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Space Light, Cosmic Shields & Moon Mysteries | Space Nuts: Astronomy Insights & Cosmic Discoveries · Space News Today

0:00
Space Nuts is taking a bit of a break at
0:02
the moment. Uh Fred and I will be back
0:04
uh in the not too distant future with
0:06
fresh episodes. In the meantime, enjoy
0:08
some of uh the key episodes that we have
0:11
presented over the years, major events
0:14
in astronomy and space science and we'll
0:17
see you real soon.
0:19
>> Space Nuts.
0:20
>> Hi there. Thanks for joining us on a Q&A
0:23
edition of Space Nuts. I'm Andrew
0:25
Dunley, your host. Once again, uh,
0:27
thanks for joining us and, um, good to
0:30
have your company. On this edition,
0:31
we're answering some questions about
0:33
light in space. Um, this one comes from
0:36
Lee. He's he's asked a very interesting
0:38
question. I've never actually thought
0:40
about this particular uh, concept, but
0:43
uh, it's it's a question that I think is
0:46
worth answering for sure. It's why we
0:48
included it. Fenton wants to know about
0:50
um shielding astronauts in the outer
0:53
reaches of the solar system and he's got
0:54
an idea on how to do that. Uh Robert
0:57
wants to talk about things we learn from
1:00
the moon and what if our moon wasn't the
1:02
same as the moon is now. Would our
1:05
learnings be different? That's a really
1:07
interesting question. And Duncan wants
1:09
to talk about ice giants and why are
1:11
they ice giants? Why don't we call them
1:12
something else? That's all coming up
1:14
shortly on this edition of Space Nuts.
1:18
15 seconds. Guidance is internal. 10 9
1:23
Ignition sequence start.
1:24
>> Space nuts.
1:25
>> 5 4 3 2
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>> 1 2 3 4 5 5 4 3 2 1
1:30
>> Space Nuts.
1:31
>> Astronauts report. It feels good.
1:34
>> Once again, we welcome the one and only
1:36
Fred Watson, astronomer at large. Hello,
1:39
Fred.
1:39
>> Hello, Andrew. How have you been since
1:41
we lost B?
1:43
>> Um, I haven't moved from this seat in
1:45
all that time.
1:48
Well, it's I know it's I can see you're
1:50
glued to your chair there at home.
1:53
>> Very much so.
1:55
>> Yes. Uh shall we get um straight into it
1:57
and answer some questions from our
1:59
audience?
2:01
>> Uh we will.
2:02
>> That's a good idea. Yeah,
2:03
>> it is. That's it's what we're here for.
2:05
This first one, Fred, comes from Lee. He
2:08
lives in New York City. Uh he's he's
2:11
asking how much light is in space. He'll
2:14
qualify that question. For example, if
2:17
you were to visit Voyager 1, where
2:19
Voyager 1 is today, would you be able to
2:21
see it? Would you see just a silhouette?
2:24
Would you be able to make out details
2:26
and colors if there if there are any
2:29
colors on it? Uh what about if you and
2:32
Voyager were midway between the sun and
2:34
Alpha Centuri? Uh can we know a
2:38
reasonably accurate answer or is it pure
2:41
speculation? Thanks. Love the show, Lee
2:43
from New York. I I've never thought
2:46
about that. I mean, we take for granted
2:47
light on Earth because it's, you know,
2:49
we're illuminated by the sun, but it's
2:51
it's a bit different in other parts of
2:53
the solar system and the universe in
2:55
general. So, yeah, if we could just go,
2:57
"Snap, we're out there next to Voyager
2:59
One, could we actually see it? Is it
3:02
illuminated in any way? Is it being
3:04
illuminated by something? What would it
3:06
be like?"
3:08
>> Uh, the answer is yes, you'd see it. Um
3:10
and um so we're talking really now about
3:14
the sensitivity of the human eye
3:16
>> u because uh with a with a camera uh you
3:19
know um with long exposure settings and
3:22
things you'd be able to see in great
3:25
detail but thinking about the human eye.
3:28
So um
3:31
I used to work as you know at Siding
3:33
Spring Observatory. Uh I spent many
3:37
hours uh outside at night there. It is a
3:41
place that is truly dark. There's no
3:43
interference from street lights. Uh
3:46
there are few blobs of light on the
3:48
horizon but nothing that affects the
3:50
pristine darkness of the night sky. And
3:53
on a starry night with the sun not in
3:55
the sky, you can see quite clearly. Um
3:59
there's enough light from the stars
4:01
themselves to let you see where you're
4:03
going. Uh let you, you know, walk around
4:08
and be quite confident that you're not
4:10
going to fall off the mountain as I
4:11
nearly did one night when it was uh
4:14
cloudy. I went out without my torch. I
4:16
thought, "Oh yeah, I'll see by the
4:17
stars." But fortunately unfortunately
4:18
the cloud had come in. I couldn't see
4:20
anything and I nearly fell fell off the
4:22
mountain.
4:23
>> I didn't in the end, but um
4:25
>> that's a that's a long drop free.
4:27
>> Yes, it is. Yes, it's quite a long drop.
4:29
Anyway, uh if you uh you know, normally
4:32
on a starry night you will see um by the
4:36
light of the stars. Now, where Voyager
4:39
is, Voyager 1, uh I just looked it up.
4:42
uh it is uh at a distance from the sun
4:47
in astronomical units which is 163
4:51
astronomical units. That's 163 times the
4:55
number of uh times the distance between
4:58
the earth and the sun. So that's 150
5:00
million kilometers. Multiply that by 163
5:04
and you will get
5:07
uh what do you get? Uh I was looking for
5:10
it in kilometers but it's not there.
5:12
I'll have to do the numbers. Anyway, it
5:13
doesn't matter. The main thing is um its
5:16
distance is 22.55 light hours away. Uh
5:19
that's how long it takes uh the signal
5:22
to get from Voyager to Earth. It's
5:24
almost a day. It's almost a light day
5:26
away. Um, so at that distance from the
5:31
sun, 160 odd astronomical units, uh,
5:34
there's still significant light coming
5:36
from the sun, not to mention Venus,
5:39
uh, and, um, you know, Jupiter and, uh,
5:43
the other planets, mostly the sun,
5:45
though, you you're being illuminated by
5:47
the sun. So that certainly ups it, uh,
5:50
as compared with just being illuminated
5:52
by the starry sky, which is what I was
5:54
just talking about. So you'd see it
5:56
really clearly. Uh you wouldn't have any
5:58
problem making it out assuming your eye
6:00
was dark adapted.
6:03
>> So [clears throat] it's um it's fairly
6:05
bright out there. I we talked about the
6:07
sensitivity of the human eye as uh you
6:10
you referred to. How how small amount of
6:13
light can we see as human beings?
6:16
>> Um I think there were some experiments.
6:20
Let me think. Was it was it one photon
6:23
or one pixel like that?
6:25
>> There was that's right. We might have
6:28
talked about this. There were
6:29
experiments done that showed that the
6:31
human eye is capable of detecting single
6:34
photons. Uh it was under special
6:36
circumstances but uh and that is just
6:40
extraordinary. Um when you think that
6:43
the human eye can also cope with broad
6:46
daylight that's the amazing thing about
6:48
the human eye. It can, you know, it's
6:50
quite happy uh to see light uh at one
6:54
brightness and then a light that's only
6:56
a millionth of as bright. Um it's fine.
7:00
You can deal with that. And that's a
7:01
combination of what's called retinal
7:03
bleaching and the the iris of your eye
7:06
opening and closing. It's all those
7:08
things come together to give you this
7:11
unbelievably versatile and sensitive
7:14
tool with which we can look at the our
7:16
surroundings. Whether it's uh the the
7:19
rock face I'm looking at now because
7:20
that's what our backyard consists of or
7:23
whether it's uh you know the night sky
7:25
where you're looking at faint objects uh
7:28
in the sky. It's quite amazing.
7:31
>> So even if you went deeper into space
7:33
way beyond our solar system you you
7:36
would probably still see objects that
7:39
you were near.
7:40
>> There'd be enough light from the stars.
7:41
The Milky Way uh is is bright. Uh it
7:44
would it would you know even if as as uh
7:47
as Lee says even even if you were
7:49
halfway between the sun and Alpha
7:52
Centuri you'd still see it because of
7:54
the ambient light u that's coming from
7:57
from the stars.
7:58
>> Yeah. And you'd still see color because
8:00
that's well if it's dark enough it might
8:03
turn into the grays which happen to
8:05
>> That's right. Yeah. And I think that's
8:06
likely I think it I don't think you
8:08
would see color. um you would you would
8:10
where it is now there's enough light
8:11
coming from the sun that you'd see color
8:13
but I think uh when you got further out
8:15
you would start to just see the you know
8:18
the as you said the that fit that sort
8:21
of pale gray appearance where you're
8:23
looking at very low light low light
8:25
levels indeed where the color cells
8:27
aren't receptive.
8:29
>> There you go Lee. Uh the answer to your
8:31
question is yes to all of the above
8:33
basically. [clears throat]
8:35
>> Great question. Excellent question. All
8:37
right, let's move on. This is from
8:39
Fenton.
8:40
>> Yeah. Hello, Fred and Andrew. This is
8:43
Fenton contacting you from St. Paul,
8:46
Minnesota in the US. Um, I sort of have
8:51
a different type of astrophysical
8:53
question for you and this is on how to
8:58
shield astronauts from radiation outside
9:02
of the Van Allen belt. Um, I was curious
9:05
if you know of any pending technologies
9:08
that would allow this. Obvious choice
9:11
would some people would say is lead, but
9:14
I can think of several reasons why this
9:16
is not a good idea. How about a
9:19
miniature Van Allen belt which could
9:22
surround a spacecraft? How does that
9:26
sound? How could this become
9:29
reality? Thank you very much. I hope you
9:32
like the question. Bye now.
9:34
>> Thanks, Fenton. Fenton always has these
9:36
intriguing thoughts. I I've noticed in
9:38
the times that we've heard from him. Um
9:41
maybe we should start by explaining what
9:42
the Van Allen belt is for those of us
9:44
who just can't remember like me.
9:48
Um it's uh so the van element bel
9:54
you know the magnetic shielding around
9:57
the earth uh which is uh
10:01
caused by the the magnetism of the
10:03
earth. It's caused by the uh the fact
10:05
that we've got an iron core and uh
10:10
basically it's in two parts. It's solid
10:11
and liquid. So it acts like a dynamo.
10:13
it's rotating and that gives us this uh
10:16
exactly the protection that um that um
10:20
um Fenton is talking about. Um yeah,
10:23
>> I was going to refer I'm a bit annoyed
10:26
actually because I've lost it. Uh there
10:29
is a very nice article on uh it's
10:34
actually on the um BBC's website uh
10:38
their Sky at Night website. There's a
10:41
lovely article on exactly this. Here it
10:43
is. I found it. I hadn't lost it. How
10:46
astronauts can hide from radiation on
10:48
Mars and it goes into uh the exactly the
10:52
problem that uh that Fenton's talking
10:54
about. How do you present how do you
10:56
prevent u astronauts basically becoming
11:00
irradiated
11:02
uh and over time it's basically lethal
11:06
uh because because of the cosmic
11:08
radiation that's coming down through
11:11
space uh and it it does cell damage uh
11:16
in your body uh and it can actually
11:19
trigger cancer. So um the the whole
11:22
study of this is uh or sorry the the
11:27
thrust of this article BBC Sky at Night
11:29
magazine uh is to discuss how you might
11:33
protect astronauts uh from the
11:35
radiation. Uh and that's not just on
11:38
Mars but on route. Uh okay.
11:42
Uh the solution that that Fenton has
11:46
suggested is covered in a paragraph. I'm
11:48
going to read it because we've quoted
11:49
where the source is. Uh, for example,
11:54
all right, let me no, let me go back a
11:55
paragraph. One, one method of helping
11:57
astronauts to avoid the radiation on
11:59
Mars is active shielding. For example,
12:03
superconducting electromagnets could be
12:05
used to create a powerful magnetic field
12:08
to deflect the incoming charged
12:09
radiation particles away just as the
12:11
Earth's field does. That's the lanel
12:14
belt. The problem is that such solutions
12:16
can demand a lot of power to run and the
12:19
technology is a long way from being
12:21
fully developed. An easier alternative
12:24
is passive shielding. Simply placing a
12:26
thick bulk of shielding material between
12:28
the crew habitat and the sky. Uh and
12:32
then they go on to consider different
12:34
materials. Aluminium aka aluminum. Uh
12:38
the metal that spacecraft are
12:40
constructed from is actually a pretty
12:42
bad radiation shield. Um, and they say
12:45
when hit by an energetic cosmic ray, its
12:48
atoms can shatter and fly onwards to
12:50
create even more radiation particles.
12:53
And Martian soil, the regalith, uh,
12:55
which if you're on Mars, you might think
12:57
about digging a hole there. Uh, it's got
13:00
the same problem, but it's it's actually
13:02
uh, you know, abundant. Um, and so you
13:06
could use that to dig a pole. If you put
13:09
a two to three meter layer on top of
13:12
your habitat, uh then you'll you'll get
13:15
some protection. But uh the thing that
13:18
surprised me, Andrew, uh is once again
13:20
it comes from this same article. Uh
13:23
hydrogen is the best shielding material
13:26
as it's light atoms. Yeah. It's light
13:28
atoms. Uh and by light, I mean not
13:32
heavy. Its light atoms don't create as
13:34
much secondary radiation. And so tanks
13:37
of rocket fuel or water, which is rich
13:40
in hydrogen, placed over crew quarters
13:42
could double up as effective radiation
13:44
shields. I've heard that before that um
13:47
you know, one way of protecting your
13:49
spacecraft as it flies to Mars is put it
13:51
put it in a tank of water. Uh it's the
13:53
last thing you'd expect to do, but uh
13:56
water is a good shielding material. And
13:58
they also uh point out the alternative
14:01
of hydrogen-rich plastics like
14:03
polyethylene could be used to cement
14:06
regalith grains together. This is on
14:08
Mars and improve their shielding effect.
14:10
Um so uh if you want to read more about
14:13
this, it's an article that originally
14:15
appeared in the August 22 2022 issue of
14:18
BBC Skylight magazine and it covers
14:21
pretty well most of the ideas uh that
14:23
have been that have been suggested for
14:25
this radiation issue. It's one that's
14:27
got to, you know, it's got to find an
14:29
answer soon because uh good old Elon and
14:32
his Starship uh is getting nearer to
14:35
thinking about going to Mars. I don't
14:36
think it's ever going to happen, but um
14:38
that's uh uh that's something he'll
14:40
definitely be thinking about.
14:42
>> Yes, indeed. Well, he's he's too busy
14:44
dealing with the Australian government
14:45
at the moment.
14:46
>> Yes, indeed. That's that's right.
14:48
>> Some of the content on Twitter that the
14:50
government wants to get rid of simply
14:53
because of its um volatility. But
14:55
anyway, that's a different story. Uh but
14:56
there plenty of water on Mars. So maybe
14:59
maybe creating those water barriers is
15:01
is probably the simplest thing to do.
15:03
You've already got the material there
15:05
>> if you've if you've landed in the right
15:07
spot where you've got or whatever.
15:09
>> That's the question. Yes, indeed. Well
15:11
done, Fent Fenton. You you actually
15:13
happened across some of the uh the
15:15
answers too in uh asking your question.
15:18
>> Uh this is Space Nuts. Andrew Dunley
15:20
here with Professor Fred Watson.
15:25
3 2 1
15:28
>> space nuts. Now Fred, uh, our next
15:31
question comes from Robert. Hi guys,
15:33
love your show. Sorry for the long
15:35
question, but feel free to paraphrase uh
15:37
or shorten it. Our moon is heavily
15:40
created and has given us a lot of
15:42
insight into the history of the solar
15:44
system and perhaps how the planets
15:46
formed. But what if we had a moon like
15:49
the icy moon Europa or the shrouded in
15:52
haze Titan, both of which don't show
15:55
immediate evidence of cratering? Would
15:58
our theory about how the planets
16:00
developed would be different? What other
16:03
insights about our solar system would be
16:05
missing or or would we be missing? And
16:08
lastly, uh would we have spent uh or
16:11
would we have sent people to land on
16:13
such moons? I.e. Uh, would they be more
16:17
dangerous for astronauts? Uh, cheers,
16:20
Robert in Vienna, Austria. Wow. I don't
16:22
think we've had a question from Vienna
16:23
before, have we?
16:25
>> Lovely to hear from you, Robert.
16:27
>> I think I think Robert might have been
16:28
in touch once before. I can't
16:30
>> Oh, I might have been too.
16:32
And here from Vienna. Yeah, I was in
16:34
Vienna at the beginning of last year and
16:36
I think I think we got something around
16:37
about the same time and I was waxing
16:40
lyrical about being in Vienna at the UN
16:42
when I was at the Copas meeting. Anyway,
16:45
uh that's another another issue. Uh what
16:48
if we had a Yeah, it's a really
16:49
interesting question. Um, what would we
16:53
not know about the solar system if our
16:57
moon was basically uh one that had been
17:01
resurfaced in recent years or millennia
17:05
because that's what makes a surface
17:07
smooth. That's how we recognize
17:10
um the fact that the universe sorry that
17:13
the
17:15
it's how we recognize the age of a
17:17
surface is by how many craters it's got.
17:19
The old the older the surface, the more
17:21
craters it has. And so the moon's south
17:24
southern region, which is heavily
17:26
cratered, as is the backside, uh tell us
17:29
that uh early on in the solar systems
17:31
history, it was a very wild and woolly
17:34
place with things charging about all
17:36
over and causing these craters. Now, if
17:38
we had a moon that was like Europa that
17:40
um had, you know, icy geysers on it that
17:45
basically covered up the craters, would
17:47
we have known about that? My guess is
17:50
yes, we would because we'd see other
17:52
bodies within the solar system uh like
17:55
you know other moons like um places like
17:59
um um series the the biggest of the
18:02
asteroids the dwarf planet that
18:04
dominates the asteroid belt that's
18:05
heavily created. Uh parts of Pluto are
18:08
heavily crated. Um
18:12
Mimas uh one of Saturn's moon is moons
18:15
is heavily created too. So, so we we'd
18:18
know about it by looking at other
18:19
objects even if our own moon was uh
18:23
smoothly surfaced. Um it's it's a but
18:26
the Robert's last point uh on this uh
18:30
would we have sent people to land on
18:33
such a moon? Uh I think um I don't know
18:37
that's a really good question. I mean we
18:38
have sent people to land on our moon as
18:40
it stands uh with an ancient surface. In
18:44
fact, where they landed were more recent
18:47
uh than the heavily cratered surfaces
18:49
because they were principally in the
18:50
Maria, the the basalt planes.
18:52
>> Yeah.
18:53
>> So maybe that suggests that we would
18:57
have landed people on Europa as well. Uh
18:59
because
19:00
>> I think we pro Yeah, we probably would
19:02
because it would have a solid surface.
19:05
There'd be places because it would be so
19:07
close to us, we'd be able to examine and
19:09
and find the the right landing points.
19:12
might be a bit more difficult with a
19:14
moon that's shrouded in land gas.
19:18
>> Yeah. Yeah.
19:19
>> Yeah, that's right. Uh and especially um
19:21
place like Titan. Uh
19:25
I I still think we'd have done it.
19:27
Actually, I think um you know the JFK's
19:30
uh promise to put astronauts on the moon
19:33
would have still held good even if it
19:35
had been a very different place. If it
19:36
had been like Io, uh, it might have been
19:39
a different story where, you know,
19:41
you've got the most volcanically active
19:43
body in the entire solar system with
19:45
stuff going off all over the place. I
19:47
think we might have been a bit more
19:48
reluctant to to land on a Yes, possibly.
19:51
So, uh, it would be interesting to have
19:54
something different, but then if we'd
19:55
always had if if we'd always had an ice
19:58
moon, we probably would have caught a
20:00
question from Robert asking, "What if we
20:03
had a rocky moon?" Now, would we Would
20:07
we have a different interpretation of
20:09
four masses of planets if there was a
20:11
rocky moon next to us instead of an ice
20:12
moon? Yes. Um, in an alternative
20:15
universe, Robert, you would have flipped
20:16
your question. Good to hear from you.
20:18
Hope all all is well in Austria. Our
20:21
final question for this episode comes
20:23
from Duncan.
20:25
>> Hello. Duncan here from Wayouth in the
20:29
UK. Again, a quick question.
20:34
just looking was just doing some reading
20:36
and I noticed that Uranus and Neptune
20:39
are often referred to as ice giants.
20:44
Now, given that ice is basically just
20:48
sort of like a rock form of water or CO2
20:53
or whatever else, but basically just a
20:56
solid form of it. Why are they not just
20:59
called rock giants? Why do we make the
21:03
definition of ice rather than just
21:05
calling them rock? It just seems odd
21:08
because the little planets in the inner
21:11
solar system are referred to as rocky
21:13
planets. So given that they're also
21:17
apparently rocky, why are they not
21:19
called rocky giants?
21:21
Okay, thank you. Bye. Thanks Duncan.
21:26
Appreciate your questions as always. Uh
21:28
yeah. Why do we call them ice giants
21:30
just for the sake of the exercise? Cuz
21:32
there's gas giants and ice giants.
21:36
>> Yeah, except one is a subset of the
21:38
other. And so all four of the outer
21:42
planets, Jupiter, Saturn, Neptune,
21:44
sorry, Uranus, and Neptune, they're all
21:46
gas giants because they have uh eye mass
21:51
uh um you know, much more in the case of
21:55
Jupiter certainly than uh than our own
21:57
planet. Um the they've got they're
22:01
giants. They're big. They've got high
22:03
mass. Uh and they don't have a visible
22:07
surface, which is why they're called gas
22:09
giants because all we see is a gasy
22:11
envelope. Um just to go to the last of
22:15
Duncan's questions there, we we wouldn't
22:17
call the inner planets rocky giants
22:20
because they're not giants. They're kind
22:21
of normal planet size. You know, if you
22:23
if you think of the Earth as being your
22:25
standard planet, then uh Mercury, Venus,
22:28
and Mars are similar in size. They're
22:32
all smaller. Venus is about the same
22:34
size, but Mercury and Mars, of course,
22:35
are smaller. So, uh so it's only when
22:38
you compare with the size of Earth that
22:40
you'd start talking about giants because
22:42
they are much much bigger than Earth.
22:44
And so, that's the gas giants. So, why
22:47
are Uranus and Neptune called ice
22:50
giants? because they have hazes of ice
22:55
in their atmosphere.
22:57
>> So, uh, and that's the the trick. It's
23:00
not a solid surface. It's not rock.
23:02
[snorts] It's it's a haze. It's kind of
23:04
like a a dust of ice which permeates
23:08
their atmosphere. And and and it's water
23:10
ice in fact, uh, mostly. Uh so that's
23:14
why they're called ice giants because
23:16
unlike Saturn and Jupiter uh which don't
23:19
have these hazes uh the the outer the
23:21
rocky rock sorry the two outer planets
23:25
Uranus and Neptune do they have ice
23:27
hazes in their atmosphere hence the
23:29
name.
23:30
Okay. Yeah. And because last episode we
23:33
learned there wasn't much water in
23:35
Jupiter's
23:37
>> in the in the two outer gas giants.
23:41
Yeah. It sounds like there is. Is that
23:42
why they're a different color? Yes. Yes,
23:46
I think that's right. They're um and and
23:48
also their their atmospheric
23:49
constituents are are different. They
23:52
don't have the same belt structure that
23:53
Saturn and Jupiter do. Uh it may be that
23:56
that's because any belts that exist are
23:58
much lower in the atmosphere and so you
24:00
don't see them. Um yeah, I mean uh
24:03
there's there's a strong body of uh of
24:08
advocacy within the space fraternity to
24:11
get get more spacecraft out to Uranus
24:16
and Neptune cuz they're the two planets
24:19
about which we know least. Um and uh
24:22
will be good to know more.
24:24
>> Yeah. Well, if you sit down in snow for
24:27
long enough, your Uranus turns into a
24:29
nice giant sun.
24:32
I couldn't help it. Sorry. Uh, yeah.
24:36
>> Which is why we call it Uranus in
24:38
politics.
24:39
>> I know. I know.
24:41
>> Yeah. But it's just a joke you've got to
24:43
tell. It's just you have to.
24:46
>> Yes. I blame Johannes Borda, who is the
24:49
person who chose the name. It's fine in
24:52
German. Uess. Uess. There's nothing
24:54
wrong with that. It's great. Yeah. Ruins
24:57
all the jokes, bro.
24:59
>> All right. So, yes, they're ice giants
25:01
for a very good reason, Duncan, because
25:03
they've got ice in them uh in the
25:05
atmosphere. But technically speaking,
25:07
they are in fact gas giants. But
25:09
>> yes, we differentiate them because of
25:11
their substantially different
25:13
atmospheres. There you are. Thanks,
25:15
Duncan. Great to hear from you. Great to
25:17
hear from everybody. Thanks for sending
25:18
in your questions. Don't forget you can
25:20
send in questions via our website
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25:24
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Send us your question. That's audio
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25:55
places. Uh Fred, as always, thank you so
25:57
much. Pleasure, Andrew. See you soon.
26:00
>> Okay, Fred Watson, astronomer at large.
26:02
We'll catch him on the next episode of
26:04
Space Nuts. might catch Hugh then as
26:06
well because um
26:09
not here today. Didn't even call in
26:11
sick. I need a note. And from me, Andrew
26:13
Dumprey, thanks very much for your
26:15
company. We'll see you again soon on the
26:17
next episode of Space Nuts. Bye-bye.
26:19
>> Space Nuts.
26:20
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26:25
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