The Colour of Empty Space

WEBVTT

0
00:00:00.000 --> 00:00:02.880
Anna: Picture the emptiest m place you can imagine.

1
00:00:03.200 --> 00:00:05.840
No stars, no dust, not a

2
00:00:05.840 --> 00:00:08.800
single atom. Now switch off the light

3
00:00:09.120 --> 00:00:11.720
and empty space still isn't

4
00:00:11.720 --> 00:00:14.240
empty. It seethes with particles that

5
00:00:14.240 --> 00:00:17.080
flicker into being and vanish again faster

6
00:00:17.080 --> 00:00:19.840
than any clock can catch them. For 90

7
00:00:20.000 --> 00:00:22.120
years, that's been a prediction on a

8
00:00:22.120 --> 00:00:24.960
chalkboard. This week, a dead star

9
00:00:24.960 --> 00:00:27.800
with an absurd magnetic field may have let

10
00:00:27.800 --> 00:00:30.760
us see it by bending starlight through the

11
00:00:30.760 --> 00:00:33.700
vacuum itself. G' day and welcome

12
00:00:33.700 --> 00:00:36.180
to Astronomy Daily. I'm Anna.

13
00:00:36.260 --> 00:00:38.640
Avery: And I'm avery. It's Friday 7th

14
00:00:38.786 --> 00:00:41.780
August 2026, and there is a lot of very good

15
00:00:41.780 --> 00:00:42.660
sky ahead of us.

16
00:00:42.980 --> 00:00:45.660
Anna: There is coming up, NASA

17
00:00:45.660 --> 00:00:48.180
rummages through the parts bin of a canceled

18
00:00:48.180 --> 00:00:50.660
space station to help build a moon base.

19
00:00:50.900 --> 00:00:53.620
Avery: Blue Origin finally says what blew up its big

20
00:00:53.620 --> 00:00:56.580
rocket back in May. And a plucky little robot

21
00:00:56.580 --> 00:00:58.540
fights the stop spinning long enough to

22
00:00:58.540 --> 00:01:00.580
rescue a beloved NASA telescope.

23
00:01:00.960 --> 00:01:03.080
Anna: And we finish where the whole world is

24
00:01:03.080 --> 00:01:05.960
looking next week, the total solar eclipse on

25
00:01:05.960 --> 00:01:08.920
the 12th paired with the best Perseids in

26
00:01:08.920 --> 00:01:11.800
years, both hemispheres and the eye safety

27
00:01:11.800 --> 00:01:14.480
rules that are absolutely non negotiable.

28
00:01:14.560 --> 00:01:17.200
But, uh, we start with the physics of nothing

29
00:01:17.200 --> 00:01:19.840
at all. Avery, want to set the scene?

30
00:01:20.240 --> 00:01:22.480
Avery: Gladly. This is a genuine

31
00:01:22.560 --> 00:01:24.840
fundamental physics lead and it's about a

32
00:01:24.840 --> 00:01:26.800
lovely Australian thread running through it.

33
00:01:27.500 --> 00:01:30.500
Anna: So on Wednesday, the journal Nature published

34
00:01:30.500 --> 00:01:33.460
a result that's been decades in the making. A

35
00:01:33.460 --> 00:01:36.300
team led by Rachel Stewart used NASA's

36
00:01:36.300 --> 00:01:39.180
IXPE X ray telescope, that's

37
00:01:39.180 --> 00:01:42.140
the Imaging X Ray Polarimetry Explorer,

38
00:01:42.300 --> 00:01:45.100
to stare at a magnetar with the catchy name

39
00:01:45.340 --> 00:01:46.816
1E

40
00:01:47.144 --> 00:01:49.220
1547.0 to

41
00:01:49.220 --> 00:01:51.980
5408. And they think

42
00:01:51.980 --> 00:01:54.380
they've caught empty space, behaving

43
00:01:54.380 --> 00:01:57.100
exactly as quantum theory says it should.

44
00:01:57.760 --> 00:02:00.240
Avery: Lets define the star first because magnetars

45
00:02:00.240 --> 00:02:01.840
are ridiculous objects.

46
00:02:02.240 --> 00:02:04.920
Anna: They really are. A magnetar is a

47
00:02:04.920 --> 00:02:07.720
neutron star, the collapsed core of a

48
00:02:07.720 --> 00:02:10.560
massive dead star. A whole sun's

49
00:02:10.560 --> 00:02:13.440
worth of mass crammed into a ball the size

50
00:02:13.440 --> 00:02:15.680
of a city. But this particular

51
00:02:15.920 --> 00:02:18.720
flavor has the strongest magnetic field

52
00:02:18.960 --> 00:02:21.880
known anywhere in the universe. We're talking

53
00:02:21.880 --> 00:02:24.840
a field around a thousand trillion times

54
00:02:24.840 --> 00:02:27.070
stronger than Earth's. Roughly a, uh,

55
00:02:27.170 --> 00:02:29.570
trillion times stronger than the beefiest

56
00:02:29.570 --> 00:02:32.010
permanent magnet ever built in a lab.

57
00:02:32.410 --> 00:02:35.130
Avery: And that monstrous field is the whole point

58
00:02:35.290 --> 00:02:38.010
because of a prediction from 1936.

59
00:02:38.570 --> 00:02:41.530
Anna: Right. This goes back to Werner Heisenberg

60
00:02:41.530 --> 00:02:43.810
and his colleagues, one of the founders of

61
00:02:43.810 --> 00:02:46.810
quantum mechanics. Quantum theory says the

62
00:02:46.810 --> 00:02:49.730
vacuum isn't truly empty. It's a

63
00:02:49.730 --> 00:02:52.010
boiling sea of virtual particles,

64
00:02:52.480 --> 00:02:54.720
electrons and their antimatter twins,

65
00:02:54.800 --> 00:02:57.440
positrons popping in and out of

66
00:02:57.440 --> 00:03:00.440
existence and vanishing before you can ever

67
00:03:00.440 --> 00:03:01.680
measure them directly.

68
00:03:02.000 --> 00:03:04.600
Avery: Which sounds like philosophy until you add a

69
00:03:04.600 --> 00:03:05.520
magnetic field.

70
00:03:05.920 --> 00:03:08.600
Anna: Exactly. Turn on a strong enough

71
00:03:08.600 --> 00:03:11.600
field and those flickering virtual particles

72
00:03:11.600 --> 00:03:14.280
line up. And when they line up, the

73
00:03:14.280 --> 00:03:17.080
empty vacuum starts to behave like a

74
00:03:17.080 --> 00:03:20.000
piece of glass, or better, like a crystal.

75
00:03:20.080 --> 00:03:22.970
It gains a grain. Light traveling

76
00:03:22.970 --> 00:03:25.410
one way through it moves slightly differently

77
00:03:25.410 --> 00:03:28.130
than light traveling another way. Physicists

78
00:03:28.130 --> 00:03:30.450
call it vacuum birefringence.

79
00:03:30.770 --> 00:03:33.330
Avery: Birefringence being the same trick a crystal

80
00:03:33.330 --> 00:03:36.130
of calcite plays. Split a light ray in two.

81
00:03:36.530 --> 00:03:39.450
Anna: The very same. The vacuum becomes a

82
00:03:39.450 --> 00:03:42.450
prism made of nothing. The catch has

83
00:03:42.450 --> 00:03:45.090
always been that you need a field so

84
00:03:45.090 --> 00:03:47.810
absurdly strong to make the effect visible

85
00:03:47.970 --> 00:03:50.450
that no laboratory on Earth can get

86
00:03:50.450 --> 00:03:53.300
anywhere near it. Only a magnetar will

87
00:03:53.300 --> 00:03:56.220
do. So we've had to wait for the universe

88
00:03:56.220 --> 00:03:58.220
to build the experiment for us.

89
00:03:58.620 --> 00:04:01.540
Avery: Enter ixpe. And, um, here's where it turns

90
00:04:01.540 --> 00:04:03.980
into a proper international relay, with

91
00:04:03.980 --> 00:04:05.820
Australia holding one of the batons.

92
00:04:06.220 --> 00:04:07.740
Anna: This is my favorite part.

93
00:04:08.140 --> 00:04:11.140
IXPE measures the polarization of

94
00:04:11.140 --> 00:04:13.620
X rays. The direction the light waves are

95
00:04:13.620 --> 00:04:16.380
wiggling. That's the fingerprint you need to

96
00:04:16.380 --> 00:04:19.180
catch birefringence. But the team didn't

97
00:04:19.180 --> 00:04:21.500
stop at one telescope. They ran

98
00:04:21.500 --> 00:04:23.940
IXPE together with NASA's

99
00:04:23.940 --> 00:04:26.820
NICER instrument on the space station and

100
00:04:26.820 --> 00:04:29.820
crucially, the Parkes radio telescope in

101
00:04:29.820 --> 00:04:31.220
central New South Wales.

102
00:04:31.460 --> 00:04:34.260
Avery: Merjang the dish, our dish,

103
00:04:34.340 --> 00:04:37.060
doing frontier quantum physics from a paddock

104
00:04:37.060 --> 00:04:38.100
outside of Parkes.

105
00:04:38.500 --> 00:04:40.700
Anna: And there's more homegrown talent in the

106
00:04:40.700 --> 00:04:43.380
byline. Dr. Marcus Lower from

107
00:04:43.380 --> 00:04:45.900
Swinburne University in Melbourne is on the

108
00:04:45.900 --> 00:04:48.780
team alongside co lead Hoa Dinh

109
00:04:48.780 --> 00:04:51.280
T at University in Houston.

110
00:04:51.680 --> 00:04:54.560
So this is genuinely a NASA and Australia

111
00:04:54.800 --> 00:04:55.200
result.

112
00:04:55.840 --> 00:04:57.520
Avery: What did the numbers actually show?

113
00:04:58.240 --> 00:05:00.960
Anna: Extraordinary polarization in the

114
00:05:00.960 --> 00:05:03.280
soft X ray band, where you're seeing the

115
00:05:03.280 --> 00:05:05.759
star's glowing surface. The light was

116
00:05:05.759 --> 00:05:08.400
polarized at around 65%.

117
00:05:08.880 --> 00:05:11.080
And at some points in the magnetar's

118
00:05:11.080 --> 00:05:13.520
rotation, it climbed to nearly 80.

119
00:05:14.000 --> 00:05:16.880
That's enormous. And the pattern shifts

120
00:05:16.880 --> 00:05:19.790
smoothly as the star turns. According to the

121
00:05:19.790 --> 00:05:22.470
team, you can't reproduce that combination,

122
00:05:22.790 --> 00:05:25.590
the X rays and the radio behavior together

123
00:05:25.910 --> 00:05:28.630
without the vacuum itself bending the light.

124
00:05:29.030 --> 00:05:31.910
In their words, the signal requires vacuum

125
00:05:31.910 --> 00:05:34.870
birefringence to be present now,

126
00:05:34.950 --> 00:05:35.390
and I

127
00:05:35.390 --> 00:05:37.350
Avery: think this is important for our listeners.

128
00:05:37.430 --> 00:05:40.070
This is not case closed, is it?

129
00:05:40.550 --> 00:05:43.430
Anna: No, and I'm glad you flagged it. The team is

130
00:05:43.430 --> 00:05:45.910
careful. They call it the most definitive

131
00:05:45.910 --> 00:05:48.790
signal to date. Not a confirmed detection.

132
00:05:49.280 --> 00:05:51.600
And there's a genuine scientific argument

133
00:05:51.600 --> 00:05:54.240
happening in real time. Back in April,

134
00:05:54.320 --> 00:05:56.480
an independent group looked at the same

135
00:05:56.480 --> 00:05:59.480
IXPE data with a different model of the

136
00:05:59.480 --> 00:06:02.360
star's geometry and concluded it wasn't

137
00:06:02.360 --> 00:06:05.120
compelling evidence yet. So there are two

138
00:06:05.120 --> 00:06:06.280
honest readings on

139
00:06:06.280 --> 00:06:08.720
Avery: the table, which is science working

140
00:06:08.880 --> 00:06:10.160
exactly as it should.

141
00:06:10.240 --> 00:06:13.160
Anna: It is to nail it down, you'd want a

142
00:06:13.160 --> 00:06:15.840
stronger dip at the specific energy where the

143
00:06:15.840 --> 00:06:18.440
effect should bite. Or the same signature

144
00:06:18.440 --> 00:06:21.190
from a whole family of magnetars, which or

145
00:06:21.190 --> 00:06:24.070
the dream, a lab experiment on Earth

146
00:06:24.070 --> 00:06:26.950
that corroborates it. None of those is in

147
00:06:26.950 --> 00:06:29.350
hand yet. But think about what's being

148
00:06:29.350 --> 00:06:32.190
claimed that we watched the empty vacuum

149
00:06:32.190 --> 00:06:34.910
of space act on light using a

150
00:06:34.910 --> 00:06:37.830
dead star as the apparatus and a radio

151
00:06:37.830 --> 00:06:40.510
dish in the central west as one of the ears.

152
00:06:40.910 --> 00:06:43.870
Avery: The emptiest thing there is finally showing

153
00:06:43.870 --> 00:06:44.590
its grain.

154
00:06:44.750 --> 00:06:47.390
Anna: That's a lead from the very big

155
00:06:47.390 --> 00:06:49.950
physics let's come back down to the moon

156
00:06:50.490 --> 00:06:53.170
where Avery someone's been raiding the parts

157
00:06:53.170 --> 00:06:53.530
bin.

158
00:06:53.930 --> 00:06:56.450
Avery: They have. Longtime listeners will remember

159
00:06:56.450 --> 00:06:59.330
that back in the autumn NASA paused the Lunar

160
00:06:59.330 --> 00:07:01.530
Gateway, the small space station that was

161
00:07:01.530 --> 00:07:03.970
meant to orbit the moon, and pivoted to

162
00:07:03.970 --> 00:07:06.010
putting infrastructure straight onto the

163
00:07:06.010 --> 00:07:08.770
surface instead. This week we learned what

164
00:07:08.770 --> 00:07:10.730
happens to the hardware that was already

165
00:07:10.810 --> 00:07:11.290
built.

166
00:07:11.770 --> 00:07:13.530
Anna: It doesn't go in a museum.

167
00:07:14.090 --> 00:07:16.650
Avery: It goes to the moon by another route.

168
00:07:17.240 --> 00:07:19.280
NASA and Northrop Grumman announced on

169
00:07:19.280 --> 00:07:22.000
Tuesday that the guts of Halo, that's the

170
00:07:22.000 --> 00:07:24.760
habitation and logistics outpost, the crew

171
00:07:24.760 --> 00:07:26.600
module that was going to be the heart of

172
00:07:26.600 --> 00:07:29.360
Gateway, will be repurposed into three

173
00:07:29.360 --> 00:07:32.120
robotic missions called Lunar Infrastructure

174
00:07:32.120 --> 00:07:34.920
Demos Lid 1, Lid 2

175
00:07:34.920 --> 00:07:36.120
and Lid 3.

176
00:07:36.760 --> 00:07:39.760
Anna: So the power systems, the avionics, the data

177
00:07:39.760 --> 00:07:42.680
plumbing, all the expensive already flight

178
00:07:42.680 --> 00:07:45.430
Avery: ready bits get reused on the

179
00:07:45.430 --> 00:07:47.910
surface instead of in orbit. And the job

180
00:07:47.910 --> 00:07:49.870
they're being pointed at is the single

181
00:07:49.870 --> 00:07:52.350
hardest problem of living at the lunar South

182
00:07:52.350 --> 00:07:54.270
Pole. Surviving the night.

183
00:07:54.830 --> 00:07:57.190
Anna: The two week night, a uh, night

184
00:07:57.190 --> 00:07:59.869
Avery: that lasts about 14 Earth days, where the

185
00:07:59.869 --> 00:08:02.430
temperature at the pole can swing wildly and

186
00:08:02.430 --> 00:08:04.990
plunge to well below minus 200

187
00:08:04.990 --> 00:08:07.710
degrees Celsius and where your solar panels

188
00:08:07.790 --> 00:08:10.760
do precisely nothing for a fortnight. If

189
00:08:10.760 --> 00:08:12.840
you want astronauts to stay for more than one

190
00:08:12.840 --> 00:08:15.240
lunar day, you have to keep the lights and

191
00:08:15.240 --> 00:08:17.920
the heaters on through that. These demos are

192
00:08:17.920 --> 00:08:20.360
meant to prove the power, thermal and

193
00:08:20.360 --> 00:08:22.920
avionics kit that makes a persistent base

194
00:08:22.920 --> 00:08:23.800
even thinkable.

195
00:08:24.200 --> 00:08:27.040
Anna: And the reasoning behind reusing Halo is

196
00:08:27.040 --> 00:08:29.000
basically don't reinvent the wheel.

197
00:08:29.480 --> 00:08:31.440
Avery: Northrop Grumman's framing is that the

198
00:08:31.440 --> 00:08:34.120
hardware is ready to fly, so it lets NASA

199
00:08:34.120 --> 00:08:36.320
move faster and start gathering real

200
00:08:36.320 --> 00:08:38.960
performance data on the surface sooner. It

201
00:08:38.960 --> 00:08:41.560
was part of a broader moon base update too.

202
00:08:41.960 --> 00:08:44.040
Four different commercial landers all

203
00:08:44.040 --> 00:08:46.520
reaching final qualification testing at once,

204
00:08:46.920 --> 00:08:48.360
which is its own milestone.

205
00:08:48.680 --> 00:08:50.920
Anna: It's a very North American story.

206
00:08:51.240 --> 00:08:53.720
Basa, Northrop Grumman, the whole

207
00:08:53.720 --> 00:08:56.280
Artemis push. But it lands for everyone

208
00:08:56.440 --> 00:08:59.040
because the South Pole and its water ice is

209
00:08:59.040 --> 00:09:01.240
where the whole world's lunar plans are

210
00:09:01.240 --> 00:09:01.880
converging.

211
00:09:02.200 --> 00:09:04.040
Avery: Waste not, want not in space.

212
00:09:04.970 --> 00:09:07.290
Anna Speaking of things that ah, didn't go to

213
00:09:07.290 --> 00:09:07.690
plan.

214
00:09:08.410 --> 00:09:11.130
Anna: Yes, some closure on a big bang from

215
00:09:11.130 --> 00:09:13.570
earlier this year. Cast your mind back to

216
00:09:13.570 --> 00:09:16.410
28 May. Blue Origin was running a

217
00:09:16.410 --> 00:09:18.930
routine engine test of a new Glenn booster on

218
00:09:18.930 --> 00:09:21.850
the pad at Cape Canaveral and it exploded

219
00:09:22.010 --> 00:09:24.850
spectacularly. It destroyed the rocket

220
00:09:24.850 --> 00:09:27.370
and did serious damage to the launch complex

221
00:09:27.690 --> 00:09:28.250
and until

222
00:09:28.250 --> 00:09:30.730
Avery: this week we didn't officially know why.

223
00:09:31.460 --> 00:09:33.780
Anna: Now we do. On Tuesday, Blue

224
00:09:33.780 --> 00:09:36.620
Origin's chief executive Dave Limp gave the

225
00:09:36.620 --> 00:09:39.340
first real update on the investigation. The

226
00:09:39.340 --> 00:09:42.220
culprit? The main oxygen valve on one of the

227
00:09:42.220 --> 00:09:44.980
rocket's seven BE4 engines. They

228
00:09:44.980 --> 00:09:47.100
traced it there, then confirmed it by

229
00:09:47.100 --> 00:09:49.060
recovering and inspecting the hardware.

230
00:09:49.540 --> 00:09:52.060
Avery: One valve on one of seven

231
00:09:52.060 --> 00:09:54.260
engines, One valve.

232
00:09:54.420 --> 00:09:56.580
Anna: That's the thing about rockets, they're

233
00:09:56.580 --> 00:09:58.900
thousands of parts that all have to behave

234
00:09:59.060 --> 00:10:01.820
and any one of them can ruin your day. The

235
00:10:01.820 --> 00:10:04.380
valve controls the flow of liquid oxygen into

236
00:10:04.380 --> 00:10:07.060
the engine and something about it initiated

237
00:10:07.060 --> 00:10:09.580
the anomaly. Limp said they've run extensive

238
00:10:09.740 --> 00:10:12.460
component level and engine hot fire tests to

239
00:10:12.460 --> 00:10:15.260
understand the failure mode and the fix is

240
00:10:15.260 --> 00:10:18.100
Avery: a redesign everything situation or a

241
00:10:18.100 --> 00:10:18.460
tweak.

242
00:10:18.940 --> 00:10:21.780
Anna: Encouragingly, a tweak. They're making small

243
00:10:21.780 --> 00:10:23.620
modifications to the valve that can be

244
00:10:23.620 --> 00:10:25.900
retrofitted to engines that already exist

245
00:10:26.140 --> 00:10:28.750
rather than starting from scratch. Blimp's

246
00:10:28.750 --> 00:10:31.310
line was simply the path forward is clear

247
00:10:31.390 --> 00:10:33.790
with updated hardware coming in the near term

248
00:10:33.790 --> 00:10:36.510
and a return to flight still targeted before

249
00:10:36.510 --> 00:10:37.470
the end of the year.

250
00:10:37.710 --> 00:10:40.590
Avery: There's a wider ripple here too. The BE4

251
00:10:40.590 --> 00:10:42.590
doesn't only fly on New Glenn.

252
00:10:42.910 --> 00:10:45.790
Anna: Good point. The same engine powers United

253
00:10:45.950 --> 00:10:48.390
Launch Alliance's Vulcan rocket. So the

254
00:10:48.390 --> 00:10:50.270
industry will be watching how this valve

255
00:10:50.270 --> 00:10:53.070
story plays out beyond Blue Origin. But

256
00:10:53.070 --> 00:10:55.690
the headline for today is a good one. They

257
00:10:55.690 --> 00:10:58.010
found it, they understand it and they think

258
00:10:58.010 --> 00:11:00.970
it's fixable. That's how you turn a very bad

259
00:11:00.970 --> 00:11:03.010
day into a flying rocket again.

260
00:11:03.570 --> 00:11:06.450
Avery: From M, a rocket that needs to fly again to a

261
00:11:06.450 --> 00:11:09.250
robot that just needs to stop spinning. This

262
00:11:09.250 --> 00:11:10.610
one's a nail biter.

263
00:11:10.850 --> 00:11:12.730
Anna: Nothing unusual in that though.

264
00:11:12.730 --> 00:11:15.650
Avery: In space it genuinely is. We've

265
00:11:15.650 --> 00:11:17.530
been following this since the launch scrubs

266
00:11:17.530 --> 00:11:19.730
back at the start of July. So let me bring

267
00:11:19.730 --> 00:11:22.630
everyone up to speed. NASA's Neil Gerald

268
00:11:22.630 --> 00:11:25.430
Swift Observatory, a much loved telescope

269
00:11:25.430 --> 00:11:27.270
that's been catching gamma ray bursts since

270
00:11:27.270 --> 00:11:29.910
2004 is slowly sinking.

271
00:11:30.150 --> 00:11:32.910
Its orbit is decaying and without a boost it

272
00:11:32.910 --> 00:11:35.350
will re enter and burn up later this year.

273
00:11:35.590 --> 00:11:37.590
Anna: And the cavalry is a robot.

274
00:11:37.750 --> 00:11:40.670
Avery: The cavalry is a robot called Link, built by

275
00:11:40.670 --> 00:11:42.670
a company called Catalyst Space out of

276
00:11:42.670 --> 00:11:45.190
Flagstaff, Arizona. They're billing it as

277
00:11:45.190 --> 00:11:47.750
America's first commercial space robot.

278
00:11:48.170 --> 00:11:50.650
Designed, built and launched in under a year.

279
00:11:50.890 --> 00:11:53.650
And its job is to fly up, grab Swift

280
00:11:53.650 --> 00:11:56.250
and gently boost it to a higher, safer

281
00:11:56.250 --> 00:11:59.010
orbit. It launched on 3 July on an air

282
00:11:59.010 --> 00:12:00.490
launched Pegasus rocket.

283
00:12:00.650 --> 00:12:01.850
Anna: So what went wrong?

284
00:12:02.410 --> 00:12:04.410
Avery: During commissioning, Link got into trouble.

285
00:12:04.490 --> 00:12:07.130
It ended up in a multi axis tumble, spinning

286
00:12:07.130 --> 00:12:09.650
at about 9 degrees per second, which caused

287
00:12:09.650 --> 00:12:12.210
it to drop in and out of communication. And

288
00:12:12.210 --> 00:12:14.410
the cause was nasty. Two of its three

289
00:12:14.410 --> 00:12:16.570
reaction wheels, the spinning disks a

290
00:12:16.570 --> 00:12:19.000
spacecraft uses to point itself while, were

291
00:12:19.000 --> 00:12:21.000
knocked out by a fault in the power system

292
00:12:21.000 --> 00:12:21.960
upstream of them.

293
00:12:22.280 --> 00:12:24.360
Anna: Losing your steering while you're tumbling,

294
00:12:24.440 --> 00:12:25.960
that's the stuff of nightmares.

295
00:12:26.760 --> 00:12:29.600
Avery: It is. But here's the clever bit. With the

296
00:12:29.600 --> 00:12:32.200
reaction wheels down, the team improvised.

297
00:12:32.520 --> 00:12:35.240
They used Lynx electric propulsion thrusters,

298
00:12:35.240 --> 00:12:37.400
the gentle ion drive meant for the long

299
00:12:37.400 --> 00:12:40.320
cruise to Swift, mounted on a gimbal and

300
00:12:40.320 --> 00:12:42.960
fired them to cancel the spin. And it's

301
00:12:42.960 --> 00:12:45.400
working. They've brought the Tumble down from

302
00:12:45.400 --> 00:12:48.240
9 degrees per second to 4, and now to

303
00:12:48.240 --> 00:12:51.080
about 1 and a half. All of it using less than

304
00:12:51.080 --> 00:12:53.360
a hundred grams of propellant. So they're not

305
00:12:53.360 --> 00:12:55.520
eating into the fuel they need for the rescue

306
00:12:55.520 --> 00:12:55.960
itself.

307
00:12:56.600 --> 00:12:59.400
Anna: A hundred grams, That's a small chocolate

308
00:12:59.400 --> 00:13:01.600
bar's worth of fuel to tame a tumbling

309
00:13:01.600 --> 00:13:02.360
spacecraft.

310
00:13:03.000 --> 00:13:05.920
Avery: Beautifully economical. And the next step is

311
00:13:05.920 --> 00:13:08.120
a big flight software upload in the coming

312
00:13:08.120 --> 00:13:10.840
days. New control code written specifically

313
00:13:10.840 --> 00:13:13.200
for the wounded spacecraft, which should hand

314
00:13:13.200 --> 00:13:15.990
full pointing control back to the team. After

315
00:13:15.990 --> 00:13:18.750
that, Link can start. The slow orbital dance

316
00:13:18.750 --> 00:13:21.350
to line up with Swift Rendezvous has slipped

317
00:13:21.350 --> 00:13:22.710
to around the end of August.

318
00:13:23.030 --> 00:13:25.190
Anna: There's a lovely echo here with our lead.

319
00:13:25.190 --> 00:13:27.670
Actually, our top story was about reading a

320
00:13:27.670 --> 00:13:30.590
magnetar with X ray telescopes. And Swift

321
00:13:30.590 --> 00:13:33.270
is itself an X ray and gamma ray observatory.

322
00:13:33.590 --> 00:13:36.190
A robot fighting to save one of the very

323
00:13:36.190 --> 00:13:38.270
instruments we use to do this kind of

324
00:13:38.270 --> 00:13:38.630
science.

325
00:13:39.350 --> 00:13:41.670
Avery: Fingers crossed for that software upload.

326
00:13:41.750 --> 00:13:43.430
We'll keep watching the dashboard.

327
00:13:43.890 --> 00:13:45.410
Anna, take us to the sky.

328
00:13:45.730 --> 00:13:48.410
Anna: With pleasure, because next Wednesday 12th

329
00:13:48.410 --> 00:13:50.850
August, as we've mentioned before, is one of

330
00:13:50.850 --> 00:13:53.250
the biggest sky days of the year. Two

331
00:13:53.250 --> 00:13:56.250
headline events in 24 hours, a total solar

332
00:13:56.250 --> 00:13:58.530
eclipse and the peak of the Perseid meteor

333
00:13:58.530 --> 00:14:01.210
shower under a beautifully dark moonless

334
00:14:01.210 --> 00:14:01.650
sky.

335
00:14:02.370 --> 00:14:04.850
Avery: Let's do the eclipse first and let's do it by

336
00:14:04.850 --> 00:14:07.850
hemisphere. The path of Totality, where the

337
00:14:07.850 --> 00:14:10.770
moon completely covers the sun, sweeps across

338
00:14:10.770 --> 00:14:13.490
northern Russia, Greenland, Iceland and

339
00:14:13.490 --> 00:14:16.210
northern Spain, clipping a tiny corner of

340
00:14:16.210 --> 00:14:18.930
Portugal for mainland Europe. It's the first

341
00:14:18.930 --> 00:14:21.330
total solar eclipse since 1999.

342
00:14:21.730 --> 00:14:23.570
If you're lucky enough to be in Spain,

343
00:14:23.650 --> 00:14:25.490
totality comes late in the day,

344
00:14:25.650 --> 00:14:28.210
Anna: low and golden for our North American

345
00:14:28.210 --> 00:14:30.650
listeners, our largest audience. You don't

346
00:14:30.650 --> 00:14:33.050
get totality this time, but the Northeast

347
00:14:33.050 --> 00:14:35.490
does get a partial. It's an afternoon event.

348
00:14:35.810 --> 00:14:38.450
The rule of thumb. You'll see more than a 10%

349
00:14:38.450 --> 00:14:41.010
bite only if you're northeast of a line

350
00:14:41.010 --> 00:14:43.530
running roughly from New York City up through

351
00:14:43.530 --> 00:14:45.990
Rock Rochester, or east of about mid

352
00:14:45.990 --> 00:14:47.150
Ontario in Canada.

353
00:14:47.710 --> 00:14:50.110
Avery: And the further into Atlantic Canada you go,

354
00:14:50.110 --> 00:14:52.590
the better it gets. Around half the sun

355
00:14:52.590 --> 00:14:55.190
covered at maximum. New England and the

356
00:14:55.190 --> 00:14:57.630
northeastern states get a smaller nibble.

357
00:14:57.790 --> 00:15:00.190
NASDAQ will stream the whole thing live from

358
00:15:00.190 --> 00:15:02.990
1:15 in the afternoon Eastern time. If your

359
00:15:02.990 --> 00:15:04.430
local sky won't play along.

360
00:15:04.910 --> 00:15:07.630
Anna: Now, the non negotiable bit. And we say this

361
00:15:07.710 --> 00:15:09.390
every single time for a reason.

362
00:15:10.180 --> 00:15:12.860
Avery: In every partial phase, you must protect your

363
00:15:12.860 --> 00:15:15.780
eyes. Use only eclipse glasses or handheld

364
00:15:15.780 --> 00:15:18.140
solar viewers certified to the ISO

365
00:15:18.140 --> 00:15:20.780
123122 safety

366
00:15:20.780 --> 00:15:23.420
standard. Ordinary sunglasses are not

367
00:15:23.420 --> 00:15:26.300
safe, no matter how dark they look. And

368
00:15:26.300 --> 00:15:29.180
never point a camera, telescope or binoculars

369
00:15:29.180 --> 00:15:31.740
at the sun while wearing eclipse glasses. The

370
00:15:31.740 --> 00:15:33.900
optics will concentrate the light and burn

371
00:15:33.900 --> 00:15:35.740
straight through the filter and into your

372
00:15:35.740 --> 00:15:36.100
eye.

373
00:15:36.520 --> 00:15:38.320
Anna: If you saved your glasses from a previous

374
00:15:38.320 --> 00:15:40.280
eclipse, check them for scratches and

375
00:15:40.280 --> 00:15:42.920
pinholes. Before you trust them in doubt,

376
00:15:42.920 --> 00:15:43.720
throw them out.

377
00:15:44.040 --> 00:15:46.420
Avery: And for the southern hemisphere, Anna. Uh,

378
00:15:46.420 --> 00:15:47.400
the honest word.

379
00:15:47.720 --> 00:15:50.240
Anna: The honest word is that here in Australia, we

380
00:15:50.240 --> 00:15:52.800
miss this one entirely. The eclipse isn't

381
00:15:52.800 --> 00:15:54.640
visible from our part of the world, and the

382
00:15:54.640 --> 00:15:57.360
Perseids are stubbornly a northern hemisphere

383
00:15:57.360 --> 00:16:00.240
shower. Their radiant point barely clears our

384
00:16:00.240 --> 00:16:03.080
northern horizon, so at best you might catch

385
00:16:03.080 --> 00:16:06.000
a stray one or two very low in the couple

386
00:16:06.000 --> 00:16:08.010
of hours before dawn on the 13th.

387
00:16:08.640 --> 00:16:10.920
Avery: But we're not left out. What Sydney can do

388
00:16:10.920 --> 00:16:13.040
next week is beautiful in its own right.

389
00:16:13.360 --> 00:16:16.280
Anna: It is. Get up before dawn and

390
00:16:16.280 --> 00:16:18.800
look for the lineup of planets stretched

391
00:16:18.800 --> 00:16:21.520
across the eastern sky. And keep an eye on

392
00:16:21.520 --> 00:16:24.480
Venus, which is climbing back into view. Add

393
00:16:24.480 --> 00:16:27.200
the winter Milky Way arching overhead from a

394
00:16:27.200 --> 00:16:30.160
dark site and you've got a genuinely lovely

395
00:16:30.160 --> 00:16:32.840
pre dawn show. No eclipse glasses

396
00:16:32.840 --> 00:16:33.280
required.

397
00:16:33.990 --> 00:16:35.870
Avery: And for our, uh, northern friends, chasing

398
00:16:35.870 --> 00:16:38.390
meteors, the Perseids peak the night of the

399
00:16:38.390 --> 00:16:41.270
12th into the pre dawn of the 13th with a

400
00:16:41.270 --> 00:16:43.470
new moon. Conditions are about as good as

401
00:16:43.470 --> 00:16:45.710
they get. From a dark rural site, you could

402
00:16:45.710 --> 00:16:48.150
see up to a hundred an hour, many of them

403
00:16:48.150 --> 00:16:51.150
bright fast and trailing. Get away from city

404
00:16:51.150 --> 00:16:53.750
lights. Give your eyes 20 minutes to adjust.

405
00:16:53.910 --> 00:16:55.590
Look up and be patient.

406
00:16:56.070 --> 00:16:58.710
Anna: That's the show. The vacuum of space

407
00:16:58.790 --> 00:17:01.670
showing its colors. A moon base built from

408
00:17:01.670 --> 00:17:04.330
spare parts. Earth. A rocket mystery solved.

409
00:17:04.330 --> 00:17:06.650
And a little robot fighting to save a

410
00:17:06.650 --> 00:17:07.330
telescope.

411
00:17:07.730 --> 00:17:09.650
Avery: All the links and sources are in your show

412
00:17:09.650 --> 00:17:12.370
notes and over at astronomydaily IO,

413
00:17:12.530 --> 00:17:14.530
where you can also grab the newsletter and

414
00:17:14.530 --> 00:17:15.330
drop us a line.

415
00:17:15.730 --> 00:17:18.530
Anna: For Avery, I'm Anna. Look after those eyes.

416
00:17:18.530 --> 00:17:20.690
Avery: Next Wednesday and until next time.

417
00:17:20.850 --> 00:17:21.810
Anna: Clear skies.

418
00:17:33.100 --> 00:17:33.820
The stories.

419
00:17:41.660 --> 00:17:42.300
Avery: Were told.