Unlocking the Mystery of Exoplanet Magnetic Fields | E348

WEBVTT

1
00:00:00.320 --> 00:00:04.080
Hello, thanks for joining us on
Space Nuts, where we talk astronomy and

2
00:00:04.200 --> 00:00:07.879
space science every week. My name
is Andrew Dunkley, your host, and

3
00:00:08.160 --> 00:00:11.480
it's so glad you can join us. Coming up today, we'll be talking

4
00:00:11.519 --> 00:00:16.640
about magnetic fields and do they exist
on exo planets. We'll also be talking

5
00:00:16.719 --> 00:00:23.480
about something quite extraordinary, the flattest
explosion ever observed in space and it was

6
00:00:23.600 --> 00:00:29.719
big too, and sad news about
Virgin orbit. We'll also be answering audience

7
00:00:29.839 --> 00:00:35.359
questions about sending high speed satellites into
the Solar System and the density of gas.

8
00:00:35.399 --> 00:00:44.000
That's all coming up on this edition
of Space Nuts and rad Internel nine

9
00:00:44.560 --> 00:00:56.000
Magnian sequenced Space Nuts three two one
Space Nuts actually boyd at Bill good and

10
00:00:56.280 --> 00:01:00.960
joining us to talk Turkey again this
week, the Turkey constellation that is Professor

11
00:01:00.119 --> 00:01:06.239
Fred Watson, Astronomer at Large.
Hello, Fred, good day, Andrew

12
00:01:06.480 --> 00:01:11.239
m Yeah, turkeys are yes.
There isn't a Turkey constellations that there should

13
00:01:11.280 --> 00:01:15.519
be, really sure, I'm sure
there's some cluster out there that looks Turkey

14
00:01:15.640 --> 00:01:21.680
like. Well, actually for most
constellations it doesn't have to look anything like

15
00:01:22.000 --> 00:01:26.599
his name is anyways, take your
peek. No, Well, the country

16
00:01:26.640 --> 00:01:30.760
of Turkey could use a bit of
a at the moment, they're a pretty

17
00:01:30.840 --> 00:01:36.760
rough time of it. Why not
the Turkey constellation that's two of Keio.

18
00:01:36.879 --> 00:01:40.799
Now, yes that's true, you're
right, Yes, yes, absolutely,

19
00:01:42.319 --> 00:01:46.439
hey Bane, Oh well thank you. Yeah, I'm still pushing back the

20
00:01:46.519 --> 00:01:49.519
frontier as well, not from which
the frontiers of knowledge, as the frontiers

21
00:01:49.560 --> 00:01:55.799
of bureaucracy. Yes, there's a
lot of that. Yeah. We had

22
00:01:56.200 --> 00:02:04.680
had a nice event last week when
a virtual reality movie of the site in

23
00:02:04.799 --> 00:02:10.759
Western Australia where the radio Murchis and
radio telescope is or where the squakulometer array

24
00:02:10.960 --> 00:02:15.879
will be a virtual reality movie of
all that, showing you what it's like

25
00:02:15.039 --> 00:02:20.120
there and what kind of landscape it
is. That was launched at the National

26
00:02:20.199 --> 00:02:24.439
Museum of Australia in Canberra on Tuesday
nights. I think it was which I

27
00:02:24.759 --> 00:02:29.360
gave a little talk about astronomy and
all the other stuff, and one of

28
00:02:29.400 --> 00:02:32.960
my colleagues at Chenko, who was
specialist working with the SKA, he also

29
00:02:34.039 --> 00:02:38.240
gave a talk and then we had
this view of the virtual reality tour,

30
00:02:38.400 --> 00:02:46.080
which is astonishing. It's my first
real experience with decent stereo glasses of a

31
00:02:46.199 --> 00:02:50.960
virtual reality movie and yeah, you've
got three hundred and sixty degree view.

32
00:02:51.039 --> 00:02:53.919
You turn your head around and you
see behind you. We did that at

33
00:02:54.000 --> 00:02:59.639
Easter. Nothing to do with astronomy, but there's an escape room in Dabo

34
00:03:00.240 --> 00:03:05.080
which is very popular and they've they've
brought in a virtual reality experience. So

35
00:03:05.560 --> 00:03:09.039
I did that with my boys at
Easter too. That's the first time I've

36
00:03:09.039 --> 00:03:15.400
ever done it too. It's it's
a bizarre thing, but it's a lot

37
00:03:15.439 --> 00:03:16.800
of fun. It's a heck of
a lot of fun. Yeah, yeah,

38
00:03:17.680 --> 00:03:22.639
And this is a fantastic production as
well. It's really well done.

39
00:03:22.800 --> 00:03:29.360
It will certainly be circulating more in
Australia maybe globally. Some of our obviously

40
00:03:29.759 --> 00:03:32.800
listeners might find it coming up.
It's called Beyond the Milky Way. Okay,

41
00:03:32.879 --> 00:03:37.639
it's the title of it. Sounds
good. All right, let's talk

42
00:03:37.639 --> 00:03:42.120
about what we came together to talk
about today, amongst other things. I

43
00:03:42.199 --> 00:03:46.199
mean, we don't always stay on
track. Occasionally we might drift just occasionally.

44
00:03:49.000 --> 00:03:53.280
I wouldn't be like us would not
at all really, but we know

45
00:03:53.360 --> 00:03:58.759
about Earth's magnetic field and how important
it is to or basically protect us from

46
00:03:58.919 --> 00:04:02.080
all the evils of the universe and
to keep our atmosphere intact. So the

47
00:04:02.199 --> 00:04:10.120
question has been raised, do you
find magnetic fields on exo planets? Now?

48
00:04:10.159 --> 00:04:13.599
This is a very important question because
obviously, if we're looking for life

49
00:04:13.680 --> 00:04:18.160
out there, we probably need to
find a planet that has a rocky surface

50
00:04:18.439 --> 00:04:25.240
with probably water or something similar,
and it would have to have a magnetic

51
00:04:25.319 --> 00:04:30.480
field, would it not? But
yes, it probably would be an important

52
00:04:30.759 --> 00:04:35.600
component because, exactly as you've said, the Earth magnetic field protects the atmosphere.

53
00:04:36.439 --> 00:04:43.439
It also protects the surface from the
more energetic subatomic particles that are floating

54
00:04:43.480 --> 00:04:47.199
around in space, many of which
are launched from the Sun with its solar

55
00:04:47.279 --> 00:04:53.439
wind and occasional solar flares. We
are largely protected, not entirely, but

56
00:04:53.639 --> 00:04:57.839
largely protected from the effects of those
things on the Earth surface by the oars

57
00:04:57.920 --> 00:05:02.560
On magnetic field. Yeah. So
yes, the question is do rocky exoplanets

58
00:05:03.120 --> 00:05:11.040
have magnetic fields? Now? I
have to say that I would assume that

59
00:05:11.240 --> 00:05:15.639
the answer to that is probably yes, because planets tend to be made in

60
00:05:15.720 --> 00:05:21.199
the same way no matter where in
the universe they are, and rocky planets

61
00:05:23.040 --> 00:05:27.759
probably usually have, like the Earth
does, a core made of iron and

62
00:05:27.879 --> 00:05:31.600
nickel, and that is what generates
the magnetic field. It acts like a

63
00:05:31.720 --> 00:05:38.600
dynamo and generates the magnetic fields as
the Earth rotage. So you'd think that

64
00:05:38.839 --> 00:05:43.360
the answer would probably yes, but
yes to the question of do rocky planets

65
00:05:43.399 --> 00:05:50.319
around other stars have magnetic fields?
And so, observations have been made with

66
00:05:51.199 --> 00:05:57.040
the Carl G. Jansky Very Large
Rate, very large array, which is

67
00:05:57.680 --> 00:06:02.000
a telescope and a ray telescope in
the United States, one of the biggest

68
00:06:02.079 --> 00:06:08.000
in the world. Actually I've visited
it. It's quite an extraordinary place operated

69
00:06:08.079 --> 00:06:14.319
by the US National Science Foundations National
Radio Astronomy Observatory, and so observations have

70
00:06:14.439 --> 00:06:21.839
been made by scientists of a star
called why zed Setti, which is a

71
00:06:23.000 --> 00:06:28.160
star that actually emits radio signals.
Now not all stars do, but this

72
00:06:28.360 --> 00:06:35.839
one does. And the what the
what the scientists have done is used the

73
00:06:36.000 --> 00:06:40.800
radio signals coming from this star,
which is about twelve light years away,

74
00:06:40.800 --> 00:06:47.439
so it's a it's a close star
to interpret what is happening to its planet.

75
00:06:47.480 --> 00:06:51.240
Because we know that why zed Setti, I should say why z Seti?

76
00:06:51.240 --> 00:06:57.720
Shouldn't I? Just for our American
listeners, that's the one yes,

77
00:06:58.480 --> 00:07:04.120
is why is it set B is
a known planet orbiting the star, and

78
00:07:05.240 --> 00:07:15.720
what has been observed are sort of
bursts of radio waves which are to do

79
00:07:16.040 --> 00:07:24.839
with the interaction between the star's magnetic
field and the planet going around it.

80
00:07:25.000 --> 00:07:28.680
Now, the good thing about this
planet is it goes around once in two

81
00:07:28.800 --> 00:07:32.560
days, so it's very close to
its parent style and that means that there

82
00:07:32.600 --> 00:07:40.439
are probably, you know, magnetic
interactions taking place between them if the planet

83
00:07:40.480 --> 00:07:44.879
has a magnetic field. So,
to cut the long story short, these

84
00:07:45.000 --> 00:07:57.720
bursts of radio emission have been analyzed
and and there is enough evidence that they

85
00:07:58.079 --> 00:08:03.079
are that the scientists in question are
convinced that what they've proved is that the

86
00:08:03.199 --> 00:08:09.879
planet whized Setti B has its own
magnetic field. So there are a number

87
00:08:09.920 --> 00:08:16.800
of different a number of different scientists
involved with this, including the director of

88
00:08:16.920 --> 00:08:22.079
the National Radio Astronomy Observatory and astronomers
from buck Mel University and the University of

89
00:08:22.160 --> 00:08:28.879
Colorado. So quite a disparate group
of principally US scientists who have been looking

90
00:08:28.879 --> 00:08:35.399
at this, and some very nice
quotes from those scientists, one of them

91
00:08:37.000 --> 00:08:41.080
who says, I'm seeing this thing
that no one has seen happen before,

92
00:08:41.240 --> 00:08:46.679
which is always a nice thing when
you're working astronomer and you're sitting at a

93
00:08:46.799 --> 00:08:54.120
big telescope somewhere and something turns up. We saw the initial burst and it

94
00:08:54.200 --> 00:08:56.960
looked beautiful. This is a quote
from another of them. When we saw

95
00:08:56.000 --> 00:09:00.120
it again, it was very indicative
that, Okay, maybe we're really they

96
00:09:00.159 --> 00:09:03.559
have something here. So what they
say saying is that as this planet goes

97
00:09:03.600 --> 00:09:13.279
around its star they have it interacts
with the magnetic field of the star in

98
00:09:13.399 --> 00:09:18.759
such a way that you get you
get bursts of radio energy, and so

99
00:09:20.720 --> 00:09:24.039
in fact, to let me read
another quote from one of the scientists,

100
00:09:28.039 --> 00:09:31.759
what we're doing is looking for a
way to see the invisible magnetic fields.

101
00:09:33.120 --> 00:09:35.240
We're looking for planets that are really
close to their stars and a similar in

102
00:09:35.320 --> 00:09:41.000
size to Earth. These planets are
way too close to their stars to be

103
00:09:41.120 --> 00:09:43.279
some way you could live. But
because they're so close to the planet,

104
00:09:43.360 --> 00:09:46.960
it's kind of plowing through a bunch
of stuff coming off the star. And

105
00:09:48.120 --> 00:09:52.120
that's the equivalent of the solar wind
that we have in the Solar System.

106
00:09:52.519 --> 00:09:54.879
If the planet has a magnetic field
and it plows through enough star stuff,

107
00:09:56.159 --> 00:10:01.080
it will cause the star to emit
bright radio waves and that's they are interpreting

108
00:10:01.320 --> 00:10:07.480
these these bursts as being In fact, they've they've kind of coined a new

109
00:10:07.519 --> 00:10:13.519
phrase, which is really nice extra
solar space weather, space weather beyond the

110
00:10:13.559 --> 00:10:16.200
Solar System. So when we think
of space weather, we think of the

111
00:10:16.600 --> 00:10:22.120
environment of the Earth principally, but
the subatomic particles within within the inner Solar

112
00:10:22.200 --> 00:10:26.759
System that comes from the Sun and
space weather. It's actually it's a big

113
00:10:26.840 --> 00:10:28.320
issue. In fact, I was
talking to one of my colleagues in the

114
00:10:28.399 --> 00:10:33.399
Space Agency yesterday about exactly this.
How you how you deal with space weather?

115
00:10:33.600 --> 00:10:39.000
Yeah, in a in a probably
in a legislative fashion, because that's

116
00:10:39.080 --> 00:10:43.720
what a lot of the what the
Space Agency does. But yeah, you've

117
00:10:43.720 --> 00:10:46.519
got to make the rules. So
how does it work? You know?

118
00:10:46.679 --> 00:10:50.840
What? What what what's the what's
the what's the story with it? Anyway?

119
00:10:52.679 --> 00:10:54.799
Sorry, go ahead, Yeah,
I'm just I don't mean to scrib

120
00:10:54.879 --> 00:11:00.480
back out of water over the discovery. But should we be surprised that except

121
00:11:00.519 --> 00:11:05.440
planets probably have magnetic field? I
mean, we were surprised when we found

122
00:11:05.440 --> 00:11:07.360
the first EXB planet, but we
always thought they'd be one, and now

123
00:11:07.399 --> 00:11:11.639
we've found thousands. So it stands
to reason that a lot of them would

124
00:11:11.639 --> 00:11:16.320
have made magnetic fields as well.
Yes, and that is certainly true,

125
00:11:16.480 --> 00:11:20.720
and it's already been established with the
bigger ones like the you know, the

126
00:11:20.799 --> 00:11:26.240
hot jupiters. Yeah, that's being
established that they that they do have magnetic

127
00:11:26.320 --> 00:11:28.600
fields. These things are bigger,
brighter, bee fear in every way,

128
00:11:28.720 --> 00:11:31.879
and so things like that are easier
to detect. But the crucial thing about

129
00:11:31.919 --> 00:11:35.960
this is that this is a rocky
planet, an earthlike planet in terms of

130
00:11:37.039 --> 00:11:39.320
its size, and that's the difference. But you know, as I said

131
00:11:39.360 --> 00:11:43.559
at the beginning, you might well
expect given that if it's a rocky planet

132
00:11:43.679 --> 00:11:48.320
made like the rocky planets in the
Solar System, it will probably have an

133
00:11:48.360 --> 00:11:54.120
iron core which will give rise to
a magnetic field. On the other hand,

134
00:11:54.360 --> 00:12:01.480
here's a counterargument to that. Andrew
Venus doesn't and I that does Mars.

135
00:12:01.480 --> 00:12:05.519
So there are two rocky planets in
our Solar System which are quite new

136
00:12:05.679 --> 00:12:15.720
by that don't have magnetic fields,
and certainly not not magnetic fields today.

137
00:12:15.960 --> 00:12:20.519
Now Mars is thought to have had
a magnetic field, but it's lost its

138
00:12:20.600 --> 00:12:26.480
magnetism because it's it's too small for
that to be sustained by the core of

139
00:12:26.519 --> 00:12:31.600
the planet, that the planet's cooled
down too much. Venis is a different

140
00:12:31.840 --> 00:12:35.639
kettle of fish though, because it's
Earth like, it's almost the same size,

141
00:12:35.639 --> 00:12:39.480
aren't we Yes, that's right.
Yeah, So yeah, if Venus

142
00:12:39.559 --> 00:12:43.279
doesn't have a magnetic field, then
it's not not a foregone conclusion that any

143
00:12:43.360 --> 00:12:50.360
rocky planet is going to have a
magnetic field. So that's the issue.

144
00:12:50.519 --> 00:12:54.000
Now, there is one twist to
this story that I found fascinating, and

145
00:12:54.159 --> 00:13:01.960
that is that magnetic fields when you've
combine them with a solar wind, and

146
00:13:01.120 --> 00:13:07.080
that's what we're talking about with space
weather, that's what produces the rory on

147
00:13:07.200 --> 00:13:11.840
the Earth, the northern and southern
lights, the Aurora Borealis, the Aurora

148
00:13:11.879 --> 00:13:15.480
Australia. When we see them on
the guest giants too, don't we do?

149
00:13:15.639 --> 00:13:18.120
Yeah, all that, all the
guest giants have rory as well.

150
00:13:18.159 --> 00:13:26.200
Now these now rory can be detected
in radio waves as well as visible light.

151
00:13:26.399 --> 00:13:28.720
That's the crucial thing. So you
can you can know about rory from

152
00:13:28.960 --> 00:13:37.519
radio astronomy. And it turns out
that this YB. Cetti's system has rory,

153
00:13:39.360 --> 00:13:45.440
but what they're actually seeing is rory
on the star. Yeah. Wow.

154
00:13:46.279 --> 00:13:50.120
Interactions between the magnetic field and the
and the wind of particles coming off

155
00:13:52.200 --> 00:13:56.759
cause magnetic disturbances which they can identify
as being due to Rory, even though

156
00:13:56.840 --> 00:14:01.320
we can't see them. But they
also think that if the planet has its

157
00:14:01.360 --> 00:14:03.679
own atmosphere, and that's certainly not
something that's known, if it did,

158
00:14:03.759 --> 00:14:09.360
that would also have rory. Quite
incredible. Yeah, that's that. That's

159
00:14:09.360 --> 00:14:11.919
another thing. Rory could be a
very common thing in the universe too,

160
00:14:13.159 --> 00:14:16.480
sounding like it, Yes, Yeah, that's right. Wow, that's that's

161
00:14:16.559 --> 00:14:22.200
quite a discovery. So I didn't
tip water on them. I just I

162
00:14:22.399 --> 00:14:28.559
know you didn't brought up an angle
that created more information more information. That's

163
00:14:28.720 --> 00:14:35.240
that's correct. Yeah, right,
It's always good to to be skeptical of

164
00:14:35.360 --> 00:14:41.919
these things. I'm an optimist when
it comes to historiomy. Indeed, actually

165
00:14:41.919 --> 00:14:46.120
I'm an optimist when it comes to
pretty well everything up to say, which

166
00:14:46.320 --> 00:14:50.759
really annoys some people. Well yes, but they're pessimists. But if you

167
00:14:50.840 --> 00:14:54.279
want to chase up this story,
you can go to one of our favorite

168
00:14:54.320 --> 00:14:58.519
websites and read up on it.
Fizz dot org. Phy s by the

169
00:14:58.559 --> 00:15:03.759
way, is dot org. This
is space Nuts. Andrew Ungle here with

170
00:15:03.120 --> 00:15:15.240
Professor Fred Watson, great space nuts. Now, Fred, this one fascinates

171
00:15:15.320 --> 00:15:20.120
me because this is only a fairly
recent discovery in terms of what we're talking

172
00:15:20.200 --> 00:15:24.559
about, only dates back to I
think twenty eighteen when they first spotted one

173
00:15:24.600 --> 00:15:33.200
of these. Um they're called an
f BOT FBOT, and basically we're describing

174
00:15:33.480 --> 00:15:37.639
a cataclysmic explosion in space. But
they're different from an explosion as we know

175
00:15:37.759 --> 00:15:41.799
it now. Most explosions sort of
go out in all directions simultaneously. This

176
00:15:43.039 --> 00:15:46.000
one didn't, and they've just discovered
another one, and it's one of the

177
00:15:46.200 --> 00:15:52.159
biggest or flattest explosions ever observed.
Yes, such, right, So,

178
00:15:52.399 --> 00:15:58.320
yeah, the f BOT, an
f BOT in this instance is a fast

179
00:15:58.480 --> 00:16:03.559
blue optical transient. Yeah, it
could. It could also it could also

180
00:16:03.679 --> 00:16:08.120
stand for a fantastically big optical telescope. It could do it, but it

181
00:16:08.240 --> 00:16:14.480
doesn't. It's a fast blue optical
transient and so that kind of tells you

182
00:16:14.879 --> 00:16:18.200
about it. Its optical, so
he sees invisible light. It's blue because

183
00:16:18.279 --> 00:16:22.919
that's the wavelength range, the blue
wavelength range that it emits its lighting.

184
00:16:23.200 --> 00:16:29.720
It's fast because it comes and goes
very quickly. And transient just is referring

185
00:16:29.799 --> 00:16:33.120
to the fact that it is something
that is not permanent, it's tempering,

186
00:16:33.440 --> 00:16:41.240
transient in its nature. This is
a star in another galaxy, a galaxy

187
00:16:41.559 --> 00:16:45.600
about one hundred and eighty million light
years away, so it's not part of

188
00:16:45.639 --> 00:16:51.559
our local group of galaxies, which
goes out to about five of ten million

189
00:16:51.679 --> 00:16:57.919
light years, perhaps a few more. But this is an explosion of a

190
00:16:59.080 --> 00:17:07.079
star that has some there's some difference
from what we normally see. Normally when

191
00:17:07.079 --> 00:17:11.519
you see an exploding star Andrew,
as you well know, is it's a

192
00:17:11.559 --> 00:17:15.200
supernova. Yeah, it's a star
that's got to the end of its life,

193
00:17:15.880 --> 00:17:19.960
run out of hydrogen, run out
of everything it needs to burn in

194
00:17:21.079 --> 00:17:25.839
a normal ways. Yeah, it
didn't paste tolls all of that, and

195
00:17:26.759 --> 00:17:30.839
you know, everything has come to
an end and it collapses and in the

196
00:17:30.000 --> 00:17:37.039
process of the collapse you get this
huge emission of energy as it winds up

197
00:17:37.359 --> 00:17:40.960
becoming or it's called becomes a neutron
star or perhaps a black hole. Yeah,

198
00:17:40.960 --> 00:17:45.279
but this is something different and it's
and it is, I have to

199
00:17:45.400 --> 00:17:52.599
say, not clear how these f
bots work. Scientists and this study has

200
00:17:52.599 --> 00:17:59.519
been done mostly by British scientists,
don't really know what causes fast blue optical

201
00:17:59.599 --> 00:18:07.359
transit, but they can observe them. And this particular one has been observed

202
00:18:08.079 --> 00:18:15.400
with a smallish telescope. And it's
actually one I know quite well because whilst

203
00:18:15.480 --> 00:18:22.759
it's not the one at Siding Spring
Observatory, which is called the Last Cumbers

204
00:18:22.839 --> 00:18:27.319
two meter telescope, this is called
the Liverpool Telescopes. It's Liverpool Telescope.

205
00:18:27.359 --> 00:18:34.960
It's a two meter diameter telescope and
it was made by a sort of corporation

206
00:18:36.079 --> 00:18:37.839
in Liverpool in the United Kingdom.
In fact, they made about five of

207
00:18:37.960 --> 00:18:42.160
them. I think one came to
our observatory here in Australia, one went

208
00:18:42.200 --> 00:18:49.759
to the island of Maui in the
Hawaiian Chain, and one called the Liverpool

209
00:18:49.799 --> 00:18:55.000
Telescope is actually on La Palma in
the Canary Islands. That's an island again

210
00:18:55.119 --> 00:18:57.640
that hosts large telescopes on one of
its volcanic peaks. I used to work

211
00:18:57.680 --> 00:19:04.200
there a lot during the nineteen nineties. So the Liverpool telescope has a piece

212
00:19:04.279 --> 00:19:12.400
of equipment on it which is specialized
in the world of astronomy, but very

213
00:19:14.079 --> 00:19:18.160
very powerful in terms of what it
can tell you. And I'm kind of

214
00:19:18.200 --> 00:19:23.400
friendly with scientists here in the University
of New South Wales who use similar equipment.

215
00:19:23.519 --> 00:19:29.359
These are called polar emitters, and
they measure polarization, not just the

216
00:19:29.960 --> 00:19:33.039
brightness of light or its color,
that's to say, it's wavelength. They

217
00:19:33.119 --> 00:19:40.480
also measure whether or not it is
polarized and whether what the amount of that

218
00:19:40.599 --> 00:19:47.680
polarization is. And we kind of
know about polarization from polarizing sunglasses. The

219
00:19:47.880 --> 00:19:56.240
idea being that the vibrations of light
waves in when the light is polarized,

220
00:19:56.279 --> 00:20:00.920
they sit in one particular plane,
or sometimes they are taste actually, which

221
00:20:00.000 --> 00:20:06.720
is more complicated, but but it's
essentially that the equipment that's on the Liverpool

222
00:20:06.759 --> 00:20:11.880
telescope is the equivalent of a pair
of polarizing sunglasses, so that as you

223
00:20:11.039 --> 00:20:18.039
rotate them you see different intensities.
In the case of polarizing sunglasses, it's

224
00:20:18.079 --> 00:20:22.519
to kill the right reflections coming off
a road or a bright surface, which

225
00:20:22.680 --> 00:20:26.960
you can do by blocking out that
that polarization of the lights. Yeah,

226
00:20:27.599 --> 00:20:33.599
so you can do something similar in
astronomy. And now polarization is caused by

227
00:20:34.480 --> 00:20:45.200
principally emission from dusty particles, things
that have got an alignment to them that

228
00:20:45.400 --> 00:20:49.200
they're that that they're you know,
perhaps shaped like a pencil or something like

229
00:20:49.319 --> 00:20:53.839
that. And if you've got lots
and lots of particles of duster aligned,

230
00:20:53.960 --> 00:21:00.000
for example, by magnetic fields,
you can work out from the polization where

231
00:21:00.039 --> 00:21:04.400
those magnetic fields go. I'm not
explaining this very well, but it lets

232
00:21:04.480 --> 00:21:11.319
you determine some structure in a you
know, a source of radiation that you

233
00:21:11.359 --> 00:21:18.200
wouldn't otherwise be able to see.
And that's how just by looking at the

234
00:21:18.319 --> 00:21:22.640
light that's come from this f bot, these scientists can tell that there is

235
00:21:22.680 --> 00:21:26.920
a flat disc of material around it, as you said, the size of

236
00:21:26.000 --> 00:21:32.400
the solar system, which is the
result of the explosion. Something has exploded,

237
00:21:32.839 --> 00:21:37.799
and it's exploded not in a spherical
fashion light we expect everything to do,

238
00:21:37.000 --> 00:21:45.279
including supernovae. It's produced a flat
disk of material and that is a

239
00:21:45.559 --> 00:21:52.880
is a mystery. How how how
does first of all, how do these

240
00:21:52.920 --> 00:21:57.960
things work? And secondly how does
it create this flat There's a scientist.

241
00:21:59.279 --> 00:22:02.920
The lead author of this study was
actually in Sheffield in the North of England.

242
00:22:03.759 --> 00:22:07.440
University of Sheffield's Department the Physics and
Astronomy, doctor Justin maun says very

243
00:22:07.480 --> 00:22:12.160
little is known about FBOT explosions.
They just don't behave like exploding stars should.

244
00:22:12.359 --> 00:22:15.559
They're too bright and they evolve too
quickly. But simply they are weird.

245
00:22:15.839 --> 00:22:21.559
If this new observation makes them even
weirder, there's a little bit more,

246
00:22:22.000 --> 00:22:26.720
perhaps I can read from doctor Maund. Hopefully this new finding will help

247
00:22:26.759 --> 00:22:30.319
us shed a bit more light on
them. We never thought that explosions could

248
00:22:30.400 --> 00:22:34.759
be this a spherical There are a
few potential explanations for it. The stars

249
00:22:34.799 --> 00:22:38.400
involved may have created a disc just
before they died, or they could be

250
00:22:38.480 --> 00:22:42.079
failed supernovers where the core of the
star collapses to a black hole or neutron

251
00:22:42.160 --> 00:22:45.480
star, which then eats the rest
of the star. What we now know

252
00:22:45.799 --> 00:22:51.599
for sure is that the levels of
asymmetry recorded are a key part of understanding

253
00:22:51.680 --> 00:22:56.440
these mysterious explosions, and it challenges
our preconceptions of how stars might explode in

254
00:22:56.480 --> 00:23:00.839
the universe. We never thought that
they'd go off bang a flat, so

255
00:23:00.319 --> 00:23:04.440
yours think of everything that explodes in
the universe is going out in all directions

256
00:23:04.480 --> 00:23:10.960
simultaneous phies spherically, Yes, may
I ask, and I don't presume to

257
00:23:11.079 --> 00:23:17.160
be sort of again tipping water on
their observations and discoveries, But could it

258
00:23:17.319 --> 00:23:21.680
be we're only seeing part of the
explosion and that there is in fact a

259
00:23:21.759 --> 00:23:26.519
spherical outburst and we just can't see
parts of it, or are they pretty

260
00:23:26.599 --> 00:23:33.240
certain this is a dead flat type
of explosion. That's a really interesting comment,

261
00:23:33.319 --> 00:23:37.039
Andrew, well done, and you
should write to these people and tell

262
00:23:37.079 --> 00:23:40.759
them that, because there are things
in the universe where we think we're seeing

263
00:23:40.880 --> 00:23:45.240
something, but what's really happening is
that we're not seeing the whole picture.

264
00:23:45.759 --> 00:23:51.599
And often it's a dust cloud or
something like that that is blocking our view

265
00:23:52.799 --> 00:23:56.960
of what's what's what else is there? If I could put it that way,

266
00:23:56.960 --> 00:24:00.759
so it's possible, you know,
you could imagine that something like a

267
00:24:00.839 --> 00:24:07.400
dust cloud could be blocking our view
on always seeing is that isn't the flattened

268
00:24:07.440 --> 00:24:11.519
exploding disc. I think what knocks
that on the head fair enough, and

269
00:24:11.640 --> 00:24:15.200
so maybe you shouldn't write the right
to them is that the way they've detected

270
00:24:15.279 --> 00:24:21.440
this is by polarization. And I
suspect if it was just a spherical explosion

271
00:24:21.599 --> 00:24:25.240
and part of it was being blocked
off, we wouldn't have that phenomenon.

272
00:24:25.359 --> 00:24:29.759
It wouldn't be the light wouldn't be
polarized. So it's something to do with

273
00:24:29.880 --> 00:24:34.720
the actual structure of this disc of
material that gives you the polarization, and

274
00:24:34.839 --> 00:24:41.319
that is telling you that it really
is a flattened disc of stuff, that

275
00:24:41.440 --> 00:24:47.920
this star is emitted rather than rather
than blocked off view of something more symmetrical.

276
00:24:48.119 --> 00:24:52.680
Yeah, and the other interesting thing
is that, like many things we

277
00:24:52.759 --> 00:24:56.640
have talked about recently, this is
a fairly new discovery. As I said

278
00:24:56.640 --> 00:25:00.079
at the start, the very first
one of these was only discovered in twenty

279
00:25:00.160 --> 00:25:04.359
eighteen. So yes, this is
this is a whole new realm that we're

280
00:25:06.240 --> 00:25:11.839
again trying to understand. It's right
up there with the dark matter and dark

281
00:25:12.000 --> 00:25:17.240
energy and even black holes. We
don't really understand a lot about them.

282
00:25:17.319 --> 00:25:21.799
This is another one. Yeah,
that's right. And of course that's the

283
00:25:21.920 --> 00:25:25.680
great thing about astronomy. When something
new like this comes up. He sends

284
00:25:25.759 --> 00:25:30.640
the theoreticians back to the drawing boards, scrutching their heads. How can we

285
00:25:30.680 --> 00:25:33.640
account for this? How can we
explain what's going on here? So push

286
00:25:33.720 --> 00:25:37.599
his physics along as well to try
and understand what what actually is happening.

287
00:25:37.799 --> 00:25:41.720
Yes, indeed, okay, that's
on the dot org website as well.

288
00:25:41.759 --> 00:25:45.079
But if you want to do some
deeper reading about it and read five hundred

289
00:25:45.119 --> 00:25:51.519
pages of authors to the Monthly Notices
of the Royal Astronomical Society. That's where

290
00:25:51.519 --> 00:25:56.680
you'll find the paper on f bots. This is based nuts Andrew Dunkly here

291
00:25:56.720 --> 00:26:04.799
with Professor Fred Watson being with a
job space nets if it before we go

292
00:26:04.960 --> 00:26:10.359
to questions this this is a story
that came as quite a surprise to me.

293
00:26:10.440 --> 00:26:15.079
And this is only a recent announcement
but has some bad news for Virgin

294
00:26:15.240 --> 00:26:19.799
Orbit. Yes, that's right.
So Virgin Orbit, which is you know,

295
00:26:19.920 --> 00:26:25.680
a spin off really from Virgin Galactic
and you remember there their stock in

296
00:26:25.759 --> 00:26:32.279
trade is the launch of orbital vehicles
using a converted bowing seven four seven ye

297
00:26:32.960 --> 00:26:36.759
to carry a rocket up to forty
thousand feet or thereabouts, where upon the

298
00:26:36.880 --> 00:26:41.079
rockets dropped and it ignites and off
it goes to launch payloads into orbit.

299
00:26:41.759 --> 00:26:47.920
It's it's got marvelous advantages actually because
you can do launches at short notice,

300
00:26:48.000 --> 00:26:52.200
you can launch from anywhere. Basically
you don't have to be you know,

301
00:26:52.279 --> 00:26:56.559
on a continent. And you would
have thought that that would have that would

302
00:26:56.640 --> 00:27:03.240
have been very commercially attractive and would
have you know, naturally resulted in a

303
00:27:03.440 --> 00:27:11.000
company at least staying viable and probably
doing very well. But what seems to

304
00:27:11.119 --> 00:27:21.680
have happened is that because of SpaceX
now being able to essentially bring down the

305
00:27:21.799 --> 00:27:26.880
cost of launched by actually recovering their
launch vehicles and using them again. We've

306
00:27:26.920 --> 00:27:30.000
talked about this many times, the
fact that SpaceX's Falcon nines can be used

307
00:27:30.079 --> 00:27:37.119
up to about twenty times now and
that's brought the price down, and the

308
00:27:37.279 --> 00:27:42.079
suspicion is that that has made Virgin
or a bit less competitive. Plus they

309
00:27:42.160 --> 00:27:49.759
had sadly their last launch didn't work. We covered it. Actually it was

310
00:27:51.440 --> 00:27:57.319
earlier this year where the rocket,
I think the second stage failed because of

311
00:27:57.400 --> 00:28:06.279
a filter that was blocked. This
was a launch made from southwest Britain from

312
00:28:06.400 --> 00:28:14.960
the aircraft took off and launched over
off the shore of Cornwall. So yeah,

313
00:28:15.079 --> 00:28:21.480
unfortunately the satellites that were launched didn't
make it. They didn't make the

314
00:28:21.559 --> 00:28:26.799
second stage because of that filter issue. And so that's that's very sad and

315
00:28:26.960 --> 00:28:33.559
that might kind of be the final
straw that's caused this company out of file

316
00:28:33.599 --> 00:28:37.400
for bankruptcy. Very sad Virgin Orbit. It's very sad, especially for us

317
00:28:37.440 --> 00:28:41.079
in Australia, because I think the
next launch was planned to take place from

318
00:28:42.119 --> 00:28:48.079
the one of the airfields in Queensland
into Womba. Remember were planning to launch

319
00:28:48.400 --> 00:28:51.240
from there. Yeah, it would
have been very exciting for the for the

320
00:28:51.319 --> 00:28:56.279
city. Torn is a beautiful place
it is, and yeah, it's it's

321
00:28:56.279 --> 00:29:00.799
a real pity. This doesn't have
any impact on Virgin Galactic at all though,

322
00:29:00.880 --> 00:29:03.240
does it not? As far as
we knew? I mean, Virgin

323
00:29:03.319 --> 00:29:08.599
Galactic's gone quiet at the moment after
I think the first flight sh if I

324
00:29:08.640 --> 00:29:12.680
remember, and I can't remember those
that was last year when Brunson flew on

325
00:29:14.039 --> 00:29:18.319
the rocket plane. But we're still
wasting for playing passengers to be launched up

326
00:29:18.359 --> 00:29:22.279
there. Yeah, all right,
they'll probably be more on this down the

327
00:29:22.359 --> 00:29:26.720
track. Yeah, okay, Fred, let's get to some questions. Got

328
00:29:26.759 --> 00:29:29.720
a couple of text questions today,
Hey, Fred, and Andrew, longtime

329
00:29:29.799 --> 00:29:34.720
listener, first time caller, and
I was wondering why we haven't seen or

330
00:29:34.839 --> 00:29:41.079
heard of more exploratory missions where we
send a satellite at extremely high velocity out

331
00:29:41.119 --> 00:29:45.480
towards objects in the Solar System or
perhaps beyond. Given the rapid advances in

332
00:29:45.559 --> 00:29:49.920
technology, is it feasible to do
fast sites in space. I assume the

333
00:29:51.000 --> 00:29:59.039
fastest man made object is also called
is also space related, and any idea

334
00:29:59.359 --> 00:30:03.960
what the fast a man made object
is and the implications of high relative velocities

335
00:30:04.000 --> 00:30:08.319
in space and the impact it has
on said object in the data that we're

336
00:30:08.359 --> 00:30:14.920
able to collect. Being expanse fans, I recall a character racing around the

337
00:30:15.000 --> 00:30:19.319
Solar System and being a gearhead myself, this topic is near and tear.

338
00:30:22.400 --> 00:30:26.599
So yeah, that's from Michael in
North Dakota, far North Dakota. He

339
00:30:26.720 --> 00:30:32.160
makes a point of saying, so, yeah, look, we've done a

340
00:30:32.240 --> 00:30:34.599
few missions out there, and of
course you think of the voyager probes which

341
00:30:34.720 --> 00:30:38.240
are still going even though they're having
to shut things down bit by bit to

342
00:30:38.319 --> 00:30:42.920
keep them alive. But yeah,
why haven't we done more? Why can't

343
00:30:42.960 --> 00:30:47.480
we, with the current technology just
go boom, send something out at super

344
00:30:47.599 --> 00:30:53.960
high speed and do some exploring.
Yeah. So, yeah, the technology

345
00:30:56.279 --> 00:31:03.160
is, it is advanced, but
you're still limited by the physics of you

346
00:31:03.240 --> 00:31:08.359
know, the chemistry of rocket propulsion
and the physics behind it. So the

347
00:31:08.559 --> 00:31:15.039
fastest launch I think I'm right in
saying this was New Horizons, Yeah,

348
00:31:15.920 --> 00:31:23.880
which had to be quickly boosted to
a velocity that would take it past Jupiter

349
00:31:25.119 --> 00:31:30.119
so that it got a sling shot
out to Pluto. It was launched in

350
00:31:30.240 --> 00:31:33.920
two thousand and six, it rolled
flu by Pluto in twenty fifteen, and

351
00:31:34.720 --> 00:31:44.200
it's now escaping the Solar System.
It's had its rendezvous with arikof that strange

352
00:31:44.279 --> 00:31:49.599
little double asteroid that was in the
headlines the beginning of the year before last,

353
00:31:49.720 --> 00:31:52.440
I boost track of these things.
It might have been the year before

354
00:31:52.480 --> 00:31:55.720
that, I think twenty twenty one. I think it was. Yeah,

355
00:31:56.000 --> 00:31:59.160
So that's the nearest thing to,
you know, to what Michael suggesting,

356
00:32:00.079 --> 00:32:05.920
and that really pushed the technology to
get new horizons up to that high initial

357
00:32:06.039 --> 00:32:13.200
launch speed. I suspect he's right
that the fastest human made object is a

358
00:32:13.319 --> 00:32:20.759
spacecraft. I'm trying to think of
terrestrial experiments. The Helius satellites, apparently,

359
00:32:20.839 --> 00:32:23.559
the first two satellites designed to study
the Sun, traveled at one hundred

360
00:32:23.559 --> 00:32:29.680
and fifty seven thousand and seventy eight
miles per hour. There, I'm told

361
00:32:29.720 --> 00:32:34.519
they're the fastest ever man made objects
in space. Okay, and the most

362
00:32:34.960 --> 00:32:38.839
object on Earth. You're going to
laugh this. This was during a nuclear

363
00:32:38.880 --> 00:32:45.680
bomb test called operation plumbob and Robert
Brownlee was asked to design the test and

364
00:32:46.039 --> 00:32:55.119
he put a he put a cover
over the test point of the test tube,

365
00:32:55.359 --> 00:33:00.480
if you like, and he wanted
to test the speed of the the

366
00:33:00.559 --> 00:33:05.720
manhole cover when the explosion happened,
and I don't know exactly how he did

367
00:33:05.799 --> 00:33:09.200
it, but it came out.
It got blown into the into the stratosphere

368
00:33:09.240 --> 00:33:14.400
at one hundred and twenty five thousand
miles an hour. So that's the fastest

369
00:33:14.519 --> 00:33:17.240
Earth based man made object as far
as I can tell. That's just a

370
00:33:17.319 --> 00:33:23.160
quick search I've done. And I
think one of the fastest objects that carried

371
00:33:23.160 --> 00:33:30.200
a person in space was Apollo ten, a Polo ten capsule at twenty four

372
00:33:30.240 --> 00:33:37.160
thousand, seven h ninety one miles
an hour. That's quick, yes,

373
00:33:37.720 --> 00:33:40.119
Um, I never think in miles
an hour, Andrew, No, I

374
00:33:40.279 --> 00:33:45.359
just I'm trying to be rapidly converting
these to kilometers per second. Yeah.

375
00:33:45.240 --> 00:33:50.240
So that last one's about eleven I
think, which is actually the escape velocity

376
00:33:50.319 --> 00:33:55.960
of um so, uh yeah,
the of the money cover. That's a

377
00:33:57.319 --> 00:34:04.599
that's a great story. The fastest, the fastest spacecraft as we speak today,

378
00:34:05.480 --> 00:34:09.800
however, is Voyager one, which
you mentioned earlier, which is still

379
00:34:09.920 --> 00:34:15.079
traveling away from the Sun. It's
just under seventeen kilometers per second, and

380
00:34:15.320 --> 00:34:22.800
that's that's the you know, in
terms of something that's ongoing. That's the

381
00:34:22.920 --> 00:34:29.800
fastest human made object. It's moving
away at that speed, and you know,

382
00:34:29.920 --> 00:34:35.559
we'll keep going forever probably pretty well
until it's something yes or not.

383
00:34:36.360 --> 00:34:38.960
It's more likely to go into orbit
around something, yeah, you know,

384
00:34:39.639 --> 00:34:45.599
if it winds up in a foreign
solar system. On the other hand,

385
00:34:45.639 --> 00:34:52.639
it could fly through a solar system
a bit like baffle any sentient beings that

386
00:34:52.960 --> 00:34:55.639
that are out there. But anyway
it can get caught in the orbit of

387
00:34:55.679 --> 00:35:00.760
another planet, because we we've had
that happen here with Earth. We had

388
00:35:00.760 --> 00:35:05.519
a second moon there for a little
while. It might still be yes,

389
00:35:05.639 --> 00:35:10.480
that's right, tiny little so so. Yeah, so Voyager one certainly holds

390
00:35:10.519 --> 00:35:16.039
the record at the moment that's being
the fastest spacecraft flying. If it was

391
00:35:16.119 --> 00:35:21.679
on its way to Proxima Centauri,
it would get that in seventy four thousand

392
00:35:21.840 --> 00:35:27.480
years. Yeah, So that cost
start that kind of makes the high speed

393
00:35:27.599 --> 00:35:31.000
technology of today is still fairly redundant
in terms of long haul space travel.

394
00:35:31.119 --> 00:35:36.360
Unfortunately, indeed, it does okay, Thank you, Michael. Let us

395
00:35:36.519 --> 00:35:40.000
move on to our next question from
another Michael, who calls himself Mike.

396
00:35:40.920 --> 00:35:46.159
He's from Brisbane. Space nutters.
The density of gas in the vacuum of

397
00:35:46.280 --> 00:35:51.559
space. We're always talking about and
looking at gas clouds in space, and

398
00:35:51.679 --> 00:35:54.880
a question is what is the density
of gas in between the planets of the

399
00:35:54.960 --> 00:35:58.920
Solar System? What is the density
of gas in between the stars and the

400
00:35:59.000 --> 00:36:01.480
galaxy? And what is the density
of gas between galaxies? Also, what

401
00:36:01.679 --> 00:36:07.800
is the density of gas in a
typical nebula. I'm assuming the answer will

402
00:36:07.800 --> 00:36:12.480
be x number of adams per cubic
meter, with X being a small number.

403
00:36:12.599 --> 00:36:16.239
Regards Mike, it's a good question. It's good and Mike's given the

404
00:36:16.280 --> 00:36:22.119
answer as well, so it is
it's a small number of atoms per cubic

405
00:36:22.239 --> 00:36:30.239
meter. Um kind of feeling that
when I wrote Space War, I wasn't

406
00:36:30.280 --> 00:36:35.119
no, was it cosmic Chronica.
I think I talked about this stuff right

407
00:36:35.199 --> 00:36:37.719
at the beginning. I can't remember, said he reaching for one of his

408
00:36:37.840 --> 00:36:44.039
own books. Yeah, it might
be. It might be easy to because

409
00:36:44.039 --> 00:36:52.599
I've talked about I talked about,
you know, finding itself in typical place

410
00:36:52.960 --> 00:37:00.559
in space. Oh yeah, before
and the answer is if it's dark and

411
00:37:00.679 --> 00:37:07.920
it's cold, and it's empty and
somewhere I thought i'd given how many atoms

412
00:37:08.039 --> 00:37:13.360
per cute Here we are if you're
lucky, all right, this is in

413
00:37:13.679 --> 00:37:20.079
This is in normal it's in a
typical a typical location, so it's between

414
00:37:20.119 --> 00:37:22.400
the galaxies. It's not in a
solar system. This is in the depths

415
00:37:22.440 --> 00:37:27.079
of space. If you're lucky,
you might find one atom of hydrogen in

416
00:37:27.559 --> 00:37:32.079
the volume of space normally taken up
by fifteen adults a cubic meter. Wow,

417
00:37:32.320 --> 00:37:38.400
so what that's that's typical, you
know, or typical of the intergalactic

418
00:37:38.480 --> 00:37:46.199
space one atom per cubic meter.
And it goes up from there with I

419
00:37:46.360 --> 00:37:52.960
guess you know. The nearer you
are. If you're in the intergalact interstellar

420
00:37:52.039 --> 00:37:57.920
medium in our galaxy, it's significantly
higher. It's probably measured in tens of

421
00:37:58.199 --> 00:38:06.000
atoms per cubic meter. The solar
environment is rather more populated. It's probably

422
00:38:06.079 --> 00:38:09.079
hundreds of attempts but qubic meter.
But it's still a vacuum to all intents

423
00:38:09.119 --> 00:38:13.159
and purposes. Yeah, I'd have
to look up the numbers, and I'm

424
00:38:13.199 --> 00:38:16.960
sure Mike is as capable as I
am of doing that to find the you

425
00:38:17.039 --> 00:38:22.960
know, density of of of the
the things to look up at interstellar,

426
00:38:23.039 --> 00:38:27.679
medium, solar wind, those sorts
of places. That's where you want to

427
00:38:27.719 --> 00:38:30.199
find the numbers, the exact numbers. But it is small, it's tiny.

428
00:38:30.440 --> 00:38:36.280
If you would talk about one of
those beautiful nebula, like the Horsehead

429
00:38:36.360 --> 00:38:39.360
nebula or something, what be the
density and something like that, it's still

430
00:38:39.760 --> 00:38:43.559
still extremely low. So you could
find through it, you could fly through

431
00:38:43.639 --> 00:38:52.400
it. Absolutely, yeah, it's
it's it's very low. Um that just

432
00:38:52.480 --> 00:38:58.639
there's an adjumpt to that little story
in the history of astronomy. And it

433
00:38:59.480 --> 00:39:04.239
kind of straits how though, these
nebular densities are, because when nebulae were

434
00:39:04.280 --> 00:39:08.199
first observed with the spectroscope by a
man called William Huggins back in London in

435
00:39:08.239 --> 00:39:16.000
the eighteen sixties, he found emission
and you know, it's the kind of

436
00:39:16.719 --> 00:39:22.039
optical fingerprint of gases that we used
to work out what's in space. He

437
00:39:22.159 --> 00:39:27.760
found he found these what would call
emission lines, this fingerprint of some gas

438
00:39:27.840 --> 00:39:32.079
that was completely unknown on Earth,
and they actually called it nibullium because they

439
00:39:32.159 --> 00:39:37.239
thought they didn't they'd discovered a new
element. That was in the eighteen sixties,

440
00:39:37.880 --> 00:39:42.719
and nibullium was one of the huge
mysteries throughout the latter days of the

441
00:39:42.960 --> 00:39:47.960
nineteenth century into the first couple of
decades of the twentieth century, because he

442
00:39:49.119 --> 00:39:52.719
got to be an even bigger mystery
because by then the periodic table had been

443
00:39:52.840 --> 00:39:57.639
invented and there were no gaps where
there could be a nebulium thing. And

444
00:39:57.800 --> 00:40:01.800
it was a man called Ira Bowen, who was an American astronomer later became

445
00:40:01.880 --> 00:40:07.480
the director of Lick Observatory, if
I remember rightly, who worked out what

446
00:40:07.599 --> 00:40:13.920
it was that He'd had some hints
by some comments by another astronomer before him,

447
00:40:13.960 --> 00:40:20.199
but he figured out that what we
were seeing was emission from a normal

448
00:40:20.400 --> 00:40:25.360
gas but a very very low pressure
where the atoms don't bump into each other

449
00:40:25.519 --> 00:40:30.239
at all, which is what you
get in the nebula. Yeah, there's

450
00:40:30.280 --> 00:40:40.280
hardly any bumping of together of atoms. Its coffee money everyone thing. Yeah,

451
00:40:42.199 --> 00:40:49.360
Andrew carn't talk to you view it
all right, we're nearly done.

452
00:40:51.320 --> 00:40:54.280
Yeah, so so it's just a
you know. It was that was when

453
00:40:54.679 --> 00:41:00.719
they recognized that this was nearly a
vacuum and this. The atoms are so

454
00:41:00.840 --> 00:41:06.280
far apart they don't interact, and
that gives you this difference signature for what

455
00:41:06.519 --> 00:41:10.320
is an otherwise normal gas. In
fact, that those spectrum lines are called

456
00:41:10.440 --> 00:41:15.760
forbidden lines because they're forbidden on Earth, right, but they're not in the

457
00:41:15.880 --> 00:41:22.199
dets for space. Fascinating. I
want a poem about it, called forbidden

458
00:41:22.280 --> 00:41:24.840
Lines. Maybe I should read it
one day. Maybe should? Maybe you

459
00:41:24.920 --> 00:41:29.519
should? Yeah, Okay, there
you go, Mica. I'm sure you're

460
00:41:29.519 --> 00:41:31.760
glad you asked the question of age. You knew the answer by the sound

461
00:41:31.800 --> 00:41:35.800
of it, Yes, very good. I don't forget. If you do

462
00:41:35.960 --> 00:41:38.519
want to send us a question,
you can go to our website space nats

463
00:41:38.559 --> 00:41:43.400
podcast dot com or spacens dot io. There's a little tab up the top

464
00:41:43.480 --> 00:41:45.400
called AMA or a link if you
like. You can click on that to

465
00:41:45.480 --> 00:41:50.840
send us audio or text questions,
or you can click the send us your

466
00:41:50.920 --> 00:41:53.920
voice message tab on the right hand
side, and don't forget to tell us

467
00:41:53.960 --> 00:41:57.599
who you are and where you're from, and wad're on there? I have

468
00:41:57.679 --> 00:42:00.639
a look around. There's the space
nats shop. There's the Astronomy Daily newsletter,

469
00:42:00.679 --> 00:42:05.320
which you can sign up for and
get a daily dose of astronomy in

470
00:42:05.360 --> 00:42:10.559
space science. You can learn about
supporting Space Nuts by becoming a patron.

471
00:42:10.639 --> 00:42:16.199
It's all on our website Space Nuts
podcast dot com. Fred. That brings

472
00:42:16.320 --> 00:42:19.679
us to the end of another episode. Thank you so much, sir.

473
00:42:21.039 --> 00:42:24.480
It's a pleasure and I'm sure we'll
do it again sometime. I reckon we

474
00:42:24.599 --> 00:42:30.159
will sometimes soon, I hope,
yeah, maybe, yeah, Okay,

475
00:42:30.320 --> 00:42:32.519
take care, we'll talk to you
in sounds. Great. Thanks Andrew,

476
00:42:32.639 --> 00:42:37.159
Fred Watson an astronomer a large part
of the team here at Space Nuts Central.

477
00:42:37.519 --> 00:42:39.920
I'll call it that from now on. And thanks to you on the

478
00:42:40.000 --> 00:42:44.559
studio for what I don't know,
but thanks anyway, and from me Andrew

479
00:42:44.679 --> 00:42:47.320
Dudley, thanks for your company.
Looking forward to joining you again on the

480
00:42:47.440 --> 00:42:53.639
next episode of Space Nuts. Bye
bye. You'll be listening to this Space

481
00:42:53.760 --> 00:43:02.079
Nuts podcast available at Apple Podcasts,
Google Podcasts, Spotify, iHeartRadio, or

482
00:43:02.159 --> 00:43:07.679
your favorite podcast player. You can
also stream on demand at bites dot com.

483
00:43:07.239 --> 00:43:12.199
This has been another quality podcast production
from bites dot com.