Earth's Ancient Impact Revealed: Dating the Oldest Crater and China's Cosmic Quest

WEBVTT

0
00:00:00.000 --> 00:00:02.584
Stuart Gary: This is space time series 29, episode

1
00:00:02.696 --> 00:00:05.557
83 for broadcast on 13 July

2
00:00:05.696 --> 00:00:08.480
2026. Coming up on Space Time.

3
00:00:08.880 --> 00:00:11.280
Planet Earth's earliest known asteroid impact

4
00:00:11.280 --> 00:00:14.000
site finally dated. A Chinese

5
00:00:14.000 --> 00:00:15.920
spacecraft has reached Earth's, uh, second

6
00:00:16.000 --> 00:00:18.960
moon and seafloor spreading seen

7
00:00:18.960 --> 00:00:21.280
in action on a large scale for the first

8
00:00:21.280 --> 00:00:24.240
time. All that and more coming up on,

9
00:00:24.240 --> 00:00:27.240
uh, Space Time. Welcome

10
00:00:27.240 --> 00:00:29.680
to Space Time with Stuart G.

11
00:00:46.060 --> 00:00:47.859
Scientists have determined the most precise

12
00:00:47.859 --> 00:00:50.500
age yet for the oldest known impact crater on

13
00:00:50.500 --> 00:00:52.140
Earth, finding it to be some

14
00:00:52.140 --> 00:00:54.780
3.024 billion years old.

15
00:00:55.420 --> 00:00:57.500
That makes it the only recognised impact

16
00:00:57.500 --> 00:01:00.020
crater from the Achaean Aeon, a time when the

17
00:01:00.020 --> 00:01:01.780
planet's earliest continents were still

18
00:01:01.780 --> 00:01:04.330
forming. The findings, reported in the

19
00:01:04.330 --> 00:01:06.770
journal Geology, provide new insights into

20
00:01:06.770 --> 00:01:09.090
how meteor strikes shaped the planet during

21
00:01:09.090 --> 00:01:12.010
its earliest history. The study's authors

22
00:01:12.010 --> 00:01:14.410
were investigating rock formations at North

23
00:01:14.410 --> 00:01:17.290
Pole Dome, a geological feature located in

24
00:01:17.290 --> 00:01:19.850
the Pilbara craton, um, some 1,600 kilometres

25
00:01:19.850 --> 00:01:21.810
north of Perth in the Western Australian

26
00:01:21.810 --> 00:01:24.570
Outback. The structure covers an area of

27
00:01:24.570 --> 00:01:27.370
around 30 by 40 kilometres and features a

28
00:01:27.370 --> 00:01:30.330
raised central dome about 16 kilometres in

29
00:01:30.330 --> 00:01:33.240
diameter. Some initial estimates suggest the

30
00:01:33.240 --> 00:01:35.440
broader original crater would have spanned up

31
00:01:35.440 --> 00:01:38.000
to 100 kilometres wide. The

32
00:01:38.000 --> 00:01:39.960
study's lead author, Chris Kirkland from

33
00:01:39.960 --> 00:01:42.280
Curtin University, says the findings helped

34
00:01:42.280 --> 00:01:44.800
resolve a long standing question about the

35
00:01:44.800 --> 00:01:47.720
timing of the impact. Kirkland says while the

36
00:01:47.720 --> 00:01:49.880
site had previously been identified as an

37
00:01:49.880 --> 00:01:52.400
ancient impact structure, its exact age

38
00:01:52.400 --> 00:01:55.160
remained uncertain. But the impact left

39
00:01:55.160 --> 00:01:57.400
behind chemical clocks dating the minerals

40
00:01:57.400 --> 00:01:59.560
that were remade or newly grown in the

41
00:01:59.560 --> 00:02:02.290
damaged rocks. Key evidence came from

42
00:02:02.290 --> 00:02:05.050
zircons, tiny but extraordinarily resilient

43
00:02:05.050 --> 00:02:07.890
minerals that can keep geological time for

44
00:02:07.890 --> 00:02:10.850
billions of years. Some of the zircons at

45
00:02:10.850 --> 00:02:13.050
North Pole Dome have unusual branching

46
00:02:13.050 --> 00:02:15.810
skeletal shapes. Herculans interpreted

47
00:02:15.810 --> 00:02:18.770
these as impact modified crystals formed

48
00:02:18.770 --> 00:02:20.730
when older zircons, uh, were disrupted,

49
00:02:20.730 --> 00:02:23.210
partly recrystallized and in places

50
00:02:23.210 --> 00:02:26.170
regrown during intense heating caused by the

51
00:02:26.170 --> 00:02:29.070
impact. These zircon uh crystals record

52
00:02:29.070 --> 00:02:31.870
an event around 3.024 billion

53
00:02:31.870 --> 00:02:34.230
years ago, which the authors believe is the

54
00:02:34.230 --> 00:02:37.230
best time estimate for the impact. To confirm

55
00:02:37.230 --> 00:02:39.390
the results, Kirkland and colleagues analysed

56
00:02:39.390 --> 00:02:41.990
a second mineral apatite, which formed as hot

57
00:02:41.990 --> 00:02:44.510
fluids moved through shock damaged rocks.

58
00:02:44.830 --> 00:02:47.030
And this independent dating method produced

59
00:02:47.030 --> 00:02:49.710
the same result. The agreement between

60
00:02:49.790 --> 00:02:52.350
two different mineral dating systems provides

61
00:02:52.350 --> 00:02:54.790
strong evidence of a signature for a single

62
00:02:54.790 --> 00:02:57.310
major event an asteroid meteor impact.

63
00:02:58.420 --> 00:03:00.580
Ancient impact craters are incredibly

64
00:03:00.580 --> 00:03:02.940
difficult to date. That's because over

65
00:03:02.940 --> 00:03:04.980
billions of years, things like plate

66
00:03:04.980 --> 00:03:07.820
tectonics and water and wind erosion erases

67
00:03:07.820 --> 00:03:10.380
impact structures. And rocks can be altered

68
00:03:10.380 --> 00:03:12.460
by Heat, pressure and fluids which can

69
00:03:12.460 --> 00:03:15.380
obscure or reset the original impact signals.

70
00:03:16.100 --> 00:03:18.780
Kirkland says this discovery pushes Earth's

71
00:03:18.780 --> 00:03:21.100
impact record much deeper into geological

72
00:03:21.100 --> 00:03:23.380
time than any previously well dated crater,

73
00:03:23.460 --> 00:03:25.540
offering a rare glimpse into the violent

74
00:03:25.540 --> 00:03:27.700
processes that shaped the early Earth.

75
00:03:27.700 --> 00:03:30.320
Professor Chris Kirkland : We find these shatter cones, the rocks in the

76
00:03:30.320 --> 00:03:32.240
Pilbara. So shatter cones are these special

77
00:03:32.560 --> 00:03:34.920
features within rocks that are the real

78
00:03:34.920 --> 00:03:37.600
smoking gun for an impact. So these are like

79
00:03:37.600 --> 00:03:39.600
upside down conical features within the

80
00:03:39.600 --> 00:03:41.360
rocks. But there was a bit of an outstanding

81
00:03:41.360 --> 00:03:44.000
question which was over the age of the

82
00:03:44.080 --> 00:03:46.680
rocks and the, indeed the impact event that

83
00:03:46.680 --> 00:03:49.320
caused these shatter cones. So, um, we

84
00:03:49.320 --> 00:03:51.760
managed to find some very delicate little

85
00:03:51.760 --> 00:03:53.880
features within the rocks themselves that

86
00:03:53.880 --> 00:03:55.960
created a new mineral. And that new mineral

87
00:03:55.960 --> 00:03:58.320
tells us about the intense heat of the impact

88
00:03:58.320 --> 00:04:01.000
and that dates it to a staggering 3 billion

89
00:04:01.000 --> 00:04:03.260
years old. So it's now the oldest impact

90
00:04:03.340 --> 00:04:04.460
crater on the planet.

91
00:04:04.460 --> 00:04:06.180
Stuart Gary: Now, this evidence, these minerals were

92
00:04:06.180 --> 00:04:08.500
zircons. What is it about zircons that makes

93
00:04:08.500 --> 00:04:10.940
them so unique as geological timekeepers?

94
00:04:10.940 --> 00:04:13.020
Professor Chris Kirkland : Yeah, the preeminent geological timekeeper,

95
00:04:13.020 --> 00:04:15.260
really. Geologist's best friend. It's really

96
00:04:15.260 --> 00:04:17.300
because they form quite readily, but once

97
00:04:17.300 --> 00:04:19.340
they're formed, they stay in the rock record.

98
00:04:19.420 --> 00:04:22.340
So they form because they contain a little

99
00:04:22.340 --> 00:04:24.340
bit of zirconium, but they also, when they

100
00:04:24.340 --> 00:04:26.460
grow, incorporate a little bit of uranium.

101
00:04:26.460 --> 00:04:28.560
And over time that uranium changes to lead.

102
00:04:28.560 --> 00:04:30.720
So it gives us this inbuilt stopwatch. Now,

103
00:04:30.720 --> 00:04:32.680
the neat thing about zircon is it while it's

104
00:04:32.680 --> 00:04:34.760
in the rock, it can change and

105
00:04:34.760 --> 00:04:37.760
recrystallize because of other processes, but

106
00:04:37.760 --> 00:04:40.160
it requires quite an extreme process to do

107
00:04:40.160 --> 00:04:43.080
that. So the zircons that

108
00:04:43.080 --> 00:04:45.120
were sitting about quite happily three and a

109
00:04:45.120 --> 00:04:46.920
half billion years ago, which is the age of

110
00:04:46.920 --> 00:04:49.320
the original rock that was there, got whacked

111
00:04:49.320 --> 00:04:51.840
by a huge impact event. And that impact event

112
00:04:51.840 --> 00:04:53.840
brought with a lot of energy and heat. And

113
00:04:53.840 --> 00:04:56.230
that heat recrystallized those zircon grains

114
00:04:56.230 --> 00:04:57.710
and it changed them into these beautiful

115
00:04:57.790 --> 00:04:59.790
forms that look like little lightning bolt

116
00:04:59.790 --> 00:05:01.870
within the rock. And those little zircons

117
00:05:01.870 --> 00:05:03.990
that are now lightning bolts give us the 3

118
00:05:03.990 --> 00:05:05.590
billion year old age. So it's a bit of

119
00:05:05.590 --> 00:05:07.270
detective work to piece that all together,

120
00:05:07.270 --> 00:05:09.390
but it gives us this really detailed history

121
00:05:09.390 --> 00:05:11.150
of the process that went on there.

122
00:05:11.230 --> 00:05:13.390
Stuart Gary: And how do you go about actually dating a

123
00:05:13.390 --> 00:05:14.830
zircon crystal? What's the process?

124
00:05:14.990 --> 00:05:17.110
Professor Chris Kirkland : Yeah, so it's a bit of laborious, pinstaking

125
00:05:17.110 --> 00:05:18.710
work, but what you do is you take, in this

126
00:05:18.710 --> 00:05:21.320
case, we took a slice of the rock, literally

127
00:05:21.320 --> 00:05:24.040
a little wafer of the rock. We cut it with a

128
00:05:24.040 --> 00:05:26.640
Rock saw with a diamond blade. And then we

129
00:05:26.640 --> 00:05:28.480
were able to use a range of different

130
00:05:28.480 --> 00:05:30.880
microscopic tools, literally everything from

131
00:05:30.880 --> 00:05:32.840
a light microscope to scanning electron

132
00:05:32.840 --> 00:05:35.000
microscope, to really go in and hunt in

133
00:05:35.000 --> 00:05:37.440
detail for these little zircon crystals. So

134
00:05:37.440 --> 00:05:39.560
the crystals themselves are really small.

135
00:05:39.560 --> 00:05:42.160
They're about 20 microns across. So you could

136
00:05:42.160 --> 00:05:44.280
fit quite a lot of them on top of a human

137
00:05:44.280 --> 00:05:46.520
hair, they're that small. And then what we

138
00:05:46.520 --> 00:05:48.950
did is we took those slices of rock and put

139
00:05:48.950 --> 00:05:51.310
them inside an instrument, an Australian

140
00:05:51.310 --> 00:05:52.870
built instrument, actually, it's called the

141
00:05:52.870 --> 00:05:55.150
shrimp, which stands for the sensitive high

142
00:05:55.150 --> 00:05:57.750
resolution ion microprobe. And that allows us

143
00:05:57.750 --> 00:06:00.550
to fire ion beams at the sample

144
00:06:00.710 --> 00:06:03.590
surface. So we targeted the zircon and

145
00:06:03.590 --> 00:06:06.230
we fired a beam of oxygen ions into that.

146
00:06:06.230 --> 00:06:08.750
Those ions, uh, ablated the surface or

147
00:06:08.750 --> 00:06:11.710
blasted the surface. And from that we were

148
00:06:11.710 --> 00:06:14.230
able to effectively count, using a

149
00:06:14.230 --> 00:06:16.670
glorified amplifier, the amount of uranium

150
00:06:16.670 --> 00:06:18.590
and lead ions that were coming off the

151
00:06:18.590 --> 00:06:21.090
surface. And because the ratio of uranium to

152
00:06:21.090 --> 00:06:23.370
lead is a clock, we were able to use that to

153
00:06:23.370 --> 00:06:25.610
calculate the age of the crystals. So it's

154
00:06:25.610 --> 00:06:28.090
really important that we use that beam based

155
00:06:28.090 --> 00:06:30.130
technique to fire beams into the crystals

156
00:06:30.130 --> 00:06:32.570
because we could find older crystals that

157
00:06:32.570 --> 00:06:35.370
were 3.5 billion years old that told us about

158
00:06:35.370 --> 00:06:38.010
the original edge of the rock that, uh, for a

159
00:06:38.010 --> 00:06:40.010
geologist is called the target rock. So we

160
00:06:40.010 --> 00:06:41.930
could work out the target rock edge, but we

161
00:06:41.930 --> 00:06:44.250
could also find these lightning bolts, like

162
00:06:44.250 --> 00:06:46.290
skeletal crystals, little skeletons of

163
00:06:46.290 --> 00:06:48.250
crystals, and they were the ones that are 3

164
00:06:48.250 --> 00:06:50.330
billion years old that help us understand the

165
00:06:50.330 --> 00:06:51.850
age of the impact event.

166
00:06:51.930 --> 00:06:53.730
Stuart Gary: And as well as the zircon, you're also able

167
00:06:53.730 --> 00:06:56.050
to find a second mineral which helped confirm

168
00:06:56.050 --> 00:06:56.490
the results.

169
00:06:56.810 --> 00:06:58.690
Professor Chris Kirkland : Yeah, that's right. So we were also able to

170
00:06:58.690 --> 00:07:01.290
find apatite. So apatite is a calcium

171
00:07:01.290 --> 00:07:03.970
phosphate mineral and it responds a little

172
00:07:03.970 --> 00:07:06.330
bit differently to zircon. So it also

173
00:07:06.730 --> 00:07:08.770
grows with a little bit of uranium. So

174
00:07:08.770 --> 00:07:10.690
because it's got a little bit uranium, we can

175
00:07:10.690 --> 00:07:12.490
look at the uranium lead ratio and that gives

176
00:07:12.490 --> 00:07:14.020
us an age for it. But if we look at the

177
00:07:14.020 --> 00:07:15.980
chemistry of the appetite, it's interesting.

178
00:07:15.980 --> 00:07:18.780
It's enriched in its kind of mid rare

179
00:07:18.780 --> 00:07:20.260
earth elements. And that's a very

180
00:07:20.260 --> 00:07:22.460
characteristic fingerprint for growth from

181
00:07:22.460 --> 00:07:24.780
hot water. So that's really interesting. So

182
00:07:24.780 --> 00:07:27.220
now we've got evidence for an event that

183
00:07:27.220 --> 00:07:29.379
brought an awful lot of heat at 3 billion

184
00:07:29.379 --> 00:07:31.860
years ago, and then an event roughly at about

185
00:07:31.860 --> 00:07:34.060
3 billion years ago that also involved a lot

186
00:07:34.060 --> 00:07:36.460
of hot water circulating and those two things

187
00:07:36.460 --> 00:07:38.980
put together in a rock that has shatter

188
00:07:38.980 --> 00:07:41.510
cones, a rock that's been Subject to

189
00:07:41.590 --> 00:07:44.070
impact shock tells us about an event

190
00:07:44.390 --> 00:07:46.790
that is the impact event itself at 3 billion

191
00:07:46.790 --> 00:07:47.230
years ago.

192
00:07:47.230 --> 00:07:49.870
Stuart Gary: Now, uh, usually when you're at a impact site

193
00:07:49.870 --> 00:07:51.830
and you fossil around, you can usually find

194
00:07:51.910 --> 00:07:54.710
little dark glassy balls on the surface.

195
00:07:54.710 --> 00:07:56.750
Spheres on the surface. Were they around or

196
00:07:56.750 --> 00:07:58.630
is this simply too old for those sort of

197
00:07:58.630 --> 00:07:59.430
things to still be there?

198
00:07:59.430 --> 00:08:01.470
Professor Chris Kirkland : Oh, uh, that's a lovely question because it

199
00:08:01.470 --> 00:08:03.670
actually gives us uh, an awful lot more

200
00:08:03.670 --> 00:08:05.630
information. So what you're talking about are

201
00:08:05.630 --> 00:08:07.670
called spherules and they're, when an impact

202
00:08:07.670 --> 00:08:10.620
hits, they will throw up uh, uh, material

203
00:08:10.620 --> 00:08:12.980
from the surface and it will rain down as

204
00:08:12.980 --> 00:08:15.020
glassy little balls. You can imagine all the

205
00:08:15.020 --> 00:08:17.020
energy that came into the planet. Now what's

206
00:08:17.020 --> 00:08:19.020
really interesting about this site in North

207
00:08:19.020 --> 00:08:21.620
Pole, probably about a decade ago in the

208
00:08:21.620 --> 00:08:23.620
Tilburg, there was actually in the same part

209
00:08:23.620 --> 00:08:25.700
of the stratigraphy where we managed to find

210
00:08:25.700 --> 00:08:27.580
the shatter cones, there was evidence found

211
00:08:27.580 --> 00:08:29.900
of these glassy black

212
00:08:29.980 --> 00:08:32.380
balls, these spherules. And um, that was

213
00:08:32.380 --> 00:08:34.960
taken as evidence of an ancient impact. So

214
00:08:34.960 --> 00:08:37.160
the reason this is really interesting is the

215
00:08:37.160 --> 00:08:39.800
rock that contains the shatter cones also

216
00:08:39.800 --> 00:08:42.520
contains these little glass balls, these

217
00:08:42.520 --> 00:08:44.400
spherules. So it actually has to tell us

218
00:08:44.400 --> 00:08:46.720
about an even older impact event. So this

219
00:08:46.720 --> 00:08:49.440
rock that contains the North Pole crater,

220
00:08:49.440 --> 00:08:52.280
that formed the shatter cones even earlier in

221
00:08:52.280 --> 00:08:54.600
its history must have been hit and

222
00:08:54.600 --> 00:08:57.400
incorporated these little glass balls and

223
00:08:57.400 --> 00:09:00.290
that pieces together to tell us about the

224
00:09:00.290 --> 00:09:02.850
early Earth and the impact history on the

225
00:09:02.850 --> 00:09:04.810
early Earth. So you know, we can go out and

226
00:09:04.810 --> 00:09:06.770
look at the Moon on a cloudless night. The

227
00:09:06.770 --> 00:09:08.890
first thing we see is the impact craters on

228
00:09:08.890 --> 00:09:11.290
it. But Earth has remarkably few impact

229
00:09:11.370 --> 00:09:13.490
craters. So the nice thing that we're able to

230
00:09:13.490 --> 00:09:16.450
now start to piece together is that the

231
00:09:16.450 --> 00:09:18.930
earlier Earth matched. Probably it was like

232
00:09:18.930 --> 00:09:21.210
the Moon record. It was getting pummelling by

233
00:09:21.210 --> 00:09:23.210
impact craters. And it's just that on Earth

234
00:09:23.370 --> 00:09:25.610
we've got erosion and plate tectonics that

235
00:09:25.670 --> 00:09:26.890
ah, remove all that evidence.

236
00:09:26.890 --> 00:09:28.610
Stuart Gary: And what is it about the North Pole Dome

237
00:09:28.610 --> 00:09:31.580
region that allowed the, the usual erosion

238
00:09:31.580 --> 00:09:33.620
of this evidence to be halted somewhat?

239
00:09:33.700 --> 00:09:35.500
Professor Chris Kirkland : Yeah, that's right. It's just a really

240
00:09:35.500 --> 00:09:37.140
special place. But it's a really special

241
00:09:37.140 --> 00:09:39.660
place because of its age and also because it

242
00:09:39.660 --> 00:09:42.420
hasn't been cooked up and metamorphosed. So

243
00:09:42.420 --> 00:09:44.190
it's one of these really special places that

244
00:09:44.190 --> 00:09:45.779
uh, is just being preserved.

245
00:09:45.779 --> 00:09:48.540
It's not really at high metamorphic grade. So

246
00:09:48.540 --> 00:09:50.940
in other words, it's not been subducted, it's

247
00:09:50.940 --> 00:09:53.860
not being heavily taken to depth.

248
00:09:53.940 --> 00:09:56.220
So it's pretty much always been floating

249
00:09:56.220 --> 00:09:58.380
around as this really Old piece of Earth's

250
00:09:58.380 --> 00:10:00.900
surface. So there are other bits like this in

251
00:10:00.900 --> 00:10:03.180
Canada and other places in Western Australia,

252
00:10:03.180 --> 00:10:05.180
but they're very few and far between. So it's

253
00:10:05.180 --> 00:10:07.300
really this deep time archive of our planet

254
00:10:07.300 --> 00:10:08.500
and it's why it's so special.

255
00:10:08.660 --> 00:10:11.100
Stuart Gary: Okay, you've worked out a date, you pretty

256
00:10:11.100 --> 00:10:13.500
well know what it was. What happens next?

257
00:10:13.500 --> 00:10:15.460
Where does one go to now? Are you going to

258
00:10:15.460 --> 00:10:17.500
try and work out what type of meteorite it

259
00:10:17.500 --> 00:10:20.340
was? Are you going to try and work out what

260
00:10:20.340 --> 00:10:21.900
direction it came from? Is that even

261
00:10:21.900 --> 00:10:23.180
possible? Where to next?

262
00:10:23.180 --> 00:10:25.260
Professor Chris Kirkland : Yeah, so I think, you know, because it's such

263
00:10:25.260 --> 00:10:28.230
an old impact site, it probably several

264
00:10:28.230 --> 00:10:31.150
kilometres underground and that we've

265
00:10:31.150 --> 00:10:33.190
stripped off quite a bit of the surface above

266
00:10:33.190 --> 00:10:35.070
it. So it doesn't look like a crater. You

267
00:10:35.070 --> 00:10:37.090
know, the land surface today there is, um,

268
00:10:37.090 --> 00:10:39.070
what was a beautiful bit of the outback. It's

269
00:10:39.070 --> 00:10:40.790
not an obvious crater unless you're a

270
00:10:40.790 --> 00:10:42.430
geologist walking over the ground and seeing

271
00:10:42.430 --> 00:10:44.230
the shatter cones. But I think one of the

272
00:10:44.230 --> 00:10:46.710
really interesting things about this site is

273
00:10:46.710 --> 00:10:49.030
it gives us an opportunity to understand what

274
00:10:49.030 --> 00:10:51.350
other processes, other chemical reactions,

275
00:10:51.350 --> 00:10:53.590
happened in the crust at the same time as an

276
00:10:53.590 --> 00:10:55.950
impact came in. So we can see all these veins

277
00:10:55.950 --> 00:10:58.050
and all these other geologists would call

278
00:10:58.050 --> 00:11:00.490
hydrothermal processes. So processes related

279
00:11:00.490 --> 00:11:03.210
to hot water penetrating through the rocks

280
00:11:03.210 --> 00:11:04.730
and modifying the rocks and creating all

281
00:11:04.730 --> 00:11:06.250
these different chemical reactions. So I

282
00:11:06.250 --> 00:11:07.850
think that's really important to understand

283
00:11:08.170 --> 00:11:10.730
those, uh, reactions and how they

284
00:11:10.890 --> 00:11:12.970
developed within the rocks, because those are

285
00:11:12.970 --> 00:11:14.330
the sorts of reactions that, uh, might have

286
00:11:14.330 --> 00:11:16.210
been important for other things happening at

287
00:11:16.210 --> 00:11:18.330
around that time, including potentially

288
00:11:18.330 --> 00:11:20.290
modifying what early life we had on the

289
00:11:20.290 --> 00:11:20.610
planet.

290
00:11:20.610 --> 00:11:22.130
Stuart Gary: Yeah, that's another thing often found at

291
00:11:22.130 --> 00:11:24.290
impact site. The chemical processes that are

292
00:11:24.290 --> 00:11:26.290
going on, they act to encourage the

293
00:11:26.290 --> 00:11:27.690
development of life in those areas.

294
00:11:27.770 --> 00:11:29.900
Professor Chris Kirkland : Yeah, exactly right. So I think, you know,

295
00:11:30.060 --> 00:11:32.460
they essentially act like catalysts to help

296
00:11:32.460 --> 00:11:35.460
kickstart prebiotic chemical reactions. So,

297
00:11:35.460 --> 00:11:38.020
um, you're right, you know, a big impactor is

298
00:11:38.020 --> 00:11:40.460
bringing in huge amounts of energy. So that

299
00:11:40.460 --> 00:11:43.420
energy will create heat. Heat starts

300
00:11:43.420 --> 00:11:46.300
to percolate and move fluids about and, um,

301
00:11:46.300 --> 00:11:47.980
kickstart chemical reactions. So you're

302
00:11:47.980 --> 00:11:49.740
really looking at, you know, starting a

303
00:11:49.740 --> 00:11:51.740
cauldron and bubbling, bubbling things away.

304
00:11:51.740 --> 00:11:53.420
And that's where you start to think about the

305
00:11:53.420 --> 00:11:56.100
development of, of prebiotic chemistry. And

306
00:11:56.100 --> 00:11:58.880
that might even lead to. What's interesting

307
00:11:58.880 --> 00:12:01.680
in the North Pole area is, we know, in the

308
00:12:01.680 --> 00:12:04.520
rock mass there, even older in the rock mass.

309
00:12:04.520 --> 00:12:06.960
So before 3 billion, uh, years, so before

310
00:12:06.960 --> 00:12:09.000
this impact happened, we know from

311
00:12:09.000 --> 00:12:11.000
stromatolites that there was already some

312
00:12:11.000 --> 00:12:13.800
form of early fossilised life there.

313
00:12:13.880 --> 00:12:15.840
So I think what we're getting is a better

314
00:12:15.840 --> 00:12:18.000
picture on our ancient planet. Our ancient

315
00:12:18.000 --> 00:12:20.480
planet was hit by not just one meteorite but

316
00:12:20.480 --> 00:12:22.120
lots of meteorites. And those meteorites

317
00:12:22.120 --> 00:12:24.160
might have been important for early chemical

318
00:12:24.160 --> 00:12:25.960
reactions and potentially those are the exact

319
00:12:25.960 --> 00:12:28.650
sorts of places that might have been the um,

320
00:12:28.700 --> 00:12:31.140
cauldrons for early um, early life

321
00:12:31.140 --> 00:12:32.780
processes. So quite exciting.

322
00:12:33.100 --> 00:12:36.060
Stuart Gary: What was that area, what was the North Pole

323
00:12:36.060 --> 00:12:38.620
dome structure like 3 billion years ago?

324
00:12:38.620 --> 00:12:40.700
Professor Chris Kirkland : It would have been a day, 3 billion years ago

325
00:12:40.700 --> 00:12:43.699
when it got hit. But um, we know that um, our

326
00:12:43.699 --> 00:12:45.940
early planet was a ah, water world. So there

327
00:12:45.940 --> 00:12:48.060
would have been a probably near global ocean

328
00:12:48.060 --> 00:12:50.260
with probably only little small bits of

329
00:12:50.260 --> 00:12:52.020
continental crust sticking up above that

330
00:12:52.020 --> 00:12:54.060
ocean. And the evidence for that is really

331
00:12:54.060 --> 00:12:56.540
quite easy to see in the rocks there. They're

332
00:12:56.540 --> 00:12:59.140
basalt flows, so dark coloured rocks but

333
00:12:59.140 --> 00:13:01.500
they've got these beautiful ships that are

334
00:13:01.580 --> 00:13:03.900
very pristinely preserved within them that

335
00:13:03.900 --> 00:13:06.220
are called pillow basalts. So they've got

336
00:13:06.220 --> 00:13:08.660
pillow like ships. And we can see the same

337
00:13:08.660 --> 00:13:10.740
sort of thing happening today on Hawaii where

338
00:13:10.740 --> 00:13:13.020
you have uh, a basaltic magma erupting

339
00:13:13.020 --> 00:13:15.180
underwater and it forms these beautiful

340
00:13:15.180 --> 00:13:17.180
structures. So we know, we know that it was a

341
00:13:17.180 --> 00:13:19.540
wet planet where the meteorite hit and it

342
00:13:19.540 --> 00:13:21.500
struck that and would have vaporised a lot of

343
00:13:21.500 --> 00:13:24.050
water. That water would have condensed in the

344
00:13:24.050 --> 00:13:26.090
atmosphere, changing atmospheric composition

345
00:13:26.090 --> 00:13:27.610
but it would also have chucked up huge

346
00:13:27.610 --> 00:13:30.410
amounts of rock dust and uh, as well. So

347
00:13:30.410 --> 00:13:32.250
there have been a bit of a nuclear winter

348
00:13:32.250 --> 00:13:34.690
situation after that. But uh, longer, longer

349
00:13:34.690 --> 00:13:37.330
term processes I think uh, are interesting to

350
00:13:37.330 --> 00:13:38.570
think about and that's when we think about

351
00:13:38.570 --> 00:13:40.490
these long term chemical reactions that would

352
00:13:40.490 --> 00:13:42.130
have been kickstarted in the rock mass

353
00:13:42.130 --> 00:13:44.330
because of the immense uh, energy brought

354
00:13:44.330 --> 00:13:44.970
into the planet.

355
00:13:44.970 --> 00:13:46.730
Stuart Gary: You talk about immense energy that can come

356
00:13:46.730 --> 00:13:49.050
from both speed and mass. Do you have any

357
00:13:49.050 --> 00:13:51.140
idea how big the impact was?

358
00:13:51.220 --> 00:13:52.820
Professor Chris Kirkland : Yeah, that's a, that's a great question.

359
00:13:52.820 --> 00:13:54.580
That's actually quite challenging to get at.

360
00:13:54.580 --> 00:13:56.740
So I think that is one area that would be

361
00:13:56.740 --> 00:13:58.580
really interesting and important to look at.

362
00:13:58.580 --> 00:14:01.380
So to do those sorts of calculations, what

363
00:14:01.700 --> 00:14:04.380
you need to kind of do from the geological

364
00:14:04.380 --> 00:14:07.380
side is look at the extent of the uh, impact

365
00:14:07.380 --> 00:14:10.220
damage rocks, give you an idea of the size of

366
00:14:10.220 --> 00:14:12.700
the impactor that's still work ongoing.

367
00:14:12.700 --> 00:14:14.900
Another interesting point is that we also

368
00:14:14.900 --> 00:14:17.660
don't really have any clue what the impactor

369
00:14:17.660 --> 00:14:19.780
was. So that meteorite coming in, we don't

370
00:14:19.780 --> 00:14:21.300
really know anything about it. It was

371
00:14:21.300 --> 00:14:23.960
completely obviously vaporised. So trying to

372
00:14:23.960 --> 00:14:26.000
track down the chemistry of that is really

373
00:14:26.000 --> 00:14:27.480
challenging because there might be

374
00:14:27.480 --> 00:14:28.960
Essentially nothing of it left.

375
00:14:29.040 --> 00:14:31.520
Stuart Gary: That's Professor Chris Kirkland from Curtin

376
00:14:31.520 --> 00:14:34.480
University. And this is space time

377
00:14:35.040 --> 00:14:38.000
still to come. A Chinese spacecraft has

378
00:14:38.000 --> 00:14:40.400
just arrived at Earth's, uh, second moon and

379
00:14:40.400 --> 00:14:43.200
the process of sea floor spreading seen in

380
00:14:43.200 --> 00:14:46.200
great detail for the first time. All that and

381
00:14:46.200 --> 00:14:48.640
more still to come on, um, space time.

382
00:15:02.960 --> 00:15:05.640
China's Tien Wentu spacecraft has arrived at

383
00:15:05.640 --> 00:15:08.080
a temporary second moon orbiting the Earth.

384
00:15:08.160 --> 00:15:10.120
Although technically this object is actually

385
00:15:10.120 --> 00:15:12.640
a small near Earth asteroid which is orbiting

386
00:15:12.640 --> 00:15:15.440
in sync with the Earth around the sun, called

387
00:15:15.440 --> 00:15:18.400
469219 Kammaawila, which means

388
00:15:18.400 --> 00:15:20.840
oscillating celestial object in Hawaiian. It

389
00:15:20.840 --> 00:15:23.840
also goes by the name of 2016 HO3

390
00:15:24.200 --> 00:15:26.640
and it's one of seven so called quasi

391
00:15:26.640 --> 00:15:28.680
satellites which share Earth's, uh, orbital

392
00:15:28.680 --> 00:15:31.520
neighbourhood. Discovered in 2016, the

393
00:15:31.520 --> 00:15:34.440
asteroid is between 40 and 100 metres wide,

394
00:15:34.600 --> 00:15:36.840
making it the smallest asteroid ever visited.

395
00:15:37.240 --> 00:15:39.240
Many scientists think it could be a missing

396
00:15:39.240 --> 00:15:41.680
piece of the moon, blasted off during a major

397
00:15:41.680 --> 00:15:44.600
asteroid impact long ago. However,

398
00:15:44.600 --> 00:15:47.320
more recent analyses suggest it may simply be

399
00:15:47.320 --> 00:15:49.800
a common type of stony asteroid known as an

400
00:15:49.800 --> 00:15:52.480
ll Chondrite, whose surface has been severely

401
00:15:52.480 --> 00:15:54.360
weathered by the harsh space environment.

402
00:15:55.400 --> 00:15:57.680
Long term orbital analyses suggest that

403
00:15:57.680 --> 00:16:00.360
Kamaawela entered its current quasi satellite

404
00:16:00.360 --> 00:16:03.280
orbit around 100 years ago. The

405
00:16:03.280 --> 00:16:05.080
Chinese mission will spend the next nine

406
00:16:05.080 --> 00:16:07.240
months orbiting this intriguing asteroid,

407
00:16:07.400 --> 00:16:09.560
studying and mapping its surface features,

408
00:16:09.560 --> 00:16:12.080
the asteroid's motion through space, the way

409
00:16:12.080 --> 00:16:14.680
it rotates and spins and its composition.

410
00:16:15.080 --> 00:16:17.760
Tianwen 2 will also be looking for a place to

411
00:16:17.760 --> 00:16:20.320
touch down and collect around 100 grammes of

412
00:16:20.320 --> 00:16:22.920
regolith for sample return to Earth. Uh, the

413
00:16:22.920 --> 00:16:25.280
Tienwen 2 mission launched from the Zhaichang

414
00:16:25.280 --> 00:16:27.240
Satellite Launch Centre back in May last

415
00:16:27.240 --> 00:16:29.800
year. The name Tienwen means

416
00:16:29.800 --> 00:16:32.320
heavenly questions in Mandarin. The

417
00:16:32.320 --> 00:16:34.960
Tienwen 2 mission carries both a touch and go

418
00:16:34.960 --> 00:16:37.280
sampling system and an anchor and attach

419
00:16:37.280 --> 00:16:39.520
mechanism equipped with drills for collecting

420
00:16:39.520 --> 00:16:42.400
surface material. It will depart the asteroid

421
00:16:42.400 --> 00:16:45.080
next April before releasing a return capsule

422
00:16:45.080 --> 00:16:47.120
that should land back on Earth in November

423
00:16:47.120 --> 00:16:50.000
2027. Following its visit

424
00:16:50.000 --> 00:16:52.760
to Kamauliwa, Tian N2 will use a gravity

425
00:16:52.760 --> 00:16:54.920
assist manoeuvre to slingshot itself to the

426
00:16:54.920 --> 00:16:57.880
Comet 311P Pan stars arriving there

427
00:16:57.880 --> 00:16:59.600
in January 2035.

428
00:17:00.640 --> 00:17:03.560
Tianwen 2's predecessor, Tianwen 1, is a

429
00:17:03.560 --> 00:17:06.080
Mars Orbiter lander and rover mission that

430
00:17:06.080 --> 00:17:08.000
successfully touched down on the Red planet

431
00:17:08.000 --> 00:17:10.800
back in May 2021, releasing its Huron

432
00:17:10.800 --> 00:17:13.720
rover to study the planet's surface. The next

433
00:17:13.720 --> 00:17:16.080
mission, Tianwen 3 is slated for launch in

434
00:17:16.080 --> 00:17:18.890
2028 and right now it looks like becoming the

435
00:17:18.890 --> 00:17:21.210
first ever sample return mission to Mars.

436
00:17:21.290 --> 00:17:23.260
Bringing back Red planet regolith to uh,

437
00:17:23.290 --> 00:17:25.970
Earth in 2031. Meanwhile,

438
00:17:25.970 --> 00:17:28.890
Tianwen 4 will launch in 2030 as a pair

439
00:17:28.890 --> 00:17:31.090
of spacecraft with one bound for Jupiter

440
00:17:31.090 --> 00:17:32.970
where it will orbit the moon Callisto, and

441
00:17:32.970 --> 00:17:35.370
the other heading for a flyby of the planet

442
00:17:35.370 --> 00:17:38.210
Uranus. Needless to say, we'll

443
00:17:38.210 --> 00:17:40.970
keep you informed. This is space time

444
00:17:41.770 --> 00:17:44.580
still to come. Seafloor spreading seen

445
00:17:44.580 --> 00:17:46.940
in detail for the first time. And later in

446
00:17:46.940 --> 00:17:49.460
the Science report, development of a new

447
00:17:49.460 --> 00:17:51.820
vaccine which has the potential to protect

448
00:17:51.820 --> 00:17:54.420
people from developing aids. All that and

449
00:17:54.420 --> 00:17:56.940
more still to come on um, space time.

450
00:18:06.060 --> 00:18:08.660
Scientists studying a seafloor site southwest

451
00:18:08.660 --> 00:18:10.910
of Australia have for the first time actually

452
00:18:10.910 --> 00:18:13.390
captured how molten rock emerges at

453
00:18:13.390 --> 00:18:15.470
boundaries between the Earth's tectonic

454
00:18:15.470 --> 00:18:18.150
plates. A report in the journal Nature

455
00:18:18.150 --> 00:18:20.030
claims researchers set up instruments

456
00:18:20.030 --> 00:18:22.430
monitoring seismic activity in seafloor

457
00:18:22.430 --> 00:18:25.270
changes around 2 kilometres underwater along

458
00:18:25.270 --> 00:18:28.110
a 2.5 kilometre long stretch of the Southeast

459
00:18:28.110 --> 00:18:30.270
Indian Ridge, which is the boundary between

460
00:18:30.270 --> 00:18:32.670
the Australian and Antarctic plates.

461
00:18:33.070 --> 00:18:35.270
The mid ocean ridges are uh, submarine

462
00:18:35.270 --> 00:18:37.550
networks of tectonic boundaries. A new

463
00:18:37.550 --> 00:18:40.060
oceanic crust is formed from cooling magma

464
00:18:40.060 --> 00:18:42.460
and added to the seafloor. While

465
00:18:42.460 --> 00:18:44.420
2/3 of the Earth's, uh, surface has been

466
00:18:44.420 --> 00:18:46.500
created by these ridges, little is actually

467
00:18:46.500 --> 00:18:48.860
known about how they behave during discrete

468
00:18:48.860 --> 00:18:51.340
spreading events. Two months into their

469
00:18:51.340 --> 00:18:53.020
study, the authors measured earthquake

470
00:18:53.020 --> 00:18:55.460
activity and the ocean floor sinking by about

471
00:18:55.460 --> 00:18:58.460
4.2 metres as millions of cubic metres

472
00:18:58.460 --> 00:19:00.540
of magma that had been stored underneath

473
00:19:00.620 --> 00:19:02.860
poured out to form new seafloor.

474
00:19:03.660 --> 00:19:06.260
They suggest this deformation was due to the

475
00:19:06.260 --> 00:19:08.980
deflation of a 2.5 kilometre wide magma

476
00:19:08.980 --> 00:19:11.840
reservoir located some 3.6 kilometres

477
00:19:11.840 --> 00:19:14.520
below the crust. The event released

478
00:19:14.520 --> 00:19:17.360
upwards of 160 million cubic metres of

479
00:19:17.360 --> 00:19:20.120
lava onto the seafloor. The seafloor

480
00:19:20.120 --> 00:19:22.280
movement peaked directly after the earthquake

481
00:19:22.280 --> 00:19:24.760
event at 5 centimetres per minute before

482
00:19:24.760 --> 00:19:27.240
slowing to 1.2 centimetres per day

483
00:19:27.480 --> 00:19:30.320
seven days later. The authors say there must

484
00:19:30.320 --> 00:19:32.480
have been decades of strain buildup at the

485
00:19:32.480 --> 00:19:34.760
plate boundaries until the ground and magma

486
00:19:34.760 --> 00:19:37.120
movement finally released it in a seafloor

487
00:19:37.120 --> 00:19:39.940
spreading event. This is space time.

488
00:20:03.710 --> 00:20:03.950
Professor Chris Kirkland : Foreign.

489
00:20:11.230 --> 00:20:13.030
Stuart Gary: Look at some of the other storeys making news

490
00:20:13.030 --> 00:20:15.150
in Science this week with the Science report.

491
00:20:16.030 --> 00:20:18.310
Researchers have developed a new vaccine with

492
00:20:18.310 --> 00:20:20.150
the potential to protect people from

493
00:20:20.150 --> 00:20:22.750
developing HIV aids. The

494
00:20:22.750 --> 00:20:25.070
findings reported in the journal Nature show

495
00:20:25.070 --> 00:20:27.590
that this new drug is the first to generate a

496
00:20:27.590 --> 00:20:30.030
high number of broadly neutralising virus

497
00:20:30.030 --> 00:20:32.710
fighting antibodies. The new vaccine

498
00:20:32.710 --> 00:20:35.150
works by intervening in a process called B

499
00:20:35.150 --> 00:20:37.870
cell maturation. B cells make

500
00:20:37.870 --> 00:20:40.350
antibodies and like many immune cells, B

501
00:20:40.350 --> 00:20:42.590
cells have an early naive stage before

502
00:20:42.590 --> 00:20:45.190
they're ready to make antibodies, they start

503
00:20:45.190 --> 00:20:47.190
to mature, uh, once they get the signal that

504
00:20:47.190 --> 00:20:49.470
a pathogen such as a virus is trying to

505
00:20:49.470 --> 00:20:52.230
attack. They then identify pieces of the

506
00:20:52.230 --> 00:20:54.270
pathogen's molecular structure and start

507
00:20:54.270 --> 00:20:56.590
producing antibodies that can bind to that

508
00:20:56.590 --> 00:20:59.430
structure and halt infection. As they

509
00:20:59.430 --> 00:21:01.470
mature, B cells tweak their antibody

510
00:21:01.470 --> 00:21:03.870
production, refining antibody structures to

511
00:21:03.870 --> 00:21:05.910
bind to a pathogen in just the right

512
00:21:05.990 --> 00:21:08.110
vulnerable places. But

513
00:21:08.110 --> 00:21:10.990
HIV's been hard to beat because it mutates

514
00:21:10.990 --> 00:21:13.310
very quickly, changes its shape when it

515
00:21:13.310 --> 00:21:15.790
infects human cells and is wrapped in an ever

516
00:21:15.790 --> 00:21:18.390
shifting cloak of sugar molecules, disguising

517
00:21:18.390 --> 00:21:20.630
itself from the immune system and not giving

518
00:21:20.630 --> 00:21:22.510
B cells the chance to develop effective

519
00:21:22.510 --> 00:21:25.110
antibodies. The newly developed broadly

520
00:21:25.110 --> 00:21:27.390
neutralising antibodies were first discovered

521
00:21:27.390 --> 00:21:29.310
in blood samples from a small number of

522
00:21:29.310 --> 00:21:32.210
people l hiv and these unique

523
00:21:32.210 --> 00:21:34.490
antibodies could recognise key viral

524
00:21:34.490 --> 00:21:36.490
structures even if the rest of the virus

525
00:21:36.490 --> 00:21:39.290
mutates. The human immunodeficiency

526
00:21:39.290 --> 00:21:41.730
virus, ah, HIV attacks the immune system,

527
00:21:41.810 --> 00:21:44.410
causing Acquired Immunodeficiency Syndrome,

528
00:21:44.410 --> 00:21:47.250
or aids. AIDS allows opportunistic

529
00:21:47.250 --> 00:21:49.450
diseases, normally easily combated by the

530
00:21:49.450 --> 00:21:51.770
body, to take hold and eventually kill the

531
00:21:51.770 --> 00:21:54.490
patient. The World Health Organisation says

532
00:21:54.490 --> 00:21:56.610
that since first being identified back in

533
00:21:56.610 --> 00:21:59.130
1981, AIDS has killed more than

534
00:21:59.130 --> 00:22:02.090
43 million people globally and has infected

535
00:22:02.090 --> 00:22:04.450
up to 113 million others, with

536
00:22:04.450 --> 00:22:07.370
1.3 million new infections recorded annually.

537
00:22:07.930 --> 00:22:10.730
HIV is transmitted through bodily fluids.

538
00:22:11.210 --> 00:22:13.690
Currently, there is no cure, although it can

539
00:22:13.690 --> 00:22:16.170
be controlled using a combination of complex

540
00:22:16.170 --> 00:22:17.370
drug cocktails.

541
00:22:18.730 --> 00:22:21.210
A new study warns that losing even a small

542
00:22:21.210 --> 00:22:23.370
amount of sleep each night could be linked to

543
00:22:23.370 --> 00:22:25.970
weight gain. The findings, reported in the

544
00:22:25.970 --> 00:22:27.890
Journal of the Annals of Internal Medicine,

545
00:22:27.890 --> 00:22:30.130
analysed two previous studies which included

546
00:22:30.130 --> 00:22:32.710
some 95 adults over the age of 20, uh, who

547
00:22:32.710 --> 00:22:35.550
normally got at least seven hours sleep. They

548
00:22:35.550 --> 00:22:37.670
found that decreasing sleep by, uh, just an

549
00:22:37.670 --> 00:22:39.750
hour and a half each night was linked to

550
00:22:39.750 --> 00:22:42.070
increases in body weight, waist circumference

551
00:22:42.070 --> 00:22:44.990
and heart and metabolic risks. The authors

552
00:22:44.990 --> 00:22:46.870
also noticed that people tend to be less

553
00:22:46.870 --> 00:22:49.150
active than usual when they have not had much

554
00:22:49.150 --> 00:22:51.310
sleep. That could also be a contributing

555
00:22:51.310 --> 00:22:52.630
factor to weight gain.

556
00:22:53.990 --> 00:22:56.310
Scientists say the algal bloom that polluted

557
00:22:56.310 --> 00:22:58.430
South Australian coastlines last year was the

558
00:22:58.430 --> 00:23:01.110
most toxic species of its kind ever studied.

559
00:23:01.830 --> 00:23:03.510
Findings reported in the journal Nature

560
00:23:03.510 --> 00:23:05.710
Ecology and Evolution followed last year's

561
00:23:05.710 --> 00:23:07.350
identification of the Microalga

562
00:23:07.350 --> 00:23:09.470
coryniacaestata as the source of the

563
00:23:09.470 --> 00:23:12.470
neurotoxin. The research by scientists at

564
00:23:12.470 --> 00:23:14.590
the University of Technology Sydney shows

565
00:23:14.590 --> 00:23:16.590
that Karenia cristata is an order of

566
00:23:16.590 --> 00:23:19.070
magnitude more toxic than the next most toxic

567
00:23:19.070 --> 00:23:21.990
microalgae ever studied. The devastating

568
00:23:22.070 --> 00:23:25.030
bloom lasted about 15 months and it

569
00:23:25.030 --> 00:23:26.710
still hasn't completely disappeared from

570
00:23:26.710 --> 00:23:29.010
South Australian waters. It's been

571
00:23:29.010 --> 00:23:30.970
responsible for the death of millions of

572
00:23:30.970 --> 00:23:32.890
fish, mammals, birds and marine

573
00:23:32.890 --> 00:23:33.730
invertebrates.

574
00:23:35.250 --> 00:23:37.490
China has test fired a nuclear capable

575
00:23:37.490 --> 00:23:39.810
missile across the Pacific Ocean just hours

576
00:23:39.810 --> 00:23:42.290
after Australia signed a new defence alliance

577
00:23:42.290 --> 00:23:45.090
with Fiji. The launch from a nuclear

578
00:23:45.090 --> 00:23:47.570
submarine in the South China Sea near Henan

579
00:23:47.570 --> 00:23:49.690
island splashed down between the Pacific

580
00:23:49.690 --> 00:23:52.690
islands of Tuvalu and Nauru. The test

581
00:23:52.770 --> 00:23:55.250
represents an escalation of Beijing's ongoing

582
00:23:55.250 --> 00:23:57.610
military expansion and was designed to send a

583
00:23:57.610 --> 00:23:59.810
clear warning to Australia, which is working

584
00:23:59.810 --> 00:24:01.790
to strengthen regional ties with Pacific

585
00:24:01.790 --> 00:24:03.990
island nations in order to counter China's

586
00:24:03.990 --> 00:24:06.070
efforts to expand its military presence in

587
00:24:06.070 --> 00:24:08.550
the region. So what do we know about the

588
00:24:08.550 --> 00:24:11.270
missile? Well, it was a JL3 submarine

589
00:24:11.270 --> 00:24:13.990
launched ballistic missile. It features a

590
00:24:13.990 --> 00:24:16.269
solid fuelled rocket motor and has a range of

591
00:24:16.269 --> 00:24:18.750
around 10,000 kilometres. The

592
00:24:18.750 --> 00:24:21.510
JL3 is MIRV capable, but usually

593
00:24:21.510 --> 00:24:24.070
carries a single 3 megaton thermonuclear

594
00:24:24.070 --> 00:24:26.590
warhead. They are launched from modified Type

595
00:24:26.590 --> 00:24:29.070
094 nuclear submarines which are based at

596
00:24:29.070 --> 00:24:31.470
Henan island in the South China Sea.

597
00:24:32.150 --> 00:24:34.600
Uh, now normally Beijing keeps its nuclear

598
00:24:34.600 --> 00:24:37.200
submarine fleet close to home, but this

599
00:24:37.200 --> 00:24:39.800
signals a clear escalation designed to let

600
00:24:39.800 --> 00:24:42.320
Western nations know that China is willing to

601
00:24:42.320 --> 00:24:44.720
send its nuclear submarine fleet much further

602
00:24:44.720 --> 00:24:47.679
afield. The Pentagon estimates China's

603
00:24:47.679 --> 00:24:49.360
nuclear stockpile currently includes more

604
00:24:49.360 --> 00:24:52.080
than 600 warheads, but says that's predicted

605
00:24:52.080 --> 00:24:54.520
to climb to over a thousand by 2030.

606
00:24:56.200 --> 00:24:58.680
What may well be Australia's most famous

607
00:24:58.680 --> 00:25:01.520
UFO sighting has just celebrated its 60th

608
00:25:01.520 --> 00:25:03.980
anniversary. The Westall High School

609
00:25:03.980 --> 00:25:06.660
UFO was seen by dozens of school kids and

610
00:25:06.660 --> 00:25:09.660
their teachers back in 1966. The

611
00:25:09.660 --> 00:25:11.660
sceptics, Timms Mendham, says even more

612
00:25:11.660 --> 00:25:13.620
intriguing than the mass sighting was how

613
00:25:13.620 --> 00:25:15.580
authorities tried to cover it all up.

614
00:25:15.580 --> 00:25:17.900
Tim Mendham: The 60th anniversary of this Westall sighting

615
00:25:17.900 --> 00:25:19.580
has just come around. So it got a bit of

616
00:25:19.580 --> 00:25:21.380
notice, the storey goes, that a young girl

617
00:25:21.380 --> 00:25:23.940
ran into a school at Westall, which is in

618
00:25:23.940 --> 00:25:25.820
southeast Melbourne, and this girl ran into

619
00:25:25.820 --> 00:25:27.460
the classroom saying, sir, sir, sir, there's

620
00:25:27.460 --> 00:25:29.500
a flying saucer outside. So all the kids went

621
00:25:29.500 --> 00:25:31.540
yay and all go running out. A teacher sort of

622
00:25:31.540 --> 00:25:33.180
went out as well. And then a lot of the kids

623
00:25:33.180 --> 00:25:35.040
in other classes went running out and they

624
00:25:35.120 --> 00:25:37.320
various numbers they reckoned of kids being

625
00:25:37.320 --> 00:25:40.160
out there. They saw a craft going through

626
00:25:40.160 --> 00:25:42.320
the sky, going a bit up and down, big speed,

627
00:25:42.320 --> 00:25:44.760
slow speed, supposedly landing, landing in a

628
00:25:44.760 --> 00:25:47.320
field nearby called the Grange. And then it

629
00:25:47.320 --> 00:25:49.480
took off again and some kids ran across to

630
00:25:49.480 --> 00:25:50.920
the Grange, you know, leaping over the

631
00:25:50.920 --> 00:25:52.360
fences, which they weren't supposed to do.

632
00:25:52.360 --> 00:25:54.680
And one of them, they came close and some of

633
00:25:54.680 --> 00:25:55.240
them felt they were

634
00:25:55.240 --> 00:25:56.160
Professor Chris Kirkland : even burned by it.

635
00:25:56.160 --> 00:25:58.480
Tim Mendham: Pretty soon after, police Turned up and

636
00:25:58.480 --> 00:26:00.560
military people turned up and we're talking

637
00:26:00.560 --> 00:26:02.640
to the kids and taking them aside saying, you

638
00:26:02.640 --> 00:26:04.640
know, you didn't see anything, you got to

639
00:26:04.640 --> 00:26:06.580
forget what you saw, don't tell anybody,

640
00:26:06.580 --> 00:26:08.420
blah, blah, blah. Supposedly said the same

641
00:26:08.420 --> 00:26:10.980
things to some of the teachers. And then the

642
00:26:10.980 --> 00:26:12.740
principal of the school said, do not talk

643
00:26:12.740 --> 00:26:14.660
about this to anybody. Don't talk to the

644
00:26:14.660 --> 00:26:16.420
press, don't talk to anyone neither. Some

645
00:26:16.420 --> 00:26:17.860
kids talk to the press and the press were

646
00:26:17.860 --> 00:26:20.140
there some photos that one of the teachers

647
00:26:20.140 --> 00:26:22.860
took disappeared mysteriously. A news

648
00:26:23.340 --> 00:26:25.620
storey or news film that was taken by a local

649
00:26:25.620 --> 00:26:27.780
TV station disappeared when they tried to

650
00:26:27.780 --> 00:26:29.940
find it years later. The kids gather every so

651
00:26:29.940 --> 00:26:32.140
often, every few years for a reunion and they

652
00:26:32.140 --> 00:26:34.340
all sort of discuss what they saw. Now,

653
00:26:34.340 --> 00:26:36.740
interesting, the drawings that people did of

654
00:26:36.740 --> 00:26:38.060
this thing vary.

655
00:26:38.060 --> 00:26:38.500
Professor Chris Kirkland : Okay.

656
00:26:38.500 --> 00:26:40.300
Tim Mendham: Some of them are quite round, some of them

657
00:26:40.300 --> 00:26:42.060
are saucer shaped, some of them have windows,

658
00:26:42.060 --> 00:26:43.900
some of them don't. One person even said they

659
00:26:43.900 --> 00:26:45.980
saw three, but most of them say they only saw

660
00:26:45.980 --> 00:26:48.540
one. What happens is that the suggestions

661
00:26:48.540 --> 00:26:50.780
were one, it's a ufo. Uh, that was very

662
00:26:50.780 --> 00:26:52.460
exciting, but they don't have a lot of

663
00:26:52.460 --> 00:26:53.380
evidence for that.

664
00:26:53.380 --> 00:26:55.300
Stuart Gary: The other thing is, is a UFO because it's

665
00:26:55.300 --> 00:26:55.820
unidentified?

666
00:26:55.820 --> 00:26:58.140
Tim Mendham: Well, yes, it is. Not. Not how we normally

667
00:26:58.140 --> 00:26:59.420
interpret the word. Right. Not a flying

668
00:26:59.420 --> 00:27:00.020
saucer.

669
00:27:00.020 --> 00:27:00.300
Professor Chris Kirkland : Right.

670
00:27:00.300 --> 00:27:02.890
Tim Mendham: The other thing was that is balloons, either

671
00:27:02.890 --> 00:27:05.810
a weather balloon or a specific balloon that

672
00:27:05.810 --> 00:27:07.730
was sort of sent up to do radiation testing.

673
00:27:07.730 --> 00:27:09.250
Don't forget that in those days there were

674
00:27:09.250 --> 00:27:10.610
radiation tests in Australia.

675
00:27:10.930 --> 00:27:13.290
Stuart Gary: This is the highball, high altitude balloon

676
00:27:13.290 --> 00:27:13.570
process.

677
00:27:13.810 --> 00:27:15.770
Tim Mendham: Yeah. And there was a weather balloon

678
00:27:15.770 --> 00:27:17.450
certainly sent up about the same time that

679
00:27:17.450 --> 00:27:19.130
morning from a place called Laverton, which

680
00:27:19.130 --> 00:27:21.570
is in the southwest of Melbourne, across the

681
00:27:21.570 --> 00:27:23.250
other side of the big bay that Melbourne is

682
00:27:23.250 --> 00:27:24.730
situated around. And it would have flown

683
00:27:24.730 --> 00:27:26.410
across to about Westall because the winds

684
00:27:26.410 --> 00:27:28.570
were coming from the westerly direction or

685
00:27:28.570 --> 00:27:30.650
southwesterly. And it would have been quite

686
00:27:30.650 --> 00:27:32.210
appropriate and quite reasonable to expect

687
00:27:32.210 --> 00:27:34.830
that it would blow over that way. Variable

688
00:27:34.830 --> 00:27:36.230
winds, gusty winds, it would go

689
00:27:36.230 --> 00:27:37.390
Professor Chris Kirkland : up and down, all sorts of things.

690
00:27:37.390 --> 00:27:40.270
Tim Mendham: The highball testing is even, possibly even

691
00:27:40.430 --> 00:27:42.430
more, ah, possible, although we don't have a

692
00:27:42.430 --> 00:27:44.390
lot of details of the actual launches of

693
00:27:44.390 --> 00:27:44.670
such.

694
00:27:44.730 --> 00:27:47.230
Stuart Gary: Uh, I believe, by the way, that's, that's

695
00:27:47.230 --> 00:27:48.030
what I think it was.

696
00:27:48.110 --> 00:27:48.310
Professor Chris Kirkland : Uh-huh.

697
00:27:48.350 --> 00:27:50.349
Tim Mendham: Yes. I tend to believe that too, actually,

698
00:27:50.349 --> 00:27:52.630
because it is more active and certainly can

699
00:27:52.630 --> 00:27:55.310
zip up at a rapid rate when the wind catches.

700
00:27:55.310 --> 00:27:56.710
Stuart Gary: And it would explain why the military got

701
00:27:56.710 --> 00:27:57.150
involved.

702
00:27:57.150 --> 00:27:58.750
Tim Mendham: Absolutely, yeah. There are also suggestions

703
00:27:58.750 --> 00:28:00.830
at times that there was small planes buzzing

704
00:28:00.830 --> 00:28:02.790
the UFO flying saucer that's what the kids

705
00:28:02.790 --> 00:28:04.590
report. They saw planes, five planes. It's

706
00:28:04.590 --> 00:28:05.790
right near an airport, so there'd be a

707
00:28:05.790 --> 00:28:07.290
plane's and down at the time. And if

708
00:28:07.290 --> 00:28:08.730
something said they saw something there, I'd

709
00:28:08.730 --> 00:28:10.770
be buzzing around it too. Finding records of

710
00:28:10.770 --> 00:28:12.490
this thing is difficult. That's one of the

711
00:28:12.490 --> 00:28:13.970
problem things. Yeah. The records are a bit

712
00:28:13.970 --> 00:28:15.730
incomplete, but yes, I would suggest that

713
00:28:15.730 --> 00:28:17.530
it's a balloon, weather balloon or a highball

714
00:28:17.530 --> 00:28:19.490
thing and that what they saw, it's silver,

715
00:28:19.490 --> 00:28:21.690
it's reflective distances are hard to gauge.

716
00:28:21.690 --> 00:28:23.170
Although people say it came down in the

717
00:28:23.170 --> 00:28:25.410
Grange, which is not that far away in this

718
00:28:25.410 --> 00:28:27.170
paddock. The excitement of the time is there

719
00:28:27.170 --> 00:28:30.090
was a time of high flying saucer fever. It

720
00:28:30.090 --> 00:28:31.770
was a topic at the time. If someone walked

721
00:28:31.770 --> 00:28:33.610
into a class and said, I saw a flying saucer,

722
00:28:33.610 --> 00:28:35.010
everyone knows what they're talking about and

723
00:28:35.010 --> 00:28:36.320
everyone gets very excited. And, um,

724
00:28:36.330 --> 00:28:38.950
everyone's already prime flying saucer. And

725
00:28:38.950 --> 00:28:40.350
this is the problem with the reunions and

726
00:28:40.350 --> 00:28:42.030
that sort of stuff, that they reinforce

727
00:28:42.030 --> 00:28:43.990
memories. And, um, as we know, as we've

728
00:28:43.990 --> 00:28:45.030
looked at other studies.

729
00:28:45.030 --> 00:28:46.710
Stuart Gary: Well, it's like the Mandela thing again,

730
00:28:46.710 --> 00:28:47.110
isn't it?

731
00:28:47.110 --> 00:28:49.030
Tim Mendham: Yeah. Reinforcing memories, saying I was

732
00:28:49.030 --> 00:28:50.550
there, saying this is what it looked like,

733
00:28:50.550 --> 00:28:52.230
all these sorts of things. Very convincing

734
00:28:52.230 --> 00:28:54.670
and convincingly told, but not necessarily

735
00:28:54.670 --> 00:28:56.590
true. It's a fascinating area to look at

736
00:28:56.590 --> 00:28:58.710
because it's 60 years ago, because it was

737
00:28:58.710 --> 00:29:00.590
mainly kids talking about it, because there

738
00:29:00.590 --> 00:29:03.230
was variation in the records, because some

739
00:29:03.230 --> 00:29:05.270
people have reacted very dismissively of it,

740
00:29:05.270 --> 00:29:06.950
because there's having trouble finding

741
00:29:06.950 --> 00:29:08.910
evidence to one way or the other. It is a

742
00:29:08.910 --> 00:29:10.410
difficult one. It's an interesting one,

743
00:29:10.410 --> 00:29:12.330
witnessed by hundreds of people, sort of

744
00:29:12.330 --> 00:29:14.210
pretty famous international researchers.

745
00:29:14.210 --> 00:29:17.050
Stuart Gary: You don't believe your eyes. That grates

746
00:29:17.050 --> 00:29:17.410
people.

747
00:29:17.490 --> 00:29:20.330
Tim Mendham: Yeah, and justifiably so too,

748
00:29:20.330 --> 00:29:22.330
I think, you know, people do believe they saw

749
00:29:22.330 --> 00:29:23.890
something with their own eyes and that

750
00:29:23.890 --> 00:29:25.730
therefore it's real. Not necessarily.

751
00:29:25.889 --> 00:29:27.450
Especially when you reinforce it with other

752
00:29:27.450 --> 00:29:29.210
people's memories. But something happened.

753
00:29:29.210 --> 00:29:31.490
What it was is the question, will we ever

754
00:29:31.490 --> 00:29:32.810
know? You're probably never going to get

755
00:29:32.810 --> 00:29:34.130
there, but it's an interesting storey.

756
00:29:34.130 --> 00:29:36.690
Stuart Gary: That's the sceptics. Tim Mendham. And this is

757
00:29:36.690 --> 00:29:37.330
Space Time.

758
00:29:53.080 --> 00:29:56.000
And that's the show for now. Space Time is

759
00:29:56.000 --> 00:29:58.120
available every Monday, Wednesday and Friday

760
00:29:58.120 --> 00:30:00.680
through bytes.com soundcloud,

761
00:30:00.760 --> 00:30:03.120
YouTube, your favourite podcast download

762
00:30:03.120 --> 00:30:04.330
provider, and from

763
00:30:04.330 --> 00:30:06.450
spacetimewithstuartgarry.com

764
00:30:07.010 --> 00:30:09.010
spacetime's also broadcast through the

765
00:30:09.010 --> 00:30:11.210
National Science foundation on Science Zone

766
00:30:11.210 --> 00:30:13.730
Radio and on both iHeartradio and

767
00:30:13.730 --> 00:30:16.610
TuneIn radio. And you can help to support our

768
00:30:16.610 --> 00:30:19.090
show by visiting the Space Time Store for a

769
00:30:19.090 --> 00:30:21.330
range of promotional merchandising goodies,

770
00:30:21.570 --> 00:30:24.330
or by becoming a Space patron, which gives

771
00:30:24.330 --> 00:30:26.530
you access to triple episode commercial free

772
00:30:26.530 --> 00:30:28.570
versions of the show, as well as lots of

773
00:30:28.570 --> 00:30:30.670
bonus audio content which doesn't get go to

774
00:30:30.670 --> 00:30:33.110
air access to our exclusive Facebook group

775
00:30:33.110 --> 00:30:35.550
and other rewards. Just go to

776
00:30:35.550 --> 00:30:37.990
spacetimewithstuartgary.com for full

777
00:30:37.990 --> 00:30:40.710
details. You've been listening to Space

778
00:30:40.710 --> 00:30:43.510
Time with Stuart Gary. This has been another

779
00:30:43.510 --> 00:30:46.390
quality podcast production from bytes.com.