Lunar Quakes, Stellar Explosions, and the Mystery of Missing Sulphur

WEBVTT

0
00:00:00.000 --> 00:00:02.880
Anna: Welcome back to Astronomy Daily, your go to

1
00:00:02.880 --> 00:00:05.400
podcast for all the latest happenings in our

2
00:00:05.400 --> 00:00:07.840
incredible universe. I'm Anna.

3
00:00:07.920 --> 00:00:10.840
Avery: And I'm Avery. We've got a big episode lined up for

4
00:00:10.840 --> 00:00:13.720
you today, packed with some truly fascinating cosmic

5
00:00:13.720 --> 00:00:14.160
updates.

6
00:00:14.480 --> 00:00:17.120
Anna: That's right, Avery. We'll be diving into new research

7
00:00:17.280 --> 00:00:20.200
about lunar seismic activity and what

8
00:00:20.200 --> 00:00:22.920
moonquakes could mean for future bases on our

9
00:00:22.920 --> 00:00:25.880
nearest celestial neighbour. Turns out the Moon

10
00:00:25.880 --> 00:00:28.000
is a lot shakier than you might think.

11
00:00:28.950 --> 00:00:31.870
Avery: And speaking of drama, we'll also explore the explosive

12
00:00:31.870 --> 00:00:34.830
end of a massive star that had a very close

13
00:00:34.830 --> 00:00:37.350
encounter with a black hole. It's a story

14
00:00:37.430 --> 00:00:40.150
straight out of a sci fi movie, but it's real.

15
00:00:40.550 --> 00:00:43.350
Anna: Plus, we're tackling some long standing cosmic

16
00:00:43.350 --> 00:00:46.310
mysteries, from the curious case of the universe's

17
00:00:46.310 --> 00:00:49.230
missing sulphur to groundbreaking new insights

18
00:00:49.230 --> 00:00:52.190
about Vesta, one of the largest objects in the

19
00:00:52.190 --> 00:00:54.750
asteroid belt. Which might be more than just an.

20
00:00:54.750 --> 00:00:57.470
Avery: Asteroid, but so buckle up because

21
00:00:57.470 --> 00:01:00.350
we're about to take a tour through the latest and greatest

22
00:01:00.350 --> 00:01:02.110
in space and astronomy news.

23
00:01:02.750 --> 00:01:05.710
Anna: Alright, let's kick things off with some big news about

24
00:01:05.710 --> 00:01:08.590
our own Moon. We often think of it as

25
00:01:08.590 --> 00:01:11.470
a quiet, unchanging place, but new research

26
00:01:11.630 --> 00:01:14.390
is challenging that idea, especially when we

27
00:01:14.390 --> 00:01:16.590
consider building long term bases there.

28
00:01:16.910 --> 00:01:19.670
Avery: That's right, Anna. It turns out our lunar

29
00:01:19.670 --> 00:01:22.590
neighbour is more seismically active than many might

30
00:01:22.590 --> 00:01:25.550
assume. A recent study focusing on the

31
00:01:25.550 --> 00:01:28.350
Lee Lincoln Fault in the Taurus Littrell

32
00:01:28.350 --> 00:01:30.910
Valley, where the Apollo 17 astronauts

33
00:01:30.910 --> 00:01:33.830
landed in 1972, highlights that these

34
00:01:33.830 --> 00:01:36.630
moonquakes could pose significant risks to future

35
00:01:36.710 --> 00:01:38.150
permanent lunar structures.

36
00:01:38.550 --> 00:01:41.430
Anna: This research, led by Smithsonian Senior

37
00:01:41.430 --> 00:01:44.150
Scientist Emeritus Thomas R. Waters,

38
00:01:44.310 --> 00:01:47.150
emphasises that the global distribution of

39
00:01:47.150 --> 00:01:50.150
these young thrust faults and their potential to still

40
00:01:50.150 --> 00:01:53.110
be active needs to be seriously considered.

41
00:01:53.600 --> 00:01:56.440
We're talking about planning locations and assessing

42
00:01:56.440 --> 00:01:59.280
the stability of any permanent outposts on the

43
00:01:59.280 --> 00:01:59.600
Moon.

44
00:01:59.920 --> 00:02:02.920
Avery: And, um, the evidence isn't new. It's based on moonquakes

45
00:02:02.920 --> 00:02:05.600
in the region over the past 90 million years.

46
00:02:06.080 --> 00:02:08.840
Much of this evidence comes from material gathered by the

47
00:02:08.840 --> 00:02:11.800
Apollo astronauts themselves. Things like chunks

48
00:02:11.800 --> 00:02:14.720
of rocks and landslides are silent. But clear

49
00:02:14.720 --> 00:02:17.280
proof of the power of even magnitude

50
00:02:17.280 --> 00:02:19.880
3.0 quakes to shift surface

51
00:02:19.880 --> 00:02:22.680
materials around it really points to the Moon

52
00:02:22.680 --> 00:02:24.640
still being geologically active.

53
00:02:25.000 --> 00:02:27.560
Anna: It makes you wonder, why does the Moon even have

54
00:02:27.560 --> 00:02:30.280
quakes here on Earth? We're very familiar with

55
00:02:30.280 --> 00:02:33.240
earthquakes, primarily caused by plate tectonics

56
00:02:33.240 --> 00:02:36.080
and volcanic activity. Think of the San Andreas

57
00:02:36.080 --> 00:02:38.880
Fault or the Ring of Fire. Magma movement

58
00:02:38.880 --> 00:02:41.880
also causes tremors, like the recent events in Hawaii

59
00:02:41.880 --> 00:02:42.680
and Iceland.

60
00:02:43.160 --> 00:02:45.960
Avery: But the Moon operates differently. Its quakes

61
00:02:45.960 --> 00:02:47.880
are most Likely caused by two main

62
00:02:48.680 --> 00:02:51.280
Earth's tidal pulling and the Moon's continuous

63
00:02:51.280 --> 00:02:54.130
cooling and shrinking. The deep moonquakes

64
00:02:54.130 --> 00:02:56.970
occurring hundreds of miles inside are due to

65
00:02:56.970 --> 00:02:59.370
Earth's gravity pulling on her satellite.

66
00:02:59.450 --> 00:03:02.090
Anna: And the weaker quakes closer to the surface are

67
00:03:02.090 --> 00:03:05.050
generally attributed to the Moon's gradual cooling and

68
00:03:05.050 --> 00:03:07.890
shrinking. Since its formation billions of years

69
00:03:07.890 --> 00:03:10.490
ago, the Moon has actually lost about

70
00:03:10.490 --> 00:03:13.410
150ft of its diameter. There

71
00:03:13.410 --> 00:03:16.330
are also minor tremors from meteoroid impacts

72
00:03:16.330 --> 00:03:19.330
or surface rocks reacting to heating and cooling from

73
00:03:19.330 --> 00:03:22.320
the sun. So it's a world that's constantly shaking.

74
00:03:22.720 --> 00:03:25.560
Avery: When we talk about the risks to future bases, it

75
00:03:25.560 --> 00:03:28.520
becomes quite significant. Short term missions like

76
00:03:28.520 --> 00:03:31.520
the Apollo landings, where astronauts were on the Moon for

77
00:03:31.520 --> 00:03:34.320
less than two weeks, didn't face much danger.

78
00:03:34.400 --> 00:03:37.400
But for permanent bases, the chances of damage

79
00:03:37.400 --> 00:03:40.000
during a quake go up simply due to the

80
00:03:40.000 --> 00:03:41.200
extended exposure.

81
00:03:41.680 --> 00:03:44.400
Anna: Nicholas Schmer put it into perspective. He

82
00:03:44.400 --> 00:03:47.320
said if astronauts are there for a day, they'd

83
00:03:47.320 --> 00:03:49.840
just have very bad luck. If there was a damaging event,

84
00:03:50.220 --> 00:03:53.170
they. But if you have a habitat or crewed mission up on

85
00:03:53.170 --> 00:03:55.410
the Moon for a whole decade, that's

86
00:03:55.410 --> 00:03:58.330
3,650 days times 1

87
00:03:58.330 --> 00:04:01.130
in 20 million. Or the risk of a hazardous

88
00:04:01.130 --> 00:04:03.970
moonquake becoming about 1 in 5,500.

89
00:04:04.450 --> 00:04:07.410
Avery: He likened it to, uh, going from the extremely low

90
00:04:07.410 --> 00:04:10.130
odds of winning a lottery to the much

91
00:04:10.130 --> 00:04:13.050
higher odds of being dealt a four of a kind poker

92
00:04:13.050 --> 00:04:15.890
hand. It really illustrates how much the probability

93
00:04:16.130 --> 00:04:17.250
increases over time.

94
00:04:18.179 --> 00:04:21.139
Anna: And it's not just habitats. Countries like

95
00:04:21.139 --> 00:04:24.139
Russia, China and the US are planning to put

96
00:04:24.139 --> 00:04:26.699
nuclear power plants on the Moon. These

97
00:04:26.699 --> 00:04:29.379
facilities would supply massive amounts of power,

98
00:04:29.379 --> 00:04:32.339
but they'd also be susceptible to quake damage.

99
00:04:32.579 --> 00:04:35.179
This means any construction will need tough

100
00:04:35.179 --> 00:04:38.179
safety margins and shouldn't be located near active

101
00:04:38.179 --> 00:04:38.979
fault lines.

102
00:04:39.699 --> 00:04:42.379
Avery: Which is a tall order considering how many fault

103
00:04:42.379 --> 00:04:45.290
lines thread through the Moon. That's why this study

104
00:04:45.290 --> 00:04:48.010
of lunar paleoseismology looking at

105
00:04:48.010 --> 00:04:50.770
evidence of past quakes is so crucial.

106
00:04:51.010 --> 00:04:53.890
It will help us chart the safest places to build

107
00:04:53.890 --> 00:04:56.810
these long term habitats and power plants. It's

108
00:04:56.810 --> 00:04:59.090
all about understanding our cosmic neighbourhood.

109
00:04:59.250 --> 00:05:01.930
Before we make ourselves at home from

110
00:05:01.930 --> 00:05:04.850
lunar shaking, let's zoom out to something truly

111
00:05:04.850 --> 00:05:07.810
dramatic happening in the cosmos. Scientists have

112
00:05:07.810 --> 00:05:10.690
captured the explosive end of a massive star

113
00:05:10.930 --> 00:05:13.810
in a scenario unlike anything they've seen before.

114
00:05:14.370 --> 00:05:17.090
Anna: That's right, Avery. This event, more than

115
00:05:17.170 --> 00:05:20.170
700 million light years away, began as

116
00:05:20.170 --> 00:05:22.890
a faint flicker. Within days, the light

117
00:05:22.890 --> 00:05:25.650
flared, faded, and then, surprisingly,

118
00:05:25.650 --> 00:05:28.370
flared again. It was completely

119
00:05:28.370 --> 00:05:31.010
unlike the standard playbook for dying stars.

120
00:05:31.810 --> 00:05:34.290
Avery: What makes this even more incredible is that an

121
00:05:34.290 --> 00:05:37.010
artificial intelligence System flagged the event

122
00:05:37.010 --> 00:05:39.650
in real time. This allowed scientists to

123
00:05:39.650 --> 00:05:42.370
capture every phase of what may be the first

124
00:05:42.370 --> 00:05:45.170
recorded case of a massive star exploding

125
00:05:45.330 --> 00:05:48.110
as it tried to devour a black hole companion.

126
00:05:48.510 --> 00:05:50.830
Talk about cosmic drama. This

127
00:05:50.830 --> 00:05:51.910
supernova, named

128
00:05:51.910 --> 00:05:54.830
SN2023ZKD, was

129
00:05:54.830 --> 00:05:57.830
first spotted in July 2023 by the Zwicky

130
00:05:57.830 --> 00:06:00.670
Transient Facility and then analysed by a team

131
00:06:00.670 --> 00:06:03.190
from the Centre for Astrophysics at Harvard and

132
00:06:03.190 --> 00:06:06.190
Smithsonian mit. Their findings, published

133
00:06:06.190 --> 00:06:09.150
in the Astrophysical Journal, provide the clearest

134
00:06:09.150 --> 00:06:11.710
evidence yet that such extreme binary

135
00:06:11.710 --> 00:06:14.230
interactions can actually trigger a stellar

136
00:06:14.230 --> 00:06:16.530
detonation. It was part of the Young

137
00:06:16.530 --> 00:06:19.370
Supernova Experiment, a project designed to

138
00:06:19.370 --> 00:06:21.970
catch these exploding stars in their earliest stages.

139
00:06:22.210 --> 00:06:25.090
The AI system gave astronomers a crucial head

140
00:06:25.090 --> 00:06:27.890
start, allowing them to follow the explosion in

141
00:06:27.890 --> 00:06:30.490
near real time from both ground and space

142
00:06:30.490 --> 00:06:31.409
observatories.

143
00:06:32.130 --> 00:06:35.130
Anna: Alexander Agliano, the lead author of

144
00:06:35.130 --> 00:06:38.130
the study, stated that their analysis shows the blast

145
00:06:38.130 --> 00:06:41.010
was sparked by a catastrophic encounter with a black

146
00:06:41.010 --> 00:06:43.940
hole companion, providing the strongest evidence

147
00:06:43.940 --> 00:06:46.780
to date that such close interactions can

148
00:06:46.860 --> 00:06:48.540
indeed detonate a star.

149
00:06:49.500 --> 00:06:52.500
Avery: The leading explanation is that this massive star and black

150
00:06:52.500 --> 00:06:55.460
hole were locked in a decaying orbit. As they drew

151
00:06:55.460 --> 00:06:58.179
closer, the black hole's immense gravity pulled

152
00:06:58.179 --> 00:07:00.940
gas from the star into a surrounding disc.

153
00:07:01.180 --> 00:07:03.940
This intense stress is believed to have triggered the

154
00:07:03.940 --> 00:07:06.860
explosion before the star could fully engulf the black

155
00:07:06.860 --> 00:07:07.260
hole.

156
00:07:08.230 --> 00:07:11.190
Anna: Another possibility is that the black hole completely

157
00:07:11.190 --> 00:07:14.150
shredded the star, with the debris's collisions

158
00:07:14.150 --> 00:07:16.910
then powering the supernova's light. In

159
00:07:16.910 --> 00:07:19.510
either scenario, the aftermath left behind

160
00:07:19.670 --> 00:07:21.110
a heavier black hole.

161
00:07:21.910 --> 00:07:24.670
Avery: What really stood out to astronomers were the unusual

162
00:07:24.670 --> 00:07:26.390
light patterns from Earth.

163
00:07:26.470 --> 00:07:29.430
SN2023ZKD initially

164
00:07:29.430 --> 00:07:32.190
looked like a normal supernova. A single burst of

165
00:07:32.190 --> 00:07:35.100
light followed by a gradual fade. But then,

166
00:07:35.260 --> 00:07:37.420
months later, it did something truly

167
00:07:37.420 --> 00:07:39.580
extraordinary. It brightened again.

168
00:07:40.540 --> 00:07:43.300
Anna: Archival records showed that the system had

169
00:07:43.300 --> 00:07:46.020
actually been slowly brightening for more than

170
00:07:46.020 --> 00:07:48.980
four years before the explosion, a

171
00:07:48.980 --> 00:07:51.820
rare and telling sign of pre death instability.

172
00:07:52.460 --> 00:07:55.420
The analysis revealed that the supernova's light was

173
00:07:55.420 --> 00:07:58.300
shaped by layers of gas shed by the star in

174
00:07:58.300 --> 00:07:59.180
its final years.

175
00:07:59.500 --> 00:08:02.420
Avery: The first brightening came from the blast wave colliding with

176
00:08:02.420 --> 00:08:05.380
diffused gas, while while that second peak was fueled by

177
00:08:05.380 --> 00:08:08.220
a slower collision with a dense disc shaped cloud.

178
00:08:08.700 --> 00:08:11.700
The structure and timing of these events strongly point to

179
00:08:11.700 --> 00:08:14.660
extreme gravitational forces from a nearby compact

180
00:08:14.660 --> 00:08:15.100
object.

181
00:08:15.340 --> 00:08:18.060
Anna: It's clear that AI played a crucial role

182
00:08:18.060 --> 00:08:20.980
here. As Gagliano mentioned, their machine

183
00:08:20.980 --> 00:08:22.500
Learning system flagged

184
00:08:22.500 --> 00:08:25.500
SN2023SKD months

185
00:08:25.500 --> 00:08:28.500
before its most unusual behaviour, which gave

186
00:08:28.500 --> 00:08:31.420
them ample time to secure the critical observations

187
00:08:31.820 --> 00:08:34.260
needed to unravel this extraordinary

188
00:08:34.260 --> 00:08:36.370
explosion V. Ashley Villar, a.

189
00:08:36.370 --> 00:08:38.950
Avery: AH co author and assistant professor of astronomy at

190
00:08:38.950 --> 00:08:41.550
cfa, added that this event shows some of the

191
00:08:41.550 --> 00:08:44.550
clearest signs they've seen of a massive star interacting

192
00:08:44.550 --> 00:08:47.350
with the companion in the years before an explosion.

193
00:08:47.510 --> 00:08:50.510
They believe this might be part of a whole class of hidden

194
00:08:50.510 --> 00:08:53.110
explosions that AI will help them discover in the future.

195
00:08:53.510 --> 00:08:56.510
Anna: With new observatories like the veracy Rubin

196
00:08:56.510 --> 00:08:59.350
Observatory soon scanning the entire sky every

197
00:08:59.350 --> 00:09:01.830
few nights and projects like the Young

198
00:09:01.910 --> 00:09:04.790
Supernova Experiment continuing to identify new

199
00:09:04.790 --> 00:09:07.690
events quickly, astronomers expect expect to catch

200
00:09:07.690 --> 00:09:10.450
more of these rare and complex explosions in

201
00:09:10.450 --> 00:09:13.210
action. It's truly a new era

202
00:09:13.210 --> 00:09:15.850
for observing the most extreme cosmic

203
00:09:15.850 --> 00:09:18.610
events. That's an incredible story of

204
00:09:18.610 --> 00:09:20.290
cosmic violence and detection.

205
00:09:20.770 --> 00:09:23.770
Now let's shift gears a bit and delve into a long

206
00:09:23.770 --> 00:09:26.610
standing cosmic mystery. The case of the

207
00:09:26.610 --> 00:09:28.690
universe's missing sulphur.

208
00:09:28.770 --> 00:09:31.730
Avery: It sounds like something out of a detective novel. For years,

209
00:09:31.730 --> 00:09:34.570
scientists have been puzzled because there simply isn't as

210
00:09:34.570 --> 00:09:37.370
much sulphur floating around in deep space as they

211
00:09:37.370 --> 00:09:40.010
expected. This is quite an enigma, considering

212
00:09:40.010 --> 00:09:42.570
Sulphur is the 10th most abundant element in the

213
00:09:42.570 --> 00:09:45.410
universe and crucial for both planets and life.

214
00:09:45.730 --> 00:09:48.450
Anna: Exactly. But a, uh, new international study

215
00:09:48.690 --> 00:09:51.010
might have finally found its hiding place.

216
00:09:51.410 --> 00:09:54.249
Researchers from the University of Mississippi, the

217
00:09:54.249 --> 00:09:56.850
University of Hawaii at Manoa and

218
00:09:56.850 --> 00:09:59.410
Georgia State University teamed up to search for

219
00:09:59.410 --> 00:10:01.970
answers, publishing their findings in Nature

220
00:10:01.970 --> 00:10:02.690
Communication.

221
00:10:03.250 --> 00:10:06.010
Avery: So where has all the sulphur been? The team's

222
00:10:06.010 --> 00:10:08.530
results suggest that it's not actually missing at all.

223
00:10:08.790 --> 00:10:11.790
Instead, it's locked away in solid forms, bound

224
00:10:11.790 --> 00:10:14.150
within icy grains of interstellar dust.

225
00:10:14.310 --> 00:10:17.230
Anna: In these frigid environments, sulphur atoms

226
00:10:17.230 --> 00:10:19.270
can arrange themselves in two main

227
00:10:19.990 --> 00:10:22.030
neat eight atom rings called

228
00:10:22.030 --> 00:10:24.909
octasulfur crowns and chains of

229
00:10:24.909 --> 00:10:27.670
sulphur atoms connected by hydrogen, known

230
00:10:27.670 --> 00:10:30.470
as polysulfons. These structures

231
00:10:30.630 --> 00:10:33.190
literally stick to icy dust grains,

232
00:10:33.190 --> 00:10:35.510
essentially freezing the sulphur out of view.

233
00:10:35.990 --> 00:10:38.910
Avery: It's fascinating how a common element on Earth found in

234
00:10:38.910 --> 00:10:41.390
volcanoes and power plants can be so

235
00:10:41.390 --> 00:10:44.270
elusive in space. Ralph Kaiser, one of the

236
00:10:44.270 --> 00:10:47.230
lead researchers, explained that the observed amount of sulphur

237
00:10:47.230 --> 00:10:50.230
in dense molecular clouds is three orders of

238
00:10:50.230 --> 00:10:52.750
magnitude less than predicted gas phase

239
00:10:52.750 --> 00:10:55.110
abundances. That's a huge difference.

240
00:10:55.350 --> 00:10:58.150
Anna: Astronomers typically identify elements in

241
00:10:58.150 --> 00:11:01.030
space by detecting the unique patterns of light

242
00:11:01.030 --> 00:11:03.990
they emit or absorb. While tools like

243
00:11:04.370 --> 00:11:07.090
James Webb Space Telescope can easily pick out

244
00:11:07.090 --> 00:11:10.010
oxygen, carbon and nitrogen, sulphur

245
00:11:10.010 --> 00:11:12.690
just doesn't follow the rules in the same way. As

246
00:11:12.690 --> 00:11:15.570
researcher uh, Ryan Fortenberry noted, when you do that

247
00:11:15.570 --> 00:11:17.410
for sulphur, it's out of whack.

248
00:11:17.570 --> 00:11:20.130
Avery: Another challenge is sulfur's shape. Shifting

249
00:11:20.130 --> 00:11:23.010
nature. Fortenberry likened it to a virus

250
00:11:23.090 --> 00:11:25.890
always changing shape as it moves, making it

251
00:11:25.890 --> 00:11:28.770
incredibly difficult to track. But this new research

252
00:11:28.770 --> 00:11:31.690
points to stable molecular forms that astronomers can

253
00:11:31.690 --> 00:11:34.690
now specifically hunt for using advanced radio

254
00:11:34.690 --> 00:11:35.330
telescopes.

255
00:11:35.750 --> 00:11:38.470
Anna: By recreating the conditions of deep space in

256
00:11:38.470 --> 00:11:41.350
laboratory experiments, the researchers confirmed

257
00:11:41.350 --> 00:11:44.350
that these solid sulphur compounds could indeed

258
00:11:44.350 --> 00:11:47.190
form on icy surfaces. And here's

259
00:11:47.190 --> 00:11:50.110
the Once these icy grains are heated in young

260
00:11:50.110 --> 00:11:52.710
star systems, the sulphur can sublime,

261
00:11:52.870 --> 00:11:55.870
meaning it transforms directly from a solid to a

262
00:11:55.870 --> 00:11:58.790
gas, making it finally detectable from Earth.

263
00:11:59.030 --> 00:12:01.550
Avery: This work could finally help astronomers piece together

264
00:12:01.550 --> 00:12:04.510
sulfur's role in both the formation of planets and

265
00:12:04.510 --> 00:12:07.420
the very chemistry that supports life. If they can

266
00:12:07.420 --> 00:12:10.300
pinpoint exactly where sulphur is stored, it could

267
00:12:10.300 --> 00:12:13.020
deepen our understanding of how essential life building

268
00:12:13.020 --> 00:12:15.750
elements are distributed across the cosmos. And, um,

269
00:12:15.860 --> 00:12:18.460
even improve models of planetary atmospheres,

270
00:12:18.540 --> 00:12:20.060
especially for exoplanets.

271
00:12:20.140 --> 00:12:22.979
Anna: It's a perfect example of astrochemistry

272
00:12:22.979 --> 00:12:25.900
forcing hard questions and leading to creative

273
00:12:25.900 --> 00:12:28.860
solutions. As Fortenberry put it, this

274
00:12:28.860 --> 00:12:31.740
kind of foundational research has the potential for

275
00:12:31.820 --> 00:12:34.700
significant unintended positive consequences

276
00:12:35.020 --> 00:12:37.500
for our broader understanding of the universe.

277
00:12:38.070 --> 00:12:39.510
Avery: That's a great point, Anna.

278
00:12:39.670 --> 00:12:42.310
Speaking of profound insights into how celestial

279
00:12:42.310 --> 00:12:44.990
bodies form, our next story completely

280
00:12:44.990 --> 00:12:47.950
redefines what we thought we knew about Vesta, one

281
00:12:47.950 --> 00:12:50.710
of the largest objects in the asteroid belt. For

282
00:12:50.710 --> 00:12:53.270
years, astronomers viewed Vesta as almost a

283
00:12:53.270 --> 00:12:56.150
miniature version of Earth, something between a rock

284
00:12:56.150 --> 00:12:59.030
in space and a full fledged planet due to its

285
00:12:59.030 --> 00:13:02.030
rocky surface, distinct layers, and volcanic

286
00:13:02.030 --> 00:13:02.310
history.

287
00:13:02.950 --> 00:13:05.750
Anna: But new research is truly shaking up that

288
00:13:05.750 --> 00:13:08.310
view. Data collected from NASA's dawn

289
00:13:08.310 --> 00:13:11.080
spacecraft, reanalyzed years later,

290
00:13:11.240 --> 00:13:13.880
is rewriting our understanding of how early

291
00:13:13.960 --> 00:13:16.760
planets may have formed and what might have gone wrong

292
00:13:16.760 --> 00:13:17.960
in Vesta's case.

293
00:13:18.000 --> 00:13:20.560
Avery: M the Dante spacecraft orbited Vesta from

294
00:13:20.560 --> 00:13:23.400
2011 to 2012, meticulously

295
00:13:23.400 --> 00:13:25.880
mapping its surface and measuring its gravity.

296
00:13:26.120 --> 00:13:28.680
Initially, this data suggested Vesta had

297
00:13:28.680 --> 00:13:31.640
undergone planetary differentiation, the

298
00:13:31.640 --> 00:13:34.320
process where dense materials sink to form a

299
00:13:34.320 --> 00:13:37.200
core and lighter materials create a mantle

300
00:13:37.200 --> 00:13:39.610
and crust. The Just like Earth or Mars,

301
00:13:40.170 --> 00:13:43.130
Vesta's volcanic surface seemed to confirm this.

302
00:13:43.930 --> 00:13:46.850
Anna: However, a decade after Dawn's mission ended

303
00:13:46.850 --> 00:13:49.850
in 2018, researchers at NASA's Jet

304
00:13:49.850 --> 00:13:52.810
Propulsion Lab, or JPL, decided to take

305
00:13:52.810 --> 00:13:55.610
a fresh look at the data, using better calibration

306
00:13:55.850 --> 00:13:58.770
and updated processing tools. And what they

307
00:13:58.770 --> 00:14:01.210
found completely challenged that long held

308
00:14:02.010 --> 00:14:04.490
Vesta may not have a core at all.

309
00:14:05.040 --> 00:14:07.840
Avery: That's a huge revelation. Ryan Park, a

310
00:14:07.840 --> 00:14:10.440
senior research scientist and principal engineer at

311
00:14:10.440 --> 00:14:13.040
jpl, expressed excitement, saying

312
00:14:13.200 --> 00:14:16.200
they were thrilled to confirm the data's strength in revealing

313
00:14:16.200 --> 00:14:18.720
Vesta's deep interior. By

314
00:14:18.720 --> 00:14:21.560
reanalyzing the dawn data, the team made a more

315
00:14:21.560 --> 00:14:24.400
precise estimate of, uh, Vesta's moment of

316
00:14:24.400 --> 00:14:25.040
inertia.

317
00:14:25.520 --> 00:14:28.360
Anna: For those wondering, the moment of inertia is a

318
00:14:28.360 --> 00:14:31.200
physics concept that reveals how mass is

319
00:14:31.200 --> 00:14:33.360
distributed within a rotating body.

320
00:14:34.100 --> 00:14:36.940
Assistant Professor Seth Jacobson of Michigan State

321
00:14:36.940 --> 00:14:39.300
University explained it with a simple

322
00:14:40.340 --> 00:14:43.140
Think of a figure skater. When they pull their

323
00:14:43.140 --> 00:14:46.060
arms in, they spin faster. When they stretch their

324
00:14:46.060 --> 00:14:49.020
arms out, they slow down. Celestial bodies

325
00:14:49.020 --> 00:14:51.900
with dense cores behave like skaters with their

326
00:14:51.900 --> 00:14:54.100
arms in rotating differently.

327
00:14:54.340 --> 00:14:57.260
Avery: And Vesta's behaviour simply didn't match what scientists

328
00:14:57.260 --> 00:15:00.180
expected from a core bearing body. Its

329
00:15:00.180 --> 00:15:02.600
moment of inertia and calculated at only

330
00:15:02.600 --> 00:15:05.560
6.6% lower than a perfectly

331
00:15:05.560 --> 00:15:08.280
uniform structure suggests its internal

332
00:15:08.280 --> 00:15:11.040
structure is. Surprisingly, even this

333
00:15:11.040 --> 00:15:14.040
value points to only a mild difference in density

334
00:15:14.040 --> 00:15:16.880
beneath its crust, not the deep layering

335
00:15:16.880 --> 00:15:19.320
we see in fully differentiated planets.

336
00:15:20.040 --> 00:15:22.760
Anna: This new perspective has forced scientists to

337
00:15:22.760 --> 00:15:25.440
rethink everything they thought they knew about Vesta's

338
00:15:25.440 --> 00:15:28.160
formation. They're now exploring two main

339
00:15:28.160 --> 00:15:31.130
ideas. The first is that Vesta began to

340
00:15:31.130 --> 00:15:34.050
differentiate. Its insides started to melt and

341
00:15:34.050 --> 00:15:36.370
separate into layers. But something

342
00:15:36.370 --> 00:15:39.090
interrupted the process. This could have been a

343
00:15:39.090 --> 00:15:42.090
late start in forming or limited exposure to

344
00:15:42.090 --> 00:15:45.049
heat producing elements like radioactive aluminium.

345
00:15:45.049 --> 00:15:47.890
Avery: 26 the second theory is even more

346
00:15:47.890 --> 00:15:50.690
dramatic. It suggests Vesta might be the

347
00:15:50.690 --> 00:15:52.930
shattered remnants of a much larger

348
00:15:52.930 --> 00:15:55.860
differentiated planet. That body could have been

349
00:15:55.860 --> 00:15:58.500
destroyed in a massive collision during the solar

350
00:15:58.500 --> 00:16:01.460
system's early years. And Vesta would then be just one

351
00:16:01.460 --> 00:16:04.460
of the reassembled pieces, essentially chunky

352
00:16:04.460 --> 00:16:07.420
space debris of, uh, a growing world that never

353
00:16:07.500 --> 00:16:10.060
quite made it. Seth Jacobson, who

354
00:16:10.060 --> 00:16:13.020
initially considered this idea a stretch years ago,

355
00:16:13.500 --> 00:16:14.940
now takes it seriously.

356
00:16:15.580 --> 00:16:18.180
Anna: The mystery deepens when you consider Vesta's

357
00:16:18.180 --> 00:16:21.100
meteorites. Researchers have collected thousands

358
00:16:21.100 --> 00:16:23.700
of space rocks on Earth believed to have come from

359
00:16:23.700 --> 00:16:26.460
Vesta. And these meteorites look like they

360
00:16:26.460 --> 00:16:29.180
formed in a molten environment showing signs of

361
00:16:29.180 --> 00:16:31.900
volcanic activity. However, they

362
00:16:31.900 --> 00:16:34.340
don't obviously suggest incomplete

363
00:16:34.340 --> 00:16:37.340
differentiation, which creates a problem for the

364
00:16:37.340 --> 00:16:39.460
first hypothesis of partial melting.

365
00:16:39.700 --> 00:16:42.620
Avery: That's quite the conundrum. The second idea,

366
00:16:42.620 --> 00:16:45.300
where Vesta is a remnant of a larger

367
00:16:45.300 --> 00:16:48.220
destroyed planet, might better explain the

368
00:16:48.220 --> 00:16:51.060
rocks by. But it also raises new questions

369
00:16:51.060 --> 00:16:53.660
about how such a colossal collision would occur.

370
00:16:54.140 --> 00:16:57.060
Jacobson's lab is actively modelling what those

371
00:16:57.060 --> 00:16:59.900
collisions m might have looked like and how debris like

372
00:16:59.900 --> 00:17:01.340
Vesta might have formed.

373
00:17:01.900 --> 00:17:04.900
Anna: Ultimately, Vesta's internal structure holds

374
00:17:04.900 --> 00:17:07.420
the key to understanding how planets grow

375
00:17:07.820 --> 00:17:10.300
or fail to. For a long time,

376
00:17:10.300 --> 00:17:12.380
Vesta seemed like a textbook

377
00:17:12.380 --> 00:17:15.260
protoplanet, an object that started forming

378
00:17:15.260 --> 00:17:17.870
but didn't quite make it. Now

379
00:17:18.110 --> 00:17:20.430
that picture has become much blurrier.

380
00:17:21.150 --> 00:17:24.150
Avery: Instead of being a failed planet, Vesta might

381
00:17:24.150 --> 00:17:26.870
be something even more intriguing. A, uh,

382
00:17:26.950 --> 00:17:29.870
survivor of cosmic violence. If it

383
00:17:29.870 --> 00:17:32.630
truly is a chunk of a planet destroyed in the

384
00:17:32.630 --> 00:17:35.470
early solar system, it could provide scientists

385
00:17:35.470 --> 00:17:38.350
with invaluable insights into the collisions

386
00:17:38.350 --> 00:17:41.110
and processes that shaped the worlds we see

387
00:17:41.110 --> 00:17:41.390
today.

388
00:17:42.420 --> 00:17:45.390
Anna: As Jacobsen puts it, no longer is the Vesta, um,

389
00:17:45.460 --> 00:17:48.420
meteorite collection a sample of a body in

390
00:17:48.420 --> 00:17:50.820
space that failed to make it as a planet.

391
00:17:51.300 --> 00:17:54.020
These could be pieces of an ancient planet

392
00:17:54.100 --> 00:17:57.100
before it grew to full completion. We just

393
00:17:57.100 --> 00:17:58.900
don't know which planet that is yet.

394
00:17:59.620 --> 00:18:02.620
Avery: This discovery is a powerful reminder that in

395
00:18:02.620 --> 00:18:05.340
science, answers often lead to more

396
00:18:05.340 --> 00:18:08.140
questions. This reanalysis of old

397
00:18:08.140 --> 00:18:11.020
data isn't just changing our understanding of one

398
00:18:11.020 --> 00:18:13.980
asteroid. It could reshape how researchers

399
00:18:13.980 --> 00:18:16.900
think about early planetary formation across the

400
00:18:16.900 --> 00:18:18.180
entire solar system.

401
00:18:18.900 --> 00:18:21.620
Anna: And that's it for this episode. What a

402
00:18:21.620 --> 00:18:24.180
journey we've had today. From the surprising

403
00:18:24.180 --> 00:18:27.180
seismic activity of our moon and the critical

404
00:18:27.180 --> 00:18:30.060
implications for future lunar bases, to the

405
00:18:30.060 --> 00:18:32.980
mind boggling explosion of a star trying to

406
00:18:32.980 --> 00:18:35.700
swallow a block whole, the universe

407
00:18:35.860 --> 00:18:37.540
certainly keeps us on our toes.

408
00:18:38.550 --> 00:18:41.430
Avery: Absolutely, Anna. Uh, and let's not forget the cosmic

409
00:18:41.430 --> 00:18:44.270
mystery of the missing sulphur, now believed to be

410
00:18:44.270 --> 00:18:46.790
hidden in icy dust, uh, grains. And the

411
00:18:46.790 --> 00:18:49.510
groundbreaking reanalysis of Vesta, which

412
00:18:49.590 --> 00:18:51.830
challenges its long held status as a

413
00:18:51.830 --> 00:18:54.350
protoplanet, suggesting it might be a

414
00:18:54.350 --> 00:18:56.070
fragment of a destroyed world.

415
00:18:56.710 --> 00:18:59.150
Anna: It's been a day packed with fascinating

416
00:18:59.150 --> 00:19:01.630
discoveries that push the boundaries of our

417
00:19:01.630 --> 00:19:02.230
understanding.

418
00:19:02.950 --> 00:19:05.750
Avery: Indeed. Thank you for joining us on Astronomy

419
00:19:05.750 --> 00:19:08.710
Daily. We hope you enjoyed diving into the latest space

420
00:19:08.710 --> 00:19:09.470
news with us.

421
00:19:10.030 --> 00:19:12.750
Anna: We look forward to having you back next time for more

422
00:19:12.750 --> 00:19:15.230
amazing insights from across the cosmos.

423
00:19:15.550 --> 00:19:17.390
Until then, keep looking up.