Latest / Space Nuts: Astronomy Insights & Cosmic Discoveries / Jupiter's Cosmic Blueprint, White Dwarf Feasts & Chiron's Evolving Rings

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Jupiter's Cosmic Blueprint, White Dwarf Feasts & Chiron's Evolving Rings · Space Nuts: Astronomy Insights & Cosmic Discoveries

0:00
Andrew Dunkley: Hello, thanks for joining us. This is Space
0:02
Nuts. My name is Andrew Dunkley, and we're
0:04
here to talk astronomy and space science. And
0:07
on this episode, we are going to look at a
0:09
study into Jupiter's role in shaping
0:12
our solar system. What shape is that?
0:15
It's rhomboid. No, we don't know. we're also
0:18
going to look at a, white dwarf star that's
0:21
chowing down on a planetesimal. Sounds
0:24
appetizing. observing a rapidly
0:26
developing ring system, and it's not far
0:28
away. And if we've got time, an exoplanet
0:31
that in inverted commas may
0:34
be a life candidate. That's all coming up on
0:37
space nuts. 15 seconds. Guidance is
0:40
internal. 10, 9.
0:43
Ignition sequence start. space nuts. 5, 4,
0:46
3, 2. 1, 2, 3, 4, 5, 5,
0:49
4, 3, 2, 1.
0:50
Jonti Horner: Space nuts.
0:52
Andrew Dunkley: Astronauts report it feels good. And it's
0:54
good to have Jonti Horner back with us again.
0:56
Professor of astrophysics at the University
0:59
of Southern Queensland. Hi, Jonti.
1:01
Jonti Horner: Good evening. How are you going?
1:02
Andrew Dunkley: I am well. Good to see you.
1:05
Jonti Horner: Oh, it's good to be back. Although I'm
1:07
admittedly a bit of a zombie, so I warn
1:09
everybody, I've had less sleep than I should
1:10
have done in the last couple of days because
1:12
of the weather. we had some weather happen on
1:15
Sunday, which led to the power here being
1:17
knocked out for 24 hours during a mini heat
1:20
wave. So I didn't get much sleep then. And
1:22
then this morning I've got a colleague from
1:24
Japan visiting, so I had to pick him, his
1:25
wife and their two lovely daughters up from
1:27
Brisbane Airport. So I've had six hours of
1:30
driving today off the back of two nights of
1:32
not much sleep. So if I seem less coherent
1:34
than normal, and I appreciate I'm normally
1:36
not that coherent to begin with, you know
1:38
why, of course.
1:40
Andrew Dunkley: Yes, we've all been there. we've had dreadful
1:42
weather here too. But it hasn't been the
1:44
extreme heat, it's been the extreme wind.
1:47
I got woken up, last night about
1:50
1am by the Fly, screens rattling. It
1:53
was so windy. Yes, they, they were just
1:55
shuddering. And I thought, I can't live with
1:57
this.
1:57
Jonti Horner: So I went outside.
1:58
Andrew Dunkley: It was freezing cold, supposed to be late
2:01
spring here, and I
2:04
just jammed some wood chips
2:07
into the. I just went off to the
2:10
garden and grabbed some mulch and shoved it
2:12
in the wind in, in the fly screens to stop
2:15
them rattling.
2:15
Jonti Horner: It worked.
2:16
Andrew Dunkley: I've done it better during the day, but,
2:18
well, that's just Been ridiculous.
2:20
Jonti Horner: I know your parents. I mean having said that
2:22
we had heat wave conditions and couldn't
2:23
sleep because of the heat, I'm happ confess
2:26
that I've had the wood serve on today because
2:27
having had 36, 38 degrees so
2:30
that's around 100 for our American friends
2:34
last few days. Today has been a toasty kind
2:36
of 15 degrees. and we've got a rain event
2:39
happening. so we've had everything in the
2:42
last week we've had kind of almost tornadic
2:45
storms, we've had hailstones the size of your
2:47
fists, we've had under a kilometer an hour
2:49
gusts and now we've got random cold that
2:52
makes me feel like I'm back in the uk. So
2:54
yeah, all happening. And this is why
2:56
Australia is an interesting place to live
2:57
even to the extent that with the
2:59
thunderstorms. We had got an email through
3:01
yesterday that our wonderful observatory,
3:03
Queensland's only professional astronomical
3:05
observatory in Mount Kent was closed
3:07
yesterday. We weren't allowed to go there
3:09
because there was a bushfire within 10km of
3:12
it that had been sparked by the lightning
3:14
from the storms and fanned by the heat wave
3:16
in a place that got lightning but no rain. So
3:19
ah, it's all happening here.
3:21
Andrew Dunkley: Yes, dry storms are not uncommon where I am.
3:24
We we do get quite a few storms every year
3:27
with lightning and thunder and nothing else.
3:30
and they, yeah, they're very well known for
3:32
sparking bushfires.
3:33
Jonti Horner: Yeah.
3:34
So while we're on the diversion of the
3:35
weather, actually I'll apologize for Maya the
3:37
dog chirping in the background but my
3:39
partner's just got home. But we're also
3:41
sitting here with an incredibly heartbreaking
3:43
record, record breaking storm in the
3:46
Caribbean. Yes, I know she's just come
3:49
home. Thank you for joining me with the
3:51
podcast Happy Dog. but yeah, there's
3:54
borderline record breaking storm in the
3:56
Caribbean which is going to be a Category 5
3:58
hurricane hitting Jamaica and doing a, ah,
4:01
hell of a lot of damage. And it's one of
4:03
these that from a scientist point of view,
4:05
fascinating watching it looking at the radar
4:07
footage and all the satellite footage and on
4:09
one hand you've got this thing of incredible
4:11
exceptional beauty and on the other hand the
4:13
devastation it's going to cause. So the
4:16
people in the, in the firing line for that.
4:18
Andrew Dunkley: Yeah, I saw the satellite images this
4:19
afternoon. It is enormous.
4:21
Jonti Horner: Yeah, you look at the false color one
4:24
with the color of the clouds which is an
4:26
indication of the severity of the storm and
4:27
the shape and it's the kind of thing that you
4:29
only see with the strongest storms we've ever
4:32
seen, typically in the Pacific. So for this
4:34
thing to not only be happening in the
4:37
Atlantic, which is less common, but
4:40
to be, you know, crosshairs on Jamaica,
4:42
which has had a bit of a charmed life with
4:45
some sacks of the high mountains that tend to
4:46
bounce and go around a bit. This one looks
4:49
like it's not so much going to bounce a
4:50
splat.
4:51
Andrew Dunkley: So yeah, when we were in Panama earlier
4:54
this year, we did the Panama Canal and
4:56
they were saying that they never get
4:58
hurricanes ever.
5:01
Jonti Horner: Too equatorial is my understanding. You need
5:04
to be far enough away from the equator to get
5:06
enough spin so. So it's very rare that you
5:08
get storms getting right up to the equator
5:10
because coriolis force and things like that.
5:13
Andrew Dunkley: Yeah, yeah, it's interesting, isn't it?
5:14
Very interesting. Okay, we better get
5:17
on with what we came here to get on with. And
5:20
we're going to start with a study
5:23
that's been released into Jupiter's role in
5:25
shaping the solar system. Now I do recall
5:27
Fred mentioning that Jupiter, if
5:30
Jupiter didn't exist we wouldn't. And this
5:33
study basically adds a lot of fuel to that
5:36
claim.
5:37
Jonti Horner: It does. Now where Fred said,
5:39
Fred and other people talk about if Jupiter
5:42
didn't exist then we probably wouldn't. Ties
5:44
into something that's a pretty big
5:47
myth in science communication, Ansel in
5:50
science papers and stuff, which is the idea
5:52
of Jupiter shielding us from impacts. And
5:55
my most favorite piece of research I ever did
5:58
in my career is proving that to be a lot of
6:00
cobblers and it's actually a lot more
6:02
complicated. Jupiter throws things at us as
6:04
well as protecting us. So I've always got a
6:06
bit of an eye on any study that says, hey
6:08
guys, if Jupiter wasn't there, neither would
6:10
we. But this is a really interesting one that
6:13
looks an entirely different aspect of
6:15
Jupiter, which is the role that Jupiter
6:18
played on the formation and evolution of the
6:20
early solar system, the formation of the
6:22
planets. And I've actually been teaching
6:24
planet formation this week to my undergrad
6:26
students. I've just, prior to recording this,
6:29
had a two hour tutorial with them where I've
6:31
been talking about planet formation and
6:33
brought this story up because it
6:36
really highlights the fact that when we
6:39
often see in documentaries and the stuff we
6:42
get taught at school, we get the impression
6:44
that everything's solved, that we know the
6:47
answers, that we know full well how the
6:49
planets formed in microscopic detail and
6:51
we've got everything figured out and the
6:53
Reality is that we haven't. We have a really
6:55
good broad picture and we're getting better
6:58
and better at understanding the processes
7:00
that went on. But there's still a lot to
7:02
learn. And part of that is that while we've
7:04
known the solar system since the year dot,
7:06
we've only known other planetary systems for
7:08
the last 30 years. And in reality we're still
7:11
learning an awful lot about the planetary
7:13
systems we find elsewhere. And learning about
7:16
them is cool and all, but it also gives us
7:18
insights that help us better understand our
7:20
planetary system and how it formed. And that
7:22
ties into this because the more we
7:25
study those other planetary systems, the more
7:27
we're getting observations of really
7:29
beautiful things like planetary systems that
7:32
are in formation, where you've got a
7:33
protoplanetary disk. And we're getting these
7:35
gorgeous images from things like the
7:38
ALMA array, the Ataccama Large Millimeter
7:41
Array that shows disks of planet
7:43
forming material around stars with gaps in
7:46
them and ripples in them and bands in them,
7:48
and all these beautiful structures. And some
7:51
of these have been previous astronomy.
7:52
Picture of the days where this ties into the
7:55
solar system is if you imagine that kind of
7:57
stereotypical image of a
8:00
protoplanetary disk, a disk of gas and dust
8:02
around a young star like the sun, where
8:05
material is feeding in through that disk to
8:07
the star. So while the gas and dust is
8:09
orbiting the star, there is this kind of
8:11
sense of inward motion where the stars kind
8:13
of nominating at the inner edge of the disk,
8:15
materials falling in, and more material from
8:17
outside flowing in to replace it. Yeah, and
8:20
some of the models of the formation of the
8:22
solar system struggle to make the terrestrial
8:24
planets as a result of that. Because the
8:27
material in the inner solar system is
8:29
destined to fall onto M the star. And how do
8:31
you stop that happening to let that material
8:33
hang around to actually form into planets?
8:37
Now it's been pretty well established for a
8:39
long time that the first planet that formed
8:41
in the solar system and got to a good size
8:42
was Jupiter. And there's good reasons for
8:45
that. It formed far enough away from the sun
8:47
that the temperature was cold enough that the
8:50
disk was rich in ice, which at, the
8:53
distance the Earth is from the sun, all that
8:55
ice would be gas. when you're forming solid
8:57
objects, you need solid objects to feed from.
8:59
And so when you've got a lot of ice, you've
9:01
got a lot more solids. So things grow
9:03
quicker, there's a lot more to eat. And it's
9:06
only when you get to about 10 or 12 times the
9:08
Mass of the Earth that You're massive enough
9:09
to effectively start gobbling up the gas as
9:12
well. So Jupiter formed beyond this point
9:14
called the snow line, where there's a lot
9:16
more solid material. It got to grow really
9:18
quickly. It grew quicker than things further
9:21
out because the further out you go, the
9:23
slower things happen. So Jupiter was very
9:24
much in the sweet spot, grew really quickly
9:27
and eventually got big enough that it started
9:29
clearing the gas and the dust it could gather
9:31
the gas as well. And it opened up a gap in
9:33
the disk. And that's very analogous to what
9:36
we're seeing with these beautiful images from
9:37
ALMA places like this. So the team of
9:40
researchers behind this work have run some
9:43
really in depth computer modeling of the
9:45
formation of the solar system formation of
9:47
Jupiter, and showed that when Jupiter opens
9:50
up the gap in the disk, its gravity will
9:53
also have an impact on the inner solar
9:55
system. It'll effectively create the
9:57
gravitational equivalent of speed bumps,
9:59
creating areas where the dust that's
10:01
spiraling inwards can pile up and be
10:04
stopped from traveling further in.
10:07
Effectively. It also creates
10:09
a gap between the in run out of solar system
10:12
that nothing crosses because if anything gets
10:14
in that gap, Jupiter noms on it. And that's
10:17
really interesting because some studies that
10:19
have looked at primordial material we've
10:21
found from in the solar system suggests that
10:23
there is a bit of a chemical difference
10:25
between material that formed in the inner
10:26
solar system and material that formed in the
10:29
outer solar system. So this gap
10:31
dividing the two gives a natural way for that
10:34
to happen. But the really big exciting result
10:37
from this is really that modeling of
10:40
the structure that Jupiter would have imposed
10:42
on the inner solar system. These kind of pile
10:44
up regions where you get more m dust and
10:46
debris than normal, the structures that, that
10:48
would carve out ripples in the disk
10:51
effectively and how that would then
10:53
contribute to the formation of the
10:54
terrestrial planets. and therefore suggesting
10:57
that not only did Jupiter help the
10:59
terrestrial planets form by creating sweet
11:01
spots where material could pile up, but it
11:04
may also have had a really strong influence
11:05
on the architecture of the inner solar system
11:08
by setting where the planets would form,
11:10
which then would go through a bit of a
11:13
randomization phase as everything collides
11:15
with each other. But it kind of possibly set
11:17
the blueprint for the inner solar system. And
11:20
therefore, if Jupiter hadn't formed where it
11:22
did and how it did, the Earth would look
11:24
very, very different and we might not be
11:26
here.
11:26
Andrew Dunkley: Yeah, it's truly fascinating. And
11:29
when you look at other systems that
11:32
we've discovered, exoplanet solar systems,
11:35
ours is starting to look a little bit more
11:38
unusual than normal.
11:41
and Jupiter may be the reason.
11:43
Jonti Horner: It could well be. And it's one of those
11:45
things, I'm reminded of the Monty Python
11:47
thing. I think it's in Life of Brian, where
11:49
you've got that thing of we're all
11:50
individuals. Yes, we're. No, we're not. I'm
11:52
not. Every
11:55
planetary system is going to be unique
11:57
because it is influenced by
12:00
such a wide variety of things going on. Even
12:03
the stars that form in the local
12:05
neighborhood, whittling it away from the
12:06
outside, it all starts going on. But what
12:09
we're seeing is there's a commonality among a
12:11
lot of the planetary systems that we find
12:13
that look very different to ours.
12:16
The thing that gives us a little bit of pause
12:18
though, is that we have these observational
12:19
biases that make us more likely to find
12:21
systems that are different to ours than we
12:24
are to find systems like ours. And so you've
12:26
always got that question of do we look
12:29
unusual because we are unusual,
12:32
or do we look unusual because we're not yet
12:33
very good at finding places that look like
12:35
home? and that's where colleagues of mine,
12:37
like professor, Rob Wittenmayer, my colleague
12:39
at unisq, have done really interesting
12:42
work where what they
12:45
do is look at what we found, but work
12:48
out what doesn't exist
12:51
based on what we haven't found yet. So they
12:54
can start getting an estimate of how common
12:56
our, ah, planetary systems like ours based on
12:59
the fact we haven't found them yet. And it's
13:01
a really kind of weird type of science where
13:04
the absence of finding thing places limits on
13:07
how common that thing is. So if you said
13:10
that every star had a planet exactly like the
13:12
Earth, on an orbit that's one year long that
13:14
is exactly the same size as us and all the
13:16
rest of it, then we can work out
13:18
statistically, based on how good our
13:20
telescopes are and our techniques are, how
13:23
many of those planets we would have found.
13:25
And we wouldn't have found anywhere near all
13:26
of them because it's really hard to do. But
13:28
we'd have found X amount. And the fact that
13:30
we've only found a very small number smaller
13:32
than that places an upper limit on how common
13:35
things can be. So you get this perverse
13:38
science where you get the observations
13:41
that tell us what we found and what we've
13:42
seen, but you can also put inferences on
13:45
what isn't there and what is there based on
13:47
what we haven't found yet, which allows you
13:50
to put limits on how common things are that
13:51
you couldn't really find very easily. Which,
13:54
if that makes your head hurt. it makes my
13:56
head hurt a little bit as well. But it's a
13:58
really kind of clever use of the data we get
14:01
to extrapolate further and draw more
14:03
conclusions. And the net result of that is
14:06
that the solar system is not hugely rare, but
14:09
it's not common either. It's usual.
14:12
And, that's really cool. And that probably
14:13
extends to everything. Like I say, we're all
14:15
individuals. The Earth, even though it's
14:18
peeing it down outside at the minute, the
14:20
Earth's actually a very dry planet. If you
14:22
took all the water off the Earth and made a
14:24
little blob of it next to the Earth, that
14:25
blob would be fairly tiny. And everybody
14:28
views the Earth as being very wet, but I view
14:29
it as being very dry because water is such a
14:32
common compound in the universe. It's made of
14:35
the first and third most common atom. You put
14:38
them together. Yet water waters everywhere.
14:40
So for the Earth to be as dry as it is is
14:42
telling you a lot about the uniqueness of the
14:44
solar system. And maybe that's partially
14:47
because of Jupiter. Not, necessarily
14:49
shielding us from impacts, but preventing
14:50
that icy material spiraling in, preventing
14:53
us from becoming an ocean world. It's also
14:56
partly down to the moon forming impact. The
14:58
moon forming impact would have stripped a lot
15:00
of the primordial Earth's water away because
15:02
it walked as light and sits near the surface.
15:05
So a lot about our Earth and a lot about the
15:07
solar system is down to the random nature of
15:10
the events around us. When we formed the moon
15:13
forming impact, a nearby star going
15:15
supernova and lacing our solar system with
15:18
radioactive aluminium. Things like this.
15:20
There's all these oddities that made our
15:21
solar system unique, but if those
15:24
hadn't happened, other things would have
15:26
happened and we'd have still ended up with
15:27
something unique because of other random
15:29
things happening.
15:30
It's all fascinating and I just love this
15:32
stuff.
15:33
Andrew Dunkley: Yeah. And it adds more and more weight to the
15:35
theory that we are just a freak accident.
15:38
Jonti Horner: Yes.
15:39
Andrew Dunkley: And probably a one off in the universe.
15:42
That's one argument. So, yeah,
15:44
who knows if, if we find a
15:47
solar system just like ours, with a planet
15:49
just like ours, orbiting a
15:52
star just like ours. That would be
15:56
the, you know, one of the greatest
15:59
discoveries in astronomical history, I
16:00
imagine. But no, we do that.
16:03
Jonti Horner: We would have to get in touch with the planet
16:05
builders at Magrathea and demand that money
16:07
back. Because we thought we had a limited
16:08
edition.
16:09
Andrew Dunkley: Yes, yes. weren't they the white mice? Was
16:11
that the white mice?
16:12
Jonti Horner: Yes, it was.
16:13
Andrew Dunkley: Yeah. All right, if you want to read all
16:15
about it, you can find, the paper,
16:18
which was published in the journal Science
16:21
Advances.
16:25
Jonti Horner: Roger, your labs are here. Also space nuts.
16:28
Andrew Dunkley: now, Jonti, let's move on to our next story.
16:30
And this one is about a planetismal,
16:34
that appears doomed. According to the, paper
16:37
I'm reading, it's a white dwarf that's
16:39
chowing down very, very hungry, hungry
16:42
individual is this one.
16:44
Jonti Horner: It is. So just to remind the audience, a
16:46
white dwarf is the kind of little husk
16:49
that's left after a cell like our sun comes
16:51
to the end of its life, burns all its
16:53
hydrogen, becomes a red giant, and then
16:56
eventually blows off its outer layers. And it
16:58
leaves a big chunk of the star's mass
17:00
compressed into an object about the size of
17:02
the Earth. That whole process will
17:05
have a fairly hefty impact on the
17:08
planetary system that star's got around it.
17:10
And of course, as we just discussed, we now
17:12
know that pretty much every star has planets.
17:14
The expectation is that when the sun reaches
17:16
this stage, unfortunately it's in about 7
17:18
billion years, so nothing to worry about.
17:20
Immediately it will swell up and it will
17:23
chow down on Mercury and chow down on Venus.
17:25
They'll just be swallowed up and gone. Yeah,
17:28
There is some debate over whether the Earth
17:30
will be swallowed up or will survive. Just
17:33
all the models of star, evolution suggest
17:35
that the sun will swell up to be about the
17:37
radius of the Earth's orbit. But whether the
17:40
Earth is there to nominal or not is still
17:41
open for debate. It may be that the loss of
17:44
mass from the sun in the time before may just
17:47
mean that the Earth nudges far enough away to
17:49
survive as a burnt husk rather than be
17:51
devoured. It still would be ideal
17:53
to be around when that wouldn't be pleasant.
17:55
I mean, that said, the Earth is going to
17:57
become uninhabitable a lot sooner than that
17:59
because the Sun's getting brighter and the
18:01
Earth's oceans will boil and it'll all go
18:04
downhill. But after all that process
18:07
happens when the sun sheds its outer layers,
18:09
that'll have a pretty cataclysmic event on
18:11
the planets and the debris that are left. So
18:14
suddenly the sun goes on the ultimate kind of
18:16
weight loss kick loses mass. And that
18:19
will mean that all of the objects going
18:21
around the sun will be held less strongly.
18:23
And so therefore their orbits will move
18:25
outwards because the gravity pulling them in
18:28
gets weaker. Now, if you suddenly Press the
18:31
button and vanished half of the mass of the
18:33
Sun. What had happened is that the speed that
18:36
any of the objects are going in their orbit
18:38
will be too quick for that orbit to be
18:40
circular. So at that instant, at that
18:43
point, they'd now be at their new perihelion,
18:45
they'd be at their closest point to the sun,
18:47
and they'd all move out onto much more
18:48
elongated orbits with a longer orbital
18:51
period, but orbits that would then cross one
18:53
another. So if you imagine you lose half of
18:56
the Sun's mass, Jupiter moves onto an orbit
18:58
where its perihelion is 5 au from the sun,
19:01
but its aphelion could be 15 au from the Sun.
19:03
Saturn at the same time would have perihelion
19:06
at 10 au and aphelion at say 20 au. And I'm
19:08
making the numbers up a bit here. So suddenly
19:11
Jupiter and Saturn are on orbits that
19:13
cross one another. Their orbits
19:16
will probably still have the same ratio of
19:19
orbital periods, so 12 years to 29 years. But
19:21
they'd scale up to be something like, I don't
19:23
know, 30 to 70 or something like that,
19:26
because they've both moved out by the same
19:28
amount. But suddenly you've got these planets
19:30
that are on orbits that cross each other and
19:32
therefore can really strongly interact. They
19:34
can stir everything else up because all of
19:36
the objects in the asteroid belt, all of the
19:38
objects beyond Neptune, this happens to
19:39
everything. Now the mass loss is a bit more
19:42
gradual than that in actuality. So what
19:44
happens is you get the orbit spiraling out,
19:46
but getting perturbed, being made more
19:48
eccentric. You've also got these objects
19:51
moving through the headwind of possibly half
19:53
a solar mass of material being blown
19:55
outwards. That provides friction and so
19:58
causes them possibly to spiral inwards a bit.
20:01
Causes Jupiter potentially to gather mass as
20:03
it numbs on all that gas that's going out. At
20:05
the same time, its atmosphere is probably
20:07
being blasted away by all this wind blowing
20:09
past. All of this complexity means
20:12
that you couldn't predict with absolute
20:14
certainty what the solar system would look
20:16
like at the end of this, but certainly
20:19
there'd be a period of chaos. A lot of stuff
20:21
would survive, but it would survive on orbits
20:24
that are now much more unstable. So you get a
20:27
lot of material flung inwards and, some of
20:29
that will be flung inwards far enough for it
20:31
to impact on the Earth sized object in the
20:33
middle and, for the white dwarf to get a
20:36
snack. Now all that's expected to happen
20:38
really early on. And over time everything
20:41
stabilizes out, things get flung around and
20:44
clean up happens a bit like the
20:46
solar system. You know, we were talking early
20:48
on about the early stages of planet
20:49
formation. Everything gets flung around and
20:51
by the time you get to now, four and a half
20:53
billion years down the road, it's fairly
20:55
quiet. There's a bit going on, but most of
20:57
the drama's finished. So the
21:00
expectation is you'd see white dwarfs that
21:02
are very young occasionally eating things
21:05
because things get flung in and they get a
21:07
bit of a snack. And the material from that
21:09
snack will be spattered over the surface of
21:11
the white dwarf and be visible in its
21:13
spectrum as anomalous added
21:16
solid material, heavy elements.
21:19
But that signal would only last a short time
21:21
because the outer layer of the white dwarf is
21:23
kind of a hydrogen soup and heavier elements
21:26
would sink down. So any given time you'd eat
21:29
something. The evidence for that meal would
21:32
only remain for a few tens of thousands of
21:34
years, SOPs before it goes away. Okay, so
21:37
the fact is we've seen some white dwarfs
21:39
which have these anomalous heavy element
21:41
readings in their atmospheres. We can tell
21:43
they're eating stuff, but typically they're
21:45
young. So you'd expect that.
21:48
The quirky thing here is that this white
21:50
dwarf, which goes by the name of
21:52
lspm, which I think is a survey name,
21:55
m followed by
21:56
J020733331.
22:00
So that's a coordinate on the sky. So that's
22:02
telling you where in the sky this is. It's
22:04
catalog number. Yeah, this thing is an old
22:07
white dwarf. It's thought to be about 3
22:08
billion years old. So in other words, the
22:10
star that formed it died 3
22:13
billion years ago and it's been sitting there
22:16
minding its own business. That's old enough
22:19
that you'd expect everything to have calmed
22:20
down around it. But what the new
22:23
observations have shown is evidence of
22:26
13 different heavy elements,
22:29
including carbon, chromium,
22:32
strontium, titanium, a lot of these different
22:34
elements, roughly in the kind of abundance as
22:37
you'd see on the Earth, added, to this white
22:40
dwarf's atmosphere. So it's
22:43
obviously just had a meal and we know it's a
22:45
case of just had a meal rather than it's been
22:47
a leftover from a long time ago, because this
22:50
stuff will sink and disappear over the next
22:51
few tens of thousands of years. So what
22:54
that means is that this white dwarf
22:57
has just had a snack. Now it might have had
23:00
that snack 30,000 years ago, or it
23:03
may still be in the process of eating as
23:05
we speak. Now what the team have been able to
23:08
do is look at the amount of material you'd
23:11
need to give the strength of signal you've
23:12
got in the spectrum of the star. And, what
23:14
they've calculated is that to get this amount
23:17
of material you'd need to eat an asteroid
23:20
about 200 kilometers in diameter.
23:23
So that's comparable to some of the larger
23:25
asteroids in the asteroid belt, but not the
23:27
largest by any means. It's within the bounds
23:29
of possibility of what we see here at home.
23:31
But the real question is why is it eating it
23:34
now? Why is this happening now when you'd
23:36
expect the system to have had plenty of time
23:38
to calm down? What
23:40
it suggests to me, and it suggests in the
23:43
paper, it suggests in the articles about this
23:45
as well, is that the only way you can get
23:48
something eating this late, after 3 billion
23:50
years have passed, is if you've still got a
23:53
number of planet mass objects in the system
23:56
serving things up, which is what we've got
23:59
in the solar system. If we look at the inner
24:00
solar system, fragments of comets and
24:03
asteroids are falling onto the sun all the
24:04
time. We've got near Earth asteroids, short
24:07
period comets and long period comets whizzing
24:09
around. And, they're being bounced around by
24:11
the planets. Jupiter's throwing a lot of
24:13
stuff away. Their orbits are constantly
24:15
getting tweaked. And so therefore the sun
24:18
is still getting this rain of solid material
24:21
falling on it as a result of the planets
24:23
stirring things up. Even though the solar
24:26
system mostly quietened down, the planets are
24:28
still injecting material to the inner solar
24:31
system, which is why we're getting meteorites
24:33
and it's why the sun occasionally gets to
24:35
numb some stuff. The idea here is
24:38
that this star reached the end of its life.
24:40
Puff dots with its outer layers. You have
24:43
this really chaotic period where everything
24:45
had got stirred up, then it settled down. But
24:47
because you still got planet mass objects
24:49
there, they're still bouncing around what
24:51
debris is left. And we're just catching this
24:54
white dwarf just at the right time, when
24:57
another asteroid has been flung inwards close
24:59
enough to be torn apart by the star's gravity
25:02
and to give it a snack. So in other words,
25:05
seeing this snack happening this late in the
25:07
life of this white dwarf is fairly strong
25:09
evidence that planets survived the death of
25:12
its star, have lived there for 3 billion
25:15
years, which a is really cool in of itself.
25:17
But it also means that here is a star that we
25:20
should look at when the Gaia data release
25:22
comes next year. Gaia Dr. AH4,
25:25
which will have been measuring this star's
25:27
position on the sky. And if there Are planets
25:29
there, we'll be able to detect the wobble and
25:31
confirm them. So it's also holding up a flag
25:33
to exoplanet people saying,
25:36
hey, folks, here's a target for you to look
25:39
at when the data release comes out where you
25:41
might be able to find some planets, because
25:42
we think there's a smoking gun here that the
25:45
planets are feeding the white dwarf, giving
25:47
it little snacks every now and again.
25:50
Andrew Dunkley: Okay, wow. All right.
25:51
so are there many white dwarf
25:54
stars out there? What, do they, sort of,
25:58
percentage wise, inhabit the star field?
26:01
Jonti Horner: There would be a fair few of them. So the
26:04
more massive a star is, the shorter its life
26:06
is. And, that's a really rapid function.
26:09
Where that works is, if your star's more
26:11
massive, its gravitational pull is stronger,
26:14
so its ability to pull material into
26:17
the middle of the star is higher, which means
26:20
that that star's got to give off a lot more
26:22
energy to balance that gravitational pull.
26:24
And so stars in the main sequence part of
26:27
their life are in equilibrium. The radiation
26:29
coming out from the nuclear fusion in the
26:31
middle balances gravity pulling in. The
26:34
more massive you are, the hotter and denser
26:36
you get in the middle, so the more energy you
26:38
give off. And the result of that is that it
26:41
roughly, it varies a little bit by star's
26:43
mass, but roughly the brightness of a star,
26:45
the luminosity of a star is proportional to
26:48
the mass of the star to the power
26:50
4.3.54. Which means if you
26:52
double the mass of a star, it'll get between
26:55
10 and 16 times brighter.
26:58
So twice the mass, Call it a factor of 10
27:01
just to keep it easy. If it's 10 times
27:02
brighter, that means it's burning its fuel 10
27:05
times quicker to produce 10 times as much
27:07
energy. But it's only twice the mass, so it's
27:10
only got twice as much fuel, so its
27:12
life will be a factor of five times shorter.
27:15
And the more massive you get, the shorter the
27:16
life gets. Now, stars of different masses
27:19
have different. A star like Proxima
27:22
Centauri will never swell up to become a red
27:24
giant. It'll just be a dull, glowing ember
27:26
and eventually go out. But even the
27:29
oldest stars like Proxima Centauri are still
27:31
really in their youth because they're burning
27:33
their fuel so slowly. Stars that are more
27:36
massive eventually get stars like the sun,
27:38
which are what form like dwarfs. And, they
27:40
eventually swell up to become a red giant,
27:42
puff off their outer layers. And for a star
27:44
of the Sun's mass, that process from
27:47
forming to the end of its life is thought to
27:49
be about 12 billion years. It used to be 10
27:51
billion models seem to have refined. So
27:54
people nowadays seem to say it's about 12
27:55
billion years. So a star of
27:58
the mass of the sun that formed when our,
28:01
Milky Way was very young will have lived and
28:03
died and become a white dwarf more than a
28:05
billion years ago. But stars more massive
28:08
than the sun can form white dwarfs as well,
28:11
up to maybe two or even three times the mass
28:13
of the sun, depending how effective it is at
28:15
shedding mass at the end. Yeah, the maximum
28:17
mass for white dwarf, you can get about 1.4
28:20
times the mass of the Sun. If stars lose half
28:22
their mass, that gives you something about
28:23
three times the mass of the sun before you
28:25
start it. Three times the mass of the sun.
28:29
Three to the power four is three times three
28:31
times three times three. That's 81 if my
28:33
mental arithmetic is correct. So three times
28:36
the mass of the sun burns its fuel 81 times
28:38
as quickly, which means it would live a 27th
28:41
as long. Which means instead of 12 billion
28:43
years, you get down to, 1.2 billion years,
28:46
you get down to or like, 600 million years,
28:48
500 million years. So there will have been a
28:51
lot of stars that were more m massive than
28:53
the sun that have lived and died and created
28:55
white dwarfs. And so there's going to be a
28:58
lot of white dwarfs out there. I saw
29:00
someone talking a while back about how old
29:03
the oldest white dwarf will be in how dim it
29:05
will be, because white dwarfs just cool and
29:07
gradually go from being blue to white to
29:10
yellow to red. You know, gradually dim down.
29:12
Yeah. but what that all means is that there
29:15
are probably a really large population of
29:17
white dwarfs out there. We know quite a large
29:19
number, but we won't know anywhere near
29:22
as many of them as we do stars that are
29:24
actually the mass of the sun, that are in the
29:25
prime of their life because they're much
29:28
fainter and harder to spot because they've
29:30
got a much smaller surface area. So even
29:31
though they're hot, they're tiny and,
29:33
therefore they're faint. and the best example
29:35
of that, of course, is a white dwarf that is
29:37
a companion to Sirius. Sirius is the
29:39
brightest star in the night sky. It's more
29:41
massive than the Sun. It's also nearby. Its
29:44
white dwarf companion is something
29:47
like a factor of a million times fainter than
29:50
Sirius is. So even though the white dwarf is
29:52
comparable in Master Sirius A,
29:55
it is like a million times dimmer because
29:58
it's so tiny. And that's why they're Hard to
30:00
find.
30:01
Andrew Dunkley: Yeah, even though there's probably a hell of
30:03
a lot of them out there. Okay, if you would
30:06
like to read more about this particular white
30:08
dwarf star that is, you know, got a case of
30:11
the munchies, probably spent too much time
30:13
smoking the juju. you can read all about it
30:17
in the Astronomical Journal. This is Space
30:20
Nuts with Andrew Dunkley and Jonti Horner.
30:23
Jonti Horner: Okay, we checked all four systems and being
30:25
with the jerk space nets,
30:28
Andrew Dunkley: Don'T know why we went down that road.
30:29
Let's go to our next story. And this
30:32
one is, this one's close to home.
30:35
a, an object that is rapidly developing
30:38
a ring system and it's it's in
30:41
the outer solar system.
30:43
Jonti Horner: It is, this is an object called Chiron,
30:47
which was the first of the centaurs to be
30:49
discovered. And I always like to talk about
30:50
the centaurs because they're what I studied
30:52
for my PhD, so, so I was at one
30:54
point, 20 odd years ago, one of the world's
30:57
experts in how these things move around the
30:59
solar system. And then science has moved on
31:00
and I haven't, so I probably can no longer
31:03
claim that. But Chiron is
31:06
an interesting object. It's an icy object,
31:08
bit more than 200km across. It was
31:11
one of, if not the first object to get both a
31:14
classification as an asteroid and as a comet.
31:16
So it was initially discovered as a tiny
31:19
speck of light moving around. It's discovered
31:20
by Cowell I think in 1970,
31:23
moving on an orbit that spends nearly all its
31:25
time between the orbits of Saturn and Uranus.
31:27
At the minute. Long term it's an unstable
31:29
orbit. There's about a, ah, one in three
31:31
chance that this will eventually end up in
31:33
the inner solar system at some point in the
31:34
next few million years. And that's part of
31:37
the work I did during my PhD was running
31:39
simulations of where this thing's going to
31:40
go. That in itself is interesting because
31:43
it's about a bit more than 200km across.
31:46
So if this thing got trapped in the inner
31:48
solar system, it will be, be a comet like
31:49
nothing we've seen in recorded history. Hale
31:52
Bopp, which was ridiculous, had a 50
31:54
kilometer nucleus. If this thing's 250
31:57
kilometers across, that's five times the
31:59
radius, which means it's something like 25
32:02
times the surface area, which means it will
32:05
be a lot more impressive. So it's obviously
32:07
an interesting object. Back in
32:10
2011, team of scientists
32:13
traveled across the world to gather to
32:16
watch Chiron block out the light from a
32:18
background star. So as this thing's moving
32:21
through space, it just happened to pass in
32:23
front of a star, from a subset of locations
32:26
across the Earth. Now the distant stars are
32:29
effectively so far away, we can consider the
32:31
light coming in perfectly parallel. And
32:33
so a 200 kilometer
32:36
centaur will cast a shadow on the earth
32:38
that's 200 kilometers across. And that shadow
32:40
will whip across our planet. As the object
32:43
and the Earth move around the sun, the shadow
32:44
moves, the Earth moves through it. And so you
32:47
get a 200 kilometer roughly scale band on the
32:50
Earth where that star will disappear, then
32:52
reappear. We know how fast everything's
32:55
moving. So if you can get in that location,
32:57
have a lot of telescopes spread out in a
32:59
line, you can observe that
33:02
occultation event and, by how long the star
33:04
vanishes from different locations, you can
33:06
actually figure out the shape and the size of
33:09
the centaur because you can essentially map
33:11
that shadow. And if you're near the edge, the
33:14
star will disappear and reappear really
33:16
quickly. If you're near the middle, you'll
33:17
get a longer period where it vanishes. So
33:20
these kind of, ah, occultation observations
33:22
are really valuable to scientists. What
33:24
happened in 2011 was they set their
33:26
telescopes up and started watching a bit
33:28
early to make sure they were looking at the
33:30
star. And they noticed the star flickered on
33:32
and off a couple of times before it properly
33:34
disappeared for the main occultation. Then
33:36
after it reappeared, it flickered on and off
33:38
again a couple of times. And that's really
33:40
weird. Now there was a kind of
33:43
precedent for this with observations that
33:45
were made in 1977, I believe,
33:48
of Uranus, which was being observed from, I
33:51
think it was the Kuiper Airborne Observatory
33:52
doing one of these occultations. And they'd
33:55
observed Uranus for this occultation because
33:58
they wanted to understand the atmosphere of
34:00
Uranus. And they figured as a stalwart behind
34:02
Uranus, you'd see it not just disappear, but
34:05
actually fade out as the light passed through
34:07
the atmosphere. So you could measure the
34:09
atmosphere and with that occultation of
34:11
Uranus, occultation by Uranus, sorry, they
34:14
got this flickering on and off thing. And
34:16
that was the discovery of Uranus, of ring
34:18
system. So basically the star vanished behind
34:21
the rings, then reappeared, then vanished
34:22
again, then reappeared, then went behind the
34:24
planet. Right. So with this
34:27
2011 event, the same kind of thing applied.
34:30
It was the discovery of a ring system around
34:32
this icy object. So this is a tiny thing,
34:35
smaller than even Mimas, that we talked about
34:37
last week with the subsurface ocean,
34:39
something so small that its gravity is
34:41
probably not strong enough to make it
34:43
spherical. It's probably peanut shaped or
34:45
rugby ball shaped or something like this.
34:47
It's probably not spherical. Around this
34:49
object, it seems that there is a system of
34:52
rings where there are three or four narrow
34:53
rings at various distances. I think the
34:55
distances are something like 273, 325, 438
34:58
and 1400 kilometers from the
35:01
center of Chiron. Got this ring
35:04
system and it's been observed again since
35:07
they did observations in 2018, 2022 and
35:10
2023, where they again figured
35:12
out that the shadow of Chiron was going to
35:14
scan across the planet, got a load of
35:17
telescopes, went on a road trip and observed
35:19
it happen to get more information about the
35:22
rings. Because having a ring system around an
35:24
object that isn't a planet is really cool.
35:27
Andrew Dunkley: Yeah.
35:27
Jonti Horner: And how did it form? How long has it been
35:29
there? What's going on? How common are ring
35:31
systems like this? Incidentally, a former PhD
35:34
student of mine, Jeremy Wood, did some really
35:37
cool dynamical studies that basically showed
35:39
that the ring system could be
35:41
primordial. It could be as old as the solar
35:44
system. From the point of view of Chiron has
35:46
never been close enough to one of the planets
35:48
to disrupt the rings. So that
35:51
doesn't put an edge limit on it, but it was
35:52
still quite cool. What the new observations
35:55
have shown though, is that, the ring system
35:57
now seems to be different to how it was in
35:59
2011. In other words, the ring
36:02
system is evolving before our very
36:05
eyes and it actually seems to be a denser,
36:07
stronger ring system now than it was 10 or 15
36:10
years ago. So it's possible that we're
36:12
actually witnessing this ring system as it is
36:14
forming or as it's changing over time.
36:17
Now I know Chiron has been quite active,
36:20
it's been outgassing because it's been closer
36:22
to the sun, hence the cometary type
36:25
classification it got. Maybe some
36:28
of the material it's ejecting in that
36:29
outgassing is being ejected gently enough
36:31
that it doesn't escape from Chiron and,
36:34
that's repopulating the rings. We just don't
36:37
know. But the only way we'll find
36:40
out is by doing more of these observations.
36:41
But I think it's just really exciting and
36:44
it's a really good reminder again that we
36:47
always kind of imagine the solar system as a
36:49
very sad and boring, placid place where not
36:51
much changing anymore because it's four and a
36:54
half billion years old. And as you get older,
36:55
you Get a bit more sedentary and not much
36:57
happens. But in fact it's a reminder that
37:00
the solar system's a really dynamic place and
37:02
things are constantly influenced, constantly
37:04
changing. We talked about it last week. The
37:06
ocean on Mimas that is possibly
37:09
only 15 million years old. Now, 50 million
37:11
years sounds like a really long time, but in
37:14
a system that's four and a half thousand
37:16
million years old, that's like something
37:19
that has happened to me in the last couple of
37:21
weeks. That's a new feature, not something
37:23
I've had since birth. And this is yet another
37:25
example of the fact that the solar system
37:27
just seems to be continually rapidly changing
37:30
and evolving.
37:31
Andrew Dunkley: Yeah, yeah, it's a really interesting
37:33
situation. how far out is
37:35
chiron?
37:37
Jonti Horner: It varies. So it's closest to the sun, It's a
37:39
little bit closer to the sun than the orbit
37:41
of Saturn. at its furthest, it's a bit
37:43
further away than the orbit of Uranus. And
37:44
that's an unstable orbit. So it bounces
37:46
around over time, it will have encounters
37:49
with them that fling it around. But at the
37:51
minute it's in the outer solar system
37:54
between the orbits of Saturn and Uranus most
37:56
of the time. Unstable solution. It probably
37:59
originated out beyond the orbit of Neptune.
38:01
And it's one of this population called the
38:03
Centaurs that are, the future parents of the
38:06
next generation of short period comets.
38:08
Effectively in the same way that the near
38:09
Earth asteroids have their origin in the
38:11
asteroid belt, short period comets have their
38:14
origin in the Transeptunian region. But to
38:17
get here from there, they've got to pass
38:18
through the outer solar system. And that's
38:19
what the Centaurs are.
38:21
Andrew Dunkley: Okay. Fascinating. Yeah, it's really
38:23
interesting and probably not one that,
38:26
too many people would be aware of. I remember
38:29
when it was making the news some
38:32
years ago, and that's why the name stuck when
38:34
you, when you sent the story to me. But, you
38:37
don't really hear much about it. But now
38:39
we've got a very good reason to look at it.
38:41
if you would like to look into that
38:43
particular paper, it's been published in
38:46
the Astrophysical Journal Letters.
38:55
Our final story, Jonti, is,
38:58
an exoplanet that the popular press are going
39:01
to say has got, some kind of life on it. it's
39:03
a, it's a maybe life candidate, story,
39:06
this one. And Yeah, but they're still
39:09
using the term super Earth.
39:11
Jonti Horner: Yeah, I'll keep this one a little bit short
39:13
and try not to get too grumpy. But one of my
39:16
big bug bears all the way through my career
39:19
is a good way for people to get media
39:22
coverage of their new planet discovery is say
39:24
it could be habitable. It's in the Goldilocks
39:26
zone. Hooray.
39:27
Andrew Dunkley: Using the L word.
39:29
Jonti Horner: Rumble, rumble, grumble, grumble.
39:30
Andrew Dunkley: It's a four letter word too, that one.
39:32
Jonti Horner: It is, and it's one of the terrible four
39:34
letter words. Part of the problem here is
39:37
there's this concept of the Goldilocks zone,
39:39
of the habitable zone, which has become
39:40
really entrenched in the popular
39:42
consciousness. And it's always viewed as
39:45
being this sweet spot for life. And the idea
39:47
is that if you have a planet in the habitable
39:49
zone, it will have liquid water on its
39:50
surface and all sorts of happy life things
39:52
will happen and everything will be good.
39:56
What it actually means is that if you took
39:58
the Earth, as it is today and put it where
40:00
that planet is, the Earth would still
40:03
maintain its liquid water because planets are
40:05
really diverse. If you took Venus and put
40:08
Venus where the Earth is, With Venus's
40:10
current atmosphere, Venus will be too hot to
40:11
have liquid water. But if you observe the
40:14
solar system from a long long way away and
40:16
you discovered Venus on the Earth's
40:18
orbit, it wouldn't look any different to the
40:21
Earth. it's a planet about the size of the
40:23
Earth, sat in the habitable sun. We, it's
40:25
habitable. Hooray. Whereas Venus is actually
40:27
so hot that on the surface it had melt lead.
40:29
And I certainly wouldn't want to visit there.
40:31
It's even hotter than my room was the other
40:34
night when the power cut had happened. And
40:36
that was bad enough and brutal enough.
40:39
so what this means is that ah, people
40:42
have become very fond of
40:45
find a planet around a star, you can work out
40:48
where the boundaries of the habitable zone
40:50
will be based on a few assumptions. And this
40:52
is work going back about a decade of the
40:55
definitions we use now. And you've got the
40:57
conservative and the optimistic habitable
40:59
zone, which are basically loosely based
41:01
around the fact that if you're as close to
41:03
the star that you get an amount of radiation
41:06
coming in comparable to Venus, you'll be too
41:08
hot. If you're about where Mars is, you'll be
41:10
too cold, but in the middle you'll be just
41:11
right m. and that's about it.
41:14
Now that definition doesn't really take any
41:16
account of the mass of the planet or its
41:18
atmosphere. What that
41:21
means is that ah, when you find a planet that
41:24
is a super Earth that Is four times the mass
41:26
of the Earth. That is almost certainly
41:29
nothing like our planet at all.
41:32
You'll do a calculation and say it sits in
41:34
the optimistic habitable zone. So there is a
41:36
potential it could have liquid water on its
41:38
surface. That's full of a whole heap
41:41
of assumptions. But to me it's a really long
41:43
stretch from saying it could have life.
41:45
Andrew Dunkley: A.
41:46
Jonti Horner: You're assuming it's got the right kind of
41:47
atmosphere to have liquid water where it's
41:49
four times the mass of the Earth. So its
41:51
atmosphere is almost certainly much, much m
41:52
thicker, Therefore
41:55
likely has a much stronger greenhouse effect,
41:58
Therefore probably runaway greenhouse. Not
42:00
good.
42:00
The other thing with this particular planet,
42:02
GJ 251C is it's a super
42:05
Earth orbiting a red dwarf star, ah,
42:08
nearby, less than 20 light years away. And
42:10
that's part of why people are excited. It's
42:12
near enough that we'll learn a lot more about
42:14
it in the future. However,
42:16
planet orbiting a red dwarf star means that
42:19
to be in the habitable zone, it's got to be
42:20
close in. This thing goes around its star
42:23
every 54 days, which means that it is
42:25
closer to its star than Mercury is to the
42:27
sun. And given the difference in the masses,
42:29
it's actually much closer in than that. That
42:32
means it's up close and personal with a red
42:34
dwarf star, which are notorious for being
42:37
active and flary and noisy, Particularly when
42:39
they're young. They're tempestuous teenagers
42:41
in their early days with mega stellar flares
42:44
and stuff like this. So it seems to be
42:47
fairly widely accepted that planets around
42:49
red dwarf stars that are close enough to be
42:51
warm enough to have liquid water will have a
42:54
hard time holding onto their atmospheres,
42:56
Particularly when the stars are young,
42:57
because it'll be having all sorts of
42:59
bonkers fun. And that's kind of borne out
43:02
with the planets around Trappist 1, which for
43:04
years have been people saying these are the
43:07
most Earth like planets ever and we'll find
43:08
life on them and hooray. And then when they
43:11
finally got to use the James Webb space
43:12
telescope and look at those planets, none of
43:15
them have an atmosphere. Now I don't know
43:17
about you, but I kind of like to breathe.
43:19
It's a fairly important part of living. And a
43:22
planet without an atmosphere is not going to
43:24
have liquid water on the surface because if
43:25
you take the atmosphere away, there's no
43:27
pressure, the oceans boil and then are blown
43:30
away by the red dwarfs, which makes that
43:32
planet a desiccated husk, which not
43:34
particularly habitable. The reason I Get
43:37
energized and activated about this. It's a
43:40
lovely discovery. It's a really interesting
43:42
planet. We'll, learn a lot more about planets
43:43
elsewhere. If there is an atmosphere, it's
43:46
around us now that's near enough to us that
43:47
with James Webb, we'll be able to study it,
43:49
learn more about the atmosphere. We'll learn
43:50
a whole heap from it. But I get really
43:53
energized about this because there's only so
43:54
many times that people can hear a story that
43:56
says we found the most Earth like planet ever
43:59
before they think we found the Earth before
44:01
they think we found life elsewhere. And that
44:04
then really devalues it. When we finally do
44:06
find planets that are, ah, properly like the
44:09
Earth, when we do find signs of life
44:11
elsewhere, scientists will be getting really
44:14
excited because we've finally done it. And
44:15
everybody will be like, well, why bother?
44:17
You've done this a million times before. The
44:19
whole boy who cried wolf thing
44:22
again, a big bugbear. And something that's
44:25
really critically important these days is
44:27
trust in science and trust in scientists. We,
44:30
we've got all the controversies about topics
44:32
that, are much more controversial than we're
44:33
talking about with astronomy, with vaccine
44:35
denial, with climate change denial, with
44:38
people refusing to evacuate in the path of a
44:40
hurricane that's coming because they don't
44:42
believe the scientists. Anything that
44:45
makes people less trusting of scientists
44:48
because they're overblowing stories is
44:51
damaging now far more than it has been in
44:54
decades past. It's part of why I get so
44:55
frustrated with Avi Loeb and Three Eye Atlas.
44:58
It's why get frustrated with the media
45:01
coverage of stories like this and the
45:02
scientists pushing, I think, somewhat
45:05
unethically an argument that this could be a
45:07
habitable planet because it makes
45:10
the rest of us look like fools. And it makes
45:12
people, it gives them ammunition to say,
45:14
well, scientists lie to us when they're not.
45:17
They're saying that this meets the criteria
45:19
for the Habitable Zone paper that was
45:21
published 10 years ago. But
45:23
it weakens that trust in science, which is so
45:26
important now more than it ever has done. And
45:28
I said I wouldn't go on a run and I'm now
45:30
waving the flag and banging the table and all
45:32
the rest of it. But it's a frustration that's
45:34
wider than this story. And this story is
45:36
lovely. It's an awesome discovery. They found
45:39
a planet going around a star. That's very
45:40
cool. We'll learn a lot more about it. It's a
45:42
brilliant result. You don't need to tag every
45:45
result like this and say that this planet
45:47
could have life.
45:49
Andrew Dunkley: And yet that's what, that's what happens.
45:52
it's sort of like, what artificial
45:53
intelligence is doing to social media. You
45:55
don't know. You don't know what you're
45:58
looking at anymore. And my
46:01
trust levels have dropped significantly in
46:03
recent months.
46:06
Jonti Horner: My dad is, 80, and
46:09
he's still on Facebook. And he doesn't like
46:10
it, but he's on it because it's a way to
46:12
communicate with people back in the uk. Moved
46:14
over here a few years ago and he's constantly
46:17
saying to me, he's getting so frustrated with
46:18
these AI stories and fake news things that he
46:21
doesn't know what to trust on there anymore
46:23
because he'll see a story that some famous
46:25
actors died and then he'll look up on
46:28
Wikipedia and they're still alive and kicking
46:29
and they've got a film coming out. But
46:31
there's this thing of, you'd never believe
46:32
the tragic photos. And it's
46:35
bizarre. And at a time when we need fidelity
46:38
and trust in our news and trust in our
46:40
science, we've got to be careful about how
46:43
much hyperbole we put into stories. I think.
46:45
Andrew Dunkley: I totally agree. Yes. If you'd like to read
46:48
about that, particular exoplanet, you can,
46:51
pick up that yarn through the Astronomical
46:54
Journal where they publish the paper. Or you
46:55
can read up on all the stories we've talked
46:57
about
46:58
today@space.com
47:01
and I'm sure a few other, platforms have
47:03
published them as well.
47:05
and that brings us to the end of, this
47:07
program. Jonti, thank you so much.
47:10
Jonti Horner: It's a pleasure. It's lovely to chat. Thanks
47:12
for bearing with me, being a bit flighty and
47:14
flirty thanks to the power cuts and the
47:15
weather.
47:16
Andrew Dunkley: You've done well. You've done well. We'll,
47:19
catch you on the next program, a Q and A
47:21
program. Johnty, Horn, a professor of
47:23
astrophysics at the University University of
47:26
Southern Queens. And thanks to Huw in the
47:28
studio, who couldn't be with us today
47:31
because he never tells me. I
47:34
have no idea. I just make up the reasons he's
47:37
not here. I honestly don't know why he didn't
47:39
turn up this week. Probably because we didn't
47:41
tell him when we were recording.
47:42
Jonti Horner: That might have been it.
47:44
Andrew Dunkley: and from me, Andrew Dunkley, thanks for your
47:46
company. Catch you on the very next episode
47:49
of Space Nuts. Bye.
47:50
Jonti Horner: Bye.
47:52
You've been listening to the Space Nuts
47:54
podcast, available at
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48:06
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