podcast. My pleasure. This

36:36

was BBC Inside Science with me

36:38

Marnie Kesterton. The producers were Louise

36:41

Orchard and Florian Baugh and

36:43

Iman Moyn. Technical production was by Gareth

36:45

Tyrrell. The show was made in Cardiff

36:48

by BBC Wales and West in collaboration

36:50

with the Open University. BBC

36:54

Sounds, music radio podcast.