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Unraveling Cosmic Mysteries: Big Rips, Neutron Collisions & Lunar Sunsets · Space Nuts: Astronomy Insights & Cosmic Discoveries

0:00
Andrew Dunkley: Hello again and thank you for joining us.
0:02
This is a Q and A edition of Space
0:04
Nuts. My name is Andrew Dunkley. Thanks for
0:07
your company. Uh, in this show we answer
0:10
audience questions and we've got,
0:13
uh, plenty. Today, uh, Martin
0:16
is asking us questions about the Big Rip.
0:19
Or is it the gnab gib. We don't know which.
0:22
Uh, Mike is wanting to know what was
0:25
around before the Big Bang. I think we've had
0:27
that one before but we will revisit it. Uh,
0:30
questions about colliding neutrons on the
0:32
stars and sunsets on the moon.
0:35
Ah, how, ah, beautiful. Sitting
0:37
there looking out over the Sea of Tranquilly
0:40
getting covered in dust a
0:43
pina colada that you can't drink because you
0:45
know. Never mind.
0:48
We'll answer all of those questions on this
0:50
episode of Space Nuts. 15 seconds.
0:53
Professor Fred Watson: Guidance is internal. 10,
0:55
9. Ignition sequence start.
0:58
Space Nuts. 5, 4, 3, 2.
1:01
1. 2, 3, 4, 5.
1:04
Speaker C: 4321.
1:04
Professor Fred Watson: Space nuts astronauts report it feels
1:07
good.
1:08
Andrew Dunkley: Joining us again to solve all of those
1:10
riddles is Professor Fred Watson Watson,
1:12
astronomer at large. Hello Fred Watson.
1:14
Professor Fred Watson: Hello Andrew. Good to hear your
1:17
uh, conjectured sunset. Uh, drinks on the Sea
1:20
of Tranquilly. I hope I can join you for it.
1:23
Andrew Dunkley: Even if you could suck on that straw. Uh,
1:26
lunar regolith probably doesn't taste very
1:28
nice.
1:30
Professor Fred Watson: That's right, yep.
1:32
Andrew Dunkley: But um, yes, one day someone will be sitting
1:35
in a, um, in a building looking out over
1:38
the lunar surface, probably, you know,
1:41
downing a beer or who knows what,
1:44
uh, or maybe they'll just have to suck it out
1:46
of the, the air in front of them because of
1:48
the gravity. Who knows? Um, shall
1:51
we get down to business and see if we can
1:53
solve some of this stuff?
1:54
Professor Fred Watson: Why not?
1:56
Andrew Dunkley: All right, our first question comes from
1:58
Martin. Now this was a really long involved
2:01
question and I' um, I
2:04
hope Martin will forgive me but uh, I sent
2:07
you the whole question but I'm just going to
2:09
do the precede version so that we're not here
2:12
for the next 25 minutes reading out. It's not
2:14
that long but anyway, uh, gents, thanks so
2:16
much for the podcast. That was the question.
2:18
No, I have uh, some questions about the Big
2:21
Crunch now it seems to be back in vogue.
2:24
One, is it in fact now the favoured
2:27
theory? And two, also if we
2:30
do get a Gnab Gibson in a
2:33
lot of ways it sounds like a super ultra
2:36
hyper massive black hole with all the matter
2:39
and energy of the universe gathering to a
2:41
singularity. Which one is it? And
2:44
uh, why? Uh, that's Martin from
2:47
Melbourne of course, he goes into a lot of
2:49
detail within his question, with
2:51
possibilities and ideas and concepts and
2:54
lefts and rights. But yeah, um, we have
2:57
talked about the, um,
3:00
the Big Crunch making a comeback. They're
3:03
starting to. Although we are still seeing an
3:05
expanding universe, it's just not
3:07
accelerating like it was, I think.
3:10
Um, so that's what's brought the Big Crunch
3:12
concept back into vogue. But, um,
3:15
at the moment, the Big Rip seems more logical
3:18
given what's happening.
3:20
Professor Fred Watson: Yes. So
3:23
it could be neither. That's
3:26
true. You're right.
3:29
Um, and Martin's right that we've seen a lot
3:31
of discussion about the
3:34
possible reduction
3:37
of, um, the acceleration.
3:40
So the
3:43
universe is expanding. We've known since
3:45
1998 that that expansion is
3:48
accelerating. Uh, that is the work
3:51
that got, uh, Adam
3:53
Reese, um, saw Perl
3:56
Mutter and uh, Brian Schmidt, their
3:59
Nobel Prize in 2011.
4:03
Now, um, the recent
4:06
evidence from the Dark Energy survey, because
4:08
we think that's caused by dark energy. We
4:10
think it's caused by an energy of space
4:13
itself. That, uh, means
4:16
that as space gets bigger, it has more
4:18
energy. And so it gets bigger, faster.
4:21
That's the bottom line. Now, dark energy is
4:24
the big puzzle. Um, what is it? Uh, how does
4:27
it behave? So the Dark Energy
4:29
Survey, which we've talked about recently,
4:32
it's presented some results, has
4:36
suggested that, uh,
4:40
um,
4:43
the acceleration may be decreasing,
4:46
um, but it's not by any means
4:49
confirmed. That still,
4:53
uh, sort of new research,
4:56
it needs a lot of verification.
4:59
Um, and even if that was
5:01
verified, we'd need to know just
5:04
by how much it is decreasing,
5:08
uh, and what phenomena might
5:11
lie ahead in order to predict
5:13
a Big Crunch or a gnab gib, as
5:16
Brian Schmidt always put it. Not a missing
5:19
BG brother. Was that Martin? Yes, that
5:22
was another Martin. If you said that.
5:24
Andrew Dunkley: Yeah, Martin Berman Govine.
5:26
Professor Fred Watson: That's the man. Yes. Um, so it's still.
5:30
I, um, think it's still a, uh, fairly
5:33
speculative idea. Uh,
5:36
I think it's very speculative that we might
5:38
end up with a Big Crunch. Uh, it's still
5:41
speculative that the acceleration is
5:43
decreasing. And I was looking, uh, a couple
5:46
of days ago at another paper,
5:48
um, actually written by, um, a
5:52
big group of authors, including some
5:54
luminaries from Australia. Ah, also
5:57
Brian Schmidt and Adam Reese, who I was just
5:59
talking about. Now, uh, they are also on this
6:01
paper, they've done a very, very careful
6:04
reanalysis of the data. Ah,
6:08
that basically was, um,
6:11
what we based the initial idea of dark
6:14
energy on. The accelerating universe. It's
6:16
all about supernova explosions. Um,
6:19
because there a recent paper that
6:22
suggested that the acceleration wasn't real,
6:26
uh, because of phenomena to do with
6:29
galaxies. But, um, it turns out that,
6:32
yes, it is definitely real.
6:35
The acceleration has been firmly confirmed.
6:38
But what hasn't been confirmed is that
6:41
it's decreasing. So at the moment, I think
6:43
the Big Rip is still the likely, you know,
6:46
the likely outcome that the universe gets so
6:49
big that space starts tearing itself to
6:51
pieces. I find that very hard to imagine.
6:54
Andrew Dunkley: I do too.
6:55
Professor Fred Watson: Um, but that seems to be the more likely
6:58
outcome than a big crunch. Or it might just
7:01
keep going forever. Look, we're talking
7:04
so far into the future now. With the
7:06
observations that we can make at the moment,
7:08
it's very hard to make any firm predictions.
7:10
Andrew Dunkley: You know what I can't get my head around,
7:12
Fred Watson, is that, uh, we've got an
7:14
expanding universe. It's expanding
7:17
at an accelerating rate. Makes me wonder
7:20
how much bigger it's getting every second
7:24
because it's expanding out in all directions.
7:26
Professor Fred Watson: It is. And actually that's a parameter that
7:29
we don't know. Uh, um,
7:34
well, no, that's not quite true. Um, there
7:37
is something that we call the scale factor.
7:40
It's just a measure of the scale of the
7:42
universe and that's getting bigger.
7:45
Uh, so
7:49
you can talk about the scale factor. You can
7:51
say that now it's, uh,
7:54
X amount bigger than it was the day before
7:57
yesterday. Um, but in terms
8:00
of the physical size of the universe, we
8:03
don't know, we don't know how big it is. Um,
8:07
uh, we know that
8:10
the expansion extends out to the horizon
8:12
beyond which we can't see any further. Uh,
8:15
but there's more universe beyond that and
8:17
it's still expanding. So we don't know how
8:20
far it goes on beyond that. And that means we
8:22
don't know how big it's getting. The scale
8:24
factor is an interesting one though. Um, and
8:27
it's what you get from redshift. If you
8:29
measure the redshift, ah, of a, uh,
8:32
distant galaxy,
8:34
um, that immediately gives
8:37
you the geometry, gives you the scale factor
8:39
from that redshift, uh, we call the redshift
8:42
Z. It's a, a M measure
8:45
of how far to the red the spectrum of a
8:48
galaxy shifted. And the increase in scale
8:51
factor, uh, as you look back,
8:54
I should say the decrease as you look
8:55
backwards, if you look out to a redshift of
8:58
Z, the difference in scale factor
9:01
between the universe now and the universe as
9:03
it was then is one over one plus Z.
9:06
It's such a simple equation. Scale factor is
9:09
one over one plus z. Uh, that's the
9:12
change in uh, scale factor and that's an
9:14
absolutely rigorous geometrical equation. So
9:17
we do know the scale factor changes but we
9:19
don't know what it means in terms of physical
9:21
size because we don't know how big the
9:23
universe is.
9:24
Andrew Dunkley: No, can't see it. Um, but uh,
9:27
it must be a massive amount of
9:30
inflation uh
9:32
every second if it's accelerating outwards
9:35
and it's already as big as it is. I mean.
9:37
Professor Fred Watson: Yes, that's right.
9:38
Andrew Dunkley: What's driving all this dark energy? Um,
9:41
probably. But uh. Oh gosh,
9:44
um, it's unthinkably huge.
9:47
But uh. M. Martin, in answer to your
9:49
question, uh, there isn't really a favoured
9:51
theory, they're just theories.
9:54
So it's um, at the moment still
9:57
expanding. Therefore the RIP concept's
9:59
probably more favourable than the crunch
10:01
concept. But maybe it won't be either. It
10:04
might just keep going forever and ever until
10:06
we bump into something else. I don't know. I
10:09
don't know. Maybe it'll be the Big Dint. I
10:12
don't know.
10:14
Professor Fred Watson: I've got one of those in my car actually.
10:16
Andrew Dunkley: Oh, haven't we all? Um, yes,
10:19
thanks for the question Martin. It's a, ah,
10:21
really interesting one to speculate about.
10:23
This is Space Nuts Andrew Dunkley with
10:25
Professor Fred Watson Watson.
10:29
Space Nuts.
10:30
Our next question is an audio question from
10:33
Mike.
10:35
Speaker C: This is Mike, uh, from Chroma in the uk.
10:39
Um, you had a question.
10:42
Uh, well on the podcast I'm listening to
10:45
the beginning of the universe as in the Big
10:47
Bang. Um, you referred to it as
10:50
being nothing before it.
10:53
Um, surely from uh,
10:56
a non science point of view it would be
10:58
better to say there was something before
11:01
the Big Bang but you don't know what it was.
11:05
Um, why do you
11:08
refer to it as nothing
11:11
before the Big Bang? Bit of a strange
11:14
question but I thought I'd ask.
11:16
Andrew Dunkley: Cheers, thank you Mike. And I'm
11:19
going to make a little correction Mike,
11:21
because I think it's me who suggested
11:24
that um, there was nothing and I think
11:26
Fred Watson corrected me and said well no, we
11:28
don't know what there was.
11:30
Professor Fred Watson: Is that the one like that? Yeah,
11:33
something along those lines. It's nice to
11:35
hear from you Mike. Um, we have uh,
11:38
Chroma here in Sydney which is just down the
11:40
road from where I live. So
11:43
you were right to put the words UK after or
11:46
the letters UK after Chroma, the
11:49
original Chroma.
11:50
Andrew Dunkley: We've had a few of these recently with people
11:53
from Vancouver in the United States. Where
11:56
was the other one? Um, which
11:58
wasn't where we'd normally think. Yeah,
12:01
anyway.
12:01
Professor Fred Watson: Well, yeah, it depends on your perspective,
12:03
doesn't it? Yes, it does. If you're in
12:04
Britain, Chrome is in the uk.
12:06
Andrew Dunkley: Yeah.
12:07
Professor Fred Watson: Um, so, so the, yes,
12:10
the, I, I mean you can say there was
12:13
nothing. Uh, look, the, the glib way of
12:15
saying of the origin of the universe is in
12:17
the beginning there was nothing and then it
12:19
exploded. And that might be what Mike's
12:21
thinking of, um, but that
12:24
is pointing you in the wrong
12:27
direction because
12:30
certainly with the best of our knowledge at
12:33
the moment, and that excludes things like
12:35
ideas of multiverses, because we simply don't
12:38
know whether multiverses exist or not.
12:41
We have a universe that we know
12:44
had a very explosive event
12:46
13.8 billion years ago. We believe
12:49
it was the beginning because, uh,
12:52
the theory of relativity says that, and
12:55
relativity, in all the tests we've thrown at
12:58
it over the hundred odd years that
13:01
it's been, you know, accepted,
13:05
um, it survived all the tests with incredible
13:08
robustness. So it's worthwhile
13:10
believing what it tells you. And
13:13
what it tells you is that time started
13:16
with the Big Bang. And so,
13:19
um, it means that
13:22
the word before doesn't mean anything
13:25
because there was no time.
13:28
Um, it was Stephen Hawking who always
13:32
drew the analogy that um, you
13:34
know, he said when you look back in
13:37
time it's like
13:41
um, going along a line of longitude on
13:44
the, ah, Earth heading, say northwards. You
13:47
keep on going northwards. What are you doing?
13:49
You're going northwards. You know where
13:50
you're going, you know what direction you're
13:52
going in. When you get to the North Pole, it
13:55
has no more meaning because you're at the
13:57
beginning, you're kind of at the origin of
13:59
it. And that's the
14:03
analogy he draws, that the Big
14:05
Bang, um, time stops
14:08
having any meaning. So you can't
14:11
describe what came before because before
14:13
doesn't exist.
14:16
Andrew Dunkley: Okay,
14:19
I see where he's getting frustrated though,
14:21
because.
14:21
Professor Fred Watson: Yeah, well, we all are. Ah, yeah. And that's
14:24
because we think in a normal four
14:27
dimensional world, three dimensions of space
14:30
and one of time. And time is such a
14:33
fundamental part of our existence, uh,
14:36
that um, it's hard to
14:38
imagine something without
14:41
time. Um, the
14:44
most recent work on this, uh,
14:47
looks as though time is actually, ah,
14:49
something that emerges from a much deeper
14:52
reality. Uh, this is what the people who are
14:55
trying to unite relativity and quantum
14:57
mechanics say that there's a
15:00
deeper reality and maybe time is just an
15:03
artefact that in fact some people say
15:05
emerges from entanglement. Quantum
15:07
entanglement. That works. I have no idea.
15:10
But, um, it's a possibility
15:13
that we might understand time a bit better,
15:16
uh, with some of the outcomes of
15:19
some of these theories, and then you might
15:22
be able to see. Well, yes, you're right.
15:25
Before the Big Bang, there was no time. So
15:26
there's no before. It doesn't exist.
15:28
Andrew Dunkley: Yeah. And I just did a
15:32
speculative question to Chatgpt what was
15:35
around before the Big Bang, and it basically
15:37
said exactly what you've just said.
15:40
Professor Fred Watson: Glad to hear that.
15:41
Andrew Dunkley: One of the answers is nothing. Uh, another
15:42
one is that, um, um, something
15:45
from nothing. A quantum origin, a, uh,
15:48
previous universe, which is the bounce model.
15:52
Professor Fred Watson: Ah.
15:53
Andrew Dunkley: Eternal inflation, multiverse
15:55
possibilities, uh, or cyclic universes. I
15:58
don't think we've talked about that before.
16:00
Um, and look, the
16:03
real answer is we just don't know.
16:06
Professor Fred Watson: No, but imagine if we could really iron out
16:09
what time is all about, then we might have
16:12
a bit better idea. We might have some sort of
16:15
lever on the Big Bang. The
16:17
only physical, um,
16:21
we understand the Big Bang quite well in
16:24
terms of the chemistry that it generated,
16:26
what happened in terms of the energy creating
16:29
atoms. That's all pretty well,
16:32
um, understood from the particle physics
16:35
theory. Uh, but
16:39
when you go to the first few gazillionths of
16:42
a second, then all these theories just break
16:45
down and we've no idea what was going on. But
16:47
if we could understand time a bit better,
16:49
then that might lead us some insights.
16:51
What I was going to say was the only real
16:53
measurements that we can make, uh, of the
16:55
cosmic microwave background radiation, and
16:57
that's been very well measured to try and
16:59
understand what the conditions were like
17:02
in the Big Bang. Um, um, what you're seeing
17:05
then is something that happened 380,000 years
17:08
after the Big Bang. So you're not talking
17:10
about the first gazillionth of a second.
17:12
You're looking at a bright surface which
17:14
corresponds with, uh, the time when the
17:17
universe was glowing brightly.
17:20
Andrew Dunkley: Yeah. My theory is that God was making
17:22
breakfast, cracked an egg, and that some of
17:24
the whites slid out of the side of the fry
17:27
pan and hit the hot plate and there was a
17:30
big bang. That's what I reckon happened.
17:33
Professor Fred Watson: Yeah.
17:35
Andrew Dunkley: Which also proves the theory that the egg
17:37
came first.
17:41
So, yeah, I solved two problems.
17:43
Professor Fred Watson: It's two problems at once. Nobody
17:46
can say you don't get good value for money
17:48
from space nuts. Very true.
17:51
Especially considering it's free. Yeah.
17:53
Yeah.
17:55
Andrew Dunkley: Unless you want to. But that's optional.
17:56
Professor Fred Watson: Unless you want to. That's right.
17:57
Andrew Dunkley: Um, but all voluntary. Mike.
18:00
Can't answer the question, really. We, we
18:02
don't really know what was around before the
18:05
Big Bang. If there was anything, I think
18:07
would be the bottom line. Thanks for the
18:09
question. Thanks for sending it in. This is
18:10
Space Nuts, a Q and A edition with Andrew
18:13
Dunkley and Professor Fred Watson Watson.
18:18
Speaker C: Three, two, one.
18:20
Andrew Dunkley: Space Nuts Radio.
18:23
Our next question, uh, is from Colin. When
18:26
two neutron stars collide, do
18:28
any FR Break off? If so,
18:31
uh, there could be billions of such high,
18:34
ultra high density fragments loose in the
18:36
universe. Uh, what would an impact mean
18:39
for a planet like Earth? Thank you, Colin.
18:42
You make us feel very cosy and safe now,
18:46
uh, after that one, um, I would
18:48
imagine because neutron stars, uh,
18:51
renowned for their intense gravity, are they
18:53
not? Would it be more or less
18:56
impossible for a bit to break off and fly off
18:58
into the universe or could that happen?
19:01
Professor Fred Watson: Yeah, um, you're right, Andrew. Um,
19:04
they coalesce, they become
19:07
one object, um, because of the
19:10
extreme gravity. Uh,
19:13
uh. And um,
19:17
there might be fragments caused, but they'd
19:19
instantly be sucked back into the
19:22
neutron star. Um, I think it's probably
19:24
better to imagine them as two blobs
19:26
that uh, that coalesce together once they
19:29
collide with a very considerable release of
19:32
energy, which we see mostly as gravitational
19:34
waves, actually.
19:36
Andrew Dunkley: Yeah, well, we're talking ultra high
19:38
density in a very small package, aren't we?
19:41
Professor Fred Watson: Yes, exactly. Something the size of a city,
19:44
uh, with a mass of a star.
19:46
Andrew Dunkley: Yeah, um, I think Los Angeles
19:49
is probably denser. No, I'm sorry, I couldn't
19:52
help that. That was, you know, I'm not
19:54
picking on Los Angeles. In fact, I probably
19:57
picked a bad target because that's a lot of
19:59
people that would be very angry with me right
20:00
now.
20:01
Professor Fred Watson: But anyway, we just lost half our audience.
20:03
Andrew Dunkley: Yes, I think we did. Um, but
20:06
no, um, they've got to understand my sense of
20:09
humour. But nobody does understand it.
20:12
Professor Fred Watson: Not even you.
20:13
Andrew Dunkley: Not even me.
20:14
But we're talking a
20:18
really interesting object in space too. Um,
20:21
neutron stars are, ah. Um.
20:24
One of the storeys we did not was a while ago
20:26
now was about the mountain ranges on neutron
20:29
stars. You know, the highest peaks are like a
20:32
few millimetres high or something.
20:33
Professor Fred Watson: Yes, they were.
20:35
Andrew Dunkley: It's very, very weird place.
20:37
Professor Fred Watson: Yeah, yeah.
20:38
Andrew Dunkley: Um, do we know how they're formed initially?
20:42
Professor Fred Watson: Yeah, yeah. By gravitational collapse at uh,
20:44
the end of a star's life when.
20:46
Andrew Dunkley: So what class of star would have existed to
20:49
create a neutron star?
20:50
Professor Fred Watson: Big ones.
20:52
Andrew Dunkley: Big sort of super blue giant.
20:53
Professor Fred Watson: Um, yeah, that's right. That's exactly
20:56
right. So, um, stars with a mass,
21:01
I think it's two to
21:04
sort of. Two to Five times the mass of the
21:06
sun or something like that. It um, might be a
21:09
bit bigger. Uh, ten times the mass of the sun
21:11
gives you a black hole basically. So
21:14
somewhere below that but in the upper reaches
21:17
will give you a neutron star collapse.
21:20
Andrew Dunkley: Okay, so, okay, so
21:23
our star won't do that. It's not big enough
21:25
to do anything. It's just going to, you know,
21:27
retire and find itself a street corner with
21:30
a, with a, you know, a beer and a brown paper
21:32
bag and a packet of cigarettes. That'll be
21:34
the end of the sun. But the bigger they
21:37
get, the more possibilities.
21:41
Professor Fred Watson: Yes, exactly. Um, look, um, the
21:44
sun, uh, is a non smoker
21:46
but it will do
21:49
something similar because it
21:52
will puff off its outer
21:55
layers.
21:56
Andrew Dunkley: Well that happens to all of us. We get fat as
21:58
we retire. So
22:01
that's what I'm saying.
22:02
Professor Fred Watson: Yeah, yeah. It puffs off its outer layers,
22:04
it'll become a white dwarf, will be the
22:07
nucleus which itself is an exotic object.
22:10
That's something the size of Earth but with
22:11
the mass of the sun. Um, um,
22:15
um, but its outer envelope will turn into
22:17
something very beautiful. Probably what we
22:20
call a planetary nebula.
22:22
Andrew Dunkley: Yeah, we won't think so.
22:23
Professor Fred Watson: We might not, but this will be a long time
22:25
after we're gone because we'll have been
22:27
swallowed up.
22:28
Andrew Dunkley: Exactly. But um, as far
22:31
as a neutron star is concerned, you've got
22:34
a lot of density in a very small package
22:37
with a hell of a lot of gravity. And um, the
22:40
easiest thing to do there would be to climb
22:41
the mountains. But I wouldn't recommend it.
22:46
Professor Fred Watson: No, quite so.
22:47
Andrew Dunkley: But the bottom line for Colin is um, bits
22:50
might break off in the collision but the
22:51
gravity is so intense they get sucked back
22:54
in. So no, we don't have to worry about
22:56
flying pieces of neutron star hitting Earth
22:59
while you're trying to sleep. I mean that
23:01
wouldn't be fun at all. Thanks Colin.
23:04
Thank you for your question.
23:05
Our final question today comes from Bill
23:08
in relation. Now this was an audio question
23:10
that Bill sent in, but the audio quality
23:14
um, was super muff for some reason.
23:17
And um, we couldn't use the
23:20
audio Bill. But um, sometimes these
23:23
things get messed up in the ether. So um,
23:26
I listened to it about four or five times and
23:28
I hope your name is actually Bill. Uh,
23:32
and I hope I got uh, the words right in the
23:34
question. But he's basically saying in
23:36
relation to the Artemis astronauts witnessing
23:39
the solar eclipse and seeing the sun's
23:41
corona, would you see the same effect
23:44
standing on the moon during a lunar
23:46
sunset? And uh, Bill's in, in Dover And
23:49
Judy and I were in Dover last year. It's
23:51
absolutely wonderful there. Went to Dover
23:54
Castle, went down into the World War II
23:56
tunnels. Although they've been around a lot
23:57
longer than that. Fascinating um, place
24:00
and the white cliffs and looked out over um,
24:03
over the English um, Channel and it was a
24:06
clear day so I could see France. Uh,
24:08
yeah. Um, something I've always wanted to
24:11
witness. The locals are probably saying, oh
24:14
gosh, he's boring. I can see that every day.
24:18
Professor Fred Watson: They might like to see a kangaroo though,
24:19
which you could see every day.
24:21
Andrew Dunkley: Yeah, you know, um, it's
24:24
a pest species.
24:25
Professor Fred Watson: Yes.
24:25
Andrew Dunkley: Uh, because, um, they've really
24:28
adapted to um, uh, life
24:31
post, um, modern agriculture and um.
24:34
Yeah, they're doing well. M.
24:37
So, um, yes. So
24:40
yeah.
24:40
Now we'll go back to the Artemis astronauts
24:42
because they did see, ah, when they went
24:44
around the moon, they saw um, um, a lunar
24:47
eclipse and witnessed the corona. They saw
24:49
a few other interesting things as well, like
24:52
impact, um, flashes on the lunar surface from
24:54
micrometeorites. Uh, but yeah,
24:57
um, could you see the same effect
24:59
standing on the moon?
25:02
Professor Fred Watson: Um, yes. The answer is yes,
25:05
because the moon doesn't have an atmosphere.
25:08
Um, what there is on the
25:10
moon is something called levitating
25:13
regolith, uh, which is
25:16
soil being lifted as a lunar soil particle.
25:19
Basically the lunar dust, very, very fine
25:22
dust. Um, and that gets
25:25
electrostatically charged up during the lunar
25:27
day and tends to fly off the
25:30
surface.
25:31
Andrew Dunkley: And that's why it ends up in your pina
25:33
colada.
25:34
Professor Fred Watson: It could be. Yes, that's right.
25:37
Uh, so that's right. Uh, so,
25:40
um, there could be a little bit
25:43
of a dust haze, uh, on the moon
25:47
which might spoil your view of the corona.
25:49
That's the only thing that I could think of
25:52
that would, um.
25:54
Uh, it's certainly true that um, the Apollo
25:57
astronauts, several of them, yes, witnessing
26:00
the. Looking for exactly what we're talking
26:03
about the corona of the sun as it rises
26:06
above the limb of the moon. They could see
26:09
this lunar dust being illuminated
26:12
and that's how we know it happens. Um,
26:15
there are some quite well known sketches made
26:18
by some of the astronauts because it's very,
26:20
very faint and with the cameras they had at
26:23
that time, it wasn't possible to
26:25
directly uh, record it, but there were
26:28
sketches that they made. So it wasn't a
26:30
solar phenomenon, it's this levitating dust.
26:34
Um, but I think you'd see the
26:37
lunar corona as well from the surface.
26:39
Andrew Dunkley: Okay.
26:40
Professor Fred Watson: Maybe one day somebody will find out because
26:42
at the moment we've never had a human
26:44
Watching a lunar sunset or moon. Sorry?
26:47
A lunar sunset or sunrise.
26:50
Andrew Dunkley: Yes, yeah, it'll happen, It'll happen.
26:53
Professor Fred Watson: It will.
26:53
Andrew Dunkley: Uh, yes, you know the way they're talking,
26:55
within a very short period of time, there
26:58
will be permanent habitation on the moon
27:01
of some kind. Research stations, maybe, um,
27:05
power generators, I don't know. They've got.
27:07
There's a lot to do and as we mentioned in
27:10
the last episode, there's, uh. They're
27:11
already looking at ways of building
27:13
infrastructure on the. On the moon using.
27:16
Using moon dust. So, um. Yeah,
27:19
we'll get there. I was going to say
27:21
eventually, but I don't think it'll be
27:23
eventual. I think it's. We're at the dawn of
27:25
it.
27:25
Professor Fred Watson: Yep. So exciting.
27:27
Andrew Dunkley: M. But yes, a sunset on the moon could be.
27:30
Could be quite fascinating. And thank you,
27:32
Bill, for your question. Hope all is well in
27:35
Dover. And if got questions for us, please
27:37
send them in to us via our website,
27:39
spacenutspodcast.com or
27:42
spacenuts IO. Click on the
27:44
AMA button at the top and, uh, that means
27:47
ask me anything. And you can send in text
27:50
questions or audio questions. If you've got a
27:52
device with a microphone, you're all set. And
27:54
that's just about everything these days. And,
27:57
um, don't forget to tell us who you are and
27:59
where you're from and have a look around on
28:00
our website while you're there. And, um,
28:02
please leave reviews wherever you listen to
28:04
us because they help, apparently. I don't
28:07
know what they help with. Probably someone
28:08
else getting paid, I don't know. But, um,
28:11
yes, reviews are always good. They move us up
28:14
the pecking order. Number one in Iceland.
28:17
Um, but yeah, uh, it's all good stuff.
28:20
And Fred Watson, thank you so much. It's been
28:22
good to talk.
28:24
Professor Fred Watson: It has. It's been a, um, great pleasure as
28:26
always.
28:27
Andrew Dunkley: We'll catch you soon. Professor Fred Watson
28:29
Watson, astronomer at large. And thanks to
28:31
Huw in the studio, who couldn't be with us
28:33
today because he likes pina coladas and walks
28:35
in the rain. Not much into health food, but
28:38
he's into champagne. That's why he's under
28:39
the table. Couldn't join us today. And from
28:42
me, Andrew Dunkley, thanks for your company.
28:44
Some people will get that joke. See you on
28:46
the next episode of Space Nuts.
28:48
Professor Fred Watson: Bye. Bye.
28:50
Andrew Dunkley: You've been listening to the Space Nuts
28:52
podcast, available at
28:55
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28:57
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28:59
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29:03
Professor Fred Watson: Com.
29:04
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29:08
Speaker C: Um,