Cosmic Auroras, Planetary Demise, and Martian Mysteries

WEBVTT

0
00:00:00.000 --> 00:00:02.600
Avery: Welcome to Astronomy Daily, the podcast that

1
00:00:02.600 --> 00:00:05.040
brings you the universe one story at a time.

2
00:00:05.120 --> 00:00:06.640
I'm your host, Avery.

3
00:00:06.800 --> 00:00:09.720
Anna: And I'm your co host, Anna. It's great

4
00:00:09.720 --> 00:00:12.160
to be with you all again, Avery.

5
00:00:12.560 --> 00:00:15.320
Here in the northern hemisphere, it feels

6
00:00:15.320 --> 00:00:17.760
like the nights are really drawing in.

7
00:00:18.240 --> 00:00:20.320
Getting colder, darker.

8
00:00:20.720 --> 00:00:23.360
Avery: They certainly are. But that darkness

9
00:00:23.360 --> 00:00:25.880
isn't always a bad thing, especially when it

10
00:00:25.880 --> 00:00:28.120
becomes a canvas for some of the universe's

11
00:00:28.120 --> 00:00:30.360
most incredible art. And we're starting

12
00:00:30.360 --> 00:00:31.840
today's show with just that.

13
00:00:32.460 --> 00:00:35.180
Anna: That's right. We have a packed episode

14
00:00:35.500 --> 00:00:38.300
from spectacular atmospheric light shows

15
00:00:38.300 --> 00:00:40.940
right here at home to the ultimate

16
00:00:40.940 --> 00:00:42.380
fate of Earth itself.

17
00:00:42.620 --> 00:00:44.980
Avery: And we'll also look at potential threats from

18
00:00:44.980 --> 00:00:47.500
outside our solar system, find a beacon of

19
00:00:47.500 --> 00:00:50.500
hope on an icy moon, and preview an exciting

20
00:00:50.500 --> 00:00:52.980
new mission to Mars. So let's get right to

21
00:00:52.980 --> 00:00:53.260
it.

22
00:00:53.420 --> 00:00:54.540
Anna: I'm ready if you are.

23
00:00:54.700 --> 00:00:57.580
Avery: Alrighty. Our first story is a visual

24
00:00:57.950 --> 00:01:00.230
feast for anyone lucky enough to be in the

25
00:01:00.230 --> 00:01:02.110
right place at the right time. Between

26
00:01:02.110 --> 00:01:05.110
November 5th and 8th, 2025, the night

27
00:01:05.110 --> 00:01:07.990
sky put on a show for the ages. A

28
00:01:07.990 --> 00:01:10.790
powerful geomagnetic storm triggered stunning

29
00:01:10.790 --> 00:01:11.550
auroras.

30
00:01:11.790 --> 00:01:14.430
Anna: It really was something special. This was

31
00:01:14.430 --> 00:01:17.390
classified as a G3 class storm on the

32
00:01:17.390 --> 00:01:19.790
five point scale, which is considered strong.

33
00:01:20.430 --> 00:01:23.390
It was all thanks to a significant coronal

34
00:01:23.390 --> 00:01:26.090
mass ejection, or cme, that

35
00:01:26.090 --> 00:01:28.210
erupted from the Sun a few days prior.

36
00:01:28.450 --> 00:01:31.170
Avery: Right. A, uh, cme. Um, so basically the sun

37
00:01:31.250 --> 00:01:34.170
threw a massive blob of plasma and

38
00:01:34.170 --> 00:01:35.490
magnetic field our way.

39
00:01:35.650 --> 00:01:38.250
Anna: Exactly. When that wave of charged

40
00:01:38.250 --> 00:01:40.929
particles hits our magnetosphere, it

41
00:01:40.929 --> 00:01:43.610
channels them towards the poles. They rain

42
00:01:43.610 --> 00:01:46.410
down into our upper atmosphere, collide with

43
00:01:46.410 --> 00:01:49.130
air molecules, and energize them, causing

44
00:01:49.130 --> 00:01:51.840
them to glow. The. The beautiful greens are

45
00:01:51.840 --> 00:01:54.360
from oxygen, while rarer pinks and

46
00:01:54.360 --> 00:01:55.960
reds come from nitrogen.

47
00:01:56.120 --> 00:01:58.280
Avery: And this storm was powerful enough that the

48
00:01:58.280 --> 00:02:00.360
lights were seen much farther south than

49
00:02:00.360 --> 00:02:02.840
usual. We saw incredible photos and time

50
00:02:02.840 --> 00:02:05.200
lapses from the northern United States, the

51
00:02:05.200 --> 00:02:08.120
UK, and all across Scandinavia. It must

52
00:02:08.120 --> 00:02:10.120
have been just breathtaking to see in person.

53
00:02:10.520 --> 00:02:13.200
Anna: It truly is an experience that connects you

54
00:02:13.200 --> 00:02:16.040
to the cosmos. It's a vivid, dynamic

55
00:02:16.040 --> 00:02:18.560
reminder that we live inside the atmosphere

56
00:02:18.560 --> 00:02:19.160
of a star.

57
00:02:19.510 --> 00:02:19.670
Avery: It's.

58
00:02:19.740 --> 00:02:22.340
Anna: And that our sun is an active, powerful

59
00:02:22.340 --> 00:02:25.220
force. We're currently in an active period

60
00:02:25.220 --> 00:02:28.020
of the solar cycle, so we might get a few

61
00:02:28.020 --> 00:02:29.740
more shows like this in the coming years.

62
00:02:30.140 --> 00:02:32.540
Avery: I certainly hope so. A, uh, beautiful event

63
00:02:32.540 --> 00:02:35.140
and a great way to start our cosmic journey

64
00:02:35.140 --> 00:02:35.420
today.

65
00:02:36.140 --> 00:02:38.620
Anna: From the beautiful effects of our star's

66
00:02:38.620 --> 00:02:41.620
activity to a more sobering look at its

67
00:02:41.620 --> 00:02:42.700
eventual demise.

68
00:02:43.260 --> 00:02:46.180
Our next story comes from NASA's Transiting

69
00:02:46.180 --> 00:02:48.770
Exoplanet Survey Satellite, which or TESS.

70
00:02:49.330 --> 00:02:51.970
And it paints a stark picture of the fate of

71
00:02:51.970 --> 00:02:54.050
planets orbiting sun like stars.

72
00:02:54.290 --> 00:02:57.050
Avery: Ah, uh, tess. Its main job is hunting for

73
00:02:57.050 --> 00:02:59.730
exoplanets. But it's great at just watching

74
00:02:59.730 --> 00:03:01.890
stars. What did it see this time?

75
00:03:02.210 --> 00:03:05.210
Anna: It was watching older stars, those beginning

76
00:03:05.210 --> 00:03:08.090
to enter their red giant phase. And the new

77
00:03:08.090 --> 00:03:11.090
study confirms that these swelling stars are

78
00:03:11.090 --> 00:03:13.770
engulfing their inner planets far more often

79
00:03:13.770 --> 00:03:16.320
than some models predicted. They the evidence

80
00:03:16.400 --> 00:03:19.320
is in the starlight itself. They can detect

81
00:03:19.320 --> 00:03:22.000
the chemical signatures of planetary material

82
00:03:22.160 --> 00:03:23.680
being consumed by the star.

83
00:03:24.160 --> 00:03:27.080
Avery: Consumed? That's a gentle word for it.

84
00:03:27.080 --> 00:03:29.520
It's more like being vaporized and

85
00:03:29.680 --> 00:03:30.320
eaten.

86
00:03:30.720 --> 00:03:33.720
Anna: A very accurate description. As a star

87
00:03:33.720 --> 00:03:36.680
like our sun exhausts hydrogen fuel in its

88
00:03:36.680 --> 00:03:39.440
core, it starts burning it in a shell, which

89
00:03:39.440 --> 00:03:42.240
causes its outer layers to expand enormously

90
00:03:42.400 --> 00:03:44.880
and it can swell to hundreds of times its

91
00:03:44.880 --> 00:03:45.760
original size.

92
00:03:46.160 --> 00:03:48.000
Avery: And um, any planets in the way.

93
00:03:48.240 --> 00:03:51.160
Anna: Any planets in the way are first subjected to

94
00:03:51.160 --> 00:03:53.400
immense tidal forces that can tear them

95
00:03:53.400 --> 00:03:56.200
apart. And then they are swallowed by the

96
00:03:56.200 --> 00:03:58.520
star's expanding atmosphere, the

97
00:03:58.520 --> 00:03:59.280
photosphere.

98
00:03:59.280 --> 00:04:01.760
Avery: Which brings us to the big scary.

99
00:04:02.800 --> 00:04:05.360
What does this mean for Mercury, Venus and

100
00:04:05.440 --> 00:04:06.560
us, uh, here on Earth?

101
00:04:06.960 --> 00:04:09.520
Anna: Well, Mercury and Venus are almost

102
00:04:09.520 --> 00:04:12.280
certainly doomed. As for Earth, the

103
00:04:12.280 --> 00:04:15.280
picture is now looking grimmer. While some

104
00:04:15.280 --> 00:04:18.040
models suggested Earth's orbit might widen

105
00:04:18.040 --> 00:04:20.960
and save us, this new data suggests

106
00:04:20.960 --> 00:04:23.880
the Sun's expansion will be too aggressive to

107
00:04:23.880 --> 00:04:24.880
overcome that shift.

108
00:04:25.200 --> 00:04:27.920
Avery: It does. But let's not forget this is about

109
00:04:27.999 --> 00:04:30.680
5 billion years in the future. So there's no

110
00:04:30.680 --> 00:04:32.560
need to sell your stocks just yet.

111
00:04:32.560 --> 00:04:34.840
Anna: Exactly. But it's a profound look into the

112
00:04:34.840 --> 00:04:37.080
celestial mechanics that govern the birth and

113
00:04:37.080 --> 00:04:39.520
death of worlds. It gives us a real sense of

114
00:04:39.520 --> 00:04:42.030
cosmic perspective. Our planet has an

115
00:04:42.030 --> 00:04:43.990
expiration date written in the stars.

116
00:04:44.070 --> 00:04:46.870
Avery: Okay. From a threat 5 billion years

117
00:04:46.870 --> 00:04:49.670
away to one that is, well, less

118
00:04:49.670 --> 00:04:52.350
predictable. A fascinating new piece of

119
00:04:52.350 --> 00:04:54.630
research is helping us understand the risk of

120
00:04:54.630 --> 00:04:57.510
impacts from interstellar objects

121
00:04:57.510 --> 00:04:58.630
or ISOs.

122
00:04:59.030 --> 00:05:01.430
Anna: These are the cosmic nomads. Objects like

123
00:05:01.430 --> 00:05:03.990
asteroids and comets that have been ejected

124
00:05:03.990 --> 00:05:06.230
from their own star systems and are now

125
00:05:06.230 --> 00:05:07.310
wandering the Milky Way.

126
00:05:07.310 --> 00:05:09.280
Avery: That's them. Um, we've had three famous

127
00:05:09.280 --> 00:05:11.800
visitors so far that we know of. The strange

128
00:05:11.960 --> 00:05:14.600
cigar shaped Oumuamua in 2017

129
00:05:14.920 --> 00:05:17.640
and the more comet like Borisov in

130
00:05:17.640 --> 00:05:20.160
2019. Then there's the current one

131
00:05:20.160 --> 00:05:22.120
everyone's talking about. 3i

132
00:05:23.240 --> 00:05:26.200
Atlas those three flybys prove that these

133
00:05:26.200 --> 00:05:27.720
objects are out there.

134
00:05:27.800 --> 00:05:29.720
Anna: Right. And now we want to know how many more

135
00:05:29.720 --> 00:05:32.200
there are and what the chances are that one

136
00:05:32.200 --> 00:05:32.920
might hit us.

137
00:05:33.000 --> 00:05:35.680
Avery: Precisely. This new study tells us where

138
00:05:35.680 --> 00:05:38.560
we're most likely to see them coming from the

139
00:05:38.560 --> 00:05:41.440
solar apex. That's the direction our

140
00:05:41.440 --> 00:05:44.000
solar system is traveling as we orbit the

141
00:05:44.000 --> 00:05:46.640
galaxy. It's what's in front of our cosmic

142
00:05:46.640 --> 00:05:48.120
windshield, so to speak.

143
00:05:48.280 --> 00:05:50.640
Anna: So we're essentially running into a stream of

144
00:05:50.640 --> 00:05:52.640
these objects as we travel through the

145
00:05:52.640 --> 00:05:53.160
galaxy.

146
00:05:53.240 --> 00:05:56.040
Avery: It does. The study also pointed to the

147
00:05:56.040 --> 00:05:58.600
galactic plane as another likely source.

148
00:05:58.840 --> 00:06:01.200
Now, to be clear, the researchers stress that

149
00:06:01.200 --> 00:06:03.760
the probability of an impact on from a large

150
00:06:03.840 --> 00:06:06.560
ISO remains extremely low.

151
00:06:06.720 --> 00:06:08.400
There's just a lot of empty space out there.

152
00:06:08.880 --> 00:06:11.240
But for planetary defense experts, this is

153
00:06:11.240 --> 00:06:13.520
crucial information. It tells them where to

154
00:06:13.520 --> 00:06:16.200
prioritize their search efforts. It's about

155
00:06:16.200 --> 00:06:17.920
being smart and looking in the right

156
00:06:17.920 --> 00:06:20.600
direction for these very faint, very fast

157
00:06:20.600 --> 00:06:21.360
moving objects.

158
00:06:21.520 --> 00:06:23.800
Anna: So it's another step towards creating a

159
00:06:23.800 --> 00:06:26.720
comprehensive map of potential hazards both

160
00:06:26.720 --> 00:06:29.040
from within and without our solar system.

161
00:06:29.730 --> 00:06:30.610
Fascinating stuff.

162
00:06:30.690 --> 00:06:33.130
Avery: Alright, let's leave the threats behind and

163
00:06:33.130 --> 00:06:35.210
travel to Saturn's icy moon

164
00:06:35.210 --> 00:06:37.930
Enceladus. It's getting more promising in the

165
00:06:37.930 --> 00:06:40.810
search for extraterrestrial life, thanks to

166
00:06:40.810 --> 00:06:43.490
a fresh look at old data from the

167
00:06:43.490 --> 00:06:44.690
Cassini mission.

168
00:06:44.690 --> 00:06:47.450
Anna: It absolutely is. Cassini orbited

169
00:06:47.450 --> 00:06:49.890
Saturn from 2004 to 2017,

170
00:06:50.210 --> 00:06:52.810
and scientists are still making incredible

171
00:06:52.810 --> 00:06:55.460
discoveries from its data archives. The big

172
00:06:55.460 --> 00:06:58.300
news we've known for years is the South Pole

173
00:06:58.300 --> 00:07:01.100
with its Deimos tiger stripe fissures that

174
00:07:01.100 --> 00:07:03.860
blast plumes of water from a subsurface ocean

175
00:07:03.860 --> 00:07:04.460
into space.

176
00:07:04.540 --> 00:07:07.140
Avery: Yeah, an underground ocean of

177
00:07:07.140 --> 00:07:09.820
liquid water. That m alone is amazing.

178
00:07:09.820 --> 00:07:12.260
Anna: It is. But the North Pole was always

179
00:07:12.260 --> 00:07:14.780
considered the boring one. Frozen,

180
00:07:14.780 --> 00:07:17.540
ancient and inactive. Well, by

181
00:07:17.540 --> 00:07:20.340
reanalyzing thermal data from Cassini's

182
00:07:20.340 --> 00:07:22.860
flybys, scientists have now discovered a

183
00:07:22.860 --> 00:07:25.380
significant heat signature coming from the

184
00:07:25.380 --> 00:07:27.670
North Pole as well. The ice is much thicker

185
00:07:27.670 --> 00:07:29.950
there, so it was trapping the heat, but it's

186
00:07:29.950 --> 00:07:31.150
definitely there.

187
00:07:31.230 --> 00:07:34.030
Avery: Wow. So the moon's internal engine is

188
00:07:34.030 --> 00:07:36.870
heating it at both poles. What does that

189
00:07:36.870 --> 00:07:37.950
imply for the ocean?

190
00:07:37.950 --> 00:07:40.510
Anna: It implies the ocean is truly global

191
00:07:40.670 --> 00:07:43.310
and that the geological activity isn't just a

192
00:07:43.310 --> 00:07:46.270
recent or temporary phenomenon. At one pole,

193
00:07:46.590 --> 00:07:49.510
a sustained global heat source means this

194
00:07:49.510 --> 00:07:52.130
ocean has likely been stable and warm from

195
00:07:52.280 --> 00:07:53.400
for billions of years.

196
00:07:53.560 --> 00:07:56.120
Avery: And that is the magic ingredient, a stable

197
00:07:56.280 --> 00:07:59.000
environment. It gives life, if it were to

198
00:07:59.000 --> 00:08:01.640
start, a real chance to take hold and evolve.

199
00:08:01.720 --> 00:08:04.080
Anna: Precisely. We're talking about a world with

200
00:08:04.080 --> 00:08:06.440
liquid water, organic molecules, which

201
00:08:06.440 --> 00:08:09.240
Cassini also found, and now a long

202
00:08:09.320 --> 00:08:12.000
lasting source of energy. That's a perfect

203
00:08:12.000 --> 00:08:14.280
trifecta for habitability. It makes

204
00:08:14.280 --> 00:08:17.080
Enceladus arguably the most compelling target

205
00:08:17.080 --> 00:08:18.920
for future astrobiology missions.

206
00:08:19.240 --> 00:08:21.600
Avery: We just have to go back, we have to sample

207
00:08:21.600 --> 00:08:24.120
those plumes and see what's really in that

208
00:08:24.120 --> 00:08:24.440
water.

209
00:08:25.400 --> 00:08:28.160
And while a mission to Enceladus is still on

210
00:08:28.160 --> 00:08:31.040
the drawing board, our final story is about a

211
00:08:31.040 --> 00:08:33.400
mission that is very much on the launchpad.

212
00:08:33.640 --> 00:08:36.600
On November 9, 2025, which is

213
00:08:36.600 --> 00:08:39.400
this Sunday, Blue Origin is set to launch

214
00:08:39.400 --> 00:08:42.280
its first ever interplanetary mission

215
00:08:42.440 --> 00:08:45.080
using its heavy lift new Glenn rocket.

216
00:08:45.910 --> 00:08:47.950
Anna: This is a big step for the commercial space

217
00:08:47.950 --> 00:08:50.390
industry and it's a NASA funded mission

218
00:08:50.390 --> 00:08:52.710
they're carrying. Right. A great example of

219
00:08:52.710 --> 00:08:54.950
public private partnership it is.

220
00:08:55.430 --> 00:08:57.910
Avery: The payload is a mission called Escapade,

221
00:08:57.910 --> 00:09:00.590
which consists of two identical probes

222
00:09:00.590 --> 00:09:01.830
destined for Mars.

223
00:09:02.150 --> 00:09:04.750
Anna: Escapade. I like the name. What's their

224
00:09:04.750 --> 00:09:05.190
purpose?

225
00:09:05.670 --> 00:09:08.230
Avery: They are designed to solve one of Mars

226
00:09:08.310 --> 00:09:11.070
biggest how it lost its

227
00:09:11.070 --> 00:09:13.540
atmosphere. We know Mars was once

228
00:09:13.620 --> 00:09:16.020
warmer and wetter with a thicker atmosphere,

229
00:09:16.260 --> 00:09:18.940
but over billions of years it was stripped

230
00:09:18.940 --> 00:09:20.420
away by the solar wind.

231
00:09:20.900 --> 00:09:22.860
Anna: Right. And that happened because Mars lost

232
00:09:22.860 --> 00:09:25.820
its global magnetic field, which acts as a

233
00:09:25.820 --> 00:09:27.940
protective shield for a planet's atmosphere.

234
00:09:28.340 --> 00:09:30.460
Earth's magnetic field protects us from the

235
00:09:30.460 --> 00:09:31.140
same fate.

236
00:09:31.620 --> 00:09:34.340
Avery: Exactly. Mars now only has

237
00:09:34.340 --> 00:09:37.300
these localized remnant pockets of magnetism

238
00:09:37.300 --> 00:09:40.200
in its crust. The two Escapade spacecraft

239
00:09:40.200 --> 00:09:43.000
will orbit in formation, allowing one

240
00:09:43.000 --> 00:09:45.920
to measure the incoming solar wind while the

241
00:09:45.920 --> 00:09:48.200
other measures the atmospheric effects at

242
00:09:48.200 --> 00:09:49.400
that exact moment.

243
00:09:50.040 --> 00:09:52.840
Anna: This will give us the first ever 3D picture

244
00:09:52.840 --> 00:09:55.520
of how the solar wind is siphoning off what's

245
00:09:55.520 --> 00:09:58.200
left of the Martian air. It's fundamental

246
00:09:58.200 --> 00:10:00.280
science for understanding how a habitable

247
00:10:00.280 --> 00:10:03.080
planet can become an inhospitable one.

248
00:10:03.400 --> 00:10:06.100
A cautionary tale, perhaps a very important

249
00:10:06.180 --> 00:10:06.580
one.

250
00:10:06.900 --> 00:10:09.780
Avery: It's a fantastic mission and a huge milestone

251
00:10:09.780 --> 00:10:11.820
for Blue Origin. We'll be watching that

252
00:10:11.820 --> 00:10:12.580
launch closely.

253
00:10:12.900 --> 00:10:14.940
Anna: And with that, we're out of time for today's

254
00:10:14.940 --> 00:10:17.620
episode. What a journey across the cosmos.

255
00:10:18.020 --> 00:10:20.780
Avery: The universe never fails to deliver. A

256
00:10:20.780 --> 00:10:22.820
huge thank you to all of you for listening to

257
00:10:22.820 --> 00:10:25.340
Astronomy Daily. Join us next time for

258
00:10:25.340 --> 00:10:27.820
another journey through the cosmos. Until

259
00:10:27.820 --> 00:10:30.100
then, stay curious and keep looking up.

260
00:10:30.340 --> 00:10:31.780
Astronomy Daily

261
00:10:33.380 --> 00:10:34.580
stories we told

262
00:10:36.540 --> 00:10:36.780
Love

263
00:10:41.340 --> 00:10:42.780
story HM Soul.