The Great Water Mystery: Jezero Crater and the Hunt for Mars' Hidden History

WEBVTT

0
00:00:00.000 --> 00:00:02.320
Anna: They went looking for the bottom of a lake.

1
00:00:02.560 --> 00:00:05.040
They found the inside of a volcano

2
00:00:05.200 --> 00:00:07.160
Avery: and then they found that water had been

3
00:00:07.160 --> 00:00:08.640
through it three separate times.

4
00:00:09.040 --> 00:00:11.320
Anna: Perseverance at the Edge of Jezero Crater

5
00:00:11.320 --> 00:00:13.760
published Monday, and it rewrites what that

6
00:00:13.760 --> 00:00:15.280
shoreline actually is.

7
00:00:15.680 --> 00:00:18.320
Avery: Also today, Europe's Jupiter probe comes home

8
00:00:18.320 --> 00:00:20.920
on Monday night and for 15 minutes it flies

9
00:00:20.920 --> 00:00:23.280
straight over Australia in a dark sky.

10
00:00:23.520 --> 00:00:25.560
Anna: Two teams, two completely different

11
00:00:25.560 --> 00:00:28.160
techniques, both pointing at a fifth planet

12
00:00:28.160 --> 00:00:30.400
hiding inside the most famous planetary

13
00:00:30.400 --> 00:00:31.910
system we have ever photograph.

14
00:00:32.700 --> 00:00:34.980
Avery: And water in an interstellar comet and what

15
00:00:34.980 --> 00:00:37.140
its heavy hydrogen says about the star that

16
00:00:37.140 --> 00:00:37.580
made it.

17
00:00:37.580 --> 00:00:38.460
Anna: I'm Anna.

18
00:00:38.460 --> 00:00:39.340
Avery: I'm, um, Avery.

19
00:00:39.420 --> 00:00:41.700
Anna: This is Astronomy AstroDailyPod. And this is

20
00:00:41.700 --> 00:00:44.260
series five, episode 200. In

21
00:00:44.260 --> 00:00:47.260
September of 2023, NASA's perseverance

22
00:00:47.260 --> 00:00:49.660
rover drove up onto a strip of ground called

23
00:00:49.660 --> 00:00:52.380
the Margin Unit. It hugs the inner edge of

24
00:00:52.380 --> 00:00:55.060
Jezero Crater's rim and it runs along what

25
00:00:55.060 --> 00:00:57.820
was once the shoreline of a lake. If you had

26
00:00:57.820 --> 00:00:59.940
asked the science team what they expected to

27
00:00:59.940 --> 00:01:01.780
find there, the answer would have been

28
00:01:01.780 --> 00:01:04.780
straightforward. Sediment, clay and silt

29
00:01:04.780 --> 00:01:07.460
laid down in layers the way sand piles up on

30
00:01:07.460 --> 00:01:10.060
a lakebed over thousands of years. There was

31
00:01:10.060 --> 00:01:12.540
a good reason to expect it. Orbiters had been

32
00:01:12.540 --> 00:01:14.900
picking up strong signals of carbonate murals

33
00:01:14.900 --> 00:01:17.300
from that spot for years. On Earth,

34
00:01:17.300 --> 00:01:19.940
carbonates very often form in shallow lakes

35
00:01:19.940 --> 00:01:22.580
and shallow seas. Exactly the kind of

36
00:01:22.580 --> 00:01:25.420
warm, wet, shallow environment where life can

37
00:01:25.420 --> 00:01:28.140
get a foothold. And exactly the kind of rock

38
00:01:28.140 --> 00:01:29.940
that is good at preserving the evidence

39
00:01:30.020 --> 00:01:32.490
afterwards. That is a large part of why

40
00:01:32.490 --> 00:01:34.930
Jezero was chosen as a landing site in the

41
00:01:34.930 --> 00:01:35.450
first place.

42
00:01:36.090 --> 00:01:38.010
Avery: So they drove up expecting a beach.

43
00:01:38.250 --> 00:01:40.890
Anna: And what the rover found was igneous rock.

44
00:01:41.050 --> 00:01:43.570
Rock that forms from magma either deep

45
00:01:43.570 --> 00:01:46.090
underground or from volcanic activity at the

46
00:01:46.090 --> 00:01:48.810
surface. The work was published on Monday in

47
00:01:48.810 --> 00:01:50.730
the journal Communications Earth and

48
00:01:50.730 --> 00:01:53.330
Environment, published by Candace Bedford, a

49
00:01:53.330 --> 00:01:55.570
research scientist at Purdue University in

50
00:01:55.570 --> 00:01:56.250
Indiana.

51
00:01:56.580 --> 00:01:58.580
It went straight to the Journal. There is no

52
00:01:58.580 --> 00:02:00.700
preprint sitting behind it. So what we are

53
00:02:00.700 --> 00:02:03.060
describing is the peer reviewed version, not

54
00:02:03.060 --> 00:02:05.580
an early draught. The instrument doing the

55
00:02:05.580 --> 00:02:08.380
heavy lifting is Supercam. It sits up on the

56
00:02:08.380 --> 00:02:10.940
rover's mast and it works by firing a laser

57
00:02:10.940 --> 00:02:13.420
at a rock from as far as six and a half

58
00:02:13.420 --> 00:02:16.340
metres away. The laser vaporises a tiny

59
00:02:16.340 --> 00:02:18.660
patch of the surface into a glowing plasma.

60
00:02:18.740 --> 00:02:20.860
And the spectrum of light coming off that

61
00:02:20.860 --> 00:02:23.300
plasma tells you what the rock is made of.

62
00:02:23.760 --> 00:02:25.640
Perseverance has done this on more than

63
00:02:25.640 --> 00:02:28.440
185 bedrock targets across

64
00:02:28.440 --> 00:02:31.360
the Margin unit. And the rover did not just

65
00:02:31.360 --> 00:02:33.920
sample one spot. It worked its way across

66
00:02:33.920 --> 00:02:36.800
about 265 metres of elevation

67
00:02:37.040 --> 00:02:39.040
from high on the unit down to the old

68
00:02:39.040 --> 00:02:42.040
lakebed. That vertical range turns out to be

69
00:02:42.040 --> 00:02:42.880
the whole storey.

70
00:02:43.440 --> 00:02:44.880
Avery: What changes as you go down?

71
00:02:45.040 --> 00:02:47.240
Anna: High up, the rock is coarse, greened and

72
00:02:47.240 --> 00:02:50.120
crystalline, and it's dominated by olivine, a

73
00:02:50.120 --> 00:02:52.880
mineral made of magnesium and iron. Coarse

74
00:02:52.880 --> 00:02:55.840
crystals mean slow cooling. This rock formed

75
00:02:55.840 --> 00:02:58.840
in a body of magma well underground, cooled

76
00:02:58.840 --> 00:03:00.920
slowly enough for its grains to grow large,

77
00:03:01.000 --> 00:03:04.000
and only reached the surface much later after

78
00:03:04.000 --> 00:03:06.480
everything above it had eroded. And up there,

79
00:03:06.480 --> 00:03:09.280
it's almost pristine. Almost no sign

80
00:03:09.280 --> 00:03:12.200
that water ever touched it. And lower down,

81
00:03:12.440 --> 00:03:15.000
lower down on the lake bed itself, the same

82
00:03:15.000 --> 00:03:17.760
rock looks transformed. The olivine grains

83
00:03:17.760 --> 00:03:19.680
are fractured and there's silica sitting

84
00:03:19.680 --> 00:03:21.800
between them. Same starting material,

85
00:03:21.880 --> 00:03:23.080
completely different history.

86
00:03:23.760 --> 00:03:25.960
That's what makes igneous rock so useful

87
00:03:25.960 --> 00:03:28.920
here. And it's slightly counterintuitive. We

88
00:03:28.920 --> 00:03:30.800
tend to think of sedimentary rock as the

89
00:03:30.800 --> 00:03:33.000
record keeper. But mineral crystals in

90
00:03:33.000 --> 00:03:35.560
igneous rock preserve the precise conditions

91
00:03:35.560 --> 00:03:37.920
of the moment they formed. And when water

92
00:03:37.920 --> 00:03:39.960
comes through later and alters them, it

93
00:03:39.960 --> 00:03:42.440
leaves a signature too. So instead of a

94
00:03:42.440 --> 00:03:44.680
beach, the team got something arguably

95
00:03:44.680 --> 00:03:47.400
better. A rock that had been written on more

96
00:03:47.400 --> 00:03:49.680
than once and kept every draught

97
00:03:50.400 --> 00:03:53.280
three separate episodes. Here is the sequence

98
00:03:53.280 --> 00:03:55.720
the team reads out of the chemistry. And I

99
00:03:55.720 --> 00:03:58.120
want to be precise about this because it is

100
00:03:58.120 --> 00:04:00.520
the finding. First, carbon

101
00:04:00.520 --> 00:04:03.320
dioxide, rich groundwater came up through the

102
00:04:03.320 --> 00:04:05.880
rock and reacted with the olivine. That

103
00:04:05.880 --> 00:04:08.520
reaction produced carbonate and it filled the

104
00:04:08.520 --> 00:04:10.680
fractures running through the bedrock at the

105
00:04:10.680 --> 00:04:13.480
low elevations. Today, those carbonate

106
00:04:13.480 --> 00:04:16.480
filled fractures are left standing proud like

107
00:04:16.480 --> 00:04:19.040
ridges, because the softer rock around them

108
00:04:19.040 --> 00:04:21.990
has worn away faster. Second, an

109
00:04:21.990 --> 00:04:24.390
episode that may well be the lake itself.

110
00:04:24.710 --> 00:04:27.630
Turning olivine into carbonate leaves silica

111
00:04:27.630 --> 00:04:30.470
behind. And Eleni Ravanis at the University

112
00:04:30.550 --> 00:04:32.950
of Hawaii at Manoa, a, uh, co author,

113
00:04:33.350 --> 00:04:36.110
puts it that they see more of that silica in

114
00:04:36.110 --> 00:04:38.550
the rocks that sat below the waterline.

115
00:04:38.950 --> 00:04:41.790
And third, in one location, in the eastern

116
00:04:41.790 --> 00:04:43.990
part of the margin unit, there are mineral

117
00:04:43.990 --> 00:04:46.990
veins about 25 centimetres thick, and

118
00:04:46.990 --> 00:04:49.990
they contain calcium sulphate and fluorite.

119
00:04:50.540 --> 00:04:53.380
Fluorite is the tell. On Earth, fluorite

120
00:04:53.380 --> 00:04:55.980
typically forms when hot water circulates

121
00:04:55.980 --> 00:04:58.860
through volcanic rock. That points to a later

122
00:04:59.020 --> 00:05:01.660
heated underground water event, something

123
00:05:01.820 --> 00:05:03.500
quite different from the first two.

124
00:05:03.980 --> 00:05:06.060
Avery: So why does any of this bear on the question

125
00:05:06.219 --> 00:05:07.580
people actually care about?

126
00:05:07.980 --> 00:05:10.700
Anna: When water interacts with olivine on Earth,

127
00:05:10.780 --> 00:05:13.780
the reaction can release hydrogen. Hydrogen

128
00:05:13.780 --> 00:05:16.380
is a food source for certain microbes, and

129
00:05:16.380 --> 00:05:19.100
the same reaction leaves behind carbonate and

130
00:05:19.100 --> 00:05:21.730
silica to two minerals that happened to be

131
00:05:21.730 --> 00:05:24.490
very good at locking in traces of whatever

132
00:05:24.490 --> 00:05:27.250
was living there. So what the Margin unit is

133
00:05:27.250 --> 00:05:29.930
describing is not a single wet moment.

134
00:05:30.010 --> 00:05:32.330
It is a place where the right chemistry was

135
00:05:32.330 --> 00:05:35.250
available repeatedly over a long stretch of

136
00:05:35.250 --> 00:05:38.250
the planet's history. Bedford's own framing

137
00:05:38.330 --> 00:05:41.290
is that this location became, quote, a

138
00:05:41.290 --> 00:05:43.770
sort of crossroads for aqueous systems.

139
00:05:43.930 --> 00:05:46.170
And she makes the point that reaches past

140
00:05:46.170 --> 00:05:48.950
Jezero. This crater sits inside

141
00:05:48.950 --> 00:05:51.550
one of the largest exposures of carbonate

142
00:05:51.550 --> 00:05:54.550
anywhere on Mars. If the carbonate here did

143
00:05:54.550 --> 00:05:57.270
not form the way everyone assumed from orbit,

144
00:05:57.430 --> 00:05:59.950
that is a question mark hanging over a lot of

145
00:05:59.950 --> 00:06:01.510
other carbonate on that planet,

146
00:06:01.830 --> 00:06:03.990
Avery: which is a slightly uncomfortable finding for

147
00:06:03.990 --> 00:06:04.950
orbital geology.

148
00:06:05.350 --> 00:06:07.670
Anna: It is, and Bedford says so almost

149
00:06:07.670 --> 00:06:10.550
cheerfully. Her line is that after 10 years

150
00:06:10.550 --> 00:06:12.870
working with Mars rovers, what she has

151
00:06:12.870 --> 00:06:15.070
learned is that Mars constantly throws

152
00:06:15.070 --> 00:06:17.950
surprises at you and that it's very rare for

153
00:06:17.950 --> 00:06:20.370
things to be as we expect them to be from

154
00:06:20.370 --> 00:06:23.330
orbital data. Now, three things to hold

155
00:06:23.330 --> 00:06:26.050
onto and none of them are optional. One,

156
00:06:26.210 --> 00:06:28.450
the team can establish the order of these

157
00:06:28.450 --> 00:06:31.410
water events. They cannot date them. We know

158
00:06:31.410 --> 00:06:34.130
first, second, third, we do not know

159
00:06:34.130 --> 00:06:36.450
when and we do not know how far apart.

160
00:06:36.930 --> 00:06:39.770
Two, and this is the important one, this is a

161
00:06:39.770 --> 00:06:42.650
habitability result. It is not a detection of

162
00:06:42.650 --> 00:06:45.170
life and it is not a biosignature.

163
00:06:45.570 --> 00:06:48.210
Nobody on this team is claiming one. We are

164
00:06:48.210 --> 00:06:50.170
saying the ingredients and the conditions

165
00:06:50.170 --> 00:06:52.790
were there more than once, which is a

166
00:06:52.790 --> 00:06:55.430
genuinely different statement and a weaker

167
00:06:55.430 --> 00:06:58.230
one. Three, the origin of the margin

168
00:06:58.230 --> 00:06:59.950
unit is still argued over.

169
00:07:00.270 --> 00:07:02.790
Earlier this year, a separate team used the

170
00:07:02.790 --> 00:07:05.790
rover's ground penetrating radar, rimfax,

171
00:07:05.950 --> 00:07:08.470
to look underneath this same ground and

172
00:07:08.470 --> 00:07:11.150
reported layered beds dipping down towards

173
00:07:11.150 --> 00:07:13.430
the basin, the sort of structure you would

174
00:07:13.430 --> 00:07:15.870
associate with a delta front. That's not

175
00:07:15.870 --> 00:07:18.750
obviously the same picture as slowly cooled

176
00:07:18.750 --> 00:07:21.600
magma from deep underground. Both results

177
00:07:21.600 --> 00:07:24.360
are real measurements. Reconciling them is

178
00:07:24.360 --> 00:07:26.840
unfinished business and we'll tell you when

179
00:07:26.840 --> 00:07:27.520
it's finished.

180
00:07:27.920 --> 00:07:29.880
Avery: And, um, is there an Australian connection to

181
00:07:29.880 --> 00:07:30.240
the storey?

182
00:07:30.640 --> 00:07:33.240
Anna: There's no Australian science team on this

183
00:07:33.240 --> 00:07:35.280
paper and we're not going to pretend

184
00:07:35.280 --> 00:07:38.120
otherwise, but there is an Australian link in

185
00:07:38.120 --> 00:07:40.840
the chain and it's a real one. Every bit of

186
00:07:40.840 --> 00:07:43.000
this data came, uh, to Earth through NASA's

187
00:07:43.000 --> 00:07:45.480
Deep Space Network. And one of the network's

188
00:07:45.480 --> 00:07:48.160
three complexes is at Tidbinbilla outside

189
00:07:48.160 --> 00:07:50.670
Canberra. The Canberra Deep Space

190
00:07:50.750 --> 00:07:53.590
Communication Complex, managed for NASA by

191
00:07:53.590 --> 00:07:56.390
the csiro. When Mars is on the

192
00:07:56.390 --> 00:07:59.190
sky over the Southern hemisphere, Canberra is

193
00:07:59.190 --> 00:08:02.070
the ear listening the laser fires on Mars.

194
00:08:02.070 --> 00:08:04.030
The answer comes home through the act.

195
00:08:04.909 --> 00:08:07.710
Supercam itself is co led by Purdue,

196
00:08:07.870 --> 00:08:10.470
Los Alamos National Laboratory and

197
00:08:10.470 --> 00:08:12.950
IRAP and CENS in

198
00:08:12.950 --> 00:08:15.230
Toulouse. It's a genuinely international

199
00:08:15.550 --> 00:08:16.110
instrument.

200
00:08:16.900 --> 00:08:19.260
Avery: Well, here's one for our Australian listeners

201
00:08:19.260 --> 00:08:21.980
to mark in their calendars next Monday night.

202
00:08:21.980 --> 00:08:24.340
If you are anywhere in Australia with a clear

203
00:08:24.340 --> 00:08:27.340
sky, there is a spacecraft passing overhead

204
00:08:27.340 --> 00:08:30.060
that is on its way to Jupiter. The

205
00:08:30.060 --> 00:08:32.620
European Space Agency confirmed the details

206
00:08:32.620 --> 00:08:35.220
on Monday. Juice, the Jupiter

207
00:08:35.220 --> 00:08:38.060
icy moons explorer, returns to Earth on

208
00:08:38.060 --> 00:08:40.820
28 September for its third gravity

209
00:08:40.820 --> 00:08:43.709
assist. Closest approach is over the Indian

210
00:08:43.709 --> 00:08:46.189
Ocean at 11:45 UTC.

211
00:08:46.749 --> 00:08:49.589
The flyby bends the spacecraft's path by

212
00:08:49.589 --> 00:08:52.229
about 20 degrees and adds roughly

213
00:08:52.229 --> 00:08:55.229
3.5 kilometres per second to its

214
00:08:55.229 --> 00:08:57.789
speed. No fuel spent, just

215
00:08:57.789 --> 00:09:00.269
geometry and the Australian part.

216
00:09:00.669 --> 00:09:03.469
Between 15 and 30 minutes before that

217
00:09:03.469 --> 00:09:06.109
closest approach, JUICE crosses Australia,

218
00:09:06.429 --> 00:09:08.269
travelling from the northeast of the country

219
00:09:08.269 --> 00:09:10.970
to the northwest. We ran the clock on that

220
00:09:10.970 --> 00:09:13.890
and it works out beautifully. That crossing

221
00:09:13.890 --> 00:09:16.850
falls between about 9:15 and 9:30

222
00:09:16.850 --> 00:09:19.370
in the evening, Eastern Standard Time, in

223
00:09:19.370 --> 00:09:22.370
Central Time roughly quarter to 9 to 9 o',

224
00:09:22.370 --> 00:09:24.890
clock, and in Western Australia between about

225
00:09:24.890 --> 00:09:27.770
7:15 and 7:30 in the evening.

226
00:09:28.250 --> 00:09:30.530
Now here is why that is worth clearing your

227
00:09:30.530 --> 00:09:33.010
Monday night for. The sun sets in

228
00:09:33.010 --> 00:09:35.890
Brisbane at 10 to 6, in Darwin

229
00:09:35.890 --> 00:09:38.690
at about 20 to 7 and in Perth at a

230
00:09:38.690 --> 00:09:41.270
quarter to 6 with which means that when Juice

231
00:09:41.270 --> 00:09:43.710
comes over, it is properly dark

232
00:09:43.950 --> 00:09:44.670
everywhere.

233
00:09:44.910 --> 00:09:47.510
The entire continent is in night and the

234
00:09:47.510 --> 00:09:50.070
spacecraft is tracking straight across the

235
00:09:50.070 --> 00:09:52.830
top of it. Make it I no,

236
00:09:52.830 --> 00:09:55.789
and let's be honest about that, ESA's own

237
00:09:55.789 --> 00:09:58.150
wording is that amateur astronomers with the

238
00:09:58.150 --> 00:10:00.950
right telescope or binocular equipment may

239
00:10:00.950 --> 00:10:03.390
be able to track it. This is a small

240
00:10:03.390 --> 00:10:06.270
spacecraft, a long way off, moving fast.

241
00:10:06.780 --> 00:10:08.740
It is a target for someone who knows what

242
00:10:08.740 --> 00:10:10.580
they are doing with a scope and a set of

243
00:10:10.580 --> 00:10:13.020
coordinates. Not something you will catch by

244
00:10:13.020 --> 00:10:15.540
looking up. But for that crowd, it is a

245
00:10:15.540 --> 00:10:17.940
genuine opportunity and there will be very

246
00:10:17.940 --> 00:10:20.780
few chances left. Juice only comes back

247
00:10:20.780 --> 00:10:23.260
Once more in January 2029.

248
00:10:23.820 --> 00:10:26.140
Anna: There's one more detail worth having because

249
00:10:26.140 --> 00:10:28.140
it's the part that makes flight controllers

250
00:10:28.140 --> 00:10:31.020
nervous in the way in. Juice passes through

251
00:10:31.020 --> 00:10:33.220
Earth's shadow for about eight and a half

252
00:10:33.220 --> 00:10:35.810
hours, ending in the early hours of Monday

253
00:10:35.810 --> 00:10:38.650
morning, European time. No sunlight at

254
00:10:38.650 --> 00:10:38.970
all.

255
00:10:39.130 --> 00:10:41.770
The spacecraft runs on battery power alone

256
00:10:42.010 --> 00:10:43.810
and then comes out the other side and

257
00:10:43.810 --> 00:10:46.330
performs the most precise manoeuvre of its

258
00:10:46.330 --> 00:10:46.650
year.

259
00:10:47.050 --> 00:10:49.450
Avery: Remind everyone where it's been launched.

260
00:10:49.450 --> 00:10:52.092
Anna: On an Ariane 5 from Kourou in April

261
00:10:52.208 --> 00:10:55.150
2023. Eight year cruise in August

262
00:10:55.270 --> 00:10:57.490
2024. It did something nobody had done

263
00:10:57.490 --> 00:11:00.050
before. A gravity assist off the moon. And

264
00:11:00.050 --> 00:11:02.170
then Earth, 336 hours apart.

265
00:11:02.570 --> 00:11:05.410
Venus in August 2025. This is

266
00:11:05.410 --> 00:11:07.850
Earth number two. Earth number three is

267
00:11:07.850 --> 00:11:10.770
January 2029. And then Jupiter in

268
00:11:10.770 --> 00:11:13.090
July 2031 where it makes

269
00:11:13.090 --> 00:11:15.690
35 flybys of the big moons before

270
00:11:15.690 --> 00:11:18.010
settling into orbit around Ganymede.

271
00:11:18.250 --> 00:11:20.730
Avery: And one small coincidence for the diary,

272
00:11:21.130 --> 00:11:23.610
Starship's Flight 14 is currently

273
00:11:23.610 --> 00:11:26.530
targeted to 12:15 UTC that

274
00:11:26.530 --> 00:11:29.310
same Monday. Juice's closest approach is

275
00:11:29.310 --> 00:11:32.030
11:45, half an hour apart on

276
00:11:32.030 --> 00:11:34.430
opposite sides of the planet in opposite

277
00:11:34.430 --> 00:11:34.990
directions.

278
00:11:35.550 --> 00:11:37.790
Anna: Alright, moving on to our next storey.

279
00:11:38.270 --> 00:11:41.230
HR 8799 is the system that

280
00:11:41.230 --> 00:11:43.390
made direct imaging of exoplanets

281
00:11:43.390 --> 00:11:46.390
real.4 giant planets photographed

282
00:11:46.390 --> 00:11:48.810
as actual points of light orbiting a uh,

283
00:11:48.910 --> 00:11:51.390
young star between a warm inner belt of

284
00:11:51.390 --> 00:11:53.390
debris and a cold outer ring.

285
00:11:53.730 --> 00:11:56.170
It's the benchmark. And for years there's

286
00:11:56.170 --> 00:11:58.450
been a hole in it, a region a few

287
00:11:58.450 --> 00:12:01.170
astronomical units out, too close in for

288
00:12:01.170 --> 00:12:03.370
conventional high contrast imaging to

289
00:12:03.370 --> 00:12:05.850
resolve. And very hard for the radial

290
00:12:05.850 --> 00:12:08.290
velocity method because the star itself

291
00:12:08.290 --> 00:12:11.170
pulsates and smears the signal. People have

292
00:12:11.170 --> 00:12:13.850
long suspected something is in there. The

293
00:12:13.850 --> 00:12:16.210
inner edge of that warm belt sits at about

294
00:12:16.290 --> 00:12:19.130
five to six astronomical units, well

295
00:12:19.130 --> 00:12:21.210
inside the orbit of the innermost known

296
00:12:21.210 --> 00:12:23.960
planet. Something appears to be sweeping it.

297
00:12:24.440 --> 00:12:26.920
Avery: And this month two groups went at it from

298
00:12:26.920 --> 00:12:27.960
opposite directions.

299
00:12:28.520 --> 00:12:31.400
Anna: They did. And the honest headline is both of

300
00:12:31.400 --> 00:12:34.120
them see something and they do not obviously

301
00:12:34.120 --> 00:12:36.600
agree about what it is. The first

302
00:12:36.760 --> 00:12:39.720
posted on 9th September is led by Jake

303
00:12:39.720 --> 00:12:42.600
Nguyen with a large team. They went back

304
00:12:42.600 --> 00:12:45.600
to archival JWST data taken with

305
00:12:45.600 --> 00:12:47.960
the aperture masking interometer and

306
00:12:47.960 --> 00:12:50.920
reprocessed it with a new pipeline. They find

307
00:12:50.920 --> 00:12:53.680
a source sitting just above their 3 sigma

308
00:12:53.680 --> 00:12:56.680
contrast curve at a projected separation of

309
00:12:56.680 --> 00:12:59.440
about 150 milliarcseconds which

310
00:12:59.440 --> 00:13:02.400
works out to roughly 7 astronomical units

311
00:13:02.400 --> 00:13:04.960
and a few to several Jupiter masses.

312
00:13:05.200 --> 00:13:08.040
And its position sits near a stable orbital

313
00:13:08.040 --> 00:13:10.960
solution for a fifth planet in a three to one

314
00:13:10.960 --> 00:13:13.600
resonance with the innermost known planet.

315
00:13:13.920 --> 00:13:15.440
Avery: And um, this is where it becomes an

316
00:13:15.440 --> 00:13:17.840
Australian storey in a way that I did not

317
00:13:17.840 --> 00:13:18.160
expect.

318
00:13:18.880 --> 00:13:21.360
Anna: The aperture masking interometer is the only

319
00:13:21.360 --> 00:13:23.960
piece of Australian designed hardware on the

320
00:13:23.960 --> 00:13:26.800
James Webb Space Telescope. It was created

321
00:13:26.800 --> 00:13:28.920
by Professor Peter Toothhill at the

322
00:13:28.920 --> 00:13:31.760
University of Sydney. It works by masking

323
00:13:31.760 --> 00:13:34.679
the telescope's mirror down to a handful of

324
00:13:34.679 --> 00:13:37.640
patches and combining their light which buys

325
00:13:37.640 --> 00:13:40.120
you resolution right in close to a bright

326
00:13:40.120 --> 00:13:42.800
star, exactly where this planet would be.

327
00:13:43.120 --> 00:13:45.280
And the pipeline that made this detection

328
00:13:45.280 --> 00:13:47.600
possible came out of that same group.

329
00:13:48.080 --> 00:13:50.760
Sydney PhD students built a software

330
00:13:50.760 --> 00:13:53.560
only calibration system to correct a

331
00:13:53.560 --> 00:13:55.720
detector effect that had been quietly

332
00:13:55.720 --> 00:13:58.680
blurring AMI's images and recovered

333
00:13:58.680 --> 00:14:01.000
the instrument's full sensitivity without

334
00:14:01.000 --> 00:14:04.000
anyone leaving the ground. The paper says in

335
00:14:04.000 --> 00:14:06.680
plain terms that the Detection was enabled by

336
00:14:06.680 --> 00:14:09.160
a pipeline accounting for the systematics

337
00:14:09.160 --> 00:14:11.200
that limited earlier analyses.

338
00:14:11.440 --> 00:14:14.360
That is the Sydney Fix doing the job it was

339
00:14:14.360 --> 00:14:17.120
built for. The second paper landed on Monday

340
00:14:17.520 --> 00:14:19.880
led by Anne Marie Lagrange, and it's

341
00:14:19.880 --> 00:14:22.400
submitted to Nature Astronomy. Completely

342
00:14:22.400 --> 00:14:24.800
different approach. Gaia's absolute

343
00:14:24.800 --> 00:14:27.040
astronomy combined with proper motion

344
00:14:27.040 --> 00:14:29.760
anomalies between Hipparcos and Gaia,

345
00:14:29.920 --> 00:14:32.400
plus radial velocities and imaging.

346
00:14:32.640 --> 00:14:35.160
They're not photographing anything, they're

347
00:14:35.160 --> 00:14:38.000
watching the star get tugged. Their allowed

348
00:14:38.000 --> 00:14:40.360
solutions span roughly a third of an

349
00:14:40.360 --> 00:14:43.120
astronomical unit out to 6, with the

350
00:14:43.120 --> 00:14:45.760
probability peaking at 2 to 3 and

351
00:14:45.760 --> 00:14:48.620
masses of about 10 to 14 jupiters.

352
00:14:48.860 --> 00:14:51.780
They also show that an object like that on a

353
00:14:51.780 --> 00:14:54.700
low eccentricity orbit can coexist with

354
00:14:54.700 --> 00:14:57.140
the long lived resonant chain of the four

355
00:14:57.140 --> 00:15:00.140
known planets and sculpt that inner belt

356
00:15:00.140 --> 00:15:00.540
edge.

357
00:15:00.940 --> 00:15:02.700
Avery: Next, the honest reading.

358
00:15:03.180 --> 00:15:05.820
Anna: So 7 astronomical units and a few

359
00:15:05.820 --> 00:15:08.780
Jupiter masses versus 2 to 3 and 10

360
00:15:08.780 --> 00:15:11.740
to 14. Those are not the same object

361
00:15:11.740 --> 00:15:14.570
as stated. They may be the same object with

362
00:15:14.570 --> 00:15:16.810
wide error bars or two different

363
00:15:16.810 --> 00:15:19.650
detections, or one of them may not survive.

364
00:15:19.970 --> 00:15:22.290
Both are preprints. Neither has been through

365
00:15:22.290 --> 00:15:24.930
peer review. This is a candidate and we've

366
00:15:24.930 --> 00:15:27.170
been here before. You'll remember from last

367
00:15:27.170 --> 00:15:29.810
week how contested the history of directly

368
00:15:29.810 --> 00:15:31.410
imaged protoplanets is.

369
00:15:31.810 --> 00:15:34.130
And for the observers, HR

370
00:15:34.130 --> 00:15:36.530
8799 is at declination

371
00:15:37.010 --> 00:15:39.330
21. It transits nearly

372
00:15:39.330 --> 00:15:42.250
77 degrees up from Los Angeles and

373
00:15:42.250 --> 00:15:45.190
about 71 from New York. From here in

374
00:15:45.190 --> 00:15:48.070
Sydney it barely clears 35. This one

375
00:15:48.070 --> 00:15:49.110
belongs to the north.

376
00:15:49.510 --> 00:15:51.150
Avery: We've been holding this one for a couple of

377
00:15:51.150 --> 00:15:52.790
weeks, waiting for the right slot.

378
00:15:52.790 --> 00:15:55.630
So here it is at last. Back in March, a

379
00:15:55.630 --> 00:15:57.910
team led by Martin Cordiner published a

380
00:15:57.910 --> 00:16:00.629
measurement of the water in 3I ATLAS,

381
00:16:00.870 --> 00:16:03.270
the third interstellar object ever found

382
00:16:03.270 --> 00:16:04.550
passing through our solar system.

383
00:16:05.110 --> 00:16:07.750
Specifically, they measured its deuterium to

384
00:16:07.750 --> 00:16:10.590
hydrogen ratio. Deuterium is heavy

385
00:16:10.590 --> 00:16:13.190
hydrogen, an ordinary hydrogen atom with a

386
00:16:13.190 --> 00:16:16.150
neutron added. And the ratio of heavy water

387
00:16:16.150 --> 00:16:18.750
to ordinary water in a comet is one of the

388
00:16:18.750 --> 00:16:21.470
most useful fingerprints we have because it's

389
00:16:21.470 --> 00:16:23.910
set by how cold it was and what was around

390
00:16:24.070 --> 00:16:25.830
when that ice first formed.

391
00:16:26.070 --> 00:16:28.630
Anna: And three I ATLAS came back high.

392
00:16:29.030 --> 00:16:31.470
Avery: And the paper we are covering Today, posted

393
00:16:31.470 --> 00:16:33.910
on 14th September by a team including

394
00:16:34.070 --> 00:16:36.710
Kenji Furuya, Cordiner himself

395
00:16:36.950 --> 00:16:39.660
and Dominique Bocole Morven, is the

396
00:16:39.660 --> 00:16:42.500
attempt to explain why. I want to be very

397
00:16:42.500 --> 00:16:44.980
clear about what this is because the framing

398
00:16:44.980 --> 00:16:47.140
matters. This is not a new measurement.

399
00:16:47.300 --> 00:16:50.180
Nobody pointed a telescope at anything. This

400
00:16:50.180 --> 00:16:52.300
is a modelling paper working out what

401
00:16:52.300 --> 00:16:54.540
conditions could produce the ratio that Was

402
00:16:54.540 --> 00:16:57.180
already measured in March and there is no

403
00:16:57.180 --> 00:16:59.580
institutional press release behind it. It is

404
00:16:59.580 --> 00:17:01.300
a preprint eight days old.

405
00:17:01.700 --> 00:17:03.380
Anna: So what does the model say?

406
00:17:03.780 --> 00:17:06.340
Avery: Their conclusion is that the high ratio is

407
00:17:06.340 --> 00:17:08.900
consistent with three I ATLs

408
00:17:09.140 --> 00:17:11.130
forming around a star with low met

409
00:17:11.199 --> 00:17:13.839
metallicity. Meaning a star poor in elements

410
00:17:13.839 --> 00:17:16.439
heavier than hydrogen and helium. Which in

411
00:17:16.439 --> 00:17:19.079
practise tends to mean an old star. An

412
00:17:19.079 --> 00:17:21.119
object assembled in a different chemical

413
00:17:21.119 --> 00:17:23.119
environment from the one that built our own

414
00:17:23.119 --> 00:17:25.719
comets. And it slots neatly against the

415
00:17:25.719 --> 00:17:27.999
result. We covered a couple of weeks back the

416
00:17:27.999 --> 00:17:30.439
first ion inventory of an interstellar

417
00:17:30.439 --> 00:17:32.999
object's tail out of Northumbria and

418
00:17:32.999 --> 00:17:35.119
Edinburgh, which found enough molecular

419
00:17:35.119 --> 00:17:37.959
nitrogen relative to carbon monoxide to

420
00:17:37.959 --> 00:17:40.510
imply this thing formed below about 3030

421
00:17:40.510 --> 00:17:43.390
Kelvin. Very cold and a long way from

422
00:17:43.390 --> 00:17:43.910
its star.

423
00:17:44.230 --> 00:17:46.670
Anna: Two independent lines pointing the same

424
00:17:46.670 --> 00:17:47.190
direction.

425
00:17:47.430 --> 00:17:50.150
Avery: Two independent lines, and they are genuinely

426
00:17:50.150 --> 00:17:53.030
independent. One is ions in a plasma

427
00:17:53.030 --> 00:17:55.710
tail, the other is heavy water. But the

428
00:17:55.710 --> 00:17:58.310
caveat is the same caveat as always with

429
00:17:58.310 --> 00:18:01.070
D2H. It is a tracer, not a direct

430
00:18:01.070 --> 00:18:01.670
reading.

431
00:18:01.830 --> 00:18:04.430
Converting a ratio into a birthplace runs

432
00:18:04.430 --> 00:18:05.910
through a chain of assumptions about

433
00:18:05.910 --> 00:18:08.530
chemistry and temperature. And this paper is

434
00:18:08.530 --> 00:18:10.850
exploring that chain rather than closing it.

435
00:18:11.250 --> 00:18:13.650
The Southern Note, as ever with this object,

436
00:18:13.890 --> 00:18:16.610
three I ATLS was discovered by the

437
00:18:16.610 --> 00:18:19.530
ATLAS Survey telescope at ah Rio Urtado in

438
00:18:19.530 --> 00:18:21.930
Chile. Whatever we end up learning about the

439
00:18:21.930 --> 00:18:24.250
star that made it, the first person to see it

440
00:18:24.250 --> 00:18:26.290
was looking up from the southern hemisphere.

441
00:18:26.770 --> 00:18:29.010
Anna: Now, three quick ones. All dates.

442
00:18:29.490 --> 00:18:32.450
Starship Flight 14 is still targeted for

443
00:18:32.450 --> 00:18:35.198
Monday 28 September 1215

444
00:18:35.366 --> 00:18:38.360
UTC. That's 10:15 on Monday evening,

445
00:18:38.360 --> 00:18:40.960
Eastern Standard Time here. The booster has

446
00:18:40.960 --> 00:18:42.960
been rolled out to the pad and the ship has

447
00:18:42.960 --> 00:18:45.440
been test fired. You will remember we had to

448
00:18:45.440 --> 00:18:47.560
correct ourselves on this flight once already

449
00:18:47.880 --> 00:18:49.640
when it moved off the 22nd.

450
00:18:50.040 --> 00:18:53.000
So we're saying targeted, not scheduled. And

451
00:18:53.000 --> 00:18:54.520
we'll believe it when the clock runs.

452
00:18:55.880 --> 00:18:58.200
Avery: NASA's own mission page still reads no

453
00:18:58.200 --> 00:19:00.950
earlier than early October. Not a date, a

454
00:19:00.950 --> 00:19:03.390
window. The crew went to quarantine on the

455
00:19:03.390 --> 00:19:05.990
17th, which is the normal run up. And the

456
00:19:05.990 --> 00:19:08.310
oxidizer valve that caused the original stand

457
00:19:08.310 --> 00:19:10.830
down was replaced weeks ago. There are

458
00:19:10.830 --> 00:19:12.870
specific dates circulating on unofficial

459
00:19:12.870 --> 00:19:14.870
trackers. We are not going to read you a date

460
00:19:14.870 --> 00:19:16.350
that NASA has not published.

461
00:19:16.750 --> 00:19:19.630
Anna: And Albania has signed the Artemis Accords.

462
00:19:19.710 --> 00:19:22.030
That happened on Monday at NASA headquarters.

463
00:19:22.190 --> 00:19:24.510
Foreign Minister Fareed Hoxha signing for

464
00:19:24.510 --> 00:19:27.470
Albania. Deputy Administrator Matt Anderson

465
00:19:27.470 --> 00:19:29.720
for NASA Albania becomes the

466
00:19:29.720 --> 00:19:31.280
73rd signatory.

467
00:19:31.840 --> 00:19:34.600
Avery: 73. It was 50 something not that long

468
00:19:34.600 --> 00:19:35.760
ago it was.

469
00:19:36.240 --> 00:19:38.520
Anna: And whatever you make of the Accords as an

470
00:19:38.520 --> 00:19:40.640
instrument, and there's a real Debate there

471
00:19:40.640 --> 00:19:42.600
about whether they substitute for treaty

472
00:19:42.600 --> 00:19:45.440
making. The sheer rate of accession is now

473
00:19:45.440 --> 00:19:46.480
the storey in itself.

474
00:19:46.880 --> 00:19:49.240
Avery: Moving on to Skywatch, let's start with the

475
00:19:49.240 --> 00:19:51.560
moment this episode goes out, because it's a

476
00:19:51.560 --> 00:19:54.480
moment, not a day. The September equinox

477
00:19:54.480 --> 00:19:56.960
falls at five minutes past midnight utc.

478
00:19:57.490 --> 00:19:59.330
That's five past ten in the morning on

479
00:19:59.330 --> 00:20:01.690
Wednesday for us in Sydney. So it happens

480
00:20:01.690 --> 00:20:03.770
while you're listening to this. In London,

481
00:20:03.770 --> 00:20:05.690
it's just after one in the morning on the

482
00:20:05.690 --> 00:20:08.690
23rd, but in New York, it's five past eight

483
00:20:08.690 --> 00:20:11.210
on the evening of the 22nd, and in Los

484
00:20:11.210 --> 00:20:13.730
Angeles, five past five that same afternoon.

485
00:20:14.210 --> 00:20:16.610
Anna: So half our audience had their equinox

486
00:20:16.610 --> 00:20:17.250
yesterday.

487
00:20:17.650 --> 00:20:20.610
Avery: Exactly. And that is not a quirk, it is the

488
00:20:20.610 --> 00:20:23.530
point. An, um, equinox is an instant, not

489
00:20:23.530 --> 00:20:26.400
a date. It is one specific moment when

490
00:20:26.400 --> 00:20:29.280
the sun crosses the celestial equator. And

491
00:20:29.280 --> 00:20:31.440
what calendar date that lands on depends

492
00:20:31.440 --> 00:20:34.360
entirely on where you are standing. We have

493
00:20:34.360 --> 00:20:37.200
said the 22nd in past episodes and for North

494
00:20:37.200 --> 00:20:40.080
America, that was right. For Australia, it is

495
00:20:40.080 --> 00:20:42.920
the 23rd. The thing to actually plan for

496
00:20:42.920 --> 00:20:43.640
is Monday.

497
00:20:43.880 --> 00:20:46.200
As we said earlier, Juice crosses Australia

498
00:20:46.440 --> 00:20:49.200
between about 9:15 and 9:30 in the

499
00:20:49.200 --> 00:20:51.760
evening Eastern time. Northeast to

500
00:20:51.760 --> 00:20:54.480
northwest in a fully dark sky from

501
00:20:54.480 --> 00:20:56.880
coast to coast. Telescope or good

502
00:20:56.880 --> 00:20:59.320
binoculars and current coordinates cheque

503
00:20:59.320 --> 00:21:01.600
ESA's own pages on the day, because the

504
00:21:01.600 --> 00:21:03.800
ephemeris will be refined right up to the

505
00:21:03.800 --> 00:21:04.320
flyby.

506
00:21:04.640 --> 00:21:06.680
Anna: For, uh, our northern listeners, this one is

507
00:21:06.680 --> 00:21:08.680
not yours. Closest to approaches over the

508
00:21:08.680 --> 00:21:10.320
Indian Ocean in the middle of your day.

509
00:21:10.400 --> 00:21:10.960
Sorry.

510
00:21:11.520 --> 00:21:14.520
Avery: Turning to the evening sky, Venus is still

511
00:21:14.520 --> 00:21:17.280
the standout after sunset and the gap between

512
00:21:17.280 --> 00:21:20.160
hemispheres is as wide as it's been all year.

513
00:21:20.830 --> 00:21:23.830
From Sydney, Venus sits 36 degrees above the

514
00:21:23.830 --> 00:21:26.270
horizon at sunset and stays up for three

515
00:21:26.270 --> 00:21:28.990
hours and one minute after the sun goes down.

516
00:21:29.310 --> 00:21:32.310
From Los Angeles, 12 degrees and gone in an

517
00:21:32.310 --> 00:21:35.230
hour and nine minutes. New York, 8 degrees,

518
00:21:35.390 --> 00:21:37.950
54 minutes. London, um, 2

519
00:21:37.950 --> 00:21:40.830
degrees and 20 minutes, which in practise

520
00:21:40.830 --> 00:21:43.510
means a clear, flat western horizon or

521
00:21:43.510 --> 00:21:44.350
nothing at all.

522
00:21:44.830 --> 00:21:47.070
Anna: And that is the ecliptic angle again.

523
00:21:48.020 --> 00:21:50.580
Avery: Same geometry we've talked about all spring.

524
00:21:50.980 --> 00:21:53.540
Around the equinox, the ecliptic stands up

525
00:21:53.540 --> 00:21:55.940
almost vertically from the western horizon in

526
00:21:55.940 --> 00:21:58.500
the southern hemisphere and lies down almost

527
00:21:58.500 --> 00:22:01.060
flat in the north. Same planet,

528
00:22:01.220 --> 00:22:03.300
same evening, completely different

529
00:22:03.300 --> 00:22:03.699
experience.

530
00:22:04.580 --> 00:22:07.580
Mercury is doing the same thing. Eighteen and

531
00:22:07.580 --> 00:22:09.940
a half degrees up from Sydney at sunset,

532
00:22:10.180 --> 00:22:12.620
three and a half from London, southern

533
00:22:12.620 --> 00:22:13.060
object.

534
00:22:13.590 --> 00:22:16.350
Anna: The Moon is a waxing gibbous, about 86%

535
00:22:16.350 --> 00:22:18.430
lit on Wednesday evening, and it's heading

536
00:22:18.430 --> 00:22:21.270
for full at 4:48 in the afternoon UTC

537
00:22:21.270 --> 00:22:24.110
on the 26th. Note the calendar split on that

538
00:22:24.110 --> 00:22:26.550
one. That instant is 10 to 3 in the morning

539
00:22:26.550 --> 00:22:29.550
of the 27th in Sydney. So Australian

540
00:22:29.550 --> 00:22:31.670
calendars will say Sunday and northern ones

541
00:22:31.670 --> 00:22:34.030
will say Saturday. It looks full both nights

542
00:22:34.030 --> 00:22:34.550
either way.

543
00:22:35.190 --> 00:22:38.070
Avery: Saturn rises at about 20 to 7 in the evening

544
00:22:38.070 --> 00:22:41.070
from Sydney and is 54 degree up, uh six hours

545
00:22:41.070 --> 00:22:43.510
later. It's heading for opposition in the

546
00:22:43.510 --> 00:22:45.750
first week of October. And as we worked out

547
00:22:45.750 --> 00:22:48.190
last week, the two standard definitions put

548
00:22:48.190 --> 00:22:50.710
it on the 4th and the 5th. Both are

549
00:22:50.710 --> 00:22:53.030
legitimate. It doesn't matter. The brightness

550
00:22:53.030 --> 00:22:55.910
holds at magnitude 0.32 and

551
00:22:55.910 --> 00:22:58.670
the disc at 19.6 arc seconds

552
00:22:58.670 --> 00:23:01.110
right across that week. So there's no wrong

553
00:23:01.110 --> 00:23:03.830
night. And now the counterweight because

554
00:23:03.830 --> 00:23:06.550
today's storeys have leaned north and the pre

555
00:23:06.550 --> 00:23:07.990
dawn sky does too.

556
00:23:08.670 --> 00:23:11.670
Mars at nautical dawn, 50 degrees up from Los

557
00:23:11.670 --> 00:23:14.550
Angeles, 48 from New York, 42

558
00:23:14.550 --> 00:23:17.470
from London and 21 from Sydney.

559
00:23:17.950 --> 00:23:20.910
Jupiter 30 degrees from Los Angeles and 10

560
00:23:20.910 --> 00:23:23.870
and a half from here. The two of them are 20

561
00:23:23.949 --> 00:23:26.350
and a half degrees apart and closing through

562
00:23:26.350 --> 00:23:28.670
Anna: spring, which is the tie back to the lead.

563
00:23:29.150 --> 00:23:31.950
Avery: It is if you want to look at the planet. We

564
00:23:31.950 --> 00:23:33.990
spent eight minutes on this morning and you

565
00:23:33.990 --> 00:23:36.310
are in the northern hemisphere. It's 50

566
00:23:36.310 --> 00:23:38.550
degrees up before sunrise and easy.

567
00:23:39.020 --> 00:23:41.740
Jezero crater is at 18 degrees north on

568
00:23:41.740 --> 00:23:44.540
Mars. So even the geology is northern today.

569
00:23:44.940 --> 00:23:46.700
Some weeks it runs the other way.

570
00:23:46.940 --> 00:23:48.900
Last Monday we gave the south the better

571
00:23:48.900 --> 00:23:51.900
geometry and the north the deep sky. Today

572
00:23:51.900 --> 00:23:54.340
the north has the science, the planets and

573
00:23:54.340 --> 00:23:57.100
the October occultation. And the south has

574
00:23:57.100 --> 00:23:59.620
Venus, Mercury and a uh, spacecraft going

575
00:23:59.620 --> 00:24:01.180
overhead on Monday night.

576
00:24:01.420 --> 00:24:03.860
Anna: And the standing reminder because we say it

577
00:24:03.860 --> 00:24:06.380
every single episode and we are not going to

578
00:24:06.380 --> 00:24:09.180
stop. If you are observing the sun at

579
00:24:09.180 --> 00:24:11.900
any point, for any reason, at any stage,

580
00:24:12.140 --> 00:24:15.100
you need filters certified to ISO

581
00:24:15.340 --> 00:24:18.300
123122. That

582
00:24:18.300 --> 00:24:21.140
is the international standard for safe solar

583
00:24:21.140 --> 00:24:23.740
viewing. Sunglasses are not adequate.

584
00:24:23.980 --> 00:24:26.460
Stacked sunglasses are not adequate.

585
00:24:26.700 --> 00:24:29.380
Exposed film, smoked glass, a

586
00:24:29.380 --> 00:24:32.260
welding filter below shade 14, none

587
00:24:32.260 --> 00:24:35.130
of those are adequate. And never ever

588
00:24:35.210 --> 00:24:37.250
look at the sun through a telescope,

589
00:24:37.250 --> 00:24:39.930
binoculars or a camera lens that does not

590
00:24:39.930 --> 00:24:42.650
have a purpose made solar filter fitted over

591
00:24:42.650 --> 00:24:43.210
the front.

592
00:24:43.530 --> 00:24:46.250
A filter that screws into the eyepiece can

593
00:24:46.250 --> 00:24:48.810
crack under the heat front of the optic.

594
00:24:48.810 --> 00:24:50.410
Certified every time.

595
00:24:50.810 --> 00:24:52.890
Avery: That's Astronomy AstroDailyPod for today.

596
00:24:53.370 --> 00:24:56.090
Anna: Three floods at the edge of Jezero Crater.

597
00:24:56.250 --> 00:24:59.210
Groundwater, then a lake, then hot water from

598
00:24:59.210 --> 00:25:01.850
below. Red out of rock that was not

599
00:25:01.850 --> 00:25:03.290
supposed to be there at all.

600
00:25:04.080 --> 00:25:06.480
Avery: Juice coming home on Monday nights and 15

601
00:25:06.560 --> 00:25:08.160
minutes of uh, it belonging to

602
00:25:08.160 --> 00:25:11.040
Anna: Australia, a candidate fifth planet

603
00:25:11.040 --> 00:25:14.000
at HR 8799. Found

604
00:25:14.080 --> 00:25:16.880
two different ways by two teams who do not

605
00:25:16.880 --> 00:25:19.840
quite agree with an Australian instrument and

606
00:25:19.840 --> 00:25:22.280
an Australian software fix in the middle of

607
00:25:22.280 --> 00:25:22.800
one of them

608
00:25:23.280 --> 00:25:25.960
Avery: and heavy water in an interstellar comet

609
00:25:25.960 --> 00:25:28.640
pointing at an old metopore star we will

610
00:25:28.640 --> 00:25:29.280
never see.

611
00:25:29.890 --> 00:25:32.050
And one small thing before we go this is

612
00:25:32.050 --> 00:25:33.970
episode 200 for the year.

613
00:25:34.530 --> 00:25:37.330
Anna: 200 episodes this year alone.

614
00:25:37.650 --> 00:25:40.410
Not many shows can say that and fewer still

615
00:25:40.410 --> 00:25:42.730
can say it without the quality going out the

616
00:25:42.730 --> 00:25:44.850
window somewhere around episode 60.

617
00:25:45.570 --> 00:25:48.130
Avery: That is not an accident and it is not one

618
00:25:48.130 --> 00:25:50.690
person. That is a team turning this around

619
00:25:50.850 --> 00:25:53.330
day after day and holding the standard while

620
00:25:53.330 --> 00:25:55.610
they do it. Thank you to everyone who makes

621
00:25:55.610 --> 00:25:58.090
it happen and thank you for listening to all

622
00:25:58.090 --> 00:25:58.950
200 of them.

623
00:25:59.500 --> 00:26:01.260
Anna: Astronomy AstroDailyPod is produced in

624
00:26:01.260 --> 00:26:03.740
Sydney. You'll find every episode, the show

625
00:26:03.740 --> 00:26:06.300
notes and the newsletter at astronomydaily

626
00:26:06.460 --> 00:26:09.020
IO and we're AstroDaily

627
00:26:09.020 --> 00:26:10.380
Pod on the socials.

628
00:26:10.700 --> 00:26:11.820
Avery: We're back tomorrow.

629
00:26:12.220 --> 00:26:13.820
Anna: Until then, Clear Skies.

630
00:26:23.550 --> 00:26:23.580
Avery: Mhm.

631
00:26:25.210 --> 00:26:25.690
Anna: The storey.