Latest / Space Nuts: Astronomy Insights & Cosmic Discoveries / Lunar Magnetism & Cosmic Signals: Insights into Moon Mysteries and Radio Discoveries

Transcript

Lunar Magnetism & Cosmic Signals: Insights into Moon Mysteries and Radio Discoveries · Space Nuts: Astronomy Insights & Cosmic Discoveries

0:00
Professor Fred Watson: Hi there.
0:00
Andrew Dunkley: Thanks for joining us. This is another
0:03
episode of Space Nuts. We talk
0:05
astronomy and space science and window
0:08
dressing. And you name it, we will talk
0:11
about it. And, uh, my name. Did I
0:13
say my name? My name is Andrew Dunkley, your
0:15
host. Good to, uh, have your company. Uh, on
0:17
today's episode, we're going to look at lunar
0:19
magnetism. Did the moon ever have, uh,
0:23
a magnetic field? Uh, or, um,
0:26
is there something else that had happened to
0:28
it in the past? They think they've got it
0:30
figured out. Maybe, uh, we're going to talk
0:33
about a not alien radio signal.
0:37
Windows, uh, in spacecraft, uh, have
0:40
come of age. And we'll tell you all about
0:42
that. I, uh, think the early astronauts
0:44
insisted. I want a window. I want a
0:46
window. And they got one.
0:48
Well, now it's, uh, very high tech and
0:51
a very interesting photograph. A chance photo
0:54
that turned out to be rather special. We'll
0:56
tell you all about it on this episode of
0:59
SpaceNarts.
0:59
Professor Fred Watson: 15 seconds. Guidance is internal.
1:02
10, 9. Ignition
1:05
sequence.
1:06
Professor Fred Watson: Star space nuts.
1:07
Professor Fred Watson: 5, 4, 3. 2. 1, 2, 3, 4,
1:10
5, 5, 4, 3, 2, 1.
1:12
Andrew Dunkley: Space nuts.
1:13
Professor Fred Watson: Astronauts report it feels good.
1:16
Andrew Dunkley: And with us again to sort out all of
1:19
that is Professor Fred Watson Watson,
1:21
astronomer at large. Hello, Fred Watson.
1:24
Professor Fred Watson: Hello, Andrew. Good to see you again. How's
1:26
your week of golf gone?
1:28
Andrew Dunkley: Um, painful. My back is, uh,
1:30
protesting. In fact, I played my
1:33
fourth round, uh, to wrap
1:36
up 72 holes of golf, uh, over five days.
1:39
We had a rest day on Wednesday. I think, um,
1:41
it should have another name like why are you
1:43
bothering day. And,
1:46
um, I tweaked my back,
1:49
strangely enough. I was just, um, bending
1:51
over to, um, adjust the ball.
1:54
And, uh, I wasn't quite balanced. So when I
1:57
moved my leg to correct my balance, my lower
2:00
back went, nope, can't do that and I'm going
2:02
to hurt you. And yeah, I spent the rest of
2:05
the round fighting that. But I had a pretty
2:07
good week. I came second in the 36 hole
2:09
event, which was terrific. And I had three
2:11
nearest the pins. That's the, that's the
2:13
closest shot to, to the hole on a par three
2:17
where the ball stays on the green. So, yeah,
2:20
um, so yeah, I had a good week. I hit the
2:23
ball quite well. I was very, very pleased.
2:26
Not, um, as pleased as if I could have won
2:27
it, but, you know, that's golf. That's golf.
2:32
How's, um, your week been? It's been a long
2:35
time since I saw you.
2:36
Professor Fred Watson: Well, yes, so I'm still, um, still
2:39
nursing the new knee. And the milestone this
2:42
week was getting out on the. On the bike
2:43
again, uh, for the first time. Which
2:46
is great because, uh, it's a good way of
2:49
extending your range of motion on the knee,
2:52
uh, which is all about
2:54
straightening it. Uh, the
2:58
straightening is what's called the extension,
3:00
which has to be zero degrees. And,
3:03
um, as it is on the knee that I had done in
3:07
2020, it, uh, took a while to get there,
3:10
but I did.
3:11
Uh, at the moment, the new knee is standing
3:13
at 2 degrees. Uh, but getting
3:16
on the bike actually lets you stretch it. Uh,
3:19
and so I'm hoping that will pull it down so
3:21
that when my physiotherapist,
3:23
um, from Doncaster in Yorkshire,
3:26
uh, measures it next week, uh, she
3:29
might find there's a bit a big a difference
3:31
down from the 2 degrees that it was this
3:33
week.
3:34
Andrew Dunkley: What you. What you don't want to hear when
3:36
you're riding a bike after knee surgery is
3:38
the clatter of titanium on tar.
3:42
You don't want to hear that.
3:44
Professor Fred Watson: That will be bad. And, um, yes,
3:46
yes, the physiotherapist tells a horror story
3:49
that's not too far from that. Oh,
3:52
really? Yeah. She said, I can
3:54
tell you this now. I can tell you this now
3:56
because your. Your wound has healed up
3:58
completely. I won't relate it,
4:01
no, but I'm imagining. Yeah, it was a horror.
4:04
Yeah, yeah. Pretty horrible. Anyway, never
4:06
mind. Nasty.
4:08
Andrew Dunkley: All right, uh, we should, uh, get down
4:11
to our stories.
4:12
And this first story takes us, uh, to
4:15
the moon. Um, the moon's been in the
4:18
news a lot lately for all sorts of different
4:20
reasons. The lack of was, I think, the last
4:22
thing we talked about. But, um,
4:25
this story is actually focusing on
4:28
the, um, magnetic field. Now, Earth's got a
4:31
magnetic field. It's generated by all the
4:33
goop inside that's doing whatever the goop
4:36
does. Um, and that, uh,
4:38
magnetic field protects us from
4:41
being burnt alive or whatever. Um,
4:45
now the question is, did the moon ever have a
4:47
magnetic field? If it did, how was it
4:49
generated? And so on and so
4:52
forth. Uh, what's the situation?
4:56
Professor Fred Watson: Uh, so, yes, the bottom line
4:59
is the Moon doesn't really have much of a
5:02
magnetic field now. Uh, it's
5:05
got traces of magnetism.
5:08
And interestingly, those
5:10
traces of magnetism tend to correspond
5:13
with, uh, what was the buzzword back in
5:16
the 1960s? The Mascons. Uh, the
5:20
mass concentrations underneath the surface of
5:23
the moon, which were discovered when, uh,
5:25
orbiting spacecraft were first sent to the
5:27
moon in advance of the Apollo
5:29
missions. Uh, so,
5:32
uh, that's a sort of pointer, the fact that
5:35
where you've got These mass concentrations
5:37
under the surface. And you detect those by
5:39
the way, by the fact that they pull down on
5:42
an orbiting spacecraft and so its
5:45
trajectory changes slightly. Uh,
5:47
so that's, um, what
5:50
basically what lets you plot them. And in
5:53
fact you can see maps of the mascons these
5:55
days because we've had many, uh, orbiting
5:58
spacecraft that have charted them. Uh, so.
6:00
But the magnetism tends to concentrate there.
6:03
And as I said, that's the first clue. So this
6:06
is some research that's been done by
6:08
scientists at, um, actually Einstein's old
6:11
university, ETH Zurich, uh,
6:13
and they have, um,
6:16
basically looked at, uh, some
6:19
of the evidence from, perhaps more carefully,
6:22
the evidence from the gravitational samples,
6:24
the fact that, uh, these can now be mapped
6:27
with great accuracy.
6:30
Um, so, uh, what they
6:32
have done, uh, this is published
6:35
now, I think it might be still being
6:37
refereed, but I think it's published.
6:39
Uh, they've looked at a, uh, region.
6:42
Um, it's, uh, actually on the far side of the
6:45
Moon. It's called Duar D E W A
6:48
R, uh, which is the name of a very
6:51
famous, um, Scotch whiskey, as probably
6:53
people would know, but it's also the name of
6:56
something on the moon. Probably came from
6:58
the same origin. I don't know. Anyway, it
7:00
turns out that, uh, this Dewar
7:03
region has one of the strongest,
7:07
what they call a magnetic field anomaly.
7:08
Which means basically there's a magnetic
7:10
field there, uh, because, um,
7:13
the Moon generally doesn't have a strong
7:16
magnetic field. So, um, one of the
7:19
authors remarks that the Dewar region is
7:21
genuine stroke of luck, one of the strongest
7:24
magnetic field anomalies on the far side of
7:26
the Moon. And a distinct gravity anomaly
7:28
coincides spatially there. They're in the
7:31
same place. Um, so it means
7:34
that, uh, the region
7:37
of the Moon's surface, um, has
7:39
rocks that are both, uh,
7:42
more strongly magnetised and
7:46
more dense, a denser concentration
7:49
of mass than elsewhere. And,
7:52
uh, the trick now is to
7:55
sort of analyse both of these aspects, the
7:57
fact that you've got a mass concentration
8:00
and, um, uh, a magnetic
8:03
field anomaly. Uh, another comment from one
8:05
of the authors. The gravity data give us
8:08
insight into the density and
8:10
thus into the material beneath the surface,
8:14
uh, where the magnetic field and gravity
8:16
signals coincide. It's possible to combine
8:18
the two and attribute the anomaly to a
8:20
specific geological structure.
8:23
Uh, this is precisely the opportunity that
8:25
Dewar offered. Uh, and so that's what they've
8:28
done. They've basically built a model that
8:32
um, actually mimics
8:35
both, uh,
8:38
the gravity concentration, the uh, increased
8:41
density and the magnetic field. And
8:44
so what the outcome is is that
8:47
somewhere below the surface of the Moon in
8:49
this region, there's a body of rock
8:52
quite big, 60 kilometres wide, uh,
8:55
going down something like nine kilometres,
8:59
uh, much denser than its surrounding, uh,
9:02
crustal region and
9:04
also strongly magnetised. And
9:07
so what they have concluded is that this
9:10
is basically solidified
9:13
magma, something that goes, uh,
9:16
back to when the Moon was
9:19
a much more molten object than it is
9:22
now, um, with a, you know, viscous mantle.
9:25
Uh, and what they're saying is that because
9:28
they think this structure is 4.2 billion
9:30
years old, it's nearly as old as the Moon is.
9:33
Um, what you can
9:36
do is, um. Well,
9:39
I'll read again from the comments from the
9:40
author. Um, because we know how much iron is
9:43
present in such a rock body, we can estimate
9:45
the minimum strength the magnetic M field
9:48
must have had as the magma cooled
9:51
slowly. That's a very important finding.
9:54
Uh, we found that the magnetic field on the
9:56
Moon at that time was very likely
9:59
stronger than 10 micro Tesla. On Earth
10:02
today, the magnetic field strength is around
10:04
50 micro Tesla. So what they're saying is
10:07
that this supports the notion that,
10:10
uh, the Moon had a primordial
10:13
magnetic field, it had magnetism, uh, when it
10:16
was a young object, rather than an
10:18
alternative explanation for the magnetism,
10:21
which is, um, that, uh, it could have
10:24
been caused locally, you know, this
10:26
magnetism being caused here and there on the
10:29
Moon's surface, maybe by impact. Uh, the
10:32
effect of the impact would be to increase the
10:34
magnetism. And so, uh,
10:37
the outcome is that that's not likely to be
10:40
the source of the magnetism. It's likely
10:43
to have been a primordial magnetic field.
10:47
Andrew Dunkley: Um, so they're suggesting that it's a
10:50
leftover effect. So the Moon did have an
10:53
internally generated magne magnetic field as
10:55
it's cooled down and solidified. This is just
10:58
a residual leftover magnetic
11:01
anomaly.
11:03
Professor Fred Watson: Exactly that.
11:04
Uh, so they say this means, yes, the
11:07
Moon was magnetic at one point.
11:10
There's a little sort of subsidiary study
11:13
though, that I think is quite interesting.
11:15
Um, we haven't talked about them, I don't
11:17
think, Andrew. But there are features on the
11:19
surface of the Moon which are called lunar
11:21
swirls. Uh, they're
11:24
sort of regions of brighter material, uh,
11:27
which form in swirls,
11:30
uh, rather than, you know, the craters and
11:33
mountains that we're used to seeing.
11:36
But what they have noticed in their work
11:39
is that wherever there's a swirl,
11:41
there's one of these magnetic anomalies. And
11:44
it turns out that the region they've been
11:47
Looking at this Dewar region, uh,
11:49
has a lunar swirl. Uh, and so,
11:53
um, you know, the struggle is
11:55
now to explain this. Why would you have these
11:58
curious features, uh, on the
12:01
Moon's surface, um, which are
12:03
linked with magnetism? And
12:06
they're basically suggesting
12:09
that you only get the
12:12
swirls when you are in
12:15
an area where the magnetic field,
12:18
the field lines, the light of force,
12:21
are actually horizontally at the surface.
12:24
Because that's the case with this Dewar
12:27
lunar, uh, swirl. And so what
12:30
they're thinking is that maybe the horizontal
12:32
field actually modifies the solar
12:35
wind, perhaps it deflects it, perhaps it
12:38
protects the surface from weathering by the
12:40
solar wind and you get this brighter, uh,
12:43
region. Uh, it's a really. Yeah.
12:46
Isn't it an interesting piece of work? It's
12:48
got so many, uh, facets to it. I think this
12:50
is one of the most interesting pieces of, uh,
12:53
lunar research that we've seen for a while
12:57
Professor Fred Watson: and.
12:57
Andrew Dunkley: Yeah. Adds another, um, element to our
13:00
growing knowledge of what the Moon is all
13:02
about.
13:02
And uh, yeah, um,
13:07
I think we're kind of lucky to have it. Uh,
13:10
I mean, it's good for life on Earth. I don't
13:13
know if we'd exist without it, would we?
13:16
Professor Fred Watson: That's right. Uh, probably not. The,
13:19
um, Earth's magnetic field almost certainly
13:21
is what's allowed us to evolve from microbes
13:24
into the.
13:26
Andrew Dunkley: When you sit down and look at all the data
13:29
and start to really analyse it, um, there
13:32
is so much that exists that
13:35
we need to exist, if that makes any
13:37
sense. Um, if one or two of those things
13:41
never happened, we wouldn't have happened
13:42
either. It just blows your mind that all of
13:44
this stuff that enabled life to
13:47
evolve to this level on Earth had
13:50
to be just right and um. Yeah, it's gotta be
13:53
a rarity.
13:55
Professor Fred Watson: That's right. And I think that's the thinking
13:57
among astrobiologists. Everything,
14:00
you know, uh, basically everything has come
14:02
right, uh, on Earth for
14:05
an intelligent species to evolve. And it's
14:08
not necessarily the case elsewhere.
14:10
Andrew Dunkley: Yeah, interesting.
14:11
If you'd like to read about, uh, the Moon's
14:14
historical magnetic field, you can
14:17
do so@phys. That's
14:19
P-H Y-S.org or you can
14:22
read the Study in Science Advances.
14:25
This is Space Nuts. Andrew Dunkley here with
14:27
Professor Fred Watson Watson.
14:33
Professor Fred Watson: Space Nuts.
14:34
Andrew Dunkley: Our, uh, next story, Fred Watson, uh, is
14:37
a not alien signal, but it's
14:40
fascinating because it is a signal, a
14:42
radio signal coming from, uh.
14:45
Yeah, they usually think it's these things
14:47
come from stars, but this one, they've
14:49
actually been Able to say, hang on a minute,
14:52
we think, in fact we are sure this one's
14:55
coming from a planet. And of course that gets
14:56
the tongue swagging. Oh, it's a planet, it
14:58
must be aliens. But it's not. It's something
15:01
else, something we all know about.
15:02
Professor Fred Watson: It is really correct. That's
15:05
absolutely right. Uh, and yes, the reason
15:08
why this is a big story is that these are ah,
15:11
radio signals that come from an exoplanet,
15:14
uh rather than a gas cloud in space
15:17
or a star or a radio galaxy, all the other
15:20
things that emit radio waves. This is
15:22
actually from a planet. Uh, and um,
15:26
the way it's been uh, proved
15:29
that it comes from a planet is really one of
15:31
the most interesting parts of the story, uh
15:33
as well as how we know it's there.
15:37
Andrew Dunkley: It was all the selfies that came in with
15:39
it.
15:41
Professor Fred Watson: Yeah, the selfies did it. So this is
15:44
um, it's a gas giant.
15:46
Uh, it is called Beta Pictoris B.
15:49
It's an exoplanet that has been known for
15:51
many years. Uh, the fact that it's called
15:54
Beta Pictoris B means it's the first
15:56
discovered planet around a star called Beta
15:59
Pictoris, which I think is about 50,
16:02
54 if I remember rightly. Light years away.
16:04
64. There you go. Uh, so
16:07
it's a uh, relatively nearby star. Um,
16:11
so um, the other thing that I find
16:13
interesting about this is uh, it uses
16:16
the, the data that have led to this
16:19
discovery have come from Meerkat, the um,
16:22
radio telescope which is similar to the
16:25
Australian Square Kilometre Array Pathfinder,
16:27
uh in Western Australia. Meerkat is its sort
16:30
of equivalent in uh, the Haikaru
16:33
region of South Africa and a very, very
16:36
effective telescope doing some fantastic
16:38
stuff. And it's been used uh, actually by
16:41
scientists at the Centre for Astrophysics,
16:43
um, uh, in the Smithsonian, Havardon
16:46
Smithsonian, uh, um, they've used
16:49
this uh, RIP meerkat to make
16:52
very, very accurate measurements of the
16:54
position of this radio noise.
16:57
And the way they've done it is a way
17:00
that uh, to some extent we've used
17:02
before and I'm not sure whether you and I
17:04
have ever spoken about it. Uh, when
17:07
you're measuring the position of objects
17:10
in space, and I mean in two dimensions now
17:12
I'm talking about the direction uh, that any,
17:16
that the radiation comes from. Uh what you
17:18
have to do is to calibrate it. You
17:21
need to know where the sort of zero point is.
17:24
So um, you need
17:27
background objects that don't change their
17:29
position, uh, to do the Relative
17:32
measurements. And those background objects
17:36
are uh, ah, things that are far, far more
17:39
distant than uh, 64 light
17:42
years. Uh, their distances are measured in
17:44
billions of light years. And they are
17:45
quasars. Quasars are very
17:48
bright in radio waves and perhaps especially,
17:51
and this is, you know, what allows you to do
17:54
this, they are effectively point sources.
17:55
They're a single point of radio waves. Very,
17:58
very compact, uh, objects and they're at
18:01
great distances. So that lets you build a
18:04
framework, um, um,
18:07
ah, almost like a map. Uh,
18:10
you can map these quasars and then look at
18:13
your foreground object and relate its
18:15
position very accurately by the fact that
18:17
the, the quasars don't change their position
18:19
in space because they're so far away. Um, and
18:22
that's how they've done it. Uh, that's how
18:24
they've uh, um, worked out
18:27
that these radio signals come not from the
18:29
star itself, Beta Pictoris, but from Beta
18:32
Pictoris B, this uh, gas giant that's in
18:35
orbit around it.
18:37
And the thing you alluded to. Right, sorry,
18:39
go ahead.
18:40
Andrew Dunkley: No, well, I was just gonna let you
18:43
reveal it.
18:44
Professor Fred Watson: And the source is, it's um,
18:47
northern and southern lights on the planet.
18:49
It's uh, the aurorae, uh, which we know,
18:52
um, are not radio noisy, uh,
18:55
auroral displays. They are on our own
18:57
planet you can detect aurorae by radio
19:00
signals. Um, I prefer to go and stand
19:02
underneath them in the far northern Arctic in
19:05
winter. Uh, and then you see
19:08
these things in all their glory. But they
19:11
do emit radio signals as well. And that's
19:14
basically how um, these signals came to
19:17
be.
19:17
So it's a big triumph. It's the first time
19:20
that we've proved that aurorae exist,
19:24
uh, on other planets in other solar
19:26
systems. We know they exist on all the gas
19:29
giants have, in our solar system. They all
19:31
have Aurory, the Earth does, Mars
19:33
occasionally does. But this is just saying
19:36
that wherever you've got a star with a planet
19:38
going around it, um, you've probably got them
19:40
as well. All you need is a planet,
19:44
sorry, a star that's giving out, uh, charged
19:47
particles, high energy particles, subatomic
19:50
particles, and a planet with an atmosphere
19:52
which is. These are the ingredients you've
19:54
got there because the high energy particles
19:56
essentially excite the atmosphere into
19:59
beaming out light and beaming out radio
20:02
signals.
20:03
Andrew Dunkley: Simple as that.
20:04
Professor Fred Watson: Yeah, simple as that. Yeah.
20:05
Andrew Dunkley: Yeah, but because.
20:06
Professor Fred Watson: Very nice work.
20:08
Andrew Dunkley: Yes. It's the first time, as you said, the
20:10
first time they've detected this sort of
20:13
signal from an exoplanet. So, um,
20:15
yeah, it's a good pickup.
20:16
I love the name Beta Pictoris B.
20:19
It's a good name for a planet. Um, if you
20:22
would like to read about that, that's on the
20:24
phys.org website as well. But they have
20:26
published their work uh, on the Arxiv
20:29
Preprint server. This is Space
20:32
Nuts and you're with Andrew Dunkley and
20:34
Professor Fred Watson Watson.
20:38
The crew of Artemis 2 now bound for the moon.
20:41
Professor Fred Watson: Humanity's next great voyage begins.
20:44
Andrew Dunkley: Space Nuts. Now Fred Watson, uh,
20:48
from um, the extraordinary Magnetism uh
20:50
on the moon and a. Ah. Rory signals from an
20:53
exoplanet to Windows.
20:56
Windows in spaceships. You know it
20:59
doesn't sound all that exciting but uh, in
21:02
the early days of the space race when the
21:04
United States and uh, and uh,
21:07
the Soviet Union trying to beat each
21:10
senseless to get to the moon, um, the early
21:13
astronauts, those very brave souls, uh,
21:15
insisted, insisted that they had to have a
21:18
window as far as I remember.
21:21
And they got it. Ah, of course they've come
21:24
of age now. Um, they've done some amazing
21:26
things with uh, windows in spacecraft.
21:28
And it's in the news again.
21:31
Professor Fred Watson: Yes, that's right. Uh, uh, and it's
21:34
partly in the news for the reasons that
21:36
you've mentioned that astronauts uh
21:38
themselves have always uh,
21:41
been very keen on having windows. As you
21:43
would if you're gonna sit, you know, 100
21:45
kilometres above the Earth's surface, uh
21:48
hurtling around at seven kilometres, seven or
21:50
eight kilometres per second. You're
21:52
definitely going to want to watch the view as
21:54
it goes past.
21:55
Andrew Dunkley: I would, I would say so. What was it like up
21:57
there? I don't know. I was looking down at
21:59
the plywood,
22:02
Professor Fred Watson: couldn't see anything. So even certainly the
22:05
first um, manned or crewed spacecraft
22:08
in the um, um, NASA's human
22:10
space flight programme, which was Mercury,
22:13
uh, Mercury had a tiny little window. It's
22:16
just a few inches in diameter, a little
22:18
almost a porthole. And it
22:21
wasn't much bigger in the Gemini spacecraft
22:23
either. They had um, forward pointing
22:26
windows which um, were sort of
22:28
scalloped out of the shape of the nose
22:31
cone. And Apollo had uh, forward pointing
22:34
windows as well, which they needed of course
22:35
by then as they did with Gemini. Uh,
22:38
and the reason why they're forward pointing
22:40
is that that's where the docking ports are.
22:43
You need to be able to you know, see where
22:45
your spacecraft is going if it's going to
22:48
dock with another spacecraft. And the docking
22:50
port is always in the narrow part in the
22:52
nose. Uh, so yeah, that's
22:55
that. Windows became essential at that point.
22:58
Andrew Dunkley: And Yuri Gagarin had a
23:01
window as well.
23:01
Professor Fred Watson: I thought he did. I was going
23:04
to muse on that, but I thought that was
23:06
right, that he had a window too. Um,
23:10
it's kind of, uh.
23:12
The window to be all windows, of
23:15
course, is the cupola. The, uh,
23:18
cupola, I should call it, give it its proper
23:20
name. Uh, it's on the International Space
23:23
Station. It has, uh. I think it's
23:26
seven. It might be nine,
23:29
uh, panels of glass, uh, which.
23:33
It's like a bay window, uh, which
23:35
Andrew Dunkley: I'm looking at a photo of it now. Yes.
23:38
Professor Fred Watson: Yeah. How many windows has it got? Is it
23:40
seven?
23:40
Andrew Dunkley: Um, one, two, three.
23:45
Probably about eight. Eight or nine.
23:47
Because there's one directly above as well.
23:50
That'd be nine.
23:50
Professor Fred Watson: I think this is the front window. Nine's what
23:52
I guessed as well. Um, and I think the
23:55
astronauts on the International Space Station
23:57
spend quite a lot of time in that enclosure.
24:00
Uh, not just because it lets you
24:03
see the various components of the space
24:05
station, uh, and watch progress
24:09
when there are, um, ext. Vehicular
24:12
or when there is extra vehicular activity
24:14
taking place. Uh, they're
24:17
important for that point of view, but they're
24:19
also important to watch the Earth going by.
24:21
And we've seen so many great
24:24
photos and videos that have been taken
24:26
through the cupola window. Um,
24:28
so that's the. Essentially,
24:31
uh, the high point
24:34
of window design on the spacecraft.
24:37
Uh, but, uh, we've also
24:40
got six windows. Is it.
24:43
Andrew Dunkley: It's described as a trapezoidal
24:46
arrangement, but six.
24:48
Professor Fred Watson: Yeah. All right, Maybe there's some blank
24:50
ports on the other side from working.
24:53
Never mind. Um, I was just going to mention
24:56
that both Virgin Galactic with their space
24:58
plane, uh, and Blue Origin with their
25:01
space plane, uh, which are now. Well,
25:04
certainly Blue Origin is no longer being used
25:06
because they're concentrating their efforts
25:08
on Artemis. But, um, they
25:11
have got big windows as well. And in fact,
25:13
Blue Origin were really quite big, uh,
25:16
almost like bay windows around the whole
25:19
spacecraft. Uh, uh, a conical spacecraft
25:21
again, carried up to suborbital
25:23
heights, uh, about 100 kilometres on
25:26
a rocket. So the.
25:29
I mean, the story here is, yes,
25:32
windows are important, uh,
25:35
but, uh, are they safe? And, ah.
25:38
Um. There's an
25:41
analysis that window glass is a.
25:44
As one of the analysts working on
25:46
this, uh, says
25:49
glass is a brittle material.
25:51
It breaks. That's what it likes to do. But
25:53
it's also beautifully transparent. Uh,
25:56
and so, um.
25:59
Uh, basically, I think what they're saying
26:01
with all this is it is a balancing
26:04
act, uh, between the glass,
26:07
uh, being safe
26:10
and you Wanting to have
26:13
as much real estate in terms of
26:16
visible or transparency as possible.
26:19
Um, so, uh, uh, the
26:22
bottom line I think is that windows
26:25
are a worry.
26:28
You would need to have,
26:30
um, some way of
26:32
evacuating or
26:35
isolating the region where there's a window,
26:38
uh, in order to protect astronauts. I mean in
26:40
the early days, the Apollo, sorry, the Gemini
26:43
and the um, Mercury capsules, uh, if
26:46
there'd been a fracture, they'd have been
26:48
into their spacesuits pretty damn quick.
26:51
Uh, whereas now, uh, you all
26:53
evacuate that chamber and shut the door.
26:56
Uh, that would be what would happen. I don't
26:58
think it ever has happened. I uh, don't think
27:01
there's ever been a broken window. I might be
27:03
wrong with that. But, um, that might be one
27:06
we can check with A.I. uh, but
27:09
the bottom line here is, uh,
27:12
our acrylics a better choice
27:15
than glass because it's a more
27:18
stable material.
27:20
Something like Perspex.
27:22
Andrew Dunkley: Yeah. Um, not
27:24
as good to look through though.
27:26
Professor Fred Watson: Uh, probably not. That's right. And there
27:29
might be other issues with acrylics,
27:32
uh, in that regard.
27:34
Professor Fred Watson: Yeah.
27:34
Andrew Dunkley: Okay, well, watch this space. Boom.
27:36
Professor Fred Watson: Boom.
27:37
Andrew Dunkley: Um, but it's through the window. Yeah. It's
27:40
an interesting problem. Uh, this wouldn't be
27:43
the same kind of glass you'd use at a house.
27:45
In a house or an office block though, would
27:47
it? It'd be pretty highly specialised.
27:50
Professor Fred Watson: Yeah. It might be more like what you. Might
27:53
be more like what you've got in your car. Um,
27:55
you know, toughened somehow in.
27:58
In a way that would, would um. If they were
28:01
going to fracture, they'd do it safely rather
28:03
than. The last thing you'd want is shards of
28:05
glass, uh, floating around in
28:09
ah, zero gravity. Um, you know, imagine a
28:12
sharp bit of glass going in front of your
28:14
face if you're um, in
28:17
orbit with uh, with microgravity.
28:20
Andrew Dunkley: Yeah, indeed. Well,
28:22
uh, you can read that story@space.com
28:25
and uh, maybe you're a glazier and you've got
28:28
their window problems sorted out. Maybe you
28:31
know that NASA doesn't um, drop them a line,
28:33
send them a bill M. And good
28:36
luck getting your money.
28:37
No, I'm kidding. Uh, but uh, yeah, space.
28:39
Space.com is the uh, place
28:42
to uh, learn about windows in spacecraft.
28:45
Uh, one little thing before we go,
28:47
Fred Watson. And this, this is a fascinating
28:49
story in that uh. It was an opportunistic,
28:53
um, photo that was taken
28:55
and um, you know,
28:58
right place, right time, exact right
29:01
moment to create, uh, this little
29:04
picture. I'll try and get Huw to put it um,
29:06
on our website as the COVID photo for this
29:09
Week's episode, episode 669, just
29:12
in case you're wondering. And, um, see if you
29:14
can take a look at it or you can look it up
29:16
at the NASA website. But, uh, yeah, tell us
29:18
about this photo, Fred Watson.
29:20
Professor Fred Watson: So, um, it's one of, uh,
29:23
NASA's astronomy pictures of the day, the
29:25
APOD. Uh, and it's for the 22nd
29:28
of September, 2026. So just a few
29:31
days ago as we're recording, um, and
29:34
it's um, a photo by, uh,
29:37
an astronomer from the Czech Republic,
29:40
uh, who was aiming to get a nice
29:43
silhouette of the International Space
29:46
Station against the sun. And
29:49
that's something that's been done before. Um,
29:52
there's a French astronomer who's kind of
29:53
made an art of it. Uh, but this is, uh,
29:56
somebody who's got a big enough telescope to
29:59
give you a great view of the sun, uh, aiming
30:01
to get. Get, uh, the International Space
30:03
Station silhouetted on the sun's disc. It's
30:05
tiny compared with the disc of the sun, of
30:07
course. Uh, and he indeed
30:10
succeeded in doing that. But he also got a
30:12
bonus because one of the exposures, and I'm
30:15
sure he took several. The International Space
30:17
Station does not dwell. Uh, it goes very
30:19
quickly across the disc of the sun.
30:22
Andrew Dunkley: Oh, yeah, it would.
30:22
Professor Fred Watson: I think it's less than a second. Um, but he
30:25
managed to catch a plane as well going across
30:27
the disc.
30:28
Andrew Dunkley: So what we're looking at at in the foreground
30:30
is the silhouette of a plane and
30:34
behind it the sun. And in between, or kind of
30:36
hanging off the back of the plane is the
30:38
International Space Station. And just to make
30:40
it even more interesting, there's a few
30:42
sunspots as well. It's a really great photo.
30:44
Very, very.
30:45
Professor Fred Watson: Yes, indeed.
30:46
Andrew Dunkley: Isn't it just a piece of luck,
30:49
uh, a chance opportunity that, um. Yeah,
30:52
turned out rather well.
30:54
Professor Fred Watson: Indeed it did. Yes. Very nice. And
30:56
congratulations to, to Peter who
30:59
did that. Uh,
31:02
I think some of our listeners will probably
31:04
be able to identify the aircraft. It
31:07
looks to me like a military aircraft.
31:09
Andrew Dunkley: Uh, yeah, it does, doesn't it?
31:11
Professor Fred Watson: Yeah. I wouldn't like to hazard a guess as
31:14
to what it was though, but yeah, well done,
31:16
Peter. It's actually Peter, not Peter P E T
31:18
R. Um, he's, uh, from the Czech
31:21
Republic.
31:22
Andrew Dunkley: Lovely. Uh, yes, go to the NASA website
31:25
and just do a search for APOD
31:27
22nd of September, 2026. If you want to have
31:30
a look at it. You should be able to find it
31:32
there, but I'll try and put it on our website
31:34
as well as the COVID shot for this
31:37
episode. And that brings us to the end.
31:39
Fred Watson, thank you so much.
31:41
Professor Fred Watson: Oh, it's a, uh, pleasure, Andrew. Haven't we
31:43
got to the end already?
31:44
Well, we have time. Goes fast when you're
31:46
enjoying yourself.
31:47
Andrew Dunkley: It does indeed, yes. Um, we'll catch you next
31:50
time, Fred Watson. Thank you.
31:51
Professor Fred Watson: Sounds good.
31:52
Andrew Dunkley: Professor Fred Watson Watson, astronomer at
31:54
large. Visit our website in between episodes,
31:56
of course, spacenutspodcast, uh, dot com.
31:59
And, uh, you can send us messages through the
32:01
Ask me Anything link. At the top it's marked
32:04
ama. You can visit the shop, you can sign up
32:06
for the astronomy newsletter. Don't forget to
32:08
leave reviews wherever you listen to us.
32:11
Apparently they help with something.
32:14
Don't know what. I guess it depends what kind
32:16
of review you leave us. Yes, uh, and
32:19
thanks to Huw in the studio. Couldn't be with
32:21
us today. Um, he was actually quite lucky.
32:23
Uh, he, um, took an
32:26
opportunist photo. When I say lucky. Uh,
32:29
yeah, the photo was, um, was a. Was a bonus.
32:31
But, um, was woman's husband was not
32:34
thrilled and he's on the run anyway, he might
32:36
be back next week if he's not in hospital.
32:39
And from me, Andrew Dunkley. Thanks for your
32:41
company. We'll catch you on the next episode
32:42
of Space Nuts.
32:44
Professor Fred Watson: Bye. Bye.
32:45
Andrew Dunkley: You've been listening to the Space Nuts
32:48
podcast, Mission complete Eastern of the
32:50
available at Apple Podcasts, Spotify,
32:53
iHeartRadio or your favourite podcast
32:56
player. You can also stream on
32:57
demand@bytes.com.
32:59
Professor Fred Watson: this has been another quality podcast
33:01
production from bytes.com.