1
00:00:01,969 --> 00:00:04,903
Jupiter is enormous.
2
00:00:04,905 --> 00:00:06,171
Arnou:
It's spinal tap.
3
00:00:06,173 --> 00:00:09,274
Everything's turned up
a little bit closer to 11.
4
00:00:09,276 --> 00:00:13,145
Jupiter is cool because
it's the biggest planet.
5
00:00:13,147 --> 00:00:14,913
And everybody loves 11.
6
00:00:17,785 --> 00:00:20,819
The great red spot,
all the vortices going around.
7
00:00:22,323 --> 00:00:25,491
Patel: These storms raging
bigger than the earth itself.
8
00:00:25,493 --> 00:00:26,658
And then, the moons.
9
00:00:26,660 --> 00:00:28,794
It's like a little solar system
in itself.
10
00:00:28,796 --> 00:00:32,464
79 moons,
four big ones.
11
00:00:32,466 --> 00:00:35,467
Io, europa, ganymede,
and callisto.
12
00:00:35,469 --> 00:00:38,203
And they are huge.
13
00:00:38,205 --> 00:00:44,343
Each one, their own world
of ice, or rock, of volcanoes.
14
00:00:44,345 --> 00:00:46,011
Bolton: You send a spacecraft
to jupiter,
15
00:00:46,013 --> 00:00:48,680
You're gonna get
fried really quick.
16
00:00:48,682 --> 00:00:51,817
The greeks weren't wrong to make
that thing the king of the gods.
17
00:00:51,819 --> 00:00:54,820
-- Captions by vitac --
www.Vitac.Com
18
00:00:54,822 --> 00:00:57,856
Captions paid for by
discovery communications
19
00:01:09,103 --> 00:01:11,270
Juno was gonna be
the first spacecraft
20
00:01:11,272 --> 00:01:13,272
To fly over the poles
of jupiter.
21
00:01:13,274 --> 00:01:18,377
And it was due to arrive
on the fourth of July.
22
00:01:18,379 --> 00:01:19,945
Bolton: That day,
I had my whole family.
23
00:01:19,947 --> 00:01:22,448
We were going in
to jpl.
24
00:01:22,450 --> 00:01:25,117
Then, I remember turning
to my kids in the back seat,
25
00:01:25,119 --> 00:01:28,020
And said, "it might not work.
Something bad could happen.
26
00:01:28,022 --> 00:01:30,556
Nasa, and the country,
and the world
27
00:01:30,558 --> 00:01:32,658
Are taking
a big risk, here."
28
00:01:35,429 --> 00:01:38,197
Bagenal:
We had no idea what this
pole environment was like.
29
00:01:38,199 --> 00:01:40,299
Some sense of
the radiation belts.
30
00:01:40,301 --> 00:01:44,903
We knew they are nasty --
really, really nasty.
31
00:01:48,242 --> 00:01:49,541
Bolton:
Juno is an armored tank,
32
00:01:49,543 --> 00:01:53,011
But it's nothing
compared to jupiter.
33
00:01:53,013 --> 00:01:54,847
Bagenal: So, we want to be
really careful.
34
00:01:54,849 --> 00:01:57,716
Go through quickly,
and get out.
35
00:01:57,718 --> 00:02:01,253
And so, juno is moving
really fast.
36
00:02:01,255 --> 00:02:07,025
Bagenal: It was coming in at
about 150,000 miles an hour,
37
00:02:07,027 --> 00:02:12,030
Which is like going around the
earth 5 times in 2 hours.
38
00:02:12,032 --> 00:02:14,366
Bolton: Not because we had this
incredible propulsion system,
39
00:02:14,368 --> 00:02:17,736
But because jupiter's gravity
was sucking us in.
40
00:02:20,007 --> 00:02:22,541
The engineers hoped that
it wasn't gonna
41
00:02:22,543 --> 00:02:23,909
Get us completely.
42
00:02:23,911 --> 00:02:26,378
We were gonna just go
really close to it.
43
00:02:30,918 --> 00:02:34,052
If it doesn't work,
it's over.
44
00:02:34,054 --> 00:02:35,154
Lights off.
45
00:02:39,193 --> 00:02:42,094
Narrator: Long before juno
would make its daring attempt,
46
00:02:42,096 --> 00:02:43,462
Scientists realized
47
00:02:43,464 --> 00:02:48,433
Jupiter's region of the
solar system was very unusual.
48
00:02:48,435 --> 00:02:52,571
Back in 1955, they detected
bursts of radio emission
49
00:02:52,573 --> 00:02:55,741
Coming from jupiter.
50
00:02:55,743 --> 00:02:58,877
This told us that jupiter
has a magnetic field,
51
00:02:58,879 --> 00:03:01,647
And perhaps more importantly,
a very strong one.
52
00:03:01,649 --> 00:03:03,916
Narrator: Some planets
have a dynamo inside,
53
00:03:03,918 --> 00:03:07,619
Surrounding themselves
with a magnetic field.
54
00:03:07,621 --> 00:03:10,255
But at this time, the power
of these magnetic fields
55
00:03:10,257 --> 00:03:12,424
Wasn't well understood.
56
00:03:12,426 --> 00:03:17,162
Then, in 1958, an experiment
around our own planet
57
00:03:17,164 --> 00:03:19,398
Helped scientists
start to understand
58
00:03:19,400 --> 00:03:22,601
The mysterious forces
at work around jupiter.
59
00:03:22,603 --> 00:03:25,871
At the end of the 1950s,
there was a huge push in america
60
00:03:25,873 --> 00:03:28,640
To have a successful satellite
in orbit.
61
00:03:28,642 --> 00:03:31,476
And the concept of
the explorer 1 mission
62
00:03:31,478 --> 00:03:32,744
Was developed.
63
00:03:32,746 --> 00:03:34,413
Now, the scientific payload
for that mission
64
00:03:34,415 --> 00:03:37,082
Was led by a person
called "james van allen,"
65
00:03:37,084 --> 00:03:40,118
Who had a big interest
in magnetic fields
66
00:03:40,120 --> 00:03:42,888
And the particle
environments
67
00:03:42,890 --> 00:03:47,092
That might be
above our heads, in space.
68
00:03:47,094 --> 00:03:49,895
Lucie: One of the things
that he was excited about
69
00:03:49,897 --> 00:03:52,798
Was really high-energy
particles.
70
00:03:52,800 --> 00:03:54,866
And so, he proposed
an instrument
71
00:03:54,868 --> 00:03:58,570
To be on explorer 1,
our very first spacecraft.
72
00:04:06,413 --> 00:04:10,449
So, explorer 1 had a very
simple detector system
73
00:04:10,451 --> 00:04:12,618
That would count particles.
74
00:04:12,620 --> 00:04:14,019
Patel:
It was a geiger-muller tube,
75
00:04:14,021 --> 00:04:15,587
The kind of thing you look
for radiation with.
76
00:04:15,589 --> 00:04:17,356
It counts -- you know, it does
the click, click, click,
77
00:04:17,358 --> 00:04:19,358
Counting for radiation.
78
00:04:19,360 --> 00:04:20,826
They wanted to fly this
on the rocket,
79
00:04:20,828 --> 00:04:22,828
To measure the radiation
up in space.
80
00:04:22,830 --> 00:04:25,264
The experiment was looking
for cosmic rays.
81
00:04:25,266 --> 00:04:27,499
Now, cosmic rays are
the radiation coming out
82
00:04:27,501 --> 00:04:31,270
From far out in the galaxy,
entering our solar system.
83
00:04:31,272 --> 00:04:33,505
And it went up there,
counting the particles --
84
00:04:33,507 --> 00:04:35,641
Zip, zip, zip, zip,
going in
85
00:04:35,643 --> 00:04:39,578
At some point, though,
the signals disappeared.
86
00:04:39,580 --> 00:04:41,980
Or, aha,
you know what's happening?
87
00:04:41,982 --> 00:04:43,548
This is saturated.
88
00:04:43,550 --> 00:04:46,184
The number of particles
are so high
89
00:04:46,186 --> 00:04:51,790
That the detector has just said,
"I'm gonna shut down."
90
00:04:51,792 --> 00:04:53,759
Lucie:
And that realization
91
00:04:53,761 --> 00:04:56,461
Actually led to
a phenomenal discovery.
92
00:04:56,463 --> 00:04:59,798
In space, there are
doughnut-shaped regions
93
00:04:59,800 --> 00:05:01,266
Around the earth,
94
00:05:01,268 --> 00:05:04,770
Where there are many, many
electrically charged particles.
95
00:05:04,772 --> 00:05:08,373
The radiation gets trapped into
this really lethal zone
96
00:05:08,375 --> 00:05:10,676
Around the earth.
97
00:05:10,678 --> 00:05:13,245
Lucie:
And they're trapped because
electrically charged particles
98
00:05:13,247 --> 00:05:16,715
Feel a force
from the magnetic field.
99
00:05:16,717 --> 00:05:19,017
Narrator: We had discovered that
the earth's magnetic field
100
00:05:19,019 --> 00:05:22,587
Creates a bubble around the
planet called a "magnetosphere,"
101
00:05:22,589 --> 00:05:24,856
That both deflects
charged particles
102
00:05:24,858 --> 00:05:26,958
And captures some,
as well.
103
00:05:26,960 --> 00:05:29,394
Critically,
many of the radiation particles
104
00:05:29,396 --> 00:05:31,596
Interacting with
the magnetosphere
105
00:05:31,598 --> 00:05:33,265
Came streaming
from the sun
106
00:05:33,267 --> 00:05:35,967
In what is called
"the solar wind."
107
00:05:35,969 --> 00:05:37,736
Lucie: This scientific discovery
is, you know,
108
00:05:37,738 --> 00:05:40,372
Fantastic on the one hand,
but it's also slightly worrying
109
00:05:40,374 --> 00:05:43,175
Because high-energy
charged particles
110
00:05:43,177 --> 00:05:45,610
Can pack a punch when
they interact with materials.
111
00:05:45,612 --> 00:05:49,181
So, let's imagine, for example,
the impact on the human body.
112
00:05:49,183 --> 00:05:51,383
If these particles
have enough energy,
113
00:05:51,385 --> 00:05:53,218
They can penetrate
the skin,
114
00:05:53,220 --> 00:05:56,922
And start to interfere
with the cells of the body.
115
00:05:56,924 --> 00:05:59,057
Bagenal: And so, we have to be
really careful,
116
00:05:59,059 --> 00:06:02,094
Not just because of humans
we don't want to be damaged,
117
00:06:02,096 --> 00:06:04,229
But also the electronics.
118
00:06:04,231 --> 00:06:05,664
Narrator:
As scientists endeavored
119
00:06:05,666 --> 00:06:08,666
To explore further out
into our solar system,
120
00:06:08,668 --> 00:06:10,702
One of the main concerns
was whether or not
121
00:06:10,704 --> 00:06:12,304
We could build a spacecraft
122
00:06:12,306 --> 00:06:14,473
That would withstand
the harsh radiation
123
00:06:14,475 --> 00:06:16,942
Permeating
the solar system.
124
00:06:16,944 --> 00:06:21,780
Lucie:
So, can we send a spacecraft
to places like jupiter?
125
00:06:21,782 --> 00:06:25,951
Will our spacecraft survive
in those kind of environments?
126
00:06:25,953 --> 00:06:27,953
Bolton: When van allen
discovered these incredibly
127
00:06:27,955 --> 00:06:30,055
High-energy radiation belts
around the earth,
128
00:06:30,057 --> 00:06:32,491
I think people started to then
look at the models
129
00:06:32,493 --> 00:06:34,626
Of what would be needed
at jupiter.
130
00:06:34,628 --> 00:06:37,095
I mean, our radiation belts,
as severe as they are,
131
00:06:37,097 --> 00:06:38,830
And dangerous
as they may be,
132
00:06:38,832 --> 00:06:42,033
Are really a piece of cake
compared to jupiter.
133
00:06:43,370 --> 00:06:49,441
♪♪
134
00:06:49,443 --> 00:06:55,547
♪♪
135
00:06:55,549 --> 00:07:00,152
Bagenal:
So, the first time we left earth
to go out in the solar system
136
00:07:00,154 --> 00:07:04,556
Beyond the orbit of mars,
there were major concerns.
137
00:07:04,558 --> 00:07:07,459
"can we send a spacecraft
through that environment?"
138
00:07:07,461 --> 00:07:10,195
So, we sent two
pioneer spacecraft.
139
00:07:12,032 --> 00:07:15,000
They were pretty crude,
with very limited
140
00:07:15,002 --> 00:07:16,968
Computational capabilities,
141
00:07:16,970 --> 00:07:20,872
And very limited power
and ability to communicate,
142
00:07:20,874 --> 00:07:23,041
So they would just make
a few measurements,
143
00:07:23,043 --> 00:07:25,043
And then send the information
back to the earth.
144
00:07:25,045 --> 00:07:26,077
Very simple.
145
00:07:26,079 --> 00:07:34,286
♪♪
146
00:07:34,288 --> 00:07:35,454
James:
So, when the pioneers
147
00:07:35,456 --> 00:07:38,390
Flew through
the magnetosphere of jupiter,
148
00:07:38,392 --> 00:07:40,091
We didn't know
how big this was.
149
00:07:40,093 --> 00:07:42,227
We didn't know how large
the magnetic field is.
150
00:07:42,229 --> 00:07:43,895
And we didn't know
how it was shaped
151
00:07:43,897 --> 00:07:45,997
Or buffeted
by the solar wind.
152
00:07:45,999 --> 00:07:50,769
♪♪
153
00:07:50,771 --> 00:07:55,474
Narrator: Pioneer 10 flew past
jupiter on December 3rd, 1973,
154
00:07:55,476 --> 00:07:58,043
And sent back
these incredible images.
155
00:07:58,045 --> 00:08:03,849
♪♪
156
00:08:03,851 --> 00:08:06,151
Bolton: Pioneer carried
some protection,
157
00:08:06,153 --> 00:08:09,454
But it probably went a little
bit closer than it should have,
158
00:08:09,456 --> 00:08:12,190
And in order to try to assess
what it was like there,
159
00:08:12,192 --> 00:08:14,659
I mean, it basically
was carrying a geiger counter.
160
00:08:14,661 --> 00:08:17,796
And I think everybody was
startled at the amount of energy
161
00:08:17,798 --> 00:08:21,199
That we're talking about.
162
00:08:21,201 --> 00:08:23,468
Narrator: During its closest
approach to jupiter,
163
00:08:23,470 --> 00:08:27,906
Pioneer 10 absorbed 1,000 times
the lethal dose of radiation
164
00:08:27,908 --> 00:08:30,141
For a human being.
165
00:08:30,143 --> 00:08:33,745
Reporter:
The spacecraft is collecting its
worst radiation exposure now.
166
00:08:33,747 --> 00:08:36,748
Tension is even greater
this time,
167
00:08:36,750 --> 00:08:38,350
And so is the relief.
168
00:08:40,387 --> 00:08:44,189
And so, after the pioneers,
we knew the extent
169
00:08:44,191 --> 00:08:48,560
Of the jovian magnetosphere,
and it is enormous.
170
00:08:54,935 --> 00:08:56,902
Arnou: If we could see it
in the night sky,
171
00:08:56,904 --> 00:08:59,571
With jupiter sitting
rather far away from us,
172
00:08:59,573 --> 00:09:04,109
It would still be roughly
five times larger than the moon.
173
00:09:04,111 --> 00:09:07,112
James: The solar wind that hits
that magnetic field
174
00:09:07,114 --> 00:09:12,150
Shapes it like a comet,
and produces a long tail.
175
00:09:12,152 --> 00:09:16,488
The tail stretches
all the way to saturn.
176
00:09:20,360 --> 00:09:23,995
Bagenal:
The primary purpose of those
pioneers was really to say,
177
00:09:23,997 --> 00:09:27,132
"can we survive
this lethal dose of radiation?"
178
00:09:27,134 --> 00:09:30,368
So then, we can follow with more
sophisticated instrumentation
179
00:09:30,370 --> 00:09:32,237
That can do a lot
of interesting science.
180
00:09:32,239 --> 00:09:35,373
Narrator: The highly anticipated
follow-up mission was voyager.
181
00:09:35,375 --> 00:09:36,708
But before launch,
182
00:09:36,710 --> 00:09:40,011
Scientists realized
it might have some design flaws.
183
00:09:40,013 --> 00:09:42,547
Casani: We had the voyager
spacecraft down at the cape,
184
00:09:42,549 --> 00:09:45,550
Ready to launch,
and it was the pioneer data
185
00:09:45,552 --> 00:09:48,153
That made us realize
that the radiation tolerance
186
00:09:48,155 --> 00:09:50,956
That we had designed
into the voyager spacecraft
187
00:09:50,958 --> 00:09:53,358
Was not gonna be adequate
for the environment
188
00:09:53,360 --> 00:09:55,760
That pioneers 10 and 11
had sent.
189
00:09:55,762 --> 00:09:57,896
It threw us into
a real turmoil
190
00:09:57,898 --> 00:10:01,299
Of trying to recover
from that.
191
00:10:01,301 --> 00:10:03,802
Bolton: By the time we got
to the voyager spacecraft,
192
00:10:03,804 --> 00:10:06,338
We were already so scared
and intimidated by jupiter
193
00:10:06,340 --> 00:10:08,406
That we started to move
away from it.
194
00:10:08,408 --> 00:10:09,708
We didn't want to
get so close,
195
00:10:09,710 --> 00:10:12,110
Because we knew,
if you got close,
196
00:10:12,112 --> 00:10:14,145
You're probably spelling
the end of the spacecraft.
197
00:10:14,147 --> 00:10:15,580
So, you've got to
stay away,
198
00:10:15,582 --> 00:10:18,116
And respect this beast,
this monster.
199
00:10:18,118 --> 00:10:20,619
It's much more powerful
than we are.
200
00:10:26,760 --> 00:10:30,195
Even with a quite small
telescope from your backyard,
201
00:10:30,197 --> 00:10:32,931
You can look up and see jupiter
on a clear night.
202
00:10:32,933 --> 00:10:35,033
And you can see
the belts and zones.
203
00:10:35,035 --> 00:10:37,035
You can see the red spot.
204
00:10:39,439 --> 00:10:42,240
But voyager saw up close.
205
00:10:46,246 --> 00:10:48,246
And it was really like
you were on the spacecraft,
206
00:10:48,248 --> 00:10:49,481
Looking out the window.
207
00:10:51,118 --> 00:10:53,485
Bagenal: You could see
these belts and zones,
208
00:10:53,487 --> 00:10:55,920
East west winds
going back and forth,
209
00:10:55,922 --> 00:10:57,155
And the great red spot
210
00:10:57,157 --> 00:11:00,892
Being caught up
in those belts and zones.
211
00:11:00,894 --> 00:11:04,896
And so, the weather system
was becoming clear.
212
00:11:04,898 --> 00:11:07,632
Arnou: As we come in
for a close view of jupiter,
213
00:11:07,634 --> 00:11:10,468
You'll see clouds orbiting
around the planet
214
00:11:10,470 --> 00:11:13,805
At different rates,
with different thickness bands.
215
00:11:13,807 --> 00:11:15,840
And these are called
the "jets."
216
00:11:15,842 --> 00:11:19,310
And these jets go around lines
of latitude, back and forth,
217
00:11:19,312 --> 00:11:22,814
Some faster than the planet,
some slower than the planet.
218
00:11:22,816 --> 00:11:24,883
And so, if you were living
on the planet,
219
00:11:24,885 --> 00:11:28,386
There would be these huge shears
at different latitudes,
220
00:11:28,388 --> 00:11:32,657
As these fight back and forth
in different directions.
221
00:11:32,659 --> 00:11:34,859
Narrator: Finding out
what causes this wild weather
222
00:11:34,861 --> 00:11:37,862
Became a key
scientific objective.
223
00:11:37,864 --> 00:11:41,766
Arnou: On jupiter, the effects
of planetary rotation
224
00:11:41,768 --> 00:11:43,068
Are incredibly important.
225
00:11:43,070 --> 00:11:44,169
Why?
226
00:11:44,171 --> 00:11:46,438
Well, the strength
of the rotational forces
227
00:11:46,440 --> 00:11:48,907
Depends on how fast
the system rotates,
228
00:11:48,909 --> 00:11:51,976
And it also depends on
how big the system is.
229
00:11:51,978 --> 00:11:53,545
And jupiter's huge.
230
00:11:53,547 --> 00:11:57,415
Narrator: Jupiter has a diameter
of over 88,000 miles.
231
00:11:57,417 --> 00:12:00,251
It was discovered that it takes
just under 10 hours
232
00:12:00,253 --> 00:12:02,520
For the planet
to make a complete rotation,
233
00:12:02,522 --> 00:12:05,156
Giving it the shortest day
in our solar system.
234
00:12:05,158 --> 00:12:07,959
So, this body
is just completely flying.
235
00:12:07,961 --> 00:12:09,861
If you think of the whole planet
as a gyroscope,
236
00:12:09,863 --> 00:12:12,330
It would be a very big,
very fast gyroscope.
237
00:12:12,332 --> 00:12:16,367
And those gyroscopic effects
dominate many of the dynamics
238
00:12:16,369 --> 00:12:18,169
We observe.
239
00:12:18,171 --> 00:12:21,906
We use this demo to explain
jupiter's great red spot,
240
00:12:21,908 --> 00:12:24,008
Which is a really
interesting phenomenon
241
00:12:24,010 --> 00:12:26,244
That we've observed
for over 200 years.
242
00:12:26,246 --> 00:12:28,713
And we think it's existed
longer than that.
243
00:12:28,715 --> 00:12:30,815
It's essentially
a massive hurricane
244
00:12:30,817 --> 00:12:35,153
That's about 1.3 times
the size of the earth.
245
00:12:35,155 --> 00:12:37,822
So, jupiter is a very strongly
rotating body,
246
00:12:37,824 --> 00:12:40,125
But it also has a lot
of strong turbulence.
247
00:12:40,127 --> 00:12:41,493
And the great red spot
248
00:12:41,495 --> 00:12:47,165
Has formed from this
rapidly rotating turbulence.
249
00:12:47,167 --> 00:12:51,069
Narrator:
As a cloud of gas or liquid
moves across a rotating surface,
250
00:12:51,071 --> 00:12:54,672
Its path begins to curve along
with the rotation.
251
00:12:54,674 --> 00:12:56,641
This is called
the "coriolis effect,"
252
00:12:56,643 --> 00:12:59,177
And it's what spins hurricanes
here on earth.
253
00:12:59,179 --> 00:13:02,580
But because jupiter is so large,
and turns so fast,
254
00:13:02,582 --> 00:13:05,784
Its weather
is far more extreme.
255
00:13:05,786 --> 00:13:07,752
Hawkins: The effect of
the coriolis force
256
00:13:07,754 --> 00:13:10,488
In the presence of turbulence
acts to generate
257
00:13:10,490 --> 00:13:13,391
Large-scale structures
like the great red spot.
258
00:13:13,393 --> 00:13:15,360
And they persist.
259
00:13:15,362 --> 00:13:17,462
Arnou: That's what you get
in rotating systems.
260
00:13:17,464 --> 00:13:22,467
You naturally roll things up
into large vertical structures.
261
00:13:24,704 --> 00:13:26,504
And they live a long,
long time
262
00:13:26,506 --> 00:13:28,439
When the system's
rapidly rotating.
263
00:13:28,441 --> 00:13:33,578
♪♪
264
00:13:33,580 --> 00:13:37,348
If the planet stopped rotating,
that organization would be gone.
265
00:13:37,350 --> 00:13:42,353
♪♪
266
00:13:42,355 --> 00:13:44,989
Narrator: Yet the genius
of the voyager spacecraft
267
00:13:44,991 --> 00:13:46,825
Was that they were not
just visiting jupiter
268
00:13:46,827 --> 00:13:48,726
In order to examine
the planet.
269
00:13:48,728 --> 00:13:52,664
The four giant galilean moons
were a key objective,
270
00:13:52,666 --> 00:13:56,167
And none more so
than the mysterious moon io.
271
00:13:56,169 --> 00:14:01,806
♪♪
272
00:14:01,808 --> 00:14:03,308
Bagenal:
As we were coming in,
273
00:14:03,310 --> 00:14:07,679
The ultraviolet instrument was
saying, "whoa, this is bright.
274
00:14:07,681 --> 00:14:10,815
There's a lot of gas
around this environment near io.
275
00:14:10,817 --> 00:14:13,551
You better be careful."
276
00:14:13,553 --> 00:14:19,757
Voyager flew by, and we saw it
covered with volcanoes.
277
00:14:19,759 --> 00:14:21,292
Narrator:
Scientists realized
278
00:14:21,294 --> 00:14:24,162
That io's volcanic gases
could be contributing
279
00:14:24,164 --> 00:14:27,699
To the unprecedented radiation
surrounding jupiter.
280
00:14:30,070 --> 00:14:33,705
Those gases were becoming
trapped in the magnetic field,
281
00:14:33,707 --> 00:14:36,441
To make this doughnut
of charged particles.
282
00:14:36,443 --> 00:14:39,444
They get accelerated
to very high energies.
283
00:14:41,481 --> 00:14:44,816
Most of them go out
to fill a big volume.
284
00:14:44,818 --> 00:14:46,451
Some of them go in.
285
00:14:46,453 --> 00:14:49,287
And as they go in,
they go to even higher energies,
286
00:14:49,289 --> 00:14:53,157
And form this very tight
environment close to jupiter --
287
00:14:53,159 --> 00:14:55,894
This lethal radiation
environment.
288
00:14:55,896 --> 00:14:58,463
That inner region
is very analogous
289
00:14:58,465 --> 00:15:01,065
To the van allen belts
of earth,
290
00:15:01,067 --> 00:15:06,504
But many times stronger,
and more nasty.
291
00:15:06,506 --> 00:15:08,740
The background radiation
here on earth
292
00:15:08,742 --> 00:15:11,276
That we're exposed to
is about 1/3 of a rad.
293
00:15:11,278 --> 00:15:16,247
At jupiter, the radiation
environment is 20 million rad.
294
00:15:18,351 --> 00:15:22,854
We did know io, europa, ganymede
are in these orbital resonances.
295
00:15:22,856 --> 00:15:24,289
The orbits are elliptical.
296
00:15:24,291 --> 00:15:28,126
And so, when I was close
to jupiter, it squeezes it.
297
00:15:28,128 --> 00:15:31,863
And when it's further away from
jupiter, the squeeze is less.
298
00:15:31,865 --> 00:15:35,033
And so, you're literally
looking at io going like this.
299
00:15:35,035 --> 00:15:38,736
That heat has got
to go somewhere.
300
00:15:38,738 --> 00:15:42,273
There had been a paper
published in science magazine
301
00:15:42,275 --> 00:15:45,677
That had come out the week
before voyager got there,
302
00:15:45,679 --> 00:15:49,914
Predicting volcanoes on io
because of this tidal flexing.
303
00:15:49,916 --> 00:15:54,752
Narrator:
But io's volcanoes wouldn't be
voyager's only lunar bombshell.
304
00:15:58,658 --> 00:16:00,792
You know, we knew there was
something weird about europa.
305
00:16:00,794 --> 00:16:03,328
It was bright, and maybe it had
these weird markings.
306
00:16:03,330 --> 00:16:05,930
But you couldn't really
see them before.
307
00:16:08,735 --> 00:16:10,435
And then, all of a sudden,
there it is.
308
00:16:10,437 --> 00:16:12,470
And as the first image
is appearing on the screen,
309
00:16:12,472 --> 00:16:14,973
You know, europa has all
these cracks in the ice,
310
00:16:14,975 --> 00:16:16,708
And these, like, lines
going across.
311
00:16:16,710 --> 00:16:19,644
[ indistinct talking ]
312
00:16:19,646 --> 00:16:21,913
In that moment,
it was just like, "whoa.
313
00:16:21,915 --> 00:16:23,247
What does that mean?
314
00:16:26,186 --> 00:16:28,353
Patel: As an airless body,
we kind of expect things
315
00:16:28,355 --> 00:16:29,687
To be bombarded
all the time,
316
00:16:29,689 --> 00:16:31,823
So you end up with a surface
peppered with craters,
317
00:16:31,825 --> 00:16:32,857
Much like our moon.
318
00:16:32,859 --> 00:16:34,892
[ indistinct talking ]
319
00:16:34,894 --> 00:16:37,528
Turtle:
Because the cratering rate
throughout the solar system
320
00:16:37,530 --> 00:16:40,131
Is relatively
well understood.
321
00:16:40,133 --> 00:16:43,534
The fact that europa
has so few craters
322
00:16:43,536 --> 00:16:45,336
Is very consistent
with it having
323
00:16:45,338 --> 00:16:47,305
A young surface,
with a surface
324
00:16:47,307 --> 00:16:50,208
That has been
geologically resurfaced.
325
00:16:53,713 --> 00:16:57,615
Bagenal:
The voyager observations
were so spectacular --
326
00:16:57,617 --> 00:16:59,684
The dynamics
of the atmosphere,
327
00:16:59,686 --> 00:17:02,620
The different kinds of moons,
and what was going on.
328
00:17:02,622 --> 00:17:04,055
Everybody said,
"we got to go back."
329
00:17:10,196 --> 00:17:13,998
Bagenal:
The voyager observations
were so spectacular,
330
00:17:14,000 --> 00:17:16,100
Everybody said,
"we got to go back."
331
00:17:16,102 --> 00:17:18,369
But this time,
we have to go back and stay.
332
00:17:18,371 --> 00:17:22,607
With voyager, we had a couple of
very short, fleeting flybys.
333
00:17:22,609 --> 00:17:24,609
Like, you know,
squeezing some pictures
334
00:17:24,611 --> 00:17:26,611
Out your car window
as you drive by,
335
00:17:26,613 --> 00:17:28,279
As opposed
to actually stopping,
336
00:17:28,281 --> 00:17:32,050
Getting out of the car,
and exploring.
337
00:17:32,052 --> 00:17:35,119
Narrator: Before voyager had
jupiter in its rearview mirror,
338
00:17:35,121 --> 00:17:37,021
Nasa had been building
a spacecraft
339
00:17:37,023 --> 00:17:40,792
They intended to go into orbit
around the giant planet.
340
00:17:40,794 --> 00:17:45,396
The mission
was called "galileo."
341
00:17:45,398 --> 00:17:48,466
Maize:
Galileo had a fitful start
right from the very beginning
342
00:17:48,468 --> 00:17:51,202
About how exactly it was
going to get to jupiter.
343
00:17:51,204 --> 00:17:54,772
Narrator: Galileo was scheduled
to launch in January 1982
344
00:17:54,774 --> 00:17:58,242
On board the space shuttle.
345
00:17:58,244 --> 00:18:01,179
The launch date slipped
to '84...
346
00:18:01,181 --> 00:18:03,381
Then '85...
347
00:18:03,383 --> 00:18:06,117
And then '86.
348
00:18:06,119 --> 00:18:07,652
And then,
the whole shuttle program
349
00:18:07,654 --> 00:18:09,821
Suffered a terrible
tragedy.
350
00:18:12,692 --> 00:18:15,593
The significance of that,
of course, the loss of life,
351
00:18:15,595 --> 00:18:17,595
And the disruption
of the whole program,
352
00:18:17,597 --> 00:18:20,698
But to us was that
we didn't have a launch vehicle.
353
00:18:20,700 --> 00:18:22,934
And so, we packed up
our spacecraft,
354
00:18:22,936 --> 00:18:24,635
And took it back
to california,
355
00:18:24,637 --> 00:18:27,438
To try and figure out
what to do.
356
00:18:27,440 --> 00:18:29,307
Narrator: Not only was
the launch delayed,
357
00:18:29,309 --> 00:18:32,810
But after the challenger
accident, nasa was rattled.
358
00:18:32,812 --> 00:18:35,680
The liquid hydrogen-fueled
rocket booster
359
00:18:35,682 --> 00:18:38,316
That was originally intended
to deliver galileo
360
00:18:38,318 --> 00:18:42,386
Directly to jupiter
was now considered unsafe.
361
00:18:42,388 --> 00:18:44,422
Maize: It was no longer possible
to take galileo
362
00:18:44,424 --> 00:18:46,157
Straight up to jupiter.
363
00:18:46,159 --> 00:18:47,892
And that's where the
mission designers, here,
364
00:18:47,894 --> 00:18:49,060
Pulled a rabbit
out of the hat,
365
00:18:49,062 --> 00:18:50,895
And found
the so-called "veega" --
366
00:18:50,897 --> 00:18:53,197
Venus-earth-earth
gravity assist trajectory
367
00:18:53,199 --> 00:18:55,500
That took another five years
to get there.
368
00:18:57,670 --> 00:18:59,604
Woman: We have a go
[indistinct]
369
00:18:59,606 --> 00:19:05,910
6...5...4...3...2...1.
370
00:19:05,912 --> 00:19:08,379
We have ignition
and liftoff of atlantis,
371
00:19:08,381 --> 00:19:11,716
And the galileo spacecraft
bound for jupiter.
372
00:19:11,718 --> 00:19:17,088
♪♪
373
00:19:17,090 --> 00:19:22,460
♪♪
374
00:19:22,462 --> 00:19:25,763
Man: Galileo is on its way
to another world.
375
00:19:25,765 --> 00:19:27,365
Fly safe.
376
00:19:27,367 --> 00:19:28,866
Maize:
After the first earth flyby,
377
00:19:28,868 --> 00:19:32,136
We knew we would be
far enough away from the sun
378
00:19:32,138 --> 00:19:36,874
That we could actually begin
to use the high-bream antenna.
379
00:19:36,876 --> 00:19:37,975
It was like an umbrella.
380
00:19:37,977 --> 00:19:40,111
You imagine an umbrella
being folded up.
381
00:19:40,113 --> 00:19:41,779
And when the time came,
382
00:19:41,781 --> 00:19:43,548
The spacecraft would
fire a device,
383
00:19:43,550 --> 00:19:45,883
And the antenna
could unfold.
384
00:19:45,885 --> 00:19:50,788
So, we activated the motor
to free the antenna.
385
00:19:50,790 --> 00:19:51,956
And it stuck.
386
00:19:54,694 --> 00:19:56,928
Can you imagine --
[ imitates machinery whirring ]
387
00:19:56,930 --> 00:19:58,062
And it stalled,
388
00:19:58,064 --> 00:20:01,265
Only partially deploying
some of the antenna.
389
00:20:01,267 --> 00:20:05,002
And the motor
doesn't reverse.
390
00:20:05,004 --> 00:20:07,838
We could tell the antenna
had deployed a little bit
391
00:20:07,840 --> 00:20:10,708
Because the spacecraft's spin
wasn't quite the same,
392
00:20:10,710 --> 00:20:12,276
It's like if you took out
one arm, and you're spinning,
393
00:20:12,278 --> 00:20:13,978
You start to do this
a little bit.
394
00:20:13,980 --> 00:20:15,346
Well, the antenna
was doing that little bit.
395
00:20:15,348 --> 00:20:16,647
So, we knew it
opened some.
396
00:20:16,649 --> 00:20:18,216
Casani:
So, why didn't it open?
397
00:20:18,218 --> 00:20:22,420
The antenna had remained stowed
for so long,
398
00:20:22,422 --> 00:20:25,756
And the fact that it went
into 2 vibration environments.
399
00:20:25,758 --> 00:20:29,360
Once, when we latched this
spacecraft up in california --
400
00:20:29,362 --> 00:20:32,997
Trucked it down to kennedy,
trucked it back to pasadena.
401
00:20:32,999 --> 00:20:34,565
Said, "let's not mess
with that antenna.
402
00:20:34,567 --> 00:20:35,733
It was all
put together right.
403
00:20:35,735 --> 00:20:37,401
We'll just leave it
the way it was."
404
00:20:37,403 --> 00:20:38,569
Back to the cape again.
405
00:20:38,571 --> 00:20:40,738
So, it made three trips
across the cape,
406
00:20:40,740 --> 00:20:43,207
And the truck was just vibrating
the whole time.
407
00:20:45,111 --> 00:20:46,410
Maize: And so,
we did a lot of things.
408
00:20:46,412 --> 00:20:49,347
We worked on calibrating
how far the antenna was open,
409
00:20:49,349 --> 00:20:51,282
Could we use it
the way it was,
410
00:20:51,284 --> 00:20:53,484
And could we do the cold turns
to free it up,
411
00:20:53,486 --> 00:20:54,952
And see if anything
springs free?
412
00:20:54,954 --> 00:20:57,888
And we'd know, again,
by seeing the spin rates change,
413
00:20:57,890 --> 00:20:59,257
If anything broke free.
414
00:20:59,259 --> 00:21:03,294
So, we spent a couple of years
working on those things.
415
00:21:03,296 --> 00:21:08,332
Narrator: Jpl never got
the high-gain antenna to open.
416
00:21:08,334 --> 00:21:09,834
Casani:
Our capability at jupiter
417
00:21:09,836 --> 00:21:11,269
With an antenna
that hadn't opened
418
00:21:11,271 --> 00:21:15,273
Was going to be dependent upon
a single low-gain antenna.
419
00:21:15,275 --> 00:21:17,375
And that just meant
we had to transmit
420
00:21:17,377 --> 00:21:20,077
A lot fewer pictures
over the same time.
421
00:21:23,983 --> 00:21:26,817
Bagenal: The galileo spacecraft
carried along with it
422
00:21:26,819 --> 00:21:30,021
A probe,
that's sort of like this size.
423
00:21:30,023 --> 00:21:33,491
And it had a big heat shield
to protect it around it.
424
00:21:33,493 --> 00:21:37,728
So, in July 1995,
we launched that probe,
425
00:21:37,730 --> 00:21:39,864
And sent it
in the direction of jupiter.
426
00:21:39,866 --> 00:21:42,199
Now, it didn't have engines,
so we weren't guiding it,
427
00:21:42,201 --> 00:21:43,801
And saying, "go there."
428
00:21:43,803 --> 00:21:47,805
We just sort of sent it
on a trajectory towards jupiter.
429
00:21:47,807 --> 00:21:53,444
Narrator: Five months later,
on December 7th, 1995,
430
00:21:53,446 --> 00:21:58,149
The galileo probe
arrived at jupiter.
431
00:21:58,151 --> 00:22:01,152
There were no cameras
on board,
432
00:22:01,154 --> 00:22:04,989
Only sensors and a small probe
that was going to have
433
00:22:04,991 --> 00:22:08,859
An extremely violent
introduction to jupiter.
434
00:22:08,861 --> 00:22:14,432
Bagenal:
It was coming in at something
like 130,000 miles an hour.
435
00:22:14,434 --> 00:22:16,734
It was pulled in
by the gravity of jupiter,
436
00:22:16,736 --> 00:22:19,737
And we had to
slow it down.
437
00:22:19,739 --> 00:22:23,541
And so, this heat shield
heated up to about three times
438
00:22:23,543 --> 00:22:25,710
The temperature
of the surface of the sun.
439
00:22:29,015 --> 00:22:31,282
Narrator: During its
maximum deceleration,
440
00:22:31,284 --> 00:22:35,586
The probe endured forces
of 228 gs,
441
00:22:35,588 --> 00:22:39,724
And then, eventually,
we kicked off the heat shield,
442
00:22:39,726 --> 00:22:42,727
Put out some parachutes.
443
00:22:42,729 --> 00:22:46,731
What we were expecting was
three separate layers of clouds.
444
00:22:46,733 --> 00:22:51,669
♪♪
445
00:22:51,671 --> 00:22:52,770
And we went down.
446
00:22:52,772 --> 00:22:55,172
It was like,
"where are the clouds?"
447
00:22:55,174 --> 00:22:58,008
Well, the hint came
from the ground.
448
00:22:58,010 --> 00:23:00,845
Telescopes on earth
were looking in the infrared,
449
00:23:00,847 --> 00:23:03,647
At jupiter, at the same time
we sent the probe in.
450
00:23:03,649 --> 00:23:07,818
We realized that the probe
went into a hotspot,
451
00:23:07,820 --> 00:23:10,921
Somewhere where there's
very little water.
452
00:23:10,923 --> 00:23:14,325
And so, I think we realized
that our whole idea of exploring
453
00:23:14,327 --> 00:23:16,360
These planets
with single probes
454
00:23:16,362 --> 00:23:20,398
Is a little bit susceptible to
going into the wrong place.
455
00:23:20,400 --> 00:23:25,236
Bagenal:
By the time the probe had got
down to about 160 kilometers,
456
00:23:25,238 --> 00:23:28,139
Something like 23 times
atmospheric pressure,
457
00:23:28,141 --> 00:23:31,041
It was now starting
to get really hot.
458
00:23:31,043 --> 00:23:33,377
And so, at that point,
the electronics
459
00:23:33,379 --> 00:23:36,714
Is just not working anymore,
and it stops communicating,
460
00:23:36,716 --> 00:23:40,618
And sending signals
back to the earth.
461
00:23:40,620 --> 00:23:42,420
What happened to it
after that?
462
00:23:42,422 --> 00:23:45,856
Well, it was so hot
that it basically vaporized.
463
00:23:48,494 --> 00:23:50,995
But let's imagine
what it would be like
464
00:23:50,997 --> 00:23:54,965
If you could be in a pressurized
capsule as you get deeper down.
465
00:23:54,967 --> 00:23:57,635
It would get a little calmer,
a little less turbulent.
466
00:23:57,637 --> 00:24:01,272
The pressure would get
higher and higher.
467
00:24:01,274 --> 00:24:04,842
Bolton: It's so hot.
Everything's vaporous.
468
00:24:04,844 --> 00:24:06,444
Eventually,
you get down to material
469
00:24:06,446 --> 00:24:08,179
That are almost like
rock clouds.
470
00:24:08,181 --> 00:24:10,514
And they're probably
precipitating.
471
00:24:10,516 --> 00:24:14,752
Bagenal:
Now, when you get down something
like 10% of the radius,
472
00:24:14,754 --> 00:24:17,855
And the density
is getting really high.
473
00:24:17,857 --> 00:24:21,926
And at that point,
hydrogen changes its phase.
474
00:24:21,928 --> 00:24:24,195
It's no longer molecules --
475
00:24:24,197 --> 00:24:27,097
Protons and electrons
connected together --
476
00:24:27,099 --> 00:24:30,835
But the protons and the
electrons are moving separately.
477
00:24:30,837 --> 00:24:33,003
And it becomes metallic.
478
00:24:33,005 --> 00:24:35,873
That is, it becomes
electrically conducting.
479
00:24:35,875 --> 00:24:38,809
And in this region, you can
generate a magnetic field,
480
00:24:38,811 --> 00:24:40,611
What's called a "dynamo."
481
00:24:40,613 --> 00:24:43,914
The fluids convert
some of their motional energy
482
00:24:43,916 --> 00:24:47,084
Into magnetic field energy,
into current.
483
00:24:49,755 --> 00:24:52,423
On earth, the dynamo
is very far from us,
484
00:24:52,425 --> 00:24:55,192
Earth's core is halfway
through the planet,
485
00:24:55,194 --> 00:24:58,362
But on jupiter, you don't even
go 10% of the way in,
486
00:24:58,364 --> 00:25:01,799
And you've got this
60,000 kilometer radius ball
487
00:25:01,801 --> 00:25:05,569
Of molten metallic
material.
488
00:25:08,841 --> 00:25:10,941
And maybe that means
it's not amazing
489
00:25:10,943 --> 00:25:14,178
That you generate
a huge magnetic field.
490
00:25:14,180 --> 00:25:17,414
Narrator:
Now that the galileo probe
had succeeded with its mission,
491
00:25:17,416 --> 00:25:20,150
And ultimately vaporized
inside jupiter,
492
00:25:20,152 --> 00:25:22,720
The mothership needed
to avoid a similar fate,
493
00:25:22,722 --> 00:25:25,556
And insert itself
safely into orbit.
494
00:25:25,558 --> 00:25:27,892
Bolton: In just that first pass,
when we were getting into orbit,
495
00:25:27,894 --> 00:25:30,594
Galileo received half
of its radiation dose --
496
00:25:30,596 --> 00:25:33,664
Like 150 kilorads
in one shot.
497
00:25:33,666 --> 00:25:37,001
Then, it went out further,
and kind of licked its wounds.
498
00:25:37,003 --> 00:25:40,137
Bagenal: Because of galileo
having this broken antenna,
499
00:25:40,139 --> 00:25:43,641
It meant that we tended
to focus further out first.
500
00:25:43,643 --> 00:25:47,378
And the first really exciting
thing we found was
501
00:25:47,380 --> 00:25:51,115
Ganymede has its own
magnetic field.
502
00:25:51,117 --> 00:25:53,784
Narrator: The seventh moon out
from the surface of jupiter,
503
00:25:53,786 --> 00:25:57,221
Ganymede is a moon
the size of a planet.
504
00:25:57,223 --> 00:25:58,956
Larger than mercury,
505
00:25:58,958 --> 00:26:02,026
It is the biggest moon
in our solar system.
506
00:26:02,028 --> 00:26:04,662
The fact that ganymede
has a magnetic field
507
00:26:04,664 --> 00:26:07,164
Means that it might have
some ability to protect itself
508
00:26:07,166 --> 00:26:09,900
From the harsh radiation
of jupiter --
509
00:26:09,902 --> 00:26:14,138
A key attribute for a habitat
where life might be found.
510
00:26:14,140 --> 00:26:17,107
So, now it starts to open up
how we think about even
511
00:26:17,109 --> 00:26:20,177
"what's a planetary body,"
right?
512
00:26:20,179 --> 00:26:23,380
These moons, how different
are they from other planets?
513
00:26:23,382 --> 00:26:25,482
They can have
their own magnetic fields.
514
00:26:30,556 --> 00:26:32,856
Narrator: But now,
the galileo spacecraft,
515
00:26:32,858 --> 00:26:34,391
Despite its troubles,
516
00:26:34,393 --> 00:26:37,261
Was about to make arguably
the most important discovery
517
00:26:37,263 --> 00:26:40,164
In the history
of space flight,
518
00:26:40,166 --> 00:26:42,933
At the mysterious moon
that voyager had visited
519
00:26:42,935 --> 00:26:46,503
17 years before --
europa.
520
00:26:51,143 --> 00:26:53,877
Woman: We have ignition
and liftoff of atlantis,
521
00:26:53,879 --> 00:26:57,848
And the galileo spacecraft
bound for jupiter.
522
00:26:57,850 --> 00:27:01,352
Narrator: When the galileo
spacecraft launched in 1989,
523
00:27:01,354 --> 00:27:03,988
The mission promised
to uncover jupiter's secrets.
524
00:27:03,990 --> 00:27:07,024
But what it revealed about
the planet's moon, europa,
525
00:27:07,026 --> 00:27:11,095
Surpassed even scientist's
wildest expectations.
526
00:27:11,097 --> 00:27:14,632
Bagenal:
What we measured as we flew by
was something quite remarkable.
527
00:27:14,634 --> 00:27:17,635
There were electrical currents
that were flowing
528
00:27:17,637 --> 00:27:23,207
Inside the moon that perturbed
the magnetic field.
529
00:27:23,209 --> 00:27:27,778
And we concluded that europa
has to have a liquid ocean
530
00:27:27,780 --> 00:27:29,013
Underneath that ice.
531
00:27:29,015 --> 00:27:35,119
♪♪
532
00:27:35,121 --> 00:27:39,423
And the reason is, ice is not
very electrically conducting.
533
00:27:39,425 --> 00:27:43,560
You need it to be liquefied
as water, in a big ocean,
534
00:27:43,562 --> 00:27:45,663
To carry those
electrical currents.
535
00:27:47,299 --> 00:27:49,633
Probably has to have
salt in it
536
00:27:49,635 --> 00:27:50,868
To be electrically
conducting,
537
00:27:50,870 --> 00:27:53,103
The way that the earth's
salty ocean
538
00:27:53,105 --> 00:27:55,105
Is electrically
conducting.
539
00:27:55,107 --> 00:27:58,442
James: And the reason why
we hardly see any craters
540
00:27:58,444 --> 00:28:00,377
On the surface of europa
541
00:28:00,379 --> 00:28:03,147
Is because that ocean
has squirted out,
542
00:28:03,149 --> 00:28:05,683
And has filled them in
over time.
543
00:28:05,685 --> 00:28:10,621
Like io, europa, which is also
in an elliptical orbit,
544
00:28:10,623 --> 00:28:14,091
And gets squeezed and relaxed
every two or so days
545
00:28:14,093 --> 00:28:18,128
As it goes around the planet,
is dissipating that heat
546
00:28:18,130 --> 00:28:20,931
By melting
that ice shell.
547
00:28:20,933 --> 00:28:24,668
We believe the ocean can be
as thick as a hundred miles,
548
00:28:24,670 --> 00:28:26,236
And maybe even thicker.
549
00:28:26,238 --> 00:28:30,007
And at the rocky surface
at the bottom of the ocean,
550
00:28:30,009 --> 00:28:32,843
I know exactly
what it looks like --
551
00:28:32,845 --> 00:28:35,713
Hydrothermal vents.
552
00:28:35,715 --> 00:28:39,416
Narrator: Such vents
are also found here on earth.
553
00:28:39,418 --> 00:28:42,720
And those hydrothermal vents
span fields.
554
00:28:42,722 --> 00:28:44,455
So, it's not just
a single chimney,
555
00:28:44,457 --> 00:28:46,590
But there's a field of chimneys,
if you like.
556
00:28:46,592 --> 00:28:48,559
And those fields,
we think, on the early earth,
557
00:28:48,561 --> 00:28:50,194
And potentially
on some moons,
558
00:28:50,196 --> 00:28:52,196
Could spread across
an entire sea floor.
559
00:28:52,198 --> 00:28:54,397
You have this kind of
porous labyrinth
560
00:28:54,399 --> 00:28:58,335
Of interconnected pores,
through hydrogen from the vents
561
00:28:58,337 --> 00:29:02,439
Mixing with co2 from the oceans,
making organic molecules.
562
00:29:02,441 --> 00:29:05,642
And here, you have a setting
which looks an awful lot
563
00:29:05,644 --> 00:29:09,179
Like the way
that modern cells work.
564
00:29:09,181 --> 00:29:10,681
And this kind of chemistry
565
00:29:10,683 --> 00:29:13,984
Was almost certainly behind
the origin of life on earth.
566
00:29:20,159 --> 00:29:23,527
When you look at europa,
and you look at the cracks,
567
00:29:23,529 --> 00:29:25,562
There is this brown,
gunky stuff
568
00:29:25,564 --> 00:29:29,500
That seems to be coming
from the interior.
569
00:29:29,502 --> 00:29:33,871
But also, could it be that
there's a source of chemistry
570
00:29:33,873 --> 00:29:36,306
Coming from io,
and io's volcanoes,
571
00:29:36,308 --> 00:29:38,976
Impacting the surface
of europa,
572
00:29:38,978 --> 00:29:40,444
Bringing sulfur --
573
00:29:40,446 --> 00:29:44,081
And perhaps more importantly,
oxygen -- into europa,
574
00:29:44,083 --> 00:29:47,818
And that material then gets
carried down into the ocean,
575
00:29:47,820 --> 00:29:51,054
Oxidizing the environment
of the ocean,
576
00:29:51,056 --> 00:29:55,125
And maybe enhancing the life
that may -- maybe is there?
577
00:29:55,127 --> 00:29:58,061
Maybe not.
We don't know.
578
00:29:58,063 --> 00:30:01,665
Grinspoon: I think that europa
is a place where,
579
00:30:01,667 --> 00:30:03,433
Given what we think
we know about life,
580
00:30:03,435 --> 00:30:04,701
There ought to be life.
581
00:30:04,703 --> 00:30:07,437
But by then,
we've kind of done
582
00:30:07,439 --> 00:30:09,540
What we were gonna do
with galileo.
583
00:30:09,542 --> 00:30:11,275
Maize: And the radiation
of jupiter is very,
584
00:30:11,277 --> 00:30:13,043
Very hard on electronics.
585
00:30:13,045 --> 00:30:14,344
So, it rips up
the spacecraft.
586
00:30:14,346 --> 00:30:16,646
It goes into saving,
stops, all the sequences,
587
00:30:16,648 --> 00:30:18,882
And you have to
restart things.
588
00:30:18,884 --> 00:30:22,553
Narrator: After having its
mission extended three times,
589
00:30:22,555 --> 00:30:27,457
It was eventually decided
in 2003 to dispose of the aging,
590
00:30:27,459 --> 00:30:30,427
Radiation-damaged
spacecraft --
591
00:30:30,429 --> 00:30:33,297
By flying it into
the clouds of jupiter.
592
00:30:36,302 --> 00:30:38,669
Bolton: We learned so much
from galileo.
593
00:30:38,671 --> 00:30:41,905
In fact, it was really
the results of galileo
594
00:30:41,907 --> 00:30:43,540
That led us to juno.
595
00:30:43,542 --> 00:30:48,645
Man: Liftoff od the atlas five,
with juno, on a trip to jupiter.
596
00:30:48,647 --> 00:30:51,181
Bagenal: The big question
of the galileo was,
597
00:30:51,183 --> 00:30:54,318
Did that probe just
go into somewhere weird,
598
00:30:54,320 --> 00:30:56,987
Or was the lack of water
599
00:30:56,989 --> 00:31:00,157
Symptomatic
of the entire planet?
600
00:31:00,159 --> 00:31:02,459
Now, this is
extremely important.
601
00:31:02,461 --> 00:31:05,162
In 30 minutes that it took
the probe to go into jupiter,
602
00:31:05,164 --> 00:31:06,730
And get this data,
603
00:31:06,732 --> 00:31:10,133
Every theory of solar system
formation was proven wrong.
604
00:31:10,135 --> 00:31:12,870
Bagenal: Because remember,
we think the gas giants formed
605
00:31:12,872 --> 00:31:17,574
By having giant snowballs, say,
30 times the mass of the earth,
606
00:31:17,576 --> 00:31:21,245
That pull in the hydrogen
to make the gas giants.
607
00:31:21,247 --> 00:31:24,248
So, at the core,
we think there was ice.
608
00:31:24,250 --> 00:31:27,551
And yet, when we went in
with that probe,
609
00:31:27,553 --> 00:31:29,720
We didn't see any --
or very little.
610
00:31:29,722 --> 00:31:31,088
So, what's going on?
611
00:31:31,090 --> 00:31:34,157
So, when juno came along,
one of its primary objectives
612
00:31:34,159 --> 00:31:39,096
Was to go in, and see how much
water and oxygen is in jupiter.
613
00:31:39,098 --> 00:31:41,465
We have to go back,
and find out.
614
00:31:41,467 --> 00:31:43,600
And we could send in
100 probes,
615
00:31:43,602 --> 00:31:46,770
But, you know, that's gonna
be expensive and difficult.
616
00:31:46,772 --> 00:31:48,705
And we thought of a clever way
of doing it.
617
00:31:53,445 --> 00:31:56,613
Bolton:
So, when juno came along,
one of its primary objectives
618
00:31:56,615 --> 00:32:01,251
Was to go in, and see how much
water and oxygen is in jupiter.
619
00:32:03,422 --> 00:32:06,590
Juno was designed
in order to make measurements
620
00:32:06,592 --> 00:32:08,325
Almost over
the whole planet,
621
00:32:08,327 --> 00:32:11,862
And look at the water,
rather than in one spot.
622
00:32:11,864 --> 00:32:15,732
And to go much deeper remotely,
not with a probe.
623
00:32:18,003 --> 00:32:22,472
The brilliant idea
was to use microwaves.
624
00:32:22,474 --> 00:32:27,711
Everyone knows that microwaves
are absorbed by water.
625
00:32:27,713 --> 00:32:31,281
So, what we want to do
is fly over jupiter,
626
00:32:31,283 --> 00:32:34,518
And map out
the distribution of water
627
00:32:34,520 --> 00:32:37,354
From the absorption
of those microwaves.
628
00:32:37,356 --> 00:32:40,190
But to find out
what it's like deep inside,
629
00:32:40,192 --> 00:32:43,327
We have to measure
the distribution of mass inside
630
00:32:43,329 --> 00:32:47,630
That changes the gravity field
in some subtle ways.
631
00:32:47,632 --> 00:32:50,133
Bolton: And to do that,
we had to go into a polar orbit.
632
00:32:50,135 --> 00:32:52,936
And we also had to
get really close.
633
00:32:55,007 --> 00:32:57,808
Now, remember, we've got
a problem with jupiter.
634
00:32:57,810 --> 00:33:00,544
Jupiter has these
radiation belts around it.
635
00:33:00,546 --> 00:33:03,180
You don't really want to take
your sensitive electronics
636
00:33:03,182 --> 00:33:05,549
Of your spacecraft
through that environment --
637
00:33:05,551 --> 00:33:08,418
At least not for long.
638
00:33:08,420 --> 00:33:11,688
Bolton: We had to somehow
get beneath the radiation belt
639
00:33:11,690 --> 00:33:13,724
If we can just
thread that needle...
640
00:33:16,929 --> 00:33:19,396
I was just praying
with my eyes closed,
641
00:33:19,398 --> 00:33:21,131
You know, that this
was gonna work.
642
00:33:22,935 --> 00:33:26,803
We were getting a few thousand
miles above the cloud tops
643
00:33:26,805 --> 00:33:29,339
When we were doing
this maneuver.
644
00:33:29,341 --> 00:33:31,174
Nothing had ever
been that close.
645
00:33:33,512 --> 00:33:35,879
Bagenal:
Fly the engines.
646
00:33:35,881 --> 00:33:37,447
Woman: Good now?
647
00:33:37,449 --> 00:33:39,416
Yeah, we see that
the engine has started.
648
00:33:41,253 --> 00:33:43,487
35 minutes,
they're firing away,
649
00:33:43,489 --> 00:33:45,856
Slowing down
the spacecraft,
650
00:33:45,858 --> 00:33:49,426
So it gets caught
in jupiter's gravity.
651
00:33:49,428 --> 00:33:51,762
Woman:
Juno, welcome to jupiter.
652
00:33:51,764 --> 00:33:53,964
[ cheering ]
653
00:33:53,966 --> 00:33:55,665
Nasa did it again.
654
00:33:57,636 --> 00:34:03,774
♪♪
655
00:34:03,776 --> 00:34:06,610
Bolton: And you know, the thing
that was also sobering was,
656
00:34:06,612 --> 00:34:07,878
We were coming back.
657
00:34:07,880 --> 00:34:09,312
This was our game plan.
658
00:34:09,314 --> 00:34:10,814
Every orbit we were
gonna have to go
659
00:34:10,816 --> 00:34:13,483
Run through that fire
with our bare feet.
660
00:34:13,485 --> 00:34:17,254
Our view of jupiter before juno
was from the equator.
661
00:34:17,256 --> 00:34:21,625
So, then, when juno flies over
the poles, and is looking down,
662
00:34:21,627 --> 00:34:24,027
And there we see
these vortices,
663
00:34:24,029 --> 00:34:27,731
All this structure,
is just extraordinary.
664
00:34:31,070 --> 00:34:33,236
Little did we know
that the poles of jupiter,
665
00:34:33,238 --> 00:34:36,940
We're gonna become this huge
science discovery by itself --
666
00:34:36,942 --> 00:34:38,508
Giant polar cyclones.
667
00:34:38,510 --> 00:34:40,577
Nobody anticipated that.
668
00:34:42,748 --> 00:34:44,214
When we fly in close,
669
00:34:44,216 --> 00:34:47,217
Measuring the perturbations
in juno's motion,
670
00:34:47,219 --> 00:34:51,321
We're beginning to get a sense
of what it's like inside.
671
00:34:51,323 --> 00:34:53,990
And what we're finding
is that it's not like
672
00:34:53,992 --> 00:34:56,126
The textbook picture,
where you have
673
00:34:56,128 --> 00:34:59,096
A metal rock core inside,
674
00:34:59,098 --> 00:35:03,366
And then a layer of hydrogen,
and then a layer of gas above.
675
00:35:03,368 --> 00:35:05,669
It's much fuzzier,
much more mixed up.
676
00:35:05,671 --> 00:35:08,038
And so, in fact,
that core is spread out
677
00:35:08,040 --> 00:35:09,940
To about 40%
of the radius.
678
00:35:09,942 --> 00:35:14,177
So, it's mixed in
with the metallic hydrogen.
679
00:35:14,179 --> 00:35:17,080
You're beginning to see
that the convection system
680
00:35:17,082 --> 00:35:18,248
We see on the outside
681
00:35:18,250 --> 00:35:20,083
Extend a long way in.
682
00:35:20,085 --> 00:35:21,585
They're much,
much deeper.
683
00:35:26,825 --> 00:35:30,827
Arnou: But what juno has not yet
been able to explain
684
00:35:30,829 --> 00:35:32,529
Is what drives the jets.
685
00:35:32,531 --> 00:35:37,067
It might be that turbulence at
the surface drives these jets,
686
00:35:37,069 --> 00:35:41,404
And then the jets burrow down
into the depths.
687
00:35:41,406 --> 00:35:43,106
But with jupiter,
so much heat
688
00:35:43,108 --> 00:35:45,075
Is coming out of the interior
of the planet
689
00:35:45,077 --> 00:35:48,311
That maybe the jets are
being driven by deep motions,
690
00:35:48,313 --> 00:35:49,946
And it's their surface
expression
691
00:35:49,948 --> 00:35:52,516
That we're seeing
at the top.
692
00:35:52,518 --> 00:35:54,851
Bolton: There's probably
something deep down
693
00:35:54,853 --> 00:35:59,055
That is driving a lot of motion
inside of jupiter.
694
00:35:59,057 --> 00:36:02,325
Bagenal: And so, we're beginning
to think about that region
695
00:36:02,327 --> 00:36:04,494
Where hydrogen
becomes metallic,
696
00:36:04,496 --> 00:36:07,531
That generates
this strong magnetic field.
697
00:36:07,533 --> 00:36:10,834
Bolton: The magnetic field is
probably moving things around,
698
00:36:10,836 --> 00:36:14,137
Driving convection, and eddies,
and all kinds of motion.
699
00:36:14,139 --> 00:36:16,606
And so, somewhere,
there's a balancing act.
700
00:36:16,608 --> 00:36:19,509
The stuff that's coming in
from the top meets the stuff
701
00:36:19,511 --> 00:36:21,178
That's coming up
from the bottom,
702
00:36:21,180 --> 00:36:22,913
And all hell
breaks loose.
703
00:36:27,986 --> 00:36:29,553
Arnou: With jupiter,
so much heat
704
00:36:29,555 --> 00:36:31,388
Is coming out of the interior
of the planet
705
00:36:31,390 --> 00:36:34,491
That maybe the jets are
being driven by deep motions,
706
00:36:34,493 --> 00:36:36,126
And it's their
surface expression
707
00:36:36,128 --> 00:36:37,694
That we're seeing
at the top.
708
00:36:39,698 --> 00:36:40,864
What's the right answer?
709
00:36:40,866 --> 00:36:44,501
We do not yet know.
Open question.
710
00:36:44,503 --> 00:36:48,338
One of the great questions,
for me, as a scientist,
711
00:36:48,340 --> 00:36:52,142
Looking at jupiter,
and studying jupiter.
712
00:36:52,144 --> 00:36:54,844
Bolton: Nobody really knows
for sure what makes the colors
713
00:36:54,846 --> 00:36:56,846
In jupiter's
zones and belts.
714
00:36:56,848 --> 00:36:58,582
We see all these oranges,
and reds,
715
00:36:58,584 --> 00:37:00,517
And beautiful yellows.
Right? And browns.
716
00:37:00,519 --> 00:37:03,587
And io is spewing out
tons of sulfur,
717
00:37:03,589 --> 00:37:07,390
Among other things,
because it's volcanic.
718
00:37:07,392 --> 00:37:08,725
So, in many ways,
719
00:37:08,727 --> 00:37:11,528
The combination of io
and its volcanoes
720
00:37:11,530 --> 00:37:14,064
With jupiter's
strong magnetic field
721
00:37:14,066 --> 00:37:19,903
Is really at the core
of an engine, or a generator.
722
00:37:19,905 --> 00:37:22,305
When we laid out
the objectives of juno,
723
00:37:22,307 --> 00:37:24,374
It was to go sort of
figure out the puzzles
724
00:37:24,376 --> 00:37:26,543
Of what it was made out of,
and how it formed.
725
00:37:26,545 --> 00:37:29,112
Nobody really conceived
of the idea that we'd go there,
726
00:37:29,114 --> 00:37:30,480
And the entire structure
727
00:37:30,482 --> 00:37:32,015
Was gonna be different
than we thought.
728
00:37:34,953 --> 00:37:38,288
It may be that
we've been a bit naive,
729
00:37:38,290 --> 00:37:40,957
That if jupiter could throw us
this many curveballs,
730
00:37:40,959 --> 00:37:45,462
That our ideas of how stars work
could be kind of wrong, too.
731
00:37:45,464 --> 00:37:46,863
I mean, there's even
more energy.
732
00:37:46,865 --> 00:37:48,465
And they're even
more massive.
733
00:37:50,469 --> 00:37:53,270
Astronomers have looked out,
and seen many stars, right?
734
00:37:53,272 --> 00:37:54,838
Billions and billions.
735
00:37:54,840 --> 00:37:57,474
Many of those
are binary systems --
736
00:37:57,476 --> 00:37:59,776
Two stars
going around each other.
737
00:37:59,778 --> 00:38:02,712
Sometimes, there's a big star
and a little star --
738
00:38:02,714 --> 00:38:05,749
Maybe a star that has only
a tiny bit of fusion inside,
739
00:38:05,751 --> 00:38:06,883
Like a brown dwarf.
740
00:38:06,885 --> 00:38:09,219
In our case,
and many others we've seen,
741
00:38:09,221 --> 00:38:12,222
Where we have a star
and a planetary system,
742
00:38:12,224 --> 00:38:15,659
The biggest planet
does not have enough mass
743
00:38:15,661 --> 00:38:18,228
To have
a fusion reaction inside.
744
00:38:18,230 --> 00:38:20,030
So, let's think of
our solar system,
745
00:38:20,032 --> 00:38:22,532
Where we have the sun,
and we have jupiter.
746
00:38:22,534 --> 00:38:27,404
And jupiter
is 1000th the volume,
747
00:38:27,406 --> 00:38:30,273
And 1000th
the mass of the sun.
748
00:38:30,275 --> 00:38:33,877
And so, it's too small
to have fusion inside.
749
00:38:33,879 --> 00:38:35,945
It's a failed star.
750
00:38:35,947 --> 00:38:38,515
But it's a very
successful planet.
751
00:38:38,517 --> 00:38:45,755
♪♪
752
00:38:45,757 --> 00:38:49,092
Narrator: Juno continues
to explore jupiter,
753
00:38:49,094 --> 00:38:51,528
Diving beneath the lethal
radiation belts
754
00:38:51,530 --> 00:38:53,930
On every daring orbit.
755
00:38:53,932 --> 00:38:56,099
And each time,
we learn a little more
756
00:38:56,101 --> 00:38:58,902
About the greatest planet
in the solar system.
757
00:39:01,106 --> 00:39:06,843
But we have unfinished business
with some of its moons.
758
00:39:06,845 --> 00:39:09,979
Juice is the next major
exploration mission
759
00:39:09,981 --> 00:39:12,582
For the european
space agency --
760
00:39:12,584 --> 00:39:16,019
Jupiter icy moons explorer.
761
00:39:16,021 --> 00:39:18,121
Its sole purpose
is to go to jupiter,
762
00:39:18,123 --> 00:39:19,889
And explore
the icy moons.
763
00:39:21,960 --> 00:39:24,094
The main aim is really
to try and understand
764
00:39:24,096 --> 00:39:26,162
What they look like
below the surface.
765
00:39:26,164 --> 00:39:28,231
How thick is
the ice layer?
766
00:39:28,233 --> 00:39:30,367
How deep is subsurface ocean?
767
00:39:30,369 --> 00:39:32,569
For places like europa,
ganymede,
768
00:39:32,571 --> 00:39:35,772
Getting below the ice layer
is the holy grail.
769
00:39:35,774 --> 00:39:38,208
Getting into that
subsurface ocean
770
00:39:38,210 --> 00:39:39,409
That is a whole
new frontier.
771
00:39:39,411 --> 00:39:41,077
And that will be
a fascinating thing,
772
00:39:41,079 --> 00:39:43,780
If we can ever
achieve that.
773
00:39:43,782 --> 00:39:46,616
Juice doesn't launch
till 2022.
774
00:39:46,618 --> 00:39:50,720
It's not gonna
get there until 2030.
775
00:39:50,722 --> 00:39:52,822
Some of the people
already working on it now
776
00:39:52,824 --> 00:39:54,324
Will have retired.
777
00:39:54,326 --> 00:39:56,092
Some will probably
have passed away.
778
00:39:56,094 --> 00:39:57,560
What I love about it
is that there's
779
00:39:57,562 --> 00:39:59,796
This generational
feeling to it.
780
00:39:59,798 --> 00:40:01,798
By the time
we get the data,
781
00:40:01,800 --> 00:40:05,234
There will be another generation
of scientists looking at it.
782
00:40:05,236 --> 00:40:08,371
Klesh:
Nasa has been funding a mission
called "europa clipper,"
783
00:40:08,373 --> 00:40:11,541
Which will take a number
of flybys of europa
784
00:40:11,543 --> 00:40:13,676
To try and get
a deeper investigation
785
00:40:13,678 --> 00:40:15,345
Of what might be happening
on the surface --
786
00:40:15,347 --> 00:40:17,514
Even a basic understanding
of some of the chemistry
787
00:40:17,516 --> 00:40:19,382
That might be there,
in preparation
788
00:40:19,384 --> 00:40:23,553
For investigations yet to come,
getting down to the oceans.
789
00:40:23,555 --> 00:40:24,754
Well, the first challenge
you have is actually
790
00:40:24,756 --> 00:40:27,090
Getting down
through the ice.
791
00:40:27,092 --> 00:40:28,958
And while people
have talked about drills,
792
00:40:28,960 --> 00:40:30,226
And other such things,
793
00:40:30,228 --> 00:40:32,228
We want to reduce
this 20 kilometers of ice
794
00:40:32,230 --> 00:40:33,696
As much as possible.
795
00:40:33,698 --> 00:40:35,965
And so,
we've built submersibles
796
00:40:35,967 --> 00:40:39,502
That can actually navigate
through tunnels and canyons,
797
00:40:39,504 --> 00:40:41,438
To be able to try and
make their way down through,
798
00:40:41,440 --> 00:40:42,772
Perhaps,
theses open crevices
799
00:40:42,774 --> 00:40:44,707
As close to the water
as possible.
800
00:40:44,709 --> 00:40:46,910
Now, if we can get
into the water itself,
801
00:40:46,912 --> 00:40:48,278
We've built
a buoyant rover
802
00:40:48,280 --> 00:40:51,080
That goes underneath
the ice, and floats.
803
00:40:51,082 --> 00:40:53,016
So, drives on the underside
of the ice
804
00:40:53,018 --> 00:40:55,585
Exactly at that ice-water
boundary on there.
805
00:40:55,587 --> 00:40:58,421
And by turning a camera
to look up at the microbes
806
00:40:58,423 --> 00:41:01,057
That we might find there
on the underside of the ice.
807
00:41:01,059 --> 00:41:03,693
And then, we've been working
on deep-ocean vessels,
808
00:41:03,695 --> 00:41:07,030
Where we hope to go down to the
bottom of the ocean on europa,
809
00:41:07,032 --> 00:41:10,033
And then bring back samples
to us of what might be
810
00:41:10,035 --> 00:41:12,035
Down at the bottom
of the ocean.
811
00:41:12,037 --> 00:41:13,036
In the mid 2020s,
812
00:41:13,038 --> 00:41:15,205
We hope to launch
europa clipper.
813
00:41:15,207 --> 00:41:17,140
Then, after a six to seven
year voyage,
814
00:41:17,142 --> 00:41:19,709
Will reach
jupiter itself.
815
00:41:19,711 --> 00:41:22,745
There is an immense
opportunity for us
816
00:41:22,747 --> 00:41:25,915
To find the first signs of life
beyond our world
817
00:41:25,917 --> 00:41:30,220
In these warm, watery,
rich environments
818
00:41:30,222 --> 00:41:34,757
That we are just beginning
to see that we can even access.
819
00:41:34,759 --> 00:41:35,992
And the rovers
that we're developing,
820
00:41:35,994 --> 00:41:37,660
And testing here
on earth,
821
00:41:37,662 --> 00:41:40,129
Are only the ancestors --
822
00:41:40,131 --> 00:41:45,001
The far ancestors of what
we might eventually send there.
823
00:41:45,003 --> 00:41:47,637
Narrator: So, perhaps one day,
we will discover life
824
00:41:47,639 --> 00:41:52,308
Residing under the ice --
a precious habitat thriving
825
00:41:52,310 --> 00:41:55,411
Despite the brutal
radioactive environment
826
00:41:55,413 --> 00:42:00,016
In the shadow of the mightiest
planet in our solar system --
827
00:42:00,018 --> 00:42:01,184
Jupiter.