Europe Launches From Europe — And Two White Dwarfs Six Minutes Apart

WEBVTT

0
00:00:00.720 --> 00:00:03.160
Anna: Hello and welcome to Astronomy daily. It's

1
00:00:03.160 --> 00:00:06.160
Monday, September 7th, 2026. I'm

2
00:00:06.160 --> 00:00:08.880
Anna and this is series five, episode

3
00:00:08.880 --> 00:00:09.920
187.

4
00:00:10.160 --> 00:00:11.980
Anna: And I'm Avery. Anna.

5
00:00:11.980 --> 00:00:14.000
Uh, we're starting the week with a rocket

6
00:00:14.000 --> 00:00:16.720
that finally worked. And it's not one of the

7
00:00:16.720 --> 00:00:18.000
usual suspects.

8
00:00:18.400 --> 00:00:21.400
Anna: It isn't. On Saturday morning our time, a

9
00:00:21.400 --> 00:00:23.840
German built rocket lifted off from an island

10
00:00:23.920 --> 00:00:26.610
inside the Arctic Circle and put six

11
00:00:26.610 --> 00:00:29.530
payloads into orbit. And in doing so,

12
00:00:29.530 --> 00:00:32.450
it became the first vehicle in history to

13
00:00:32.450 --> 00:00:33.170
reach orbit

14
00:00:33.170 --> 00:00:36.050
Anna: from western European soil 69

15
00:00:36.050 --> 00:00:37.690
years into the space age.

16
00:00:38.410 --> 00:00:41.370
Anna: 69 years into the space age. Europe

17
00:00:41.370 --> 00:00:43.530
has been launching for decades from South

18
00:00:43.530 --> 00:00:46.410
America. On Saturday, it launched from home.

19
00:00:46.890 --> 00:00:49.850
Anna: That's our lead then. Three pieces of

20
00:00:49.850 --> 00:00:52.050
science that all quietly tell you something

21
00:00:52.050 --> 00:00:53.850
about how hard measurement is.

22
00:00:54.750 --> 00:00:56.750
Astronomers have found that the gaps in

23
00:00:56.750 --> 00:00:59.430
stellar streams. One of our best tools for

24
00:00:59.430 --> 00:01:02.430
finding dark matter might not be dark matter

25
00:01:02.430 --> 00:01:02.990
at all.

26
00:01:03.470 --> 00:01:05.790
Anna: A pair of white dwarfs in the far southern

27
00:01:05.790 --> 00:01:08.550
sky are circling each other every six

28
00:01:08.550 --> 00:01:11.070
minutes and we can now watch the orbit

29
00:01:11.070 --> 00:01:13.910
shrinking. That is gravity carrying energy

30
00:01:13.910 --> 00:01:16.590
away as waves measured with X rays.

31
00:01:16.990 --> 00:01:19.940
Anna: And on Venus, proteins, orbital or

32
00:01:19.940 --> 00:01:22.940
the beginnings of them, peptides that fold up

33
00:01:22.940 --> 00:01:25.740
properly and stay folded in concentrated

34
00:01:25.740 --> 00:01:28.700
sulfuric acid. Which is not what anybody

35
00:01:28.700 --> 00:01:30.140
expected then

36
00:01:30.540 --> 00:01:32.140
Anna: because a lot of you have written in about

37
00:01:32.140 --> 00:01:34.980
it. What on earth is Link actually

38
00:01:34.980 --> 00:01:37.620
doing up there? The Swift rescue that didn't

39
00:01:37.620 --> 00:01:39.860
rescue Swift has turned into something more

40
00:01:39.860 --> 00:01:42.100
interesting. And it's got about two weeks

41
00:01:42.100 --> 00:01:42.460
left,

42
00:01:42.860 --> 00:01:45.300
Anna: plus the sky for the week ahead, both

43
00:01:45.300 --> 00:01:47.860
hemispheres. And there's an occultation

44
00:01:47.860 --> 00:01:50.220
tomorrow that comes with a serious safety

45
00:01:50.220 --> 00:01:51.260
warning attached.

46
00:01:51.820 --> 00:01:52.300
Anna: Big Monday.

47
00:01:52.780 --> 00:01:55.780
Anna: Let's go right, set the scene for

48
00:01:55.780 --> 00:01:58.340
me because I want to understand why this is a

49
00:01:58.340 --> 00:02:00.300
first when Europe has been in the launch

50
00:02:00.300 --> 00:02:02.060
business since the 70s.

51
00:02:02.540 --> 00:02:04.820
Anna: That's exactly the right question. And the

52
00:02:04.820 --> 00:02:07.699
answer is geography. Europe's launch site

53
00:02:07.699 --> 00:02:10.420
is Kourou in French Guiana on the

54
00:02:10.420 --> 00:02:13.220
northeast coast of South America. It's been

55
00:02:13.220 --> 00:02:15.420
Europe's spaceport since 1968.

56
00:02:15.980 --> 00:02:18.160
Ariane Vega album, all of it.

57
00:02:18.400 --> 00:02:20.960
Superb location, 5 degrees off the equator.

58
00:02:21.200 --> 00:02:22.760
You get a free kick from the Earth's

59
00:02:22.760 --> 00:02:23.280
rotation.

60
00:02:23.680 --> 00:02:26.400
Anna: But it's 8,000 kilometres from Paris.

61
00:02:26.960 --> 00:02:29.200
Anna: 7,000 odd. And that's the point.

62
00:02:29.760 --> 00:02:32.280
Europe has had access to space for 50 years

63
00:02:32.280 --> 00:02:34.560
without having launch capability on its own

64
00:02:34.560 --> 00:02:37.480
continent. Every European satellite that

65
00:02:37.480 --> 00:02:40.080
went up on a European rocket went up from

66
00:02:40.080 --> 00:02:43.040
South America or from Cape Canaveral

67
00:02:43.600 --> 00:02:46.520
or for a long stretch from Kazakhstan on

68
00:02:46.520 --> 00:02:47.440
a Soyuz.

69
00:02:47.840 --> 00:02:49.920
Anna: And on Saturday that changed.

70
00:02:50.320 --> 00:02:53.160
Anna: On Saturday that changed. The company is

71
00:02:53.160 --> 00:02:56.080
Isar Aerospace, German, founded

72
00:02:56.080 --> 00:02:58.960
2018. Spun out of the technical University of

73
00:02:58.960 --> 00:03:01.760
Munich. The rocket is called Spectrum.

74
00:03:02.000 --> 00:03:04.240
It lifted off at 10:12 in the evening,

75
00:03:04.320 --> 00:03:07.200
Central European Time, on Friday the 5th,

76
00:03:07.360 --> 00:03:09.760
which is 6:12 on Saturday morning for those

77
00:03:09.760 --> 00:03:12.540
of us in Sydney from Andoya spaceport.

78
00:03:12.860 --> 00:03:15.260
Anna: And Andoya is where exactly?

79
00:03:15.340 --> 00:03:18.220
Anna: Northern Norway. An Island about 300

80
00:03:18.220 --> 00:03:20.860
kilometres inside the Arctic Circle. It's

81
00:03:20.860 --> 00:03:23.500
been a sounding rocket range since 1962,

82
00:03:23.900 --> 00:03:26.340
so there's real heritage there. But this is

83
00:03:26.340 --> 00:03:28.900
its first orbital launch pad and it's a

84
00:03:28.900 --> 00:03:31.780
genuinely useful location. You launch north

85
00:03:31.780 --> 00:03:33.940
over open ocean and you get straight into

86
00:03:33.940 --> 00:03:36.750
polar and sun synchronous orbits, which is

87
00:03:36.750 --> 00:03:38.910
where most Earth observation satellites want

88
00:03:38.910 --> 00:03:39.270
to be.

89
00:03:39.350 --> 00:03:40.550
Anna: Tell me about the rocket.

90
00:03:40.870 --> 00:03:43.630
Anna: Spectrum's a two stage vehicle, about 28

91
00:03:43.630 --> 00:03:46.510
metres tall, 2 metres across. Nine

92
00:03:46.510 --> 00:03:49.070
engines on the first stage, one vacuum

93
00:03:49.070 --> 00:03:51.470
optimised engine on the second. And they're

94
00:03:51.470 --> 00:03:53.910
all the same engine. It's called Aquila and

95
00:03:53.910 --> 00:03:56.430
Isar built it in house. The propellant

96
00:03:56.430 --> 00:03:58.830
combination is the interesting bit. Liquid

97
00:03:58.830 --> 00:04:00.230
oxygen and propane.

98
00:04:00.710 --> 00:04:03.310
Anna: Propane, not kerosene, not

99
00:04:03.310 --> 00:04:05.080
methane, propane.

100
00:04:05.400 --> 00:04:08.280
Anna: It sits between the two, denser than methane,

101
00:04:08.440 --> 00:04:10.800
cleaner burning than kerosene, and you can

102
00:04:10.800 --> 00:04:13.760
buy it anywhere. It's an unusual choice. And

103
00:04:13.760 --> 00:04:16.760
it's theirs. The second stage restarts, which

104
00:04:16.760 --> 00:04:18.960
matters in a minute. And the numbers are

105
00:04:18.960 --> 00:04:21.520
small, launcher numbers. About 700

106
00:04:21.520 --> 00:04:23.760
kilogrammes to sun synchronous orbit out of

107
00:04:23.760 --> 00:04:26.640
Andoya, around a tonne to low Earth orbit, if

108
00:04:26.640 --> 00:04:28.520
they ever fly it from French Guiana.

109
00:04:28.920 --> 00:04:31.320
Anna: So this is not an Ariane competitor?

110
00:04:32.020 --> 00:04:34.420
Anna: Not remotely, and nobody's pretending it is.

111
00:04:34.660 --> 00:04:37.580
Ariane 6 lifts 20 tonnes. This is

112
00:04:37.580 --> 00:04:39.980
the small satellite end of the market. The

113
00:04:39.980 --> 00:04:42.660
rocket lab electron end, roughly. But the

114
00:04:42.660 --> 00:04:45.420
strategic question was never about mass. It

115
00:04:45.420 --> 00:04:47.180
was about whether Europe could do this at

116
00:04:47.180 --> 00:04:49.900
all. From Europe, without asking anyone's

117
00:04:49.900 --> 00:04:50.340
permission.

118
00:04:50.980 --> 00:04:53.060
Anna: Now, this wasn't the first attempt.

119
00:04:53.700 --> 00:04:55.940
Anna: No, and I want to be fair about the first

120
00:04:55.940 --> 00:04:58.936
one. Spectrum's maiden flight was 30

121
00:04:59.077 --> 00:05:01.700
March 2025, from the same pad.

122
00:05:02.020 --> 00:05:05.020
It flew for about 30 seconds, lost attitude

123
00:05:05.020 --> 00:05:07.980
control and came down. The cause was a

124
00:05:07.980 --> 00:05:09.940
vent valve that opened when it shouldn't have

125
00:05:09.940 --> 00:05:12.660
during the pitchover manoeuvre. Isar spent

126
00:05:12.660 --> 00:05:15.300
the time since on software changes and on

127
00:05:15.300 --> 00:05:16.820
widening the vehicle's margins.

128
00:05:17.460 --> 00:05:19.300
Anna: 18 months between flights.

129
00:05:19.780 --> 00:05:22.460
Anna: 18 months and a, uh, run of scrubs this year.

130
00:05:22.460 --> 00:05:25.060
On top of that, a pressurisation valve in

131
00:05:25.060 --> 00:05:27.630
January weather, range issues.

132
00:05:28.270 --> 00:05:29.830
There were people writing them off as

133
00:05:29.830 --> 00:05:32.590
Anna: recently as last week and then Friday night.

134
00:05:32.590 --> 00:05:33.550
It just worked.

135
00:05:33.950 --> 00:05:36.830
Anna: It just worked. Nine engines lit clean.

136
00:05:36.830 --> 00:05:39.470
Ascent stage separation fairing away.

137
00:05:39.710 --> 00:05:41.830
And the second stage put itself into an

138
00:05:41.830 --> 00:05:44.590
elliptical orbit. Roughly 180 by

139
00:05:44.590 --> 00:05:47.190
500 kilometres, then restarted and

140
00:05:47.190 --> 00:05:50.150
circularised. That restart is the thing I'd

141
00:05:50.150 --> 00:05:52.750
point to. A lot of small launchers need a

142
00:05:52.750 --> 00:05:55.380
separate kick stage. To do that. Isar built

143
00:05:55.380 --> 00:05:57.140
the capability into the second stage.

144
00:05:57.620 --> 00:05:58.660
Anna: What was on board?

145
00:05:58.900 --> 00:06:01.740
Anna: Six payloads. And I love this manifest

146
00:06:01.740 --> 00:06:04.740
because it's so unglamorous in the best

147
00:06:04.820 --> 00:06:07.740
way. 5 cubesats from the technical

148
00:06:07.740 --> 00:06:09.740
University of Berlin, from

149
00:06:09.740 --> 00:06:12.540
NTNU in Norway, from the

150
00:06:12.540 --> 00:06:15.460
University of Maribor in Slovenia, from

151
00:06:15.460 --> 00:06:18.380
TU Wien in Austria, and one from

152
00:06:18.380 --> 00:06:21.220
endurosat, which is Bulgarian, plus

153
00:06:21.220 --> 00:06:23.420
a non deployable experiment from a German

154
00:06:23.420 --> 00:06:26.420
company called D Cubed that stayed bolted to

155
00:06:26.420 --> 00:06:28.340
the stage. Universities,

156
00:06:28.980 --> 00:06:31.540
Universities mostly. They're testing things

157
00:06:31.540 --> 00:06:34.060
like radiation tolerant perovskite solar

158
00:06:34.060 --> 00:06:36.260
cells and how batteries cope with being

159
00:06:36.260 --> 00:06:39.180
hibernated in orbit. It is exactly the kind

160
00:06:39.180 --> 00:06:41.060
of payload that has spent the last decade

161
00:06:41.060 --> 00:06:43.340
queuing for a rideshare slot on somebody

162
00:06:43.340 --> 00:06:46.020
else's rocket, on somebody else's schedule.

163
00:06:46.590 --> 00:06:49.150
Anna: So the significance isn't the six satellites,

164
00:06:49.230 --> 00:06:50.350
it's the queue.

165
00:06:50.830 --> 00:06:53.670
Anna: The significance is the cue. And

166
00:06:53.670 --> 00:06:56.230
it's sovereignty, which is a word that's

167
00:06:56.230 --> 00:06:58.590
doing a lot of work in European space policy

168
00:06:58.670 --> 00:07:01.390
Right now. ESA has been running a launcher

169
00:07:01.390 --> 00:07:04.030
challenge specifically to get more than one

170
00:07:04.030 --> 00:07:06.910
European company flying precisely because

171
00:07:06.910 --> 00:07:09.830
relying on a single vehicle or on somebody

172
00:07:09.830 --> 00:07:12.430
else's vehicle turned out to be uncomfortable

173
00:07:12.430 --> 00:07:15.190
when the geopolitics moved. Isar has

174
00:07:15.190 --> 00:07:17.270
raised well north of half a billion euros

175
00:07:17.270 --> 00:07:19.790
against that thesis and their Munich factory

176
00:07:19.790 --> 00:07:22.270
is built for more than 30 vehicles a year.

177
00:07:22.910 --> 00:07:25.790
Anna: Explain the geopolitics bit, because I think

178
00:07:25.790 --> 00:07:27.630
that's the piece people underestimate.

179
00:07:28.190 --> 00:07:30.030
Anna: It's not complicated, it's just

180
00:07:30.109 --> 00:07:32.870
uncomfortable. For years, a good

181
00:07:32.870 --> 00:07:35.390
slice of European payloads flew on Russian

182
00:07:35.390 --> 00:07:38.190
Soyuz rockets, including out of Kourou.

183
00:07:38.510 --> 00:07:41.460
That ended abruptly in 2022 at

184
00:07:41.460 --> 00:07:44.220
almost exactly the same moment Ariane 5

185
00:07:44.220 --> 00:07:46.860
retired and Ariane 6 wasn't ready and

186
00:07:46.860 --> 00:07:49.700
Vega C was grounded after a failure. So

187
00:07:49.700 --> 00:07:51.580
Europe spent a stretch of two or three years

188
00:07:51.580 --> 00:07:53.980
in the strange position of being a first rank

189
00:07:53.980 --> 00:07:56.779
space power that had to buy rides from SpaceX

190
00:07:56.779 --> 00:07:59.340
to launch its own science missions, including

191
00:07:59.500 --> 00:08:01.900
missions it built itself, including

192
00:08:01.980 --> 00:08:04.660
flagship missions it built itself. That was

193
00:08:04.660 --> 00:08:07.140
the wake up. And the response wasn't to build

194
00:08:07.140 --> 00:08:09.940
one bigger rocket, it was to stop having a

195
00:08:09.940 --> 00:08:12.300
single point of failure, which is where a

196
00:08:12.300 --> 00:08:14.580
German startup flying from a Norwegian island

197
00:08:14.580 --> 00:08:17.220
fits in. It's not that spectrum replaces

198
00:08:17.220 --> 00:08:19.660
anything. It's that if you have three or four

199
00:08:19.660 --> 00:08:22.660
independent European ways to reach orbit, no

200
00:08:22.660 --> 00:08:25.340
single failure, retirement or foreign policy

201
00:08:25.420 --> 00:08:27.740
decision can ground the continent again.

202
00:08:28.300 --> 00:08:30.260
Anna: And Norway gets something out of this

203
00:08:30.260 --> 00:08:32.860
Anna: too, Norway gets a great deal out of it.

204
00:08:33.020 --> 00:08:35.830
Andoya Space is majority state owned and.

205
00:08:35.900 --> 00:08:37.940
And Norway has just gone from hosting a

206
00:08:37.940 --> 00:08:40.500
sounding rocket range to hosting the only

207
00:08:40.500 --> 00:08:43.060
orbital launch site on the European mainland

208
00:08:43.060 --> 00:08:45.780
side of the Atlantic. There are two more pads

209
00:08:45.780 --> 00:08:48.060
planned there. If you're a European small

210
00:08:48.060 --> 00:08:50.660
satellite operator, that is suddenly a very

211
00:08:50.660 --> 00:08:52.660
short truck ride compared to shipping your

212
00:08:52.660 --> 00:08:54.140
spacecraft to South America.

213
00:08:54.540 --> 00:08:56.540
Anna: Which they now have to actually deliver.

214
00:08:56.940 --> 00:08:59.460
Anna: Which they now have to actually deliver. And

215
00:08:59.460 --> 00:09:02.310
that's the honest caveat. One successful

216
00:09:02.310 --> 00:09:05.310
flight is one successful flight. Vehicles

217
00:09:05.310 --> 00:09:07.710
three through seven are in production. But

218
00:09:07.710 --> 00:09:10.230
Cadence is where small launchers historically

219
00:09:10.230 --> 00:09:12.590
go to die. Ask anyone who's watched that

220
00:09:12.590 --> 00:09:13.590
market for 10 years.

221
00:09:14.310 --> 00:09:17.110
Anna: Alright, Southern hemisphere angle. I

222
00:09:17.110 --> 00:09:18.150
know you have one.

223
00:09:18.550 --> 00:09:21.390
Anna: I do. And it's close to home because the

224
00:09:21.390 --> 00:09:23.670
storey Isar just wrote is the storey Gilmour

225
00:09:23.670 --> 00:09:25.430
Space is trying to write in Queensland.

226
00:09:25.910 --> 00:09:26.630
Anna: Eris.

227
00:09:27.200 --> 00:09:30.040
Anna: Eris, Australia's first home built

228
00:09:30.040 --> 00:09:32.440
orbital rocket, launched from the Bowen

229
00:09:32.440 --> 00:09:34.560
Orbital Spaceport in July last year.

230
00:09:35.040 --> 00:09:37.840
Flew for 14 seconds and came back down.

231
00:09:38.160 --> 00:09:40.480
Adam Gilmour's line about it afterwards was

232
00:09:40.480 --> 00:09:42.560
that most companies need about three attempts

233
00:09:42.560 --> 00:09:44.680
to make orbit and that they're not going to

234
00:09:44.680 --> 00:09:46.640
give up. He said that at the International

235
00:09:46.800 --> 00:09:49.200
Astronautical Congress in Sydney.

236
00:09:49.520 --> 00:09:52.240
Anna: And Isar's second attempt made orbit

237
00:09:52.320 --> 00:09:52.640
after

238
00:09:52.640 --> 00:09:54.800
Anna: a first flight that lasted 30 seconds.

239
00:09:55.440 --> 00:09:58.320
Gilmour's first lasted 14. That is

240
00:09:58.320 --> 00:10:00.720
not a prediction. Rockets don't work by

241
00:10:00.720 --> 00:10:03.160
analogy. But if you want to know what the

242
00:10:03.160 --> 00:10:05.920
road out of a 14 second flight looks like,

243
00:10:06.160 --> 00:10:08.680
Friday night in Norway is a fairly

244
00:10:08.680 --> 00:10:09.920
encouraging map.

245
00:10:10.320 --> 00:10:12.880
Anna: Same problem, opposite ends of the planet,

246
00:10:13.200 --> 00:10:15.920
Anna: and the same underlying argument. A country

247
00:10:15.920 --> 00:10:18.160
or a continent that can build satellites but

248
00:10:18.160 --> 00:10:20.930
can't launch them is a customer, not a

249
00:10:20.930 --> 00:10:23.770
space power. Norway just stopped being only

250
00:10:23.770 --> 00:10:26.250
a customer. Queensland is trying to

251
00:10:26.730 --> 00:10:27.970
Storey 2 and

252
00:10:27.970 --> 00:10:30.370
Anna: it's a bit of a spoiler for a method a lot of

253
00:10:30.370 --> 00:10:31.530
people were counting on.

254
00:10:32.090 --> 00:10:34.810
Anna, uh, remind everyone what a stellar

255
00:10:34.810 --> 00:10:35.530
stream is.

256
00:10:36.170 --> 00:10:38.970
Anna: So a globular cluster or a small

257
00:10:38.970 --> 00:10:41.530
satellite galaxy falls into the Milky Way

258
00:10:41.690 --> 00:10:44.170
and our galaxy's gravity pulls it apart.

259
00:10:44.650 --> 00:10:47.210
What you're left with is a long, thin ribbon

260
00:10:47.210 --> 00:10:49.730
of stars strung out along the orbit the

261
00:10:49.730 --> 00:10:52.130
cluster used to have. There are dozens of

262
00:10:52.130 --> 00:10:54.890
them wrapped around our galaxy. GD1 is the

263
00:10:54.890 --> 00:10:55.570
famous one.

264
00:10:55.970 --> 00:10:58.010
Anna: And the reason people care is that they're

265
00:10:58.010 --> 00:10:58.610
delicate.

266
00:10:59.010 --> 00:11:01.490
Anna: Exactly. They're the most fragile structures

267
00:11:01.490 --> 00:11:04.450
in the galaxy, which makes them a detector.

268
00:11:04.690 --> 00:11:07.450
The idea has been if a clump of dark matter

269
00:11:07.450 --> 00:11:09.810
drifts through a stream, it gives the ribbon

270
00:11:09.810 --> 00:11:12.650
a gravitational kick and you get a gap or a

271
00:11:12.650 --> 00:11:15.410
kink or a little spur of stars. Flung off to

272
00:11:15.410 --> 00:11:18.300
the side. Find the gaps and you've found dark

273
00:11:18.300 --> 00:11:19.860
matter you cannot otherwise see.

274
00:11:20.420 --> 00:11:21.940
Anna: That's a beautiful idea.

275
00:11:22.340 --> 00:11:24.580
Anna: It's a genuinely beautiful idea. And it's

276
00:11:24.580 --> 00:11:26.460
been the great hope for testing what dark

277
00:11:26.460 --> 00:11:27.780
matter is actually made of.

278
00:11:28.100 --> 00:11:30.020
And this is where the new work comes in.

279
00:11:30.340 --> 00:11:33.100
Arpit Aurora with Nora Shipp and colleagues

280
00:11:33.100 --> 00:11:35.540
at the University of Washington published in

281
00:11:35.540 --> 00:11:37.860
the astrophysical journal on the 27th of

282
00:11:37.860 --> 00:11:40.700
August. They simulated four Milky Way

283
00:11:40.700 --> 00:11:43.200
sized galaxies and inside them

284
00:11:43.440 --> 00:11:45.760
about 15,000 stellar streams

285
00:11:45.920 --> 00:11:48.160
evolving over 5 billion years.

286
00:11:48.880 --> 00:11:49.280
Anna: And.

287
00:11:49.760 --> 00:11:52.320
Anna: And roughly 3/4 of the streams developed

288
00:11:52.320 --> 00:11:54.720
gaps, spurs or kinks.

289
00:11:55.040 --> 00:11:57.200
Only about 70 of the 15,000

290
00:11:57.600 --> 00:12:00.480
stayed genuinely smooth from dark matter

291
00:12:00.480 --> 00:12:03.040
clumps. That's the point. No,

292
00:12:03.360 --> 00:12:05.760
from the galaxy itself. The bar in the

293
00:12:05.760 --> 00:12:08.510
middle, the disc, the spiral arms, the

294
00:12:08.510 --> 00:12:11.270
ordinary visible furniture of a spiral galaxy

295
00:12:11.270 --> 00:12:13.670
is enough to chew up a stellar stream all on

296
00:12:13.670 --> 00:12:16.350
its own. Aurora's line is that in their

297
00:12:16.350 --> 00:12:19.030
simulations the host galaxies alone

298
00:12:19.030 --> 00:12:21.350
cause the same kinds of irregularities we

299
00:12:21.350 --> 00:12:23.150
actually observe in real streams.

300
00:12:23.630 --> 00:12:25.630
Anna: So a, uh, gap is not evidence.

301
00:12:26.270 --> 00:12:29.230
Anna: A gap on its own is not evidence.

302
00:12:29.710 --> 00:12:31.590
And they found the effect is worst for

303
00:12:31.590 --> 00:12:33.710
streams that formed closer to the galactic

304
00:12:33.710 --> 00:12:36.090
centre, which is where a lot of the observed

305
00:12:36.090 --> 00:12:38.650
ones are. Their honest conclusion is that at

306
00:12:38.650 --> 00:12:40.650
present we cannot tell you what made any

307
00:12:40.650 --> 00:12:41.650
particular gap.

308
00:12:41.890 --> 00:12:43.570
Anna: Is that the end of the method?

309
00:12:43.970 --> 00:12:46.410
Anna: No, and this is why I like the paper. Rather

310
00:12:46.410 --> 00:12:48.490
than finding it depressing. It's a

311
00:12:48.490 --> 00:12:50.610
recalibration, not a demolition.

312
00:12:51.250 --> 00:12:53.290
What it says is that you can't do this one

313
00:12:53.290 --> 00:12:55.290
stream at a time. You need the whole

314
00:12:55.290 --> 00:12:57.890
population statistically, how many gaps,

315
00:12:58.290 --> 00:13:01.180
how deep distributed how compared

316
00:13:01.180 --> 00:13:03.020
against simulations with dark matter and

317
00:13:03.020 --> 00:13:03.300
without,

318
00:13:03.700 --> 00:13:06.180
Anna: which needs a lot more streams and

319
00:13:06.180 --> 00:13:08.260
Anna: much better motions for the stars in them.

320
00:13:08.740 --> 00:13:10.700
That is more or less a job description for

321
00:13:10.700 --> 00:13:13.660
the Vera Rubin Observatory in Chile, which

322
00:13:13.660 --> 00:13:16.619
is going to find streams by the dozen. And

323
00:13:16.619 --> 00:13:19.060
for the next Gaia class, astrometry.

324
00:13:19.460 --> 00:13:22.180
So the tool isn't broken, it just turns out

325
00:13:22.180 --> 00:13:24.540
to need a much bigger sample before it tells

326
00:13:24.540 --> 00:13:25.140
the truth.

327
00:13:26.670 --> 00:13:29.190
Alright, moving on. And Storey 3 is one of my

328
00:13:29.190 --> 00:13:32.190
favourite kinds of result. An object we

329
00:13:32.190 --> 00:13:34.710
already knew about that just did something we

330
00:13:34.710 --> 00:13:35.310
could measure.

331
00:13:35.470 --> 00:13:36.590
Anna: Give me the object.

332
00:13:36.990 --> 00:13:39.230
Anna: It has a name only a catalogue could love.

333
00:13:39.710 --> 00:13:41.390
Erasu J

334
00:13:41.390 --> 00:13:44.162
060-8395

335
00:13:44.778 --> 00:13:47.550
-704014.

336
00:13:47.950 --> 00:13:50.270
We'll call it J0608.

337
00:13:50.750 --> 00:13:53.410
It's two white dwarfs orbiting each other and

338
00:13:53.410 --> 00:13:55.890
the orbital period is 374

339
00:13:55.890 --> 00:13:56.490
seconds.

340
00:13:57.050 --> 00:13:59.290
Anna: 374 seconds.

341
00:13:59.690 --> 00:14:01.210
That's six minutes and change.

342
00:14:01.930 --> 00:14:04.690
Anna: Six minutes and 14 seconds. A complete

343
00:14:04.690 --> 00:14:07.410
year for that pair in the Time it takes to

344
00:14:07.410 --> 00:14:10.290
boil an egg badly. The whole system would fit

345
00:14:10.290 --> 00:14:11.610
comfortably inside our sun.

346
00:14:12.170 --> 00:14:13.210
Anna: How was it found?

347
00:14:13.610 --> 00:14:16.610
Anna: By Erosita, the German X ray telescope

348
00:14:16.610 --> 00:14:19.540
on the Spectre RG spacecraft. During its all

349
00:14:19.540 --> 00:14:22.500
sky surveys, it showed up as an X ray Source,

350
00:14:22.500 --> 00:14:25.220
pulsing every 374 seconds.

351
00:14:25.380 --> 00:14:28.220
And the pulsing is dramatic. The flux

352
00:14:28.220 --> 00:14:30.940
goes to essentially zero and back about

353
00:14:30.940 --> 00:14:33.300
50% on, 50% off.

354
00:14:33.860 --> 00:14:36.860
Then XMM Newton followed up in X rays and

355
00:14:36.860 --> 00:14:39.220
the Dark Energy Camera in Chile picked it up

356
00:14:39.220 --> 00:14:39.700
optically.

357
00:14:40.260 --> 00:14:41.540
Anna: So what's new this week?

358
00:14:42.020 --> 00:14:44.140
Anna: This week Rahul Sharma and colleagues

359
00:14:44.140 --> 00:14:45.740
published in the Astrophysical Journal

360
00:14:45.740 --> 00:14:47.990
Letters. And what they've measured is that

361
00:14:47.990 --> 00:14:50.430
the orbit is shrinking measurably.

362
00:14:50.990 --> 00:14:52.950
And the rate at which it's shrinking matches

363
00:14:52.950 --> 00:14:55.430
what general relativity says it should be if

364
00:14:55.430 --> 00:14:58.070
the system is radiating away energy as

365
00:14:58.070 --> 00:14:59.150
gravitational waves.

366
00:14:59.790 --> 00:15:02.309
Anna: So we're watching gravitational waves carry

367
00:15:02.309 --> 00:15:04.630
energy off using an X ray

368
00:15:04.630 --> 00:15:05.310
telescope.

369
00:15:05.390 --> 00:15:07.590
Anna: That's precisely what's happening. And I

370
00:15:07.590 --> 00:15:09.670
think it's a lovely thing. We're not

371
00:15:09.670 --> 00:15:12.110
detecting the waves, we're watching the bill

372
00:15:12.110 --> 00:15:14.980
being paid. The energy leaves as

373
00:15:14.980 --> 00:15:17.660
gravitational radiation. The orbit

374
00:15:17.660 --> 00:15:20.220
tightens, the clock speeds up and you can

375
00:15:20.220 --> 00:15:20.700
time it.

376
00:15:21.020 --> 00:15:23.180
Anna: Which makes it useful to Lisa.

377
00:15:23.500 --> 00:15:26.140
Anna: Which makes it very useful to Lisa,

378
00:15:26.460 --> 00:15:28.620
the Space Based Gravitational Wave

379
00:15:28.620 --> 00:15:30.820
Observatory ESA is flying in the

380
00:15:30.820 --> 00:15:33.780
mid-2030s. Lisa is tuned to

381
00:15:33.780 --> 00:15:36.660
low frequencies and tight binaries like

382
00:15:36.660 --> 00:15:39.550
this sit right in its band. The chirp

383
00:15:39.550 --> 00:15:42.190
mass here works out to about 0.43

384
00:15:42.190 --> 00:15:44.030
solar masses, which makes

385
00:15:44.030 --> 00:15:46.510
J0608 one of the

386
00:15:46.510 --> 00:15:48.710
loudest known verification binaries,

387
00:15:49.270 --> 00:15:51.190
a source we already know the position and

388
00:15:51.190 --> 00:15:54.030
period of. So when LISA switches on, it

389
00:15:54.030 --> 00:15:56.950
should hear it. If it doesn't, something is

390
00:15:56.950 --> 00:15:59.350
wrong with the instrument, not the universe.

391
00:15:59.750 --> 00:16:01.030
Anna: A tuning fork.

392
00:16:01.430 --> 00:16:03.430
Anna: A tuning fork you build the observatory

393
00:16:03.430 --> 00:16:05.700
around. And here's our bit.

394
00:16:06.100 --> 00:16:09.020
J0608 sits at declination

395
00:16:09.020 --> 00:16:12.020
minus 70. It's in the direction of the Large

396
00:16:12.100 --> 00:16:15.020
Magellanic Cloud in front of it in our

397
00:16:15.020 --> 00:16:18.020
own galaxy's halo, somewhere between 1 and

398
00:16:18.020 --> 00:16:20.940
5 kiloparsecs out, which means it is

399
00:16:20.940 --> 00:16:23.860
a southern hemisphere object. It never rises

400
00:16:23.860 --> 00:16:26.460
for most of Europe and North America. It was

401
00:16:26.460 --> 00:16:28.780
found by an all sky survey confirmed from

402
00:16:28.780 --> 00:16:31.060
Chile. And if you're listening in Sydney or

403
00:16:31.060 --> 00:16:33.580
uh, Auckland or Cape Town, it is over your

404
00:16:33.580 --> 00:16:34.900
head and nobody else's.

405
00:16:35.460 --> 00:16:38.420
Anna: Storey 4 takes us to Venus and it picks

406
00:16:38.420 --> 00:16:41.300
up a thread. We were on last week, it does.

407
00:16:41.860 --> 00:16:43.940
Anna: On Friday we talked about the Venus Life

408
00:16:43.940 --> 00:16:46.900
Finder mission. MIT and Rocket Lab,

409
00:16:46.980 --> 00:16:49.020
the first privately funded mission to another

410
00:16:49.020 --> 00:16:51.500
planet, which is built and waiting on

411
00:16:51.500 --> 00:16:53.660
Neutron's first flight. This is the

412
00:16:53.660 --> 00:16:55.820
laboratory half of that storey and it lands

413
00:16:55.820 --> 00:16:56.500
very nicely.

414
00:16:56.900 --> 00:16:58.180
Anna: Sara Seeger again.

415
00:16:58.760 --> 00:17:01.120
Anna: Sarah Seager's group at mit, published in the

416
00:17:01.120 --> 00:17:02.960
Proceedings of the National Academy of

417
00:17:02.960 --> 00:17:05.800
sciences released on 31 August.

418
00:17:06.440 --> 00:17:09.320
Here's the setup. Venus's cloud deck at

419
00:17:09.320 --> 00:17:12.280
48 to 60 kilometres up has Earth like

420
00:17:12.280 --> 00:17:14.680
temperatures and pressures. It's the one

421
00:17:14.680 --> 00:17:17.280
genuinely temperate place on the planet. The

422
00:17:17.280 --> 00:17:19.240
problem is that the droplets up there are

423
00:17:19.240 --> 00:17:21.840
concentrated sulfuric acid, which we

424
00:17:21.840 --> 00:17:24.600
assume destroys everything and specifically

425
00:17:24.600 --> 00:17:27.540
destroys the molecules life needs. So the

426
00:17:27.540 --> 00:17:30.100
team took peptides, short chains of amino

427
00:17:30.100 --> 00:17:32.220
acids, the building blocks that fold into

428
00:17:32.220 --> 00:17:34.540
proteins, put three of them into

429
00:17:34.620 --> 00:17:37.540
98% sulfuric acid and watched

430
00:17:37.540 --> 00:17:39.980
them with nuclear magnetic resonance and they

431
00:17:39.980 --> 00:17:42.620
survived. They did better than survive.

432
00:17:42.779 --> 00:17:45.620
They folded, they took up stable, well

433
00:17:45.620 --> 00:17:48.340
defined three dimensional structures and held

434
00:17:48.340 --> 00:17:51.100
them for weeks. And the folding is the part

435
00:17:51.100 --> 00:17:53.230
that matters because. Because a protein that

436
00:17:53.230 --> 00:17:55.750
isn't folded correctly is just a string.

437
00:17:56.150 --> 00:17:58.230
Seeger's framing is that life needs

438
00:17:58.230 --> 00:18:00.830
specifically shaped proteins so they have a

439
00:18:00.830 --> 00:18:03.390
target they can latch onto. Shape is

440
00:18:03.390 --> 00:18:03.910
function.

441
00:18:04.310 --> 00:18:06.150
Anna: Why does the acid not shred them?

442
00:18:06.310 --> 00:18:09.150
Anna: Because there's no water. Our intuition about

443
00:18:09.150 --> 00:18:11.430
acid is really an intuition about acid

444
00:18:11.430 --> 00:18:13.990
dissolved in water. Take the water out

445
00:18:14.150 --> 00:18:16.310
and the chemistry is a different animal.

446
00:18:16.870 --> 00:18:19.390
Concentrated sulfuric acid turns out to be a

447
00:18:19.390 --> 00:18:21.590
solvent that some molecules can be perfectly

448
00:18:21.590 --> 00:18:22.390
comfortable in.

449
00:18:23.300 --> 00:18:26.220
Anna: Now the caveat, because I can hear you

450
00:18:26.220 --> 00:18:28.300
winding up to one, you know

451
00:18:28.300 --> 00:18:31.140
Anna: me too well, this is not life on Venus.

452
00:18:31.380 --> 00:18:33.780
It is not evidence of life on Venus.

453
00:18:34.020 --> 00:18:36.620
Nobody in that group is claiming it is. What

454
00:18:36.620 --> 00:18:39.300
it removes is an objection. The standard

455
00:18:39.300 --> 00:18:41.700
reply to Venus cloud habitability was always

456
00:18:42.020 --> 00:18:44.500
the biochemistry simply cannot hold together

457
00:18:44.500 --> 00:18:47.220
in that environment. This says for one

458
00:18:47.220 --> 00:18:49.540
important class of molecule and it can.

459
00:18:50.020 --> 00:18:52.180
That's a smaller claim and it's a much

460
00:18:52.180 --> 00:18:53.060
sturdier one.

461
00:18:53.540 --> 00:18:55.500
Anna: And it's the sort of thing you'd want to know

462
00:18:55.500 --> 00:18:57.540
before you spend money going there.

463
00:18:57.940 --> 00:18:59.940
Anna: It's exactly the sort of thing you'd want to

464
00:18:59.940 --> 00:19:02.340
know before you go. Which is why the timing

465
00:19:02.340 --> 00:19:04.740
is neat. The mission is sitting on the ground

466
00:19:04.819 --> 00:19:07.460
waiting for a rocket and the case for flying

467
00:19:07.460 --> 00:19:08.740
it just got firmer.

468
00:19:08.820 --> 00:19:11.620
Next storey five is here today because you

469
00:19:11.620 --> 00:19:14.220
asked for it. We've had a run of messages

470
00:19:14.220 --> 00:19:16.760
through the website about link, what happened

471
00:19:16.760 --> 00:19:19.720
to it, what it's doing now and whether Swift

472
00:19:19.720 --> 00:19:22.000
is going to be alright. So let's do the whole

473
00:19:22.000 --> 00:19:22.680
thing properly.

474
00:19:22.760 --> 00:19:24.880
Anna: Start at the beginning. For anyone joining us

475
00:19:24.880 --> 00:19:26.120
late, the Neil

476
00:19:26.120 --> 00:19:28.720
Anna: Garrels Swift Observatory has been NASA's

477
00:19:28.720 --> 00:19:31.160
Rapid Response Gamma Ray Burst telescope

478
00:19:31.240 --> 00:19:34.200
since 2004. Brilliant machine,

479
00:19:34.600 --> 00:19:37.160
22 years of service and one design

480
00:19:37.160 --> 00:19:39.960
limitation, no propulsion, it

481
00:19:39.960 --> 00:19:42.330
cannot raise its own orbit. It launched at

482
00:19:42.330 --> 00:19:45.210
around 600 kilometres and atmospheric drag

483
00:19:45.210 --> 00:19:47.250
has been quietly walking it down ever since.

484
00:19:47.890 --> 00:19:50.610
It's near 400 kilometres now and without

485
00:19:50.610 --> 00:19:52.210
help it re enters.

486
00:19:52.690 --> 00:19:54.130
Anna: So NASA hired someone.

487
00:19:54.690 --> 00:19:57.689
Anna: In September last year, NASA gave Catalyst

488
00:19:57.689 --> 00:20:00.370
Space technologies a uh, $30 million contract

489
00:20:00.450 --> 00:20:03.250
to build a spacecraft, fly it up, grab

490
00:20:03.250 --> 00:20:06.130
Swift and push it higher. That Spacecraft is

491
00:20:06.130 --> 00:20:08.860
linked 425 kilogrammes,

492
00:20:08.940 --> 00:20:11.900
three robotic arms, hall effect thrusters

493
00:20:12.220 --> 00:20:14.980
six metres across when it's deployed. It

494
00:20:14.980 --> 00:20:17.660
launched on 3 July this year on a Pegasus

495
00:20:17.660 --> 00:20:19.340
XL Air launched out

496
00:20:19.340 --> 00:20:22.260
Anna: of Kwajalein Atoll, which was itself

497
00:20:22.260 --> 00:20:25.060
a storey Pegasus hadn't flown in

498
00:20:25.060 --> 00:20:25.420
years.

499
00:20:26.060 --> 00:20:28.460
Anna: Dusted off specially and then

500
00:20:28.860 --> 00:20:31.220
three weeks after launch, on the 25th of

501
00:20:31.220 --> 00:20:34.100
July, link lost attitude control and started

502
00:20:34.100 --> 00:20:36.860
tumbling. When they worked out why it

503
00:20:36.860 --> 00:20:39.860
wasn't good, two of its three reaction wheels

504
00:20:39.860 --> 00:20:42.180
weren't working and the cold gas thruster

505
00:20:42.180 --> 00:20:43.580
system was degraded as well.

506
00:20:44.060 --> 00:20:45.340
Anna: Tumbling. How fast?

507
00:20:45.500 --> 00:20:48.140
Anna: About 9 degrees a second multi

508
00:20:48.140 --> 00:20:50.380
axis, which is fast enough that

509
00:20:50.380 --> 00:20:52.980
communications were dropping in and out. What

510
00:20:52.980 --> 00:20:55.420
the Catalyst team then did is the part of

511
00:20:55.420 --> 00:20:58.380
this storey I genuinely admire. They

512
00:20:58.380 --> 00:21:00.700
used the electric thrusters, which were never

513
00:21:00.700 --> 00:21:03.020
designed for attitude control, to take the

514
00:21:03.020 --> 00:21:05.860
spin down. By 5 August they

515
00:21:05.860 --> 00:21:08.420
had it to 1.47 degrees a second

516
00:21:08.660 --> 00:21:11.340
and then uploaded new flight software with

517
00:21:11.340 --> 00:21:13.660
attitude controllers written for a spacecraft

518
00:21:13.660 --> 00:21:15.380
that had lost half its hardware.

519
00:21:15.780 --> 00:21:17.700
Anna: But they didn't go for the capture

520
00:21:18.180 --> 00:21:20.300
Anna: on the 19th of August they stood down from

521
00:21:20.300 --> 00:21:22.100
it. And that was the right call.

522
00:21:22.740 --> 00:21:25.500
Docking with a tumbling, uncontrolled 22 year

523
00:21:25.500 --> 00:21:28.260
old telescope using a spacecraft that has

524
00:21:28.260 --> 00:21:31.250
itself lost most of its attitude control is a

525
00:21:31.250 --> 00:21:32.930
way to make one problem into two.

526
00:21:33.490 --> 00:21:36.410
Anna: So where does that leave Swift doing science?

527
00:21:36.410 --> 00:21:39.410
Anna: Actually, Swift restarted two of its three

528
00:21:39.410 --> 00:21:42.170
instruments on 26 August and it's

529
00:21:42.170 --> 00:21:44.690
observing, it's just observing on a clock.

530
00:21:44.930 --> 00:21:46.450
It comes down when it comes down

531
00:21:47.010 --> 00:21:49.970
Anna: and Link, this is what people are asking.

532
00:21:50.370 --> 00:21:53.050
Anna: This is the fresh part from NASA's Swift blog

533
00:21:53.050 --> 00:21:55.970
on Friday. Link has raised its own orbit.

534
00:21:56.050 --> 00:21:58.210
It has adjusted its plane to match Swift's.

535
00:21:58.760 --> 00:22:01.200
It has closed to within 12 to 15 kilometres

536
00:22:01.200 --> 00:22:03.840
of the telescope and it is deliberately going

537
00:22:03.840 --> 00:22:06.720
no closer. And in the last few days it has

538
00:22:06.720 --> 00:22:08.680
deployed all three robotic arms

539
00:22:08.680 --> 00:22:11.480
simultaneously and fired all three xenon

540
00:22:11.480 --> 00:22:12.440
thrusters at once.

541
00:22:13.160 --> 00:22:15.400
Anna: So it's running the mission it can run.

542
00:22:15.960 --> 00:22:18.040
Anna: Every one of those is a real in space

543
00:22:18.040 --> 00:22:20.160
servicing test that nobody had data on

544
00:22:20.160 --> 00:22:22.920
before, performed by a damaged spacecraft.

545
00:22:23.160 --> 00:22:25.400
And NASA's framing is that they're collecting

546
00:22:25.400 --> 00:22:27.640
data to inform future servicing technology

547
00:22:27.720 --> 00:22:30.620
and operations. Catalyst Reckon Link

548
00:22:30.620 --> 00:22:32.660
has about two to three more weeks in orbit

549
00:22:32.660 --> 00:22:34.940
before they deorbit it, which is a, ah,

550
00:22:35.060 --> 00:22:35.860
genuinely

551
00:22:35.860 --> 00:22:37.900
Anna: different ending to the one we expected.

552
00:22:38.700 --> 00:22:40.940
Anna: It's uh, a much better ending than it broke.

553
00:22:41.100 --> 00:22:44.060
The rescue failed, the demonstration didn't.

554
00:22:44.060 --> 00:22:46.260
And in space servicing is a field where

555
00:22:46.260 --> 00:22:48.740
almost nobody has flown anything. So a

556
00:22:48.740 --> 00:22:51.060
fortnight of hard data from a wounded vehicle

557
00:22:51.060 --> 00:22:53.580
is worth having. Keep the questions coming.

558
00:22:53.900 --> 00:22:55.780
That's what got this segment into today's

559
00:22:55.780 --> 00:22:56.300
episode.

560
00:22:56.890 --> 00:22:59.130
Anna: And that brings us to the sky for the week

561
00:22:59.130 --> 00:23:01.970
ahead. Anna, uh, this is a dark

562
00:23:01.970 --> 00:23:02.330
week.

563
00:23:02.810 --> 00:23:05.370
Anna: It's a dark week and that's the headline.

564
00:23:05.770 --> 00:23:08.570
New Moon is on Friday the 11th at about 3:30

565
00:23:08.570 --> 00:23:10.770
in the morning Greenwich time. So that's

566
00:23:10.770 --> 00:23:13.290
early Friday afternoon in Sydney and Thursday

567
00:23:13.290 --> 00:23:15.970
evening across North America, which means

568
00:23:15.970 --> 00:23:18.010
from about Tuesday right through to next

569
00:23:18.010 --> 00:23:20.410
Monday you have properly dark skies.

570
00:23:20.890 --> 00:23:22.690
If you have been waiting for a night to go

571
00:23:22.690 --> 00:23:25.410
somewhere without streetlights, this is the

572
00:23:25.410 --> 00:23:25.690
week.

573
00:23:26.170 --> 00:23:28.250
Anna: But before the dark, there's an event

574
00:23:28.250 --> 00:23:31.130
tomorrow and this one comes with a warning.

575
00:23:31.290 --> 00:23:34.090
Anna: It does, and I want to do the warning first.

576
00:23:34.650 --> 00:23:37.290
Tomorrow, 8th September, the

577
00:23:37.290 --> 00:23:40.289
moon passes in front of Jupiter. And for

578
00:23:40.289 --> 00:23:42.410
most of the places that can see it, this

579
00:23:42.410 --> 00:23:44.890
happens in broad daylight. That's parts of

580
00:23:44.890 --> 00:23:47.530
the United States, Canada, Greenland,

581
00:23:48.010 --> 00:23:50.170
eastern Russia and the North Pacific.

582
00:23:51.230 --> 00:23:53.310
Anna: Daylight with the sun in the sky.

583
00:23:53.790 --> 00:23:56.550
Anna: Daylight with the sun in the sky. And that is

584
00:23:56.550 --> 00:23:59.190
the whole safety issue. You will be sweeping

585
00:23:59.190 --> 00:24:01.910
around with binoculars or a telescope looking

586
00:24:01.910 --> 00:24:04.710
for a thin moon in a bright blue sky. And

587
00:24:04.710 --> 00:24:07.710
the sun is not far away. Never

588
00:24:07.790 --> 00:24:10.630
point any optical instrument at or near the

589
00:24:10.630 --> 00:24:13.150
sun. If you want to look at the sun at any

590
00:24:13.150 --> 00:24:15.670
point, you need a proper solar filter that

591
00:24:15.670 --> 00:24:16.750
meets the ISO

592
00:24:16.750 --> 00:24:19.470
123122 standard

593
00:24:19.890 --> 00:24:22.170
fitted over the front of the instrument, not

594
00:24:22.170 --> 00:24:24.530
a filter that screws into the eyepiece. And

595
00:24:24.530 --> 00:24:27.490
not sunglasses, welding glass, exposed film

596
00:24:27.650 --> 00:24:30.650
or a smoked plate. If you are not completely

597
00:24:30.650 --> 00:24:32.730
certain what you are pointing at, put the

598
00:24:32.730 --> 00:24:35.530
equipment down. An eclipse style pair of

599
00:24:35.530 --> 00:24:38.330
ISO 123122

600
00:24:38.330 --> 00:24:40.650
glasses will not protect you when you are

601
00:24:40.650 --> 00:24:43.290
looking through magnifying optics either. The

602
00:24:43.290 --> 00:24:45.880
safe way to do a daytime occultation is, is

603
00:24:45.880 --> 00:24:47.880
to set up in the shadow of a building so the

604
00:24:47.880 --> 00:24:50.440
sun is physically blocked and to know your

605
00:24:50.440 --> 00:24:52.080
Moon's position before you start.

606
00:24:52.800 --> 00:24:54.880
Anna: That said, if you do it safely,

607
00:24:54.960 --> 00:24:57.880
Anna: it's spectacular, it's genuinely

608
00:24:57.880 --> 00:25:00.560
wonderful. Jupiter is a tiny bright

609
00:25:00.560 --> 00:25:03.080
disc and you watch it wink out behind the

610
00:25:03.080 --> 00:25:05.400
Moon's limb and then reappear on the other

611
00:25:05.400 --> 00:25:08.400
side. Cheque the exact timings for your town

612
00:25:08.800 --> 00:25:11.000
because they vary enormously across that

613
00:25:11.000 --> 00:25:11.600
footprint.

614
00:25:12.290 --> 00:25:15.290
Anna: Right. Planets Southern hemisphere first this

615
00:25:15.290 --> 00:25:15.650
week.

616
00:25:16.050 --> 00:25:18.730
Anna: For those of us down south, Venus is the one

617
00:25:18.730 --> 00:25:21.730
to catch, and there's urgency. It's low

618
00:25:21.730 --> 00:25:24.370
in the west after sunset and sinking, but

619
00:25:24.370 --> 00:25:26.570
it's brilliant and it's building toward

620
00:25:26.570 --> 00:25:29.570
Greatest Brilliancy on 18 September at

621
00:25:29.570 --> 00:25:32.570
magnitude -4.8. Find a

622
00:25:32.570 --> 00:25:35.570
clear western horizon. Look about 20 to 30

623
00:25:35.570 --> 00:25:38.340
minutes after sunset from Sydney. That's

624
00:25:38.340 --> 00:25:39.980
around a quarter past six this week.

625
00:25:40.460 --> 00:25:41.500
Anna: And Saturn?

626
00:25:41.980 --> 00:25:44.220
Anna: Saturn is the evening planet for everybody.

627
00:25:44.540 --> 00:25:47.020
It rises in the east not long after dark, and

628
00:25:47.020 --> 00:25:49.580
it's up all night climbing toward opposition

629
00:25:49.580 --> 00:25:52.100
on the 4th of October. So it gets better

630
00:25:52.100 --> 00:25:54.940
every week between now and then. Even a small

631
00:25:54.940 --> 00:25:57.380
telescope will show you the rings and they're

632
00:25:57.380 --> 00:25:59.140
opening back up after the ring plane

633
00:25:59.140 --> 00:26:01.100
crossing, so there's something to see again.

634
00:26:01.740 --> 00:26:03.900
Anna: Anything else worth being outside for down

635
00:26:03.900 --> 00:26:04.220
here?

636
00:26:04.760 --> 00:26:07.360
Anna: The galactic core. It's still high in the

637
00:26:07.360 --> 00:26:09.280
early evening through September from southern

638
00:26:09.280 --> 00:26:11.720
latitudes. And with a new moon on Friday,

639
00:26:12.040 --> 00:26:14.160
you're getting the last really good look at

640
00:26:14.160 --> 00:26:16.040
it for this year before it slides west.

641
00:26:16.600 --> 00:26:19.480
Sagittarius and Scorpius overhead. Dark

642
00:26:19.480 --> 00:26:21.640
sky, no moon. Take the drive.

643
00:26:22.200 --> 00:26:25.160
Northern hemisphere northerners, your planets

644
00:26:25.160 --> 00:26:27.920
are in the morning. Mars and Jupiter are both

645
00:26:27.920 --> 00:26:30.850
well placed before dawn. Jupiter especially.

646
00:26:30.930 --> 00:26:33.170
And it's the same Jupiter the Moon covers

647
00:26:33.170 --> 00:26:35.930
tomorrow. Saturn is the same good evening

648
00:26:35.930 --> 00:26:38.410
object. It is everywhere. Venus is a much

649
00:26:38.410 --> 00:26:40.890
harder catch from the north this month. It's

650
00:26:40.890 --> 00:26:43.810
very low. There's also a minor meteor shower,

651
00:26:43.970 --> 00:26:46.850
the September Epsilon Perseids, peaking

652
00:26:46.850 --> 00:26:49.530
on the 9th at maybe 8 an hour under perfect

653
00:26:49.530 --> 00:26:51.570
skies. Northern favoured

654
00:26:52.130 --> 00:26:54.810
modest, but it's a dark week, so you may as

655
00:26:54.810 --> 00:26:55.410
well look up.

656
00:26:56.300 --> 00:26:58.820
Anna: And one to diarize, one to

657
00:26:58.820 --> 00:26:59.660
diarize.

658
00:26:59.900 --> 00:27:02.620
Anna: On the 14th, the moon occults Venus,

659
00:27:02.860 --> 00:27:05.820
and that one's for Europe, Africa, the Middle

660
00:27:05.820 --> 00:27:08.780
east and southern and Southeast Asia. If

661
00:27:08.780 --> 00:27:11.340
that's you, look it up now. It's the better

662
00:27:11.340 --> 00:27:13.700
of the two occultations this week, and the

663
00:27:13.700 --> 00:27:15.420
same daylight safety rules apply.

664
00:27:16.140 --> 00:27:18.540
Anna: And that's Astronomy daily from Monday

665
00:27:18.540 --> 00:27:19.380
7th

666
00:27:19.380 --> 00:27:22.140
Anna: September, a rocket from an Arctic island

667
00:27:22.140 --> 00:27:24.100
that made Europe a launching continent for

668
00:27:24.100 --> 00:27:26.890
the first time. A dark matter detector that

669
00:27:26.890 --> 00:27:28.650
turned out to be detecting the galaxy

670
00:27:28.650 --> 00:27:31.490
instead. Two white dwarfs six minutes

671
00:27:31.490 --> 00:27:33.810
apart, paying their bill in gravitational

672
00:27:33.810 --> 00:27:35.770
waves over southern skies,

673
00:27:36.250 --> 00:27:39.210
Peptides folding in acid and a broken

674
00:27:39.210 --> 00:27:40.810
repair robot doing good science.

675
00:27:40.810 --> 00:27:43.770
Anna: Anyway, not a bad Monday. If

676
00:27:43.770 --> 00:27:46.090
you want the links to every paper and release

677
00:27:46.090 --> 00:27:48.370
we've talked about, they're all in the show

678
00:27:48.370 --> 00:27:49.930
notes and on the website.

679
00:27:50.660 --> 00:27:53.300
Anna: That's astronomydaily IO. The full back

680
00:27:53.300 --> 00:27:55.260
catalogue is there, along with the newsletter

681
00:27:55.260 --> 00:27:57.620
if you'd like this in your inbox and there's

682
00:27:57.620 --> 00:28:00.060
a contact form, which is how the link segment

683
00:28:00.060 --> 00:28:01.860
happened today. So it does work.

684
00:28:02.340 --> 00:28:05.300
Anna: You'll find us on X at astrodaily Pod

685
00:28:05.460 --> 00:28:08.460
and wherever you get your podcasts, if

686
00:28:08.460 --> 00:28:10.980
you've got a minute. A, uh, rating helps more

687
00:28:10.980 --> 00:28:12.660
people find us than you'd think.

688
00:28:12.980 --> 00:28:15.860
Anna: We're back tomorrow. Until then, clear skies.

689
00:28:15.860 --> 00:28:17.500
And if you're anywhere with a dark one this

690
00:28:17.500 --> 00:28:18.740
week, use it.

691
00:28:19.140 --> 00:28:22.060
Anna: And remember, keep looking up. You

692
00:28:22.060 --> 00:28:24.020
just never know what you might see.

693
00:28:44.030 --> 00:28:44.430
Anna: We told.

694
00:28:51.070 --> 00:28:52.270
Anna: Storeys. We told.

695
00:28:59.070 --> 00:29:00.030
Storeys to.

696
00:29:07.630 --> 00:29:08.030
To

697
00:29:11.370 --> 00:29:11.390
Anna: m.