Latest / Space Nuts: Astronomy Insights & Cosmic Discoveries / Celebrating 25 Years of the ISS, Moon Crater Mining & Cutting-Edge Rocket Tech

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Celebrating 25 Years of the ISS, Moon Crater Mining & Cutting-Edge Rocket Tech · Space Nuts: Astronomy Insights & Cosmic Discoveries

0:00
Andrew Dunkley: Hi there. Thanks for joining us. This is
0:02
Space Nuts, where we talk astronomy, space
0:04
science and whatever else turns up. Sometimes
0:07
we talk about dogs and cats. Uh,
0:10
uh, coming up on the programme today we
0:12
are going to look at the upcoming
0:15
anniversary of the International Space
0:17
Station and other uh, space
0:20
stations that are in low Earth orbit.
0:22
Because, um, come November,
0:24
25 years of continuous occupation
0:27
of space by human humans. That
0:30
is rather wonderful in terms
0:33
of an achievement. We'll uh, also talk about
0:35
the future of the ISS because it's not going
0:38
to be around for that much longer. Um,
0:41
we're also going to look at the moon because
0:42
it might have valuable craters that
0:45
could be worth mining. I don't know how
0:48
Fred Watson feels about digging around on the
0:49
moon, but we will ask him. And
0:52
3D printed rocket motors,
0:55
yes, they are a thing or things. Uh,
0:57
we'll talk about all of that on this episode
1:00
of space nuts. 15 seconds.
1:02
Guidance is internal.
1:04
Professor Fred Watson: 10, 9. Ignition
1:07
sequence start. Uh, space Nuts.
1:14
Space dust.
1:15
Andrew Dunkley: Astronauts report it feels good.
1:18
And we once again welcome his royal self,
1:21
Professor Fred Watson Watson, Astronomer at
1:23
large. Hello, friend.
1:24
Professor Fred Watson: Thank you, Andrew. Thank you. Um,
1:27
um. Uh. I was at an event in rural
1:30
Victoria last week and somebody uh, the
1:32
organiser described me as astronomy
1:35
royalty. So I thought well I'll take that.
1:38
Andrew Dunkley: That's nice. Yes, I didn't know that.
1:41
Professor Fred Watson: It's not true.
1:42
Andrew Dunkley: But there's more than one person that thinks
1:44
that. Fred Watson.
1:45
Professor Fred Watson: Uh, well, that's nice too. Anyway,
1:48
it was um. Yeah. Um, so, uh, I'm not his
1:51
Royal Highness though I'm basically. And uh,
1:53
that's how I'll stay probably for the.
1:56
Andrew Dunkley: Didn't they make a movie called King
1:57
Fred Watson or something like that? Yeah,
2:00
yeah, Some time m ago.
2:02
Professor Fred Watson: Fred's a good name. It's um, uh, in
2:05
high energy physics which kind of impacts
2:08
on astronomy. It's an acronym uh, for
2:11
fast rise exponential decay.
2:14
Fast rise exponentially K. It's um.
2:17
I'm not sure whether that describes me or
2:19
not, but it's an acronym.
2:22
Andrew Dunkley: It sounds more like Live fast, die young.
2:24
Professor Fred Watson: Yeah, that's a booty.
2:25
Andrew Dunkley: Not you.
2:26
Professor Fred Watson: Yeah, that's right. Live slow. Last
2:29
a long time. That's the idea.
2:31
Andrew Dunkley: Now you mentioned uh, before we started that
2:34
there was a uh, conference
2:36
in Is it city at the moment.
2:39
Professor Fred Watson: Yeah. What's that about? Yes, that's. This is
2:42
not the one I was at last week. The one I was
2:43
at last week was uh, an astronomy education
2:46
conference in Melbourne. And followed up by,
2:49
and a shout out to them, the Sea Lake Astro
2:51
Fest. It's the Royal, uh, the uh,
2:55
uh, Astronomical Society of Victoria's annual
2:58
dark sky event. And Sea Lake is a rural
3:01
town, a small rural town, northern Victoria,
3:04
two hours drive south of Mildura. And I spent
3:06
a glorious weekend there uh, with a lot of
3:08
uh, like minded people talking about
3:10
astronomy in space. What's on this week
3:12
though I haven't been invited to
3:15
so I can't be that much astronomer. Astronomy
3:18
royalty. Um, it's the International
3:20
Astronautical Congress and this um,
3:23
is a major international meeting. I think
3:26
there are 11,000 delegates,
3:29
um, and it's on at the convention uh, centre
3:32
here in Sydney. And uh, a lot of really
3:34
fascinating stuff uh, being discussed and
3:37
described. Some extraordinary technology
3:40
turning up in there. Um, um, it's a
3:43
showcase for the world of astronautics.
3:46
Um, uh, but you know it's very much space
3:49
orientated. But it was that in mind that I
3:51
chose the three topics that we're going to
3:52
talk about today because I thought they all,
3:54
all relate to astronautics and space flight.
3:56
Andrew Dunkley: 11,000 delegates did you say?
3:58
Professor Fred Watson: Yeah, yeah.
3:59
Andrew Dunkley: That's a lot of, it's a lot of plastic
4:01
chairs.
4:02
Professor Fred Watson: It is, yeah.
4:03
Andrew Dunkley: IKEA must be thrilled.
4:05
Professor Fred Watson: Uh, probably, yeah.
4:09
Sorry, go on.
4:10
Andrew Dunkley: I was going to say you got to wonder about
4:11
organising something like that. I mean a
4:13
logistics on a loan.
4:16
Professor Fred Watson: Now I used to, when I was a sort of, you
4:18
know, proper productive astronomer doing real
4:20
work, uh, rather than just talking to you,
4:26
um, I used to go to conferences
4:29
uh, organised by an organisation called
4:32
spie which was originally, what was
4:35
it, the Society of Photo Optical
4:37
Instrumentation Engineers I think. But they
4:40
in the end just called themselves spie.
4:43
Uh, so I used to build um, astronomical
4:46
instruments mostly involving fibre optics and
4:48
things of that sort back in the day which
4:50
eventually turned out to be quite productive.
4:52
And we did some great surveys with some of
4:54
them. But uh, the annual conferences
4:56
for instrumentation people were these SBIE
4:59
conferences. And uh, I think the last one I
5:01
went to, which was probably 20 years ago,
5:03
already had more than 4,000 delegates and it
5:06
felt like you didn't really know anybody.
5:09
The early ones you kind of knew most of the
5:11
people there, but with 4,000 you didn't
5:14
know anybody. And the other thing about big
5:17
conferences that always I struggle with is
5:20
the parallel sessions. So you've often got
5:22
three streams of sessions running and if you
5:25
want to catch the papers and presentations
5:27
you've got to be ducking in and out of doors
5:29
and standing in the back of rooms and things
5:30
like that. And I'm sure the IAC will uh, be
5:33
like that this week as well. Uh, it's not my
5:36
Idea of a party.
5:37
Andrew Dunkley: I can imagine.
5:38
Professor Fred Watson: Yeah.
5:39
Andrew Dunkley: Anyway, I'm sure it will go well.
5:42
Uh, speaking of space and
5:44
things in space, uh, we are looking at
5:48
in November 25 years of continuous
5:50
occupation of space by humans.
5:54
And we're talking about the ISS amongst other
5:56
things. But there's more than one space
5:57
station up there now, so um, it
6:00
will continue even when the ISS is
6:03
decommissioned in a few years time. That's an
6:05
extraordinary achievement.
6:07
Professor Fred Watson: Isn't it just? Yeah. 25 years
6:10
of constant, of continuous occupation in
6:12
space. It tells you that um, we are
6:16
a world or a species that's able to
6:19
face the challenge of getting off the Earth
6:21
and getting off our home planet and into
6:23
space. Even though. Yes, for those 25 years,
6:26
uh, what's the ISS done? It's gone around in
6:28
circles, but the fact that it's up there,
6:31
um, uh, it's about a height of 400
6:34
kilometres. It's still within the Earth's
6:37
uh, protective shield magnetically so that
6:39
we're within the radiation belts. Um,
6:42
but m. You know, it's still the vacuum of
6:45
space. It's a very
6:48
challenging environment and yeah, we've made
6:51
it work. Uh, and it's once again I think um,
6:54
one of the, perhaps the best things about uh,
6:57
the iss, particularly in this day and age, is
7:00
just a model of international cooperation.
7:03
Yeah. Still, you know those major players
7:06
of uh, European Space Agency,
7:09
NASA, Roscosmos, the Russian Space Agency
7:12
and jaxa. Ah, the Japanese Space Agency, the
7:14
Canadian Space Agency, they're the main
7:16
players in the ISS and they're working
7:19
together and um, you know, in the environment
7:22
that we're in now. That's a shining example
7:24
that um, I hope continues beyond the end
7:27
of the iss. Yes.
7:30
Andrew Dunkley: And uh, Australia has been involved as well.
7:33
Um, we've had uh, ah, a
7:35
couple of people up there I think. Um, and
7:38
um, just as I was thinking of their names, it
7:41
all drops out.
7:41
Professor Fred Watson: Yes they do. Um, so Andy Thomas was
7:45
one of Australian astronauts. Uh, I think he
7:48
flew on the space station. He's best known
7:49
for his missions to the Mia,
7:52
uh space station which was a kind of
7:54
precursor. And uh, Paul
7:57
Scully Power, um, another um,
8:00
uh, uh, Australian grown
8:03
but NASA employed astronaut. Uh,
8:07
Paul's a character and a half. I've um, met
8:09
him a few times, hung out with him once. I'm
8:12
sure he led me up to some bar, uh,
8:15
somewhere that I never thought we'd get away
8:17
from. Uh, he's a great guy. Um, but
8:20
um, of course we now have Catherine, uh,
8:22
Bennell Pegg, who is um, uh Also
8:24
selected for the astronaut corps. She
8:27
is an Australian astronaut with a. We uh,
8:30
all hope she'll fly uh, quite soon.
8:33
She's very enthusiastic, a ah, fantastic
8:36
mentor for young uh, kids, especially
8:39
young girls, you know, doing great work
8:41
in, in stem. So uh, yes, we've, we've played
8:44
a part. But you're right, the um,
8:47
it's, it's not the only thing up there of
8:49
course, the Tianwen, ah, it's
8:52
Tiangong isn't it? I should get the name
8:54
right. Space uh, station. The um,
8:58
the Chinese one space station, uh, which has
9:01
uh, been in orbit actually for probably three
9:04
or four years now I think.
9:06
And uh, that's
9:09
uh,
9:11
a growing enterprise in China.
9:14
It is Tiangong. Uh, there's
9:17
Tianwen's uh, spacecraft that's actually
9:20
going to rendezvous with a near Earth
9:22
asteroid not very far down the track. So I've
9:24
got all these names in my head, pick the
9:26
wrong ones. Uh, um, it's about
9:29
the same height, uh, 400 kilometres above the
9:32
Earth's surface. Crew of three
9:35
compared with the crew of the International
9:37
Space Station which is normally um, six
9:40
people but uh, there was one stage this year
9:42
when it was up to 11, ah, with people kind
9:45
of camping around different bits of the
9:48
different bits of the space station, finding
9:50
somewhere to sleep. Uh, but it's big enough
9:52
that you can do that and still have a bit of
9:54
privacy about it. Yes. So um, yeah,
9:57
so uh, it's been a, you know, it has been a
9:59
fantastic resource. Uh, a lot of people
10:02
in the early days complain, you know, what's
10:04
it doing? It's just going around in circles.
10:06
It's conducted more than 4,000 experiments.
10:09
Andrew Dunkley: Yeah.
10:09
Professor Fred Watson: Uh, and for more than 4,000,
10:12
4,400 research publications uh,
10:15
which have come about, uh, many of which are
10:18
ah, about quite earthy things, you know, how,
10:21
uh, medical issues, uh, things that we might
10:24
learn from, uh, our occupation of space that
10:26
will help to improve um, our
10:29
life down on Earth. Um,
10:32
yeah, uh, it's been terrific. So
10:35
the end of the road will come uh, in five
10:38
years time, uh, not sure what time of year
10:41
but 2030, uh, the plan is to deorbit
10:44
it uh, and to send it down
10:47
into that um, sort of graveyard region
10:50
in the Pacific Ocean. It's that point that's
10:52
the furthest away from land of any part of
10:55
the ocean, uh, on the whole of the planet.
10:58
And there's a lot of space hardware on the
11:00
floor of the ocean there and it's going to
11:02
include the International Space Station.
11:03
Yeah.
11:04
Andrew Dunkley: Okay. So they probably won't recover
11:07
it uh, fairly deep there I
11:10
imagine, but uh, uh, they're
11:13
bringing it back down. But that won't end the
11:15
presence of humans in orbit because the
11:17
Chinese will be there and NASA is working
11:19
with private companies to put
11:22
more hardware in low earth orbit.
11:25
Professor Fred Watson: That's correct, yes. So um,
11:28
commercial partners is the
11:31
watchword as we've seen from ferrying
11:33
astronauts up and down to the space station.
11:35
The way we've got um, both uh, Blue
11:38
Origin and SpaceX as major players in the
11:40
Artemis programme. So all of that
11:44
uh, is in place. Um, I think
11:47
uh, there's something, yeah something called
11:50
the Phase two partnership, um
11:53
uh, which is proposals for commercial
11:56
space stations and that NASA uh
11:59
apparently issued um, their draught
12:01
announcement of this phase two partnership
12:03
this month, uh September 2025.
12:07
So uh, that will allow
12:10
um, companies to
12:12
uh, get funding to
12:15
do critical design reviews,
12:18
uh, maybe demonstrators. Uh, one
12:21
of the demonstrators that we're hearing about
12:23
is the idea of a four person space
12:25
station, uh, with a lifetime of at
12:28
least 30 days. Um, you know, so it
12:31
is um, it's an ongoing business and
12:35
I think you and I are going to have a great
12:37
time in the next five years because we'll
12:39
start to see what is coming up uh,
12:42
as being the replacement for the
12:44
International Space Station. It could even be
12:45
an inflatable module.
12:47
Andrew Dunkley: Uh, I know they were experimenting with that.
12:50
Professor Fred Watson: They were.
12:50
Andrew Dunkley: That was m. Yeah.
12:52
Professor Fred Watson: Uh, sounds pretty good. Yeah,
12:55
well it sounds ridiculous to me but
12:57
apparently uh, inflatable space stations are
13:00
actually more uh, resistant or
13:03
more resilient to space debris than
13:06
solid ones because you can make the, you can
13:09
make the fabric of which you make uh, which
13:11
you can construct it. Um, you can make
13:14
it out of many different layers including you
13:16
know, the bulletproof material and things of
13:19
that sort. And in some ways it becomes self
13:21
healing. You put, put a hole in it and, and
13:23
it just goes oh right. And covers comes up
13:26
the whole.
13:26
Andrew Dunkley: Like that stuff you used to put in a car
13:28
tire.
13:28
Professor Fred Watson: What was it called?
13:29
Andrew Dunkley: Fini Leak or something? Yeah, you got it, you
13:31
got a flat and you just pumped it back up and
13:33
it was fixed.
13:35
Professor Fred Watson: Yes, I've heard from people that that didn't
13:37
always work terribly well.
13:40
M. Um. When we discovered that
13:43
Marnie's uh, Suzuki doesn't have a
13:46
spare wheel a ah couple of weeks ago because
13:48
she had a Hampshire. Anyway,
13:51
that was a different story but um. Uh, it
13:54
was, was it Bigelow? I think that's the name
13:55
of the company. They back 20 years ago
13:58
were um. In fact they launched two
14:01
spacecraft whose names I can't remember now,
14:04
uh, which were um, basically aimed at
14:07
the space tourism industry. Um, to have
14:10
an orbiting hotel which was um,
14:13
basically constructed of fabric rather than
14:16
solid metal. And I think the two of them are
14:19
still up there. Uh, actually I think they're
14:21
still in orbit.
14:21
Yeah, no people on them. One of them was
14:24
filled up with bits of paper with people's
14:25
photographs on and their names, uh, uh,
14:28
so you could see a photograph. There was a
14:31
camera that showed all these things floating
14:33
around in zero g.
14:34
Andrew Dunkley: Yeah, yeah, look, the space hotel.
14:37
That's going to be a thing for sure one day,
14:39
no doubt about it. But uh,
14:42
25 years of continuous human occupation of
14:45
space and uh, counting, it's um,
14:48
going to. And the other point is, um, uh, in
14:50
those 25 years there has never been a time
14:53
where there was not an American in space.
14:56
Professor Fred Watson: Yes, that's true. That's, that's true.
14:58
Andrew Dunkley: Yeah, that too is impressive. Yes. All
15:00
right, uh, you can read all about it in a
15:03
great article on the conversation.com.
15:05
this is space Nuts Andrew Dunkley here with
15:08
Professor Fred Watson Watson.
15:11
Space Nuts. Let's move a little further out
15:14
from low Earth orbit to uh, our uh, one and
15:17
only natural satellite, the Moon. And it's
15:20
being looked at the, with very, very um,
15:23
um, what's the word I'm looking for?
15:26
Uh, enticing attitudes. They
15:29
want to uh, look into the craters because uh,
15:32
they think that those craters
15:35
may contain some rich deposits of
15:38
precious metals, uh, that um,
15:41
we could probably use.
15:44
Professor Fred Watson: Yeah. I love the logic of this research,
15:48
uh, Andrew. Um, it's kind
15:51
of flawless really. But it's something that
15:53
we haven't thought of before and that is that
15:57
people um, uh,
16:00
have thought, been thinking perhaps for the
16:03
last 15 years about the metal and
16:06
mineral reserves that we know exist on
16:08
asteroids. Uh, and 15
16:11
years ago I'm sure you and I talked about it
16:14
probably when you were on ABC Western
16:16
Plains then rather than the podcast.
16:19
Uh, there were companies set up. One was
16:21
Planetary Resources Deep, uh, Space
16:24
Industries was another. Uh, I think they've
16:26
all been taken over by blockchain companies
16:29
now. They're not really active anymore. But
16:30
the idea was to set up a
16:33
space, a kind of off planet economy where
16:36
you go and mine these asteroids for
16:39
uh, resources. Um,
16:43
but there are all kinds of pitfalls
16:45
with even these near Earth asteroids. It's
16:48
actually for a start, uh, you know,
16:51
they've got so little gravity that um, any
16:54
mining apparatus that you put on it
16:57
risks just floating away, uh, as
17:00
it tries to dig up stuff.
17:02
Um, they're quite
17:05
complicated um, to
17:07
reach as well, even though the nearest Earth,
17:10
uh, asteroids of course, ah, come near the
17:12
Earth. Uh, but that um, places
17:15
some demands on the astrodynamics
17:18
needed to get there. Um,
17:21
here's the other thing and this probably,
17:24
uh, is one of the things that makes it
17:26
difficult. They tumble in space.
17:30
You know, they're rotating, they're all
17:32
rotating sometimes in uh, you know, if
17:35
you've got a small one, they'll rotate once
17:37
in not just a few hours but um, you
17:40
know, a few minutes really. Uh, and if you've
17:43
got something I'm um, trying to stick onto it
17:45
and dig holes in it, that's quite a
17:48
challenge. So here's the logic though.
17:51
Um, if uh,
17:54
uh, we think that there are
17:56
valuable minerals uh,
18:00
in asteroids, why don't we
18:03
go and find the debris
18:06
that was left by asteroids when they hit the
18:09
moon? Uh, and that is the
18:12
material that uh, is
18:15
in and around lunar craters.
18:18
Uh, so this is research that's been done by
18:20
uh, I think it's a team, there are
18:23
universities involved, but I think it's an
18:24
independent astronomer who's led it. Um,
18:28
if you uh, think about the
18:31
craters of the moon, uh,
18:34
you can actually analyse a lot of
18:37
what their geology is like from above just by
18:39
looking at the spectrum colours of the rocks.
18:42
You're basically doing something called
18:44
spectrophotometry where you're breaking up
18:46
basically using filters, uh, to find
18:49
them. And they suggest, these researchers
18:51
suggest that there are up to
18:55
6,500 impact craters that
18:57
might contain the platinum group metals
19:00
like rhodium, palladium and platinum itself.
19:03
And they also suspect about half that number
19:07
might be water bearing, that they've
19:10
got hydrated minerals in it and it's a
19:12
molecule that basically you can extract water
19:15
from. Um, and so
19:18
um, in fact what the team writes, and I'm
19:21
reading here partly from Michelle, uh,
19:23
Starr's article, uh, on Science Alert.
19:26
Michelle Starr, one of our um, heroines, I
19:28
think in terms of uh, science journalism, uh,
19:31
she's written a very nice article on this,
19:33
but she quotes uh, one of the
19:36
team members, these numbers, the
19:38
6500 and about 3400 impact
19:41
craters with water. These values are one to
19:44
two orders of magnitude larger than the
19:46
number of ore bearing near Earth asteroids,
19:49
um, uh, that we could, you know, we
19:52
could effectively mine. Uh, that implies
19:55
that it may be more advantageous and hence
19:57
more profitable to mine asteroids that have
20:00
impacted the Moon rather than the ones that
20:03
are important than it, that are in orbit. Uh,
20:06
and so yeah, that's um, a really
20:08
Interesting idea. It is. Um,
20:11
and as you say, as you said in your intro,
20:14
there are ethical considerations with this as
20:17
well. Um, I'm interested in your view of
20:20
that, Andrew.
20:21
Andrew Dunkley: What? Mining the moon?
20:22
Professor Fred Watson: Yeah.
20:23
Andrew Dunkley: Well, it takes it away from Earth, um,
20:26
and then it's, it's got limited resources
20:29
and um, there's a lot of controversy about
20:32
mining the m. Moon. Uh, mining the Earth
20:35
because of the environmental impact, because
20:37
so many creatures, including humans,
20:40
rely on a decent environment. Um,
20:43
mining the moon, not the same problem. Um,
20:47
I'm, I'm m. Not that much against it,
20:50
to be honest. I think, uh, if there's stuff
20:52
there that we need and we can use.
20:56
Professor Fred Watson: Yeah, I think, Kami, we should have a crack.
20:59
I think I agree with that. I still
21:02
think, um, the Moon needs to be
21:05
handled with great care in the sense
21:07
that. Yeah. Uh, except we're not mining
21:10
Antarctica because I was about to mine.
21:12
Andrew Dunkley: Not yet.
21:13
Professor Fred Watson: No. Well, not yet. That's right. Um,
21:16
so do you want to, uh, pass
21:19
legislation that says the Moon is used for
21:21
purely scientific purposes, or do you want to
21:24
open up the possibility of maybe just
21:27
limited mining in certain areas? Um,
21:31
uh, it's something I'd be ambivalent about as
21:33
well, I think, um. I don't think I'd rule it
21:36
out completely, but I think it would have to
21:38
be done within an ethical framework. And that
21:41
to me means international collaboration,
21:43
which we don't have at the moment. What we've
21:46
got is a race to the Moon, uh, effectively.
21:48
And perhaps this is one of the, um,
21:51
you know, this is one of the carrots that is,
21:54
uh, dragging that race to the Moon along or
21:57
accelerating that race to the Moon.
21:59
Andrew Dunkley: Well, there are already things on the Moon
22:02
that um, we see as
22:04
valuable that don't exist or are
22:07
easily accessible on Earth.
22:10
So that's another thing that's probably got
22:12
them rushing.
22:13
Professor Fred Watson: Yeah, you're probably thinking of, um, helium
22:15
3, the rare isotope of helium that would.
22:19
Has the promise of cheap, uh,
22:22
fusion reactors, cheap and safe
22:24
fusion reactors because of the low levels of
22:27
radiation that they emit. M. Um, that's still
22:29
an unproven technology. I don't think we've
22:31
got Enough helium, helium 3 on the Earth to
22:34
build a reactor. It's very rare on our
22:36
planet, but, um, it's thought to be fairly
22:39
prolific on the Moon because it's formed from
22:41
the solar radiation. So you know that.
22:44
Yeah, that's another issue. So, yes, I think,
22:47
um, I'd be certainly open to the
22:50
debate, but I would like it to be in an
22:51
international forum and maybe the forum
22:54
would be the one I was involved with a couple
22:56
of years ago, kopos, the Committee on the
22:58
Peaceful Uses of Outer Space. Uh, which is a
23:02
subset of unusa, the UN Office of Outer Space
23:04
Affairs. Um, one would hope that they will
23:07
be deeply involved with something like this.
23:10
Um, and um, that some sort of
23:12
contestants might emerge from it.
23:15
Andrew Dunkley: Yes, I hope so. Um, of course if they do
23:18
end up going up there and digging around and
23:20
going ah, this is just junk. It's just, you
23:23
know, um, maybe the dairy industry will find
23:25
something easy. So.
23:29
Professor Fred Watson: I think that's, that is quite a leap of uh.
23:33
Andrew Dunkley: I don't know. When I was a kid, when I.
23:35
Professor Fred Watson: Was a kid I thought the cow jumped over the
23:38
moon. It didn't actually land on it.
23:40
Andrew Dunkley: I was told that the moon was made of cheese.
23:42
Professor Fred Watson: Cheese, yeah. Anyway, uh,
23:45
yeah, there you go.
23:46
Andrew Dunkley: There are all sorts of possibilities, but the
23:49
possibility of water.
23:50
Professor Fred Watson: Uh, yeah, that's right.
23:51
Andrew Dunkley: In some of these craters too.
23:53
Professor Fred Watson: And I think you know, Artemis, um, well,
23:56
Artemis 2 is going to be a flyby.
23:57
Artemis 3, the first landing on the mission.
23:59
We hope in about two years time if
24:02
Blue Origin and um, SpaceX get their act
24:05
together with their respective lunar landers,
24:07
which are still uh, quite a long way from
24:09
being ready, that uh, that could start to
24:12
tell us, uh, because we'll naturally there'll
24:15
be samples coming back which will be uh,
24:18
checked for all these hydrated molecules and
24:20
perhaps um, just for ice itself because
24:23
uh, you're going to be near some of the
24:25
craters that have never seen sunlight,
24:28
uh, on the moon's south pole. Yeah, so we're
24:31
in a really interesting time, Andrew. And uh,
24:33
so much ahead that M may or may not
24:36
contrafete fruition.
24:38
Andrew Dunkley: We will wait and see. Uh, you can read all
24:40
about it in the paper that's been
24:43
published in Planetary and Space Science or
24:45
you can read the
24:46
article@sciencealert.com
24:49
this is space Nuts with Andrew Dunkley and
24:51
Fred Watson Watson. Three, two,
24:54
one. Space Nuts.
24:57
Our final story on this episode, Fred Watson,
25:00
uh, is about uh,
25:02
creating a, a, uh, new rocket
25:05
motor. But uh, this one's a bit
25:08
different. They're going to 3D print them and
25:11
it is an Australian project.
25:14
Professor Fred Watson: That's right, 3D printed
25:17
rocket motors are not new. Um,
25:20
there's I think rocket lab in
25:23
New Zealand might. Oh yeah, and
25:26
possibly Gilmour as well here in Australia.
25:29
Uh, but this is uh,
25:32
different and it's uh, a first of a different
25:35
kind because it's uh. This
25:38
blows my mind I have to say. It's a
25:40
3D printed rocket motor
25:43
made out of two different metals. And
25:46
as I understand it as in the 3D
25:49
printing process you can lay
25:52
these metals down independently and ah,
25:55
maybe even m mix them. But you can, I think
25:57
you can structure the thing so that the
25:59
different bits of it uh, have the metals
26:01
where you want them to be. Um, which is an
26:03
extraordinary thing. There's a lot of things
26:05
that surprise me about um,
26:09
this story Andrew, which is actually on Space
26:12
Connect, uh, which is an Australian
26:14
homegrown space uh
26:18
website. Um, the first is that
26:22
this work has been done by
26:25
uh, using
26:29
an off the shelf 3D printer and it's
26:32
apparently called a Nikon SLM Solutions
26:34
SLM2082MA M metal
26:37
printer. The fact that you can buy something
26:40
like that uh, is just you know,
26:43
a reflection of the era that we live in. And
26:44
um, it may well be that some of our SpaceNots
26:47
listeners are in the 3D printing industry and
26:49
they might say oh this is old stuff, this is
26:51
completely old hat. And I have to say uh,
26:54
back in 2000 um, when we were building
26:57
the 60F instrument for the UK Schmidt
26:59
telescope, remember I used to build
27:01
instruments, we actually did 3D print some of
27:03
the components for that but they were made of
27:06
plastic effectively. But it was a really good
27:08
way of doing it. And it was one of our
27:10
scientists, Will Saunders, Dr. Will Saunders,
27:12
he suggested the 3D printing process and it
27:15
turned out very successfully. So 3D printing
27:18
is not a new technology. But um, you
27:21
know the fact that you could go and buy
27:22
something that will print with two different
27:24
metals to me blows my mind.
27:26
Um, so uh, Space Machines company
27:29
is smc, uh and they are the
27:32
uh, delivery agency for this
27:36
uh, uh new facility and it's in
27:38
partnership with our national science agency,
27:40
the csiro, uh
27:43
Commonwealth Science and Industrial Research
27:45
Organisation, um with uh,
27:48
some number of colleagues from there. I was
27:50
at, with last week at the uh, conference. So
27:53
CSRO and SMC Space Machines
27:55
company have uh, built this thruster
27:59
uh for something called the Optimus
28:01
Viper spacecraft which is an Australian built
28:04
platform designed for on orbit
28:06
inspection, servicing and logistics. As we
28:09
read in their blur.
28:10
Andrew Dunkley: It sounds like a cool spacecraft.
28:12
Professor Fred Watson: Yeah it does.
28:13
Andrew Dunkley: Viper.
28:13
Professor Fred Watson: Yeah I like that too.
28:16
So um, it's uh,
28:19
really um. I think part of this is, and
28:22
we hear this a lot these days, it's our
28:24
sovereign capability, uh we're
28:27
striving uh to build a sovereign space
28:29
capabilities um by
28:32
developing manufacturing and operating
28:35
space technology right here in Australia.
28:36
That comes from uh, Darren Lovett who is
28:41
the executive director of something called
28:43
Ilaunch. Ilaunch is a.
28:46
Is, uh, basically a collaboration. I'm very
28:49
glad to see that one of the universities I
28:50
have an adjunct
28:53
professorship with, uh, is part and parcel of
28:55
it. The University of Southern Queensland and
28:57
the Australian National University are
28:59
involved as well, along with the University
29:01
of South Australia. So a big partnership that
29:03
is, um, sort of masterminding, if
29:06
you like, some of these, um, new
29:09
technologies. But uh, yes, to see
29:11
this little thruster. And actually on the
29:13
Space Connect article that I
29:16
just referred to, there's a very nice. A, uh,
29:19
very nice photograph of it. A little chunk of
29:21
metal, quite complicated shape, uh, very,
29:24
uh, interestingly presented and no
29:27
doubt will do its stuff admirably when it
29:30
is in space.
29:31
Andrew Dunkley: Yeah. Combining two metals in a single build,
29:34
um, brazing of copper and steel
29:37
components. So, uh, it's. It's, you know,
29:39
that's. That's. That's tough stuff.
29:41
Professor Fred Watson: It is. It's steel for strength and
29:44
copper for, uh, thermal conductivity, as I
29:47
understand it.
29:47
Andrew Dunkley: Yeah, that's impressive. Yeah, uh, that's a
29:50
great story with a, ah, great Australian
29:52
connection and, uh, no doubt, um, another
29:55
giant leap forward for humankind in the
29:58
space race. And you can read about it, as
30:00
Fred Watson mentioned at Space Connect
30:03
online. And uh, that's
30:06
about all we've got time for. Fred Watson,
30:07
thank you very much.
30:09
Professor Fred Watson: So, thank you. We'll take our
30:11
bimetallic thrusters and zoom off into the
30:14
wide blue yonder. Good to talk to.
30:15
Andrew Dunkley: Sure will indeed. Good to talk to you too.
30:18
And uh, we often get suggestions from people
30:21
asking about stories or things that they'd
30:23
like us to talk about. So if you do have
30:26
something in mind that, uh, you think we
30:28
should cover, uh, or if you spot something in
30:30
the media that we don't, that you think is,
30:33
uh, worth a mention, uh, we. We'd
30:35
encourage you to jump on our website and send
30:37
us, uh, the details and we'll see if we can
30:39
chase it up. More than happy to do so. Saves
30:42
us a lot of work. And, um.
30:45
Oh, sorry, Fred Watson. Go
30:48
on.
30:48
Professor Fred Watson: No, yes, you're quite right. It saves us a
30:50
lot of work.
30:53
Andrew Dunkley: Well, if we're talking about what the
30:54
audience wants us to talk about, that's all
30:56
the setup. All right, thanks, Fred Watson.
30:58
We'll see you soon.
31:00
Professor Fred Watson: Sounds good. Thanks, Andrew.
31:01
Andrew Dunkley: Fred Watson Watson, astronomer at large. And
31:03
thanks to Huw in the studio who didn't turn
31:05
up again today because, uh, well,
31:09
he got arrested by a copper. And from
31:12
me, Andrew Dunkley. Think about it.
31:15
Next to your company, we'll see you on the
31:16
very next episode of Space Nuts. Bye bye.
31:19
Professor Fred Watson: Hi there.
31:20
Andrew Dunkley: Welcome to a Q and A edition of Space
31:22
Nuts. My name is Andrew Dunkley, your host.
31:25
Good to have your company again. Uh,
31:27
questions coming today from Pete. Uh, he's
31:30
looking at the collapse of the universe.
31:33
Wants to know where he needs to be when it
31:35
happens, so he gets a good view. Actually, I
31:37
think it's about something else. Uh, we've
31:39
also got a question from Tad, who's brought
31:42
up a really interesting point about falling
31:44
into a black hole. From an observer's
31:46
perspective, if we were to watch someone or
31:49
something do, uh, really is
31:53
a great piece of science to talk about. Uh,
31:55
Mark is bringing up something from an
31:58
episode four years ago, I think, uh,
32:01
antimatter stars. And Dave
32:04
wants um, to know about the best time and
32:06
place to aim a camera for, uh, low light
32:09
astrophotography. Uh, that
32:12
is a great question. Uh, I've had so much
32:14
trouble with that myself. We'll get stuck
32:16
into it right now on this edition of space
32:19
nuts. 15 seconds. Guidance is
32:21
internal.
32:22
Professor Fred Watson: 10, 9.
32:24
Andrew Dunkley: Ignition sequence start.
32:26
Professor Fred Watson: Space nuts. 5, 4, 3, 2. 1. 2,
32:29
3, 4, 5, 5, 4, 3, 2, 1.
32:33
Andrew Dunkley: Astronauts reported bill.
32:34
Professor Fred Watson: Good.
32:35
Andrew Dunkley: And here he is again, Professor Fred Watson
32:37
Watson, Astronomer at large. Hello,
32:39
Fred Watson.
32:40
Professor Fred Watson: Hello, Andrew. Fancy seeing you here.
32:42
Yes, yes.
32:43
Andrew Dunkley: And we're in similar coloured shirts today.
32:46
Professor Fred Watson: That's right. I think we're very chic green.
32:48
Andrew Dunkley: Judy reckons green's my colour, but I've
32:50
never really liked green. But
32:53
anyway, she's more of a
32:55
fashionista than I am, so I'll take her word
32:57
for it. Uh, how you been?
33:00
Professor Fred Watson: Very well, thank you. Yes, all seems to be
33:03
going well so far.
33:05
Andrew Dunkley: You look and sound as well as the last time I
33:07
saw you.
33:08
Professor Fred Watson: Well, that's right, you know, uh,
33:11
uh, it seems like only a few
33:14
minutes ago. It does, doesn't it?
33:16
Andrew Dunkley: Funny that um, that's because of a black
33:18
hole.
33:19
Professor Fred Watson: It could be a black bill for nothing.
33:23
Andrew Dunkley: Although we must point out that this will be
33:25
your last show for a short while. You're
33:28
taking uh, a bit of a trip which will take
33:30
um, you into time zones that are just not
33:32
compatible with life on Earth in Australia.
33:34
So, um, uh, we will be
33:37
bringing our, uh, stand in Johnty Horner in
33:40
to look after things while you're away for
33:42
about 7ish weeks, something like that.
33:46
We knew this was going to happen this year
33:48
with me away for three months and you away
33:51
for uh, a couple of months. So we knew this
33:53
was going to happen and we planned ahead so
33:56
that the show could go on. So, um,
33:58
anyway, um, we'll look forward to chatting
34:01
with Jonty and, uh, wish you well on your
34:03
trip. Um, where are you going?
34:06
Professor Fred Watson: Uh, we've got about two and a half weeks in
34:09
Japan. Uh, then we're back in
34:12
Australia very briefly and then we're off up
34:14
to Ireland for a Dark sky conference
34:17
and, uh, skipping over to the UK to
34:19
hang out with my family for a little bit in
34:21
the UK and uh, that'll take us to the end
34:24
of November.
34:25
Andrew Dunkley: Why wouldn't you? It's just a short hop,
34:27
isn't it, really?
34:28
Professor Fred Watson: Yeah, that's right. Yeah. It's stupid going
34:29
to Ireland or going to the uk. That's right.
34:33
So we'll do a few, uh, things. We're going
34:34
to, uh. Marnie's got a nice itinerary for us.
34:37
We're going to go to places that I have
34:39
wanted to go ever since I was a child and
34:41
never made it in the uk. So that's fantastic.
34:44
We'll tell you about it when we get back.
34:46
Andrew Dunkley: Love to hear about it. Um, we better get
34:49
into the, uh, questions.
34:51
Professor Fred Watson: Yes, yes.
34:51
Andrew Dunkley: Yeah, I guess so. Yeah. Yeah.
34:53
Our first question's an audio question, uh,
34:56
coming from Pete.
34:57
Professor Fred Watson: Hi, Fred Watson and Andrew. Pete from Long
35:00
Point got a question. I know that
35:03
it's. There's contested as to
35:06
what's going to happen in the future with the
35:08
universe they're going to,
35:11
or however it's pronounced or expansion or
35:14
the big grip or whatever. The question if, if
35:16
the universe is going to collapse
35:19
back in itself. I get the concept of
35:22
the gravity bringing
35:25
sort of physical matter back together and I
35:27
know that's only what, 5% of the universe,
35:30
but I don't understand how that would work
35:34
with the basically pulling
35:37
of light backwards. So you have light
35:40
is expanding ever
35:42
increasingly obviously at the speed of light.
35:45
Um, basically what happens with that
35:48
in the event there is a collapse back to
35:51
another singularity? Um,
35:54
yeah, I'm confused. Thanks guys.
35:57
Andrew Dunkley: I think a lot of people are, uh. Um, yeah, he
36:00
was referring to the gnab gib, which is the
36:02
reverse idig bang. Yeah. Uh, but
36:05
it's an interesting question because if it
36:07
does happen, rather than a big rip, uh,
36:10
the universe stops expanding and then
36:13
starts receding back in on itself,
36:16
what does happen to the light and the
36:18
dark matter and all that other stuff that we
36:21
don't understand.
36:23
Professor Fred Watson: So, um, uh,
36:27
this. No, thanks very much, Pete.
36:30
Great question, uh, which has arisen because,
36:34
um, I think it might be while you were away,
36:36
Andrew, we covered the new
36:38
observations that have come from the dark
36:41
energy, uh, instrument, um,
36:45
which is, uh, on
36:48
the mail telescopes, a telescope very similar
36:50
to our Anglo Australian telescope, uh,
36:53
uh, which has been surveying the universe as
36:55
you do such instruments, um, getting
36:58
the redshifts, which means the distances of
37:00
all the galaxies and building up a map. And
37:03
that map, um, has just the first hint
37:06
that the acceleration of the
37:09
universe, which we attribute to this dark
37:11
energy, whatever it is, the acceleration of
37:14
the universe is actually slowing down. It's
37:16
still only a hint, it's not confirmed yet.
37:18
But if the acceleration is slowing down,
37:21
then it does raised once again
37:24
the possibility that we talked about a lot in
37:26
the 1970s and 80s, uh, the idea
37:29
of an eventual collapse, a reversal of the
37:32
expansion of the universe to a collapse.
37:34
Uh, and the end product of that is often
37:37
called the Big Crunch. But we like the Gnab
37:40
gib. That was the name that Brian Schmidt
37:42
gave to it. It's a great name. So what
37:45
happens in the Gnab gib? Well, um,
37:48
it is interesting. You've got gravity taking
37:51
over and it doesn't just
37:54
sort of bring together the,
37:58
the objects in space, it doesn't just
38:00
collapse all the galaxies towards one place,
38:03
it actually collapses space time with it,
38:06
um, because the, you know, the
38:09
matter bends space. We know. And that bending
38:12
is effectively what you, what you would call
38:14
the collapse, uh, in the run up to
38:17
the, or the run down to the Gnab gib.
38:20
And so in a sense, uh, the light,
38:24
uh, so what I'm saying is that,
38:27
um, the distances that
38:30
the distances that we measure between
38:32
galaxies becomes less, but
38:35
it's because the space time has shrunk
38:37
basically. Uh, and so not just that
38:40
the galaxies have got closer together. Um,
38:43
and that means, uh, that yes, light will
38:45
still continue to travel through spacetime at
38:48
300,000 kilometres per second, but that space
38:51
time has got less space in it. Um,
38:54
and so the light just shrinks with the
38:56
universe. It doesn't kind of escape or
38:59
anything that many gazillions
39:02
of photons that are currently traversing the
39:05
universe and will continue to do that, uh, as
39:07
long as things are shining and there's energy
39:08
to provide that they will have shorter
39:11
distances to go. Uh, and we will find
39:14
that the universe just gets smaller. As it
39:17
gets smaller, the light goes with it and we
39:19
end up with a bundle of stuff, uh, subatomic
39:22
particles, including photons, particles of
39:25
light, a whole lot of stuff that is going to
39:26
hit, um, an almighty singularity,
39:29
uh, uh, which we might call the Gnab
39:32
gib. Yeah. Wow.
39:34
Andrew Dunkley: Um, correct me if I'm wrong, but didn't
39:37
we talk in the past. About a time where the
39:40
universe will become dark and
39:43
cold and there won't be
39:46
any light.
39:47
Professor Fred Watson: Well, um, that's right. If the universe
39:50
continues expanding, then eventually
39:53
there will be light there, but it won't be
39:54
able to reach you because it'll be beyond
39:57
your horizon. Uh, uh,
39:59
so the light will still be going through the
40:01
universe, but that light source will be
40:04
receding from us, um, too
40:07
fast for the light ever to get to us. So,
40:10
yes, it becomes dark and dreary. Uh, but,
40:12
yeah, light is still there.
40:14
Andrew Dunkley: All right, there you go, Pete. Um, it will
40:17
all be cataclysmic and horrible, and we'll,
40:19
uh, all be a lot shorter.
40:23
Professor Fred Watson: Every dimension.
40:25
Andrew Dunkley: Indeed, yes. Although I'm starting to like
40:27
the idea of a big rip. Because a big rip
40:29
might open us to another universe and we
40:31
could all escape.
40:33
Professor Fred Watson: Well, yeah, maybe. Well, of course, with the
40:36
big. The gnab gib, you could get the big
40:38
bounce. Uh, you know, it could just bounce
40:40
back. So you've suddenly got an expanding
40:42
universe immediately.
40:44
Andrew Dunkley: It's hard to get your head around. And I
40:47
understand why Pete feels confused, because
40:49
it really is beyond our imagination in many
40:52
ways, isn't it?
40:53
Professor Fred Watson: That's right. Indeed it is.
40:54
Andrew Dunkley: Thanks, Pete. Great question. Hope you're
40:56
well.
40:56
Uh, let's go to a question from Tad.
40:59
Uh, this one's really interesting. Uh, we
41:01
understand that due to extreme gravitational
41:04
dilation, from the perspective of an outside
41:07
observer, anyone falling into a black hole
41:10
takes an infinite amount of time to cross the
41:12
event horizon, even if, from that person's
41:15
perspective, they actually do in real time.
41:18
Uh, if this is true, how do black holes
41:21
and their event horizons even form in the
41:23
first place? From an outsider's perspective?
41:26
And does this mean that technically nothing
41:29
has ever fallen into a black hole from our
41:31
perspective here on Earth? I love this
41:33
question. Thank you, Tad. Uh,
41:36
he's bringing up the point where if you're
41:38
watching someone fall into the. Into a black
41:40
hole because of the
41:43
effect, the gravitational effect on time
41:46
space, it never happens, but
41:49
that person experiences it in
41:52
real time until they get spaghettified.
41:55
So, um, yeah, how come we see
41:58
black holes when this effect
42:01
should suggest we should never see
42:04
it happen? Is that what he's
42:07
saying?
42:09
Professor Fred Watson: Yeah. How do black holes form in the first
42:11
place? Uh,
42:15
so, yes, so in that regard,
42:18
that time dilation is a kind of optical
42:21
illusion because the thing has crossed the
42:23
event horizon, whatever it is has
42:26
contributed to the mass of the black hole.
42:29
So, uh, the reality is. Yes,
42:31
you're. You know, if it's you, you get
42:33
spaghettified and then you get absorbed by
42:36
the black hole itself a gazillionth of a
42:37
second later. Um, it's from the outside
42:40
perspective. Uh, I've always struggled with
42:43
this actually in trying to envisage it
42:45
because, yeah, you imagine some poor person
42:47
who's fallen into a black hole. Um,
42:50
it's be like the, um, you know those chalk,
42:53
uh, chalk things on the road where
42:56
somebody's got hit by a car. There'd
42:59
be this chalk mark of somebody, uh, on the
43:01
surface of the event horizon. Um,
43:05
uh, but they'd also, uh,
43:08
along with that person, there'd be everything
43:09
else that's gone into it. And black holes are
43:12
notorious for accreting material. So all the
43:14
stuff that's spiralling into it from an
43:16
outsider's perspective just ends up looking
43:18
as though it's stuck on the top surface of
43:20
the event horizon, even though it's actually
43:22
been absorbed by the, by the black hole.
43:25
So it is a kind of optical illusion. Yes,
43:27
it's very weird. Uh, it just means that from,
43:30
you know, what it highlights is, uh,
43:33
it's all about your reference frame. Uh, our
43:36
reference frame is an um, observer looking
43:38
out, looking in from the outside.
43:41
If you've got the reference frame of the
43:43
person who's falling into the black hole,
43:44
things are a lot different. Uh, we can watch,
43:47
um, from the sidelines and cheer people on
43:50
as they fall through the black hole event
43:52
horizon. All, uh, we see is them
43:54
frozen on the event horizon,
43:57
uh, which must be a very messy place with all
43:59
the stuff that's falling into it.
44:01
Andrew Dunkley: Yeah.
44:02
Professor Fred Watson: So, um, yeah,
44:06
to me that transforms what the event horizon
44:08
might look like. It's probably not that nice
44:10
sphere of darkness that we imagine, but it's
44:12
got, become splattered with lots of stuff.
44:15
And in fact, we know that the magnetism of a
44:17
black hole actually plays a huge role
44:20
in, um, directing material
44:23
so that some of the stuff is actually
44:25
accelerated perpendicular to the accretion
44:27
disc, uh, upwards and
44:30
downwards. And that in itself is a process
44:32
that it's very hard to get your head around
44:35
how stuff that's swirling in towards the
44:36
black hole suddenly gets dragged up, up, uh,
44:39
and shot out the, the poles of the
44:42
black hole, top and bottom. Um, So a
44:45
lot of hard work to conjecture. I hope that
44:48
helps Tad, to envisage what's going on.
44:51
Uh, but, um. Because it's all about your
44:54
perspective, basically.
44:55
Andrew Dunkley: Yeah, yeah. Ah, so the, the black hole,
44:58
uh, has happened.
45:02
My brain had an idea and it just fell into a
45:05
black hole and then I can't remember. But,
45:08
uh, we see the black hole
45:12
because it's already happened. Is that.
45:15
Professor Fred Watson: Well, yeah, the black hole's been created.
45:18
I mean, typically in the collapse of
45:20
a star at the end of its life. Uh,
45:24
so that's a straightforward gravitational
45:26
collapse. The material of the star basically
45:29
collapses down so that nothing will hold
45:31
it out and it becomes this singularity, a
45:34
point of infinite density, which is how we
45:36
define it. Um, and that's. It's during
45:39
that collapse that the event horizon forms.
45:41
And you've got that. As I said, it's an
45:44
optical illusion. That's the main point to
45:46
recognise. It's an optical illusion as seen
45:48
from the outside, um,
45:51
that nothing reaches the black hole.
45:54
Andrew Dunkley: M I'm sure we'll get some more questions on
45:56
this one, but, uh, you've probably opened a
45:58
can of spaghetti there. Yeah.
46:00
Professor Fred Watson: Which is great, because Jonty can deal with
46:02
all that.
46:04
Andrew Dunkley: Yeah. Yes, that's for sure.
46:07
All right, Tad, thank you for the question.
46:09
This is Space Nuts, a Q and A edition with
46:11
Andrew Dunkley and Professor Fred Watson
46:13
Watson.
46:14
Professor Fred Watson: Space Nuts.
46:16
Andrew Dunkley: Now, uh, our next question's an audio
46:18
question. It comes from Mark.
46:21
Professor Fred Watson: Hi, it's Mark in London and Canada.
46:24
I just listened to an episode from
46:28
March 2021 and Fred Watson mentioned the
46:31
possible existence of an antimatter
46:33
star and how. Obviously we wouldn't want to
46:36
get, uh, anywhere near it,
46:39
but I was wondering, is it possible? Does it
46:42
exist? Uh, and how could we tell if we're
46:44
looking at a star from Earth? Can we tell
46:47
if it's regular matter or antimatter
46:50
or what if the entire Andromeda Galaxy was
46:53
antimatter, would we have a way of
46:56
figuring that out? Thanks. Bye.
46:59
Andrew Dunkley: M. Uh, I would ask my Auntie
47:02
Shirley, but she wouldn't know either. Um,
47:05
thank you, Mark. Antimatter stars. We did. I
47:07
remember us talking about them. Uh, we do
47:09
know there is antimatter. There's just
47:12
a hell of a lot less of it than actual
47:15
matter, if I recall correctly. But if you've
47:17
got, um, a molecule of matter and a molecule
47:20
of antimatter and they collide, they just
47:23
cease to exist. Is that how it goes?
47:26
Professor Fred Watson: Yes, that's right, yeah. Um, what you get,
47:29
um, is. So if you. The
47:32
difference between a normal matter
47:34
particle, uh, like an electron
47:37
and its antimatter equivalent
47:40
is the electrical charge is the opposite.
47:43
So the antimatter equivalent of an electron
47:46
is a positron. Um, it's got positive
47:48
electrical charge. Uh, and
47:52
when two
47:55
particles like that meet, they
47:57
annihilate. And what you get is a
48:00
gamma ray. You get a photon of Gamma ray
48:03
energy which has ah,
48:07
a uh, characteristic um, frequency
48:10
distribution. We actually, in gamma rays we
48:12
call it energy. Uh, in light we think of it
48:14
as wavelength, in radio waves we think it as
48:16
frequency. But it's the same thing basically
48:20
uh, at different levels of energy. So you get
48:23
these gamma rays which will be emitted with a
48:25
specific and characteristic frequency. And
48:28
that's the way that you might be able to
48:31
detect an antimatter star.
48:37
I think this story actually goes back, it
48:39
does go back to 2021. I've just found the
48:42
article that we referred to. Stars made of
48:44
antimatter might be lurking in the universe.
48:46
It's from scientists, Scientific American, a
48:47
very authoritative source. Um,
48:51
but what they were starting the story
48:53
with was something that happened in 2018
48:56
when uh, one of the
48:59
experiments on the outside of the
49:01
International Space Station which we talked
49:02
about in the last episode with great warmth
49:05
and uh, admiration, um,
49:08
one of those experiments may have detected
49:11
uh, two uh, basically
49:14
nuclei of anti helium, um, these
49:17
are anti helium particles. And
49:20
so you mix that with normal helium and you
49:23
get gamma rays. Um
49:25
and so the question is
49:30
where does that come from? And
49:32
that was um, the outcome of this,
49:36
the suggestion that the easiest way to
49:38
produce anti helium is inside anti
49:41
stars, um, which
49:44
we still don't know whether they exist or
49:46
not. Uh, but really the point of
49:49
Marx's question is a good one. I um, don't
49:52
think we know much more about this uh,
49:56
since that you know that speculation.
49:59
Um, but what they're
50:01
suggesting I might actually
50:04
read uh, from that Scientific American
50:07
article and acknowledge the source there.
50:11
It was written by ah, ah,
50:13
Leto Supuna, who's the author
50:16
of that. Um, and I think it
50:19
sort of puts it a lot better than I can.
50:22
Antistars would shine much as normal ones
50:25
do, producing light of the same wavelengths,
50:27
but they would exist in a matter dominated
50:30
universe. And so as particles and
50:33
gases made of regular matter fell into
50:35
an antistar's gravitational pull and made
50:38
contact with its antimatter, the resulting
50:40
annihilations would produce a flash of high
50:42
energy light. That's the gamma rays I
50:44
mentioned. We can see this light as. There
50:47
you go. We can see this light as a specific
50:49
colour of gamma rays. Um, and
50:52
so one of the teams that they're Talking
50:53
about took 10 years of data, uh,
50:56
which amounted to roughly 6,000 light
50:59
emitting objects. They paired the list down
51:00
to sources that shone with the right gamma
51:03
ray frequency and that were not ascribed to
51:05
previously catalogued astronomical object.
51:07
Um, so this left us with
51:10
14 candidates. This is one of the Authors,
51:13
uh, talking which in my opinion and my co
51:15
author's opinion too, are, um, not anti
51:17
stars. Um, yeah,
51:20
so. But they say if all those sources were
51:23
such stars, that means one antistar would
51:25
exist for every 400,000 ordinary ones in our
51:28
stellar neck of the woods. So
51:31
we're still struggling to get our heads
51:33
around this. And I'm not sure whether any
51:35
more of, uh, these characteristic
51:38
gamma ray flashes, uh, have
51:41
been observed or what the latest is on this
51:44
topic. But it is a very interesting one, I
51:46
think. Thank Mark for raising it again
51:48
because it's one we should perhaps look at in
51:50
a bit more detail. Like try and, um, dig out
51:53
some stories for when I return to space,
51:55
nuts on, um, antistars and see
51:58
what we've got in that.
52:00
Andrew Dunkley: Do you think they could exist, Frank?
52:02
Professor Fred Watson: I do think they could exist, yeah. Um, I
52:05
mean, you know, it's one of the big puzzles
52:06
of the universe as to why there's so much
52:09
matter and so little antimatter. When our
52:12
best theories of the origin of the universe
52:14
suggest that antimatter and matter were
52:16
created in equal, you know, in equal
52:19
proportions. So, uh, it's
52:21
one of these. It is, it's one of these issues
52:24
that, um, is. Keeps on bubbling up and, uh,
52:27
uh, you know, challenging our understanding.
52:30
Andrew Dunkley: Yeah, uh, I'm m. Probably dredging up
52:33
the same joke I used four and a half years
52:34
ago, but there's a lot of. There's a lot of
52:36
doesn't matter in astronomy as well.
52:41
See, I can hear you got a.
52:43
Professor Fred Watson: No, not a majority there. Yeah.
52:46
Andrew Dunkley: Um, but, yeah, antimatter stars are
52:49
right up there with white holes. Uh, we've
52:51
never seen one. But there's, you know,
52:54
there's certain elements of
52:57
science that think these things exist. Uh,
53:01
but we've just never found the direct
53:04
evidence or proof, have we?
53:06
Professor Fred Watson: No, that's. Excuse me. That's correct.
53:08
Um, just along those lines, there's, uh,
53:11
something that cropped, um, up about a week
53:14
ago or two weeks ago. Um, it's a
53:16
gravitational wave event which I think
53:19
dates back to 2019. And you know,
53:22
gravitational waves measured by LIGO and uh,
53:25
Kagra and Virgo, the three big gravitational
53:28
wave detectors in the world. Ah, they, um,
53:32
uh, this particular and most, most
53:34
gravitational waves come from either neutron
53:36
stars colliding or neutron stars colliding
53:38
with black holes or black holes colliding.
53:40
And they always have a characteristic
53:41
signature. They spiral together and then when
53:44
they come together at the end, they produce
53:46
this characteristic chirp, um,
53:49
which is when they merge. Um,
53:52
and that usually lasts a few Seconds that,
53:55
um, run up to the chirp. Uh, but this
53:58
one in 2019 only lasted, I think it was a
54:01
tenth of a second. Uh, and
54:05
one interpretation of that is that,
54:08
uh, it was two very massive
54:11
black holes. I think that's the way around.
54:13
It goes. Could be the other way around.
54:15
Anyway, um, a, uh, recent paper
54:18
from China, and I think this was two weeks
54:20
ago, proposed that you could get nearly
54:23
the same modelling, which, because they model
54:26
these gravitational wave phenomena, if,
54:29
uh, it turned out that what you were looking
54:31
at was not colliding black holes but a
54:34
collapsing wormhole. Um, and
54:37
that's the first evidence that I think
54:39
anybody has put forward for the existence of
54:41
wormholes. But it's still very
54:44
conjectural because the, um, likelihood, you
54:47
know, the model of just two black holes
54:49
colliding actually fits the data slightly
54:51
better than the model of the collapsing
54:53
wormhole. But people are still looking at
54:55
these things as they are for white holes and,
54:58
um, I hope also for antimatter stars.
55:00
Andrew Dunkley: Yes. Yeah, well, um, I
55:03
suppose there's so much to consider in the
55:06
universe that some things just don't get the
55:09
amount of time and attention they probably
55:11
deserve. But the workforce
55:14
is spread so thin in astronomy and space
55:16
science, I would imagine so, um,
55:21
it's hard to deal with everything.
55:22
Professor Fred Watson: With everything. That's right. There's
55:24
certainly enough questions to keep us busy
55:26
for a long time in the world of astronomy.
55:28
Absolutely.
55:29
Andrew Dunkley: Yeah. All right, Mark, thank you. Hope all
55:32
is well in Canada.
55:34
Our final question comes from Dave. And, uh,
55:37
Dave is from Inverel in, uh, northern New
55:40
South Wales, Australia. As someone who is
55:42
lucky enough to enjoy fairly low light
55:44
pollution where I live, I like to
55:47
attempt some nighttime photography now and
55:49
then. Lately I've been using the nightcap
55:52
app on my phone. I've got that one as well.
55:55
Uh, with, uh, the meteor setting, he says
55:58
to try and capture some meteor photos.
56:01
Uh, I find the best time to see a great
56:03
falling star is just as I'm getting the phone
56:05
set up, ready to start shooting.
56:09
Uh, just wondering if you have any advice for
56:11
when to try and capture a meteor on camera.
56:15
Example, uh, time of night, direction, etc.
56:17
Or should I just, uh, wait until a good
56:20
meteor shower turns up? Uh, and how many
56:23
meteors would we expect to see collide in
56:26
our atmos, uh, collide with our atmosphere on
56:28
any given night? Um, also
56:31
great, uh, to hear you back, Andrew, and
56:33
hearing. Enjoy, uh, hearing your travels, uh,
56:36
when you talk of Iceland, it makes me very
56:39
keen to return.
56:39
Can I ask which company you cruised with,
56:42
Dave? From Inverel. Yes you can.
56:46
Uh, the uh, the answer is uh, Princess.
56:49
It was Princess Cruises. Uh, we made the
56:52
news early in the cruise when we got smashed
56:55
just southwest, um, corner of Australia by a
56:58
squall that knocked the ship over, not
57:00
completely seven degree list, uh, which
57:02
we took three hours to straighten up. I had
57:05
to go up to the bridge and help the captain
57:07
by, you know, using my weight to stand at
57:09
the. No, I didn't. Uh, but uh, it was um,
57:12
yeah, pretty uh, hair raising for a while
57:14
there. Uh, we made the news all over
57:16
Australia apparently. But um, yeah, it was
57:18
the Princess Cruise Line. Uh, and we've been
57:21
with them many times on other cruises and
57:23
they're uh, I, I really enjoy them.
57:26
Uh, they probably uh, it's
57:28
debatable but I think food wise they're
57:30
probably the best. But yes, um,
57:34
now, and you mentioned the. Sorry, go on.
57:37
Professor Fred Watson: I was just going to say if you want to avoid
57:39
uh, the rigours of sea travel, you could come
57:41
with Dark Sky Traveller. We go up to Iceland
57:43
pretty regularly too. Yes. Well there's a
57:45
thought. Yeah.
57:46
Andrew Dunkley: Um, yeah. So the downside of cruising is it's
57:49
slow. Yeah, I mean it's very relaxing. But if
57:52
you do want to get somewhere in a hurry, it's
57:54
um, probably not the way to do it. Um,
57:58
and uh, Dave also mentioned the nightcap
58:00
app. Uh, I do have that one on my phone. I
58:03
haven't had an opportunity to really use it
58:05
because it uh, there's too much
58:08
light around here.
58:10
Professor Fred Watson: What does it do, Andrew? What's the, what's
58:12
the purpose of the nightcap?
58:14
Andrew Dunkley: I haven't got my phone with me. But uh, you
58:16
can preset it to
58:19
photograph in low light
58:22
and you can either put it in manual
58:25
mode or you can have this series of presets
58:27
where you can, if you know what you want to
58:29
photograph, it will set up the phone
58:32
to create the exact situation you need to
58:35
take that particular photograph. It's really,
58:37
it's really good software. Um, but I
58:40
haven't really had a chance to use it
58:43
properly. But uh, it can do time lapse and
58:45
all sorts of things.
58:46
Professor Fred Watson: It's.
58:47
Andrew Dunkley: Yeah, it's really good gear. Uh, so
58:49
yeah, when and where and
58:52
how to take low light
58:55
photographs, Fred Watson.
58:56
Professor Fred Watson: Of meteors. That was a crucial
58:59
thing. Yeah, from, from Dave's question. And
59:01
yeah, so Dave up in Verralle will have
59:04
um, pretty easy access to dark skies.
59:07
Andrew Dunkley: Uh, yeah, that's, you know why? You know why?
59:09
Because they're not putting the electricity
59:11
on up there for another 10 years.
59:14
Professor Fred Watson: Okay.
59:15
Andrew Dunkley: Sorry. Everyone asks,
59:18
in the 30 odd years I've lived here, people
59:20
have often asked, do you have electricity
59:21
where you are? Um, so I couldn't help that
59:24
joke.
59:25
Professor Fred Watson: No. Well, you do. Uh, we did include a
59:27
bourbon as well, but we were at the end of
59:28
the line and uh, so if ever there was a
59:31
thunderstorm, we usually left our
59:32
electricity.
59:33
Andrew Dunkley: You were gone. Yeah, we had that problem the
59:35
first 15 years we lived here.
59:37
Professor Fred Watson: All right, yeah. Um, but they do have
59:39
electricity in Varel and they also have dark
59:42
skies, relatively easily accessible by just
59:44
driving up a few kilometres further up
59:47
the highway one way or the other.
59:49
Um, so meteors. Um,
59:52
yeah, Dave's question, how many meteors are
59:54
coming in? Uh, quite a large number. We think
59:57
it's something like 100 tonnes, 50 to 100
1:00:00
tonnes a day meteoritic material hits the
1:00:03
atmosphere that's worldwide. Uh, but that
1:00:05
means there are billions of meteors streaking
1:00:08
through the atmosphere because most of them
1:00:09
are specks of dust. Um, and they
1:00:12
can, yeah, sporadic meteors as they're
1:00:14
called. They can whiz through the earth's
1:00:16
atmosphere at any time. People talking about
1:00:18
this stargazing I was doing at uh, Sea
1:00:21
Lake, uh, in rural Victoria last week,
1:00:24
um, quite a few people were spotting meteors
1:00:26
as they flashed through the sky. I was
1:00:28
looking at screens so I missed most of them.
1:00:31
Um, but, uh, probably
1:00:34
the time to
1:00:37
uh, really concentrate on,
1:00:39
um, uh, a few serious. And I think you kind
1:00:41
of need an all sky lens effectively for good
1:00:44
meteor photography. Um, um,
1:00:47
uh, the new generation of
1:00:50
phones do have very wide angle lenses,
1:00:53
but they're not fisheye in the sense that you
1:00:55
can see the sky. Um, but they're wide enough
1:00:59
probably to use. The snag
1:01:01
with them is that they've got a low,
1:01:05
uh, aperture. So a high
1:01:07
focal ratio, uh, the
1:01:10
ratio of the focal length to aperture and
1:01:13
what you need is a low focal ratio to give
1:01:15
you fast imaging. It's what we call a fast
1:01:17
lens. Whereas these wide angle ones tend not
1:01:19
to have that. Uh, and so you're tossing up,
1:01:22
you know, the relative merits of a very wide
1:01:25
angle view or likely
1:01:28
to capture more meteors or a narrow angle of
1:01:31
view but greater sensitivity, so you'll see
1:01:33
fainter meteors. So, um, that's,
1:01:36
you know, taking all that into consideration.
1:01:38
Um, I haven't tried meteor photography with
1:01:40
my phone. I've done a lot of aurora borealis
1:01:42
photography with it and that works really
1:01:44
well because they're sensitive. But it will
1:01:46
be an interesting thing to try. Uh, it's the
1:01:49
fact that you need A long. You need the
1:01:50
shutter open for a long time. But I guess
1:01:52
what you can do is just keep on taking
1:01:55
short snapshots. Um, point I
1:01:58
was going to get to is when you think about
1:02:00
the Earth, uh, uh, in its orbit around the
1:02:03
sun. Uh, the forward facing
1:02:06
side of the orbit is where you are after
1:02:08
midnight. So after midnight
1:02:11
means that you're on the leading edge of the
1:02:14
Earth and that's where you're going to get
1:02:16
the most meteors, basically. Uh, as
1:02:19
the Earth ploughs through the various clouds
1:02:21
of dust, you've got meteor showers which come
1:02:23
from big clouds of dust that the Earth goes
1:02:26
through. Uh, but these things are always best
1:02:28
seen in the early morning, um, when you're
1:02:31
on the side after midnight. So that's the
1:02:34
best advice I can give. I'd be interested to
1:02:36
hear how you get home, Dave, and uh, what
1:02:37
sort of results you might get. Yeah, yeah.
1:02:40
Andrew Dunkley: And if you do get a couple of good ones, send
1:02:42
them in and we'll um, we'll post them on our
1:02:44
Facebook page or you can post them yourself
1:02:46
on the Facebook group, whatever you like. Um,
1:02:49
love to see what you come up with. We do get,
1:02:50
um, some great astrophotography
1:02:53
from uh, Space Arts listeners on the Facebook
1:02:56
group sometimes. So, yeah, um, more than
1:02:58
happy to uh, have
1:03:01
you uh, post them on that
1:03:04
page, Dave, and hopefully that will help. But
1:03:06
uh, yeah, the idea of having to get up and do
1:03:08
it in the middle of the night, not, not
1:03:10
appealing. But, uh, that's life in astronomy,
1:03:12
isn't it, Fred Watson?
1:03:13
Professor Fred Watson: It is a bit, yeah.
1:03:16
Andrew Dunkley: Yeah. All right, Dave, thanks very much for
1:03:18
your question. Don't forget, if you've got a
1:03:20
question, send it in to us because we'd love
1:03:22
to try, uh, and answer it. No guarantees of
1:03:25
course. Uh, but you go to our website,
1:03:27
spacenutspodcast.com
1:03:29
spacenuts.IO click on the AMA tab and
1:03:32
you can send uh, uh, questions there, audio
1:03:35
or text. Just remember to tell us who you are
1:03:37
and where you're from and we'll do the rest.
1:03:40
Or Huw in the studio will, if he ever turns
1:03:43
up again, because he didn't turn up today.
1:03:47
I don't know what he was doing. Probably
1:03:49
trying astrophotography in the middle of the
1:03:51
day. Just never listens to us.
1:03:54
That's his problem. Uh, Fred Watson, thank
1:03:56
you as always and uh, bon voyage.
1:03:59
Have a safe journey. Enjoy uh, your time in,
1:04:02
uh, in Japan and Ireland and the UK
1:04:05
and uh, yeah, and look forward to hearing
1:04:08
about your travels when you get back. And we
1:04:11
will welcome Jon, uh, Horner from the
1:04:13
University of Southern Queensland. Uh, with
1:04:17
Space, um, nuts for the foreseeable future.
1:04:20
So take care, Fred Watson, and thank you.
1:04:22
Professor Fred Watson: Thank you, Andrew. Uh, I'll miss you all.
1:04:25
But, um, I'll be glad to come back and, uh,
1:04:27
talk to you sometime before Christmas.
1:04:29
Andrew Dunkley: Okay, Catch you then. Professor, uh,
1:04:31
Fred Watson Watson, Astronomer at large. And
1:04:33
from me, Andrew Dunkley. Thanks again for
1:04:35
your company. We'll see you on the very next
1:04:36
episode of Space Nuts. Until then, bye. Bye.