Would you like to inspect the original subtitles? These are the user uploaded subtitles that are being translated:
1
00:00:03,740 --> 00:00:08,380
Lift off of Messenger on Nasa's
mission to Mercury.
2
00:00:08,420 --> 00:00:15,260
โช They'll say no-one can see us
3
00:00:15,300 --> 00:00:22,660
โช That we're estranged
and all alone
4
00:00:22,700 --> 00:00:30,020
โช They believe
nothing can reach us
5
00:00:30,060 --> 00:00:37,340
โช And pull us out of
the boundless gloom
6
00:00:37,380 --> 00:00:40,680
โช They're wrong
7
00:00:40,720 --> 00:00:43,980
โช They're wrong
8
00:00:44,020 --> 00:00:48,660
โช They're wrong. โช
9
00:01:05,820 --> 00:01:07,980
Beyond the inner solar system...
10
00:01:09,260 --> 00:01:10,940
past the asteroid belt...
11
00:01:12,820 --> 00:01:13,860
lies Jupiter.
12
00:01:16,580 --> 00:01:20,740
The largest of the planets
is a giant swirling ball of gas...
13
00:01:24,700 --> 00:01:28,660
its marbled appearance generated
by violent winds
14
00:01:28,700 --> 00:01:30,860
that rage through its clouds.
15
00:01:40,580 --> 00:01:44,580
Jupiter is a world as strange
as it is remote.
16
00:01:50,300 --> 00:01:53,580
If you fly upwards, only about
100km or so,
17
00:01:53,620 --> 00:01:56,940
you reach the edge of our atmosphere
and the blackness of space.
18
00:01:56,980 --> 00:01:58,880
It's really not that far.
19
00:01:58,920 --> 00:02:00,780
But once you're in space,
20
00:02:00,820 --> 00:02:04,540
the distance scales are sort of
incomprehensible.
21
00:02:04,580 --> 00:02:08,580
I mean, Venus, the closest planet,
is over 40 million kilometres away.
22
00:02:08,620 --> 00:02:11,900
Jupiter around 650 million
kilometres.
23
00:02:11,940 --> 00:02:15,980
It takes our fastest spacecraft
years to get there.
24
00:02:16,020 --> 00:02:20,660
So, the idea that those planets
could have any influence on us
25
00:02:20,700 --> 00:02:22,780
here on Earth seems fanciful.
26
00:02:22,820 --> 00:02:24,660
And, indeed, if you're talking about
27
00:02:24,700 --> 00:02:27,460
your chances of meeting a handsome
stranger
28
00:02:27,500 --> 00:02:31,160
or your life plans requiring a
moderate reconfiguration
29
00:02:31,200 --> 00:02:34,820
about a week on Wednesday,
then you would be right.
30
00:02:34,860 --> 00:02:39,740
However, if you ask more profound
questions, deeper questions like,
31
00:02:39,780 --> 00:02:42,100
"Why is the Earth the way that it
is?
32
00:02:42,140 --> 00:02:44,240
"Why is there life on Earth?
33
00:02:44,280 --> 00:02:46,340
"Why do we exist at all?"
34
00:02:46,380 --> 00:02:49,900
then it turns out that the planets,
and Jupiter in particular,
35
00:02:49,940 --> 00:02:52,620
have had a profound effect.
36
00:03:08,660 --> 00:03:12,700
Early in its life, the young
Jupiter went on the rampage.
37
00:03:20,660 --> 00:03:24,180
The giant planet embarked
on a voyage of destruction
38
00:03:24,220 --> 00:03:25,940
across the solar system...
39
00:03:27,140 --> 00:03:30,500
that transformed the destiny
of the planets,
40
00:03:30,540 --> 00:03:32,820
and the course of life on Earth.
41
00:03:43,780 --> 00:03:47,180
Jupiter is the godfather
of the planets.
42
00:03:49,260 --> 00:03:53,740
Understand it and you understand
how the solar system came to be.
43
00:04:15,620 --> 00:04:20,180
On Earth, we can see glimpses
of Jupiter's power...
44
00:04:20,220 --> 00:04:21,500
in the scars it's left...
45
00:04:22,940 --> 00:04:24,820
on the face of the planet.
46
00:04:37,580 --> 00:04:41,020
This is the famous Barringer
Meteor Crater in Arizona.
47
00:04:41,060 --> 00:04:43,420
It is about a kilometre across,
48
00:04:43,460 --> 00:04:46,980
170 metres from the rim to the
crater floor
49
00:04:47,020 --> 00:04:50,500
and it was created about 50,000
years ago
50
00:04:50,540 --> 00:04:55,860
when a meteorite, 50 metres across,
entered the Earth's atmosphere
51
00:04:55,900 --> 00:04:59,260
travelling at about 13km per
second.
52
00:04:59,300 --> 00:05:01,740
That means it would have taken
around, what, seven seconds
53
00:05:01,780 --> 00:05:04,920
to go from the top of the atmosphere
to the ground
54
00:05:04,960 --> 00:05:08,100
and it hit with such force that the
energy released
55
00:05:08,140 --> 00:05:11,240
was equivalent to ten megatons of
TNT.
56
00:05:11,280 --> 00:05:14,380
And that is a very large
nuclear bomb.
57
00:05:19,220 --> 00:05:21,340
The meteorite that hit the Earth
here
58
00:05:21,380 --> 00:05:24,020
is thought to have come from the
asteroid belt...
59
00:05:26,100 --> 00:05:29,940
the ring of rocky debris
that orbits at the edge
60
00:05:29,980 --> 00:05:31,820
of the inner solar system.
61
00:05:35,180 --> 00:05:37,820
And it was deflected from its orbit
62
00:05:37,860 --> 00:05:41,820
most likely by the gravitational
influence of Jupiter.
63
00:05:50,540 --> 00:05:54,340
Jupiter is a completely different
class of planet to the Earth.
64
00:05:55,620 --> 00:05:57,820
A gas giant.
65
00:05:59,500 --> 00:06:03,580
A swirling ball of hydrogen
and helium so large
66
00:06:03,620 --> 00:06:06,420
you could fit 1,300 Earths inside.
67
00:06:13,220 --> 00:06:16,700
Jupiter can exert such a powerful
influence on the asteroids
68
00:06:16,740 --> 00:06:18,260
because it's so massive.
69
00:06:18,300 --> 00:06:21,660
It's about two-and-a-half times
the mass of all the other planets,
70
00:06:21,700 --> 00:06:25,520
moons and asteroids in the solar
system combined.
71
00:06:25,560 --> 00:06:29,030
And, therefore, it has a strong
gravitational pull.
72
00:06:29,070 --> 00:06:32,500
And this means that Jupiter
exerts an influence
73
00:06:32,540 --> 00:06:35,820
across the entire solar system
that's second only to the sun.
74
00:06:37,580 --> 00:06:41,580
And that influenced us far
more than create the odd crater.
75
00:06:41,620 --> 00:06:44,260
It can change the history
of worlds.
76
00:06:55,660 --> 00:06:59,900
To understand how Jupiter rose
to such dominance,
77
00:06:59,940 --> 00:07:04,180
you have to go back to a time before
the solar system even existed.
78
00:07:15,500 --> 00:07:18,380
Nearly five billion years ago,
79
00:07:18,420 --> 00:07:23,260
a distant exploding star sent
a shock wave across the galaxy...
80
00:07:32,300 --> 00:07:34,780
causing the cloud of gas and dust
81
00:07:34,820 --> 00:07:38,540
that would become our solar system
to collapse...
82
00:07:40,420 --> 00:07:42,780
as the sun began to form.
83
00:07:51,620 --> 00:07:55,940
But further out, something
else was growing.
84
00:08:02,260 --> 00:08:03,940
After 50 million years...
85
00:08:06,420 --> 00:08:09,260
the sun's nuclear furnace ignited.
86
00:08:20,180 --> 00:08:22,500
The light of its first dawn...
87
00:08:23,900 --> 00:08:25,220
revealing Jupiter...
88
00:08:26,940 --> 00:08:29,300
the solar system's first world.
89
00:08:33,580 --> 00:08:37,660
A planet born so early, it swept
up most of the material
90
00:08:37,700 --> 00:08:40,620
left over from the formation of the
sun.
91
00:08:47,180 --> 00:08:50,580
Because of its dominance, Jupiter
had a profound effect
92
00:08:50,620 --> 00:08:53,100
on the newly forming solar system
93
00:08:53,140 --> 00:08:56,700
and paved the way for our living
world to form.
94
00:09:00,500 --> 00:09:03,020
This is a model of our solar system.
95
00:09:03,060 --> 00:09:07,660
So, here's the sun, and then we have
the four inner rocky planets,
96
00:09:07,700 --> 00:09:11,500
Mercury, Venus, Earth and Mars.
97
00:09:11,540 --> 00:09:15,300
Then comes the asteroid belt,
98
00:09:15,340 --> 00:09:20,260
the ring of millions of smaller
pieces of rock
99
00:09:20,300 --> 00:09:22,220
orbiting around the sun.
100
00:09:22,260 --> 00:09:24,140
And then the gas giants.
101
00:09:24,180 --> 00:09:28,780
Jupiter, Saturn, Uranus and Neptune.
102
00:09:28,820 --> 00:09:31,900
Now, this has a pleasing regular
structure about it.
103
00:09:31,940 --> 00:09:34,300
All the rocky planets close to the
star
104
00:09:34,340 --> 00:09:36,380
and the gas giants further out.
105
00:09:36,420 --> 00:09:40,420
And we thought that this must be the
natural order of things,
106
00:09:40,460 --> 00:09:43,660
the way that solar systems
have to form,
107
00:09:43,700 --> 00:09:47,500
until we started to detect planets
around distant stars
108
00:09:47,540 --> 00:09:52,140
and then we found that this
arrangement is not typical at all.
109
00:09:57,460 --> 00:10:02,420
Our sun is just one of around
300 billion stars in our galaxy...
110
00:10:06,220 --> 00:10:08,880
and almost every one of those
stars
111
00:10:08,920 --> 00:10:11,580
is home to its own system of
planets.
112
00:10:16,220 --> 00:10:21,580
In most other systems, the region
where our planet orbits is empty.
113
00:10:24,820 --> 00:10:29,140
Instead, closer to the star, we see
super-Earths,
114
00:10:29,180 --> 00:10:33,500
vast rocky planets
many times bigger than our own.
115
00:10:37,260 --> 00:10:39,580
But, crucially, these worlds are
thought
116
00:10:39,620 --> 00:10:42,580
to have thick toxic atmospheres,
117
00:10:42,620 --> 00:10:45,780
making them completely inhospitable
to life.
118
00:10:51,540 --> 00:10:54,380
And that raises a very interesting
question.
119
00:10:54,420 --> 00:10:57,860
Why, then, is our solar system
the way that it is?
120
00:11:07,300 --> 00:11:08,740
To answer that question,
121
00:11:08,780 --> 00:11:12,060
we've sent spacecraft to every one
of the planets...
122
00:11:14,620 --> 00:11:17,140
and they've uncovered strange
anomalies
123
00:11:17,180 --> 00:11:19,700
that reveal our solar system's past.
124
00:11:22,780 --> 00:11:26,660
Our missions to Venus found
that it once had far more water
125
00:11:26,700 --> 00:11:30,060
than you'd expect for a planet
so close to the sun...
126
00:11:31,500 --> 00:11:33,340
just as Earth does today.
127
00:11:38,780 --> 00:11:40,940
The spacecraft we've sent to Mars
128
00:11:40,980 --> 00:11:45,140
touched down on a world that is
curiously just half the size
129
00:11:45,180 --> 00:11:48,500
of her sister planets Earth and
Venus.
130
00:11:55,020 --> 00:11:56,540
And in the asteroid belt,
131
00:11:56,580 --> 00:11:59,620
we've uncovered a graveyard
of failed worlds...
132
00:12:00,980 --> 00:12:04,180
their growth mysteriously cut
short.
133
00:12:14,060 --> 00:12:15,740
To cause all these anomalies,
134
00:12:15,780 --> 00:12:19,900
it's thought that something
catastrophic must have happened
135
00:12:19,940 --> 00:12:22,300
very early in the solar system's
history.
136
00:12:25,380 --> 00:12:29,260
All the evidence suggests
that around 4.5 billion years ago,
137
00:12:29,300 --> 00:12:31,260
Jupiter's orbit began to change,
138
00:12:31,300 --> 00:12:34,100
triggering a period of unprecedented
violence
139
00:12:34,140 --> 00:12:38,260
which completely transformed the
face of the young solar system.
140
00:12:38,300 --> 00:12:40,820
And we know this because
the marauding planet
141
00:12:40,860 --> 00:12:43,500
left a trail of destruction in its
wake.
142
00:12:51,740 --> 00:12:56,340
Early in its life, Jupiter began
to move inwards towards the sun...
143
00:12:59,700 --> 00:13:03,460
and the effects of that journey
can be seen to this day.
144
00:13:13,500 --> 00:13:17,220
In between the orbits of Mars
and Jupiter...
145
00:13:17,260 --> 00:13:18,900
lies the asteroid belt...
146
00:13:21,940 --> 00:13:24,060
a desolate wasteland of debris
147
00:13:24,100 --> 00:13:27,460
left over from the beginning
of the solar system.
148
00:13:36,660 --> 00:13:40,900
Rocky bodies too small to be planets
in their own right.
149
00:13:57,220 --> 00:14:00,540
In science fiction films, the
asteroid belt is often depicted
150
00:14:00,580 --> 00:14:03,780
as an un-navigable
mass of tumbling rubble.
151
00:14:03,820 --> 00:14:05,140
But it's not like that at all.
152
00:14:05,180 --> 00:14:08,460
So much so, in fact, that modern
spacecraft engineers
153
00:14:08,500 --> 00:14:12,120
can fly a spacecraft through without
making any course corrections.
154
00:14:12,160 --> 00:14:16,050
The reason for that is there's not
much mass in the asteroid belt.
155
00:14:16,090 --> 00:14:19,980
A sum total of all of them is only
about 4% the mass of the moon
156
00:14:20,020 --> 00:14:23,460
and they're spread out in a huge
sort of ring,
157
00:14:23,500 --> 00:14:27,540
out beyond the orbit of Mars.
So, it's a vast amount of space.
158
00:14:27,580 --> 00:14:31,540
That means that the average distance
between any two large asteroids
159
00:14:31,580 --> 00:14:35,540
is about eight times the distance
between the Earth and the moon.
160
00:14:35,580 --> 00:14:38,300
So, I could stand on one of those
large asteroids
161
00:14:38,340 --> 00:14:39,820
and look out into space
162
00:14:39,860 --> 00:14:43,780
and my nearest neighbour would just
be a dim star in the dark.
163
00:14:48,700 --> 00:14:51,460
But scattered amongst the rubble
are objects
164
00:14:51,500 --> 00:14:53,780
that are far more than mere rocks.
165
00:14:54,940 --> 00:14:57,700
Five, four, three,
166
00:14:57,740 --> 00:15:02,340
two, main engine start, one,
zero and lift off
167
00:15:02,380 --> 00:15:03,500
of the Delta II Rocket.
168
00:15:06,060 --> 00:15:08,380
In 2007, Nasa's Dawn mission
169
00:15:08,420 --> 00:15:12,900
was sent to explore the two largest
objects in the asteroid belt.
170
00:15:35,220 --> 00:15:39,140
After a year in orbit around
the giant asteroid Vesta...
171
00:15:44,980 --> 00:15:47,580
in March 2015...
172
00:15:47,620 --> 00:15:50,820
Dawn made its final approach
on a body so large
173
00:15:50,860 --> 00:15:54,900
it makes up almost a third of the
mass of the entire asteroid belt...
174
00:15:57,900 --> 00:16:00,460
Ceres.
175
00:16:22,300 --> 00:16:25,940
On arrival, the first images Dawn
sent back to Earth
176
00:16:25,980 --> 00:16:28,780
contained something entirely
unexpected...
177
00:16:36,780 --> 00:16:41,420
mysterious bright patches in one
of Ceres' largest craters.
178
00:16:51,020 --> 00:16:52,940
Spectral analysis of the images
179
00:16:52,980 --> 00:16:55,700
showed that the patches were, in
fact,
180
00:16:55,740 --> 00:16:59,620
the salty residue left
behind by liquid water...
181
00:17:02,220 --> 00:17:05,260
suggesting there must be large
amounts of ice
182
00:17:05,300 --> 00:17:07,180
just beneath the crust.
183
00:17:16,660 --> 00:17:21,860
Dawn went on to discover over 300
bright spots all over the surface.
184
00:17:26,940 --> 00:17:29,580
And this means that beneath
this thin crust,
185
00:17:29,620 --> 00:17:34,380
Ceres has a thick ice rich mantle
surrounding its rocky core...
186
00:17:39,020 --> 00:17:43,780
evidence that the dwarf planet
is made up of multiple layers.
187
00:17:56,980 --> 00:18:01,380
The interior of Ceres is like
nothing else in the asteroid belt.
188
00:18:01,420 --> 00:18:05,820
The differentiation, that separation
into layers, observed by Dawn
189
00:18:05,860 --> 00:18:09,880
is more characteristic of a planet
than an asteroid.
190
00:18:09,920 --> 00:18:13,940
So, 4.5 billion years ago, Ceres
was well on its way
191
00:18:13,980 --> 00:18:15,860
to becoming a fully-fledged world.
192
00:18:28,780 --> 00:18:32,540
It's thought that's in its infancy
Ceres was very different.
193
00:18:36,460 --> 00:18:41,540
The water that now lies frozen
within its interior was once liquid.
194
00:18:45,940 --> 00:18:48,740
Protected beneath a thin
layer of ice...
195
00:18:50,860 --> 00:18:54,700
Ceres was once covered
by a deep saltwater ocean.
196
00:19:12,700 --> 00:19:15,180
Before Ceres had reached
its full potential,
197
00:19:15,220 --> 00:19:17,620
a great disturbance sent shock
waves through
198
00:19:17,660 --> 00:19:20,060
what would one day become the
asteroid belt
199
00:19:20,100 --> 00:19:22,140
and cut its development short.
200
00:19:34,540 --> 00:19:37,180
As Jupiter circled the young sun,
201
00:19:37,220 --> 00:19:40,340
it started to clear a path
through the gas and dust
202
00:19:40,380 --> 00:19:42,340
that shrouded the early
solar system...
203
00:19:48,860 --> 00:19:52,940
but that process caused it to do
something alarming.
204
00:19:55,340 --> 00:19:59,140
Gravitational interactions with the
gas made the giant planets
205
00:19:59,180 --> 00:20:01,220
spiral inwards towards the sun...
206
00:20:04,580 --> 00:20:06,860
ploughing straight through the
region of space
207
00:20:06,900 --> 00:20:09,020
that would become the asteroid
belt...
208
00:20:11,540 --> 00:20:13,940
scattering the material
from which Ceres
209
00:20:13,980 --> 00:20:15,540
would otherwise have grown.
210
00:20:22,340 --> 00:20:25,060
Computer simulations of the early
solar system
211
00:20:25,100 --> 00:20:28,580
suggest that the asteroid belt once
contained enough material
212
00:20:28,620 --> 00:20:31,560
to build a planet the size of the
Earth.
213
00:20:31,600 --> 00:20:34,540
And perhaps that was Ceres's
destiny.
214
00:20:34,580 --> 00:20:37,420
But when Jupiter passed through,
215
00:20:37,460 --> 00:20:41,500
it scattered 99.9% of the material
away,
216
00:20:41,540 --> 00:20:43,580
and Ceres's fate was sealed.
217
00:20:50,180 --> 00:20:54,100
Within 100 million years, Ceres's
ocean froze
218
00:20:54,140 --> 00:20:56,300
and was buried beneath its crust.
219
00:21:00,540 --> 00:21:03,460
The young planet's development
cut short
220
00:21:03,500 --> 00:21:05,980
before it could fulfil its promise.
221
00:21:18,820 --> 00:21:22,580
But Jupiter's reign of terror was
far from over.
222
00:21:29,420 --> 00:21:31,420
It would continue its journey
inwards
223
00:21:31,460 --> 00:21:34,060
towards the place our planet
was beginning to form...
224
00:21:37,180 --> 00:21:40,220
threatening the very existence of
Earth.
225
00:21:45,420 --> 00:21:49,660
Jupiter had such an overwhelming
effect on the young solar system
226
00:21:49,700 --> 00:21:52,180
because of its powerful
gravitational field...
227
00:22:11,660 --> 00:22:15,140
the effects of which we can
still witness today.
228
00:23:09,700 --> 00:23:12,580
Jupiter exerts its influence
across the solar system
229
00:23:12,620 --> 00:23:14,500
through its gravitational field...
230
00:23:23,220 --> 00:23:26,360
which is by far the most powerful
of all the planets,
231
00:23:26,400 --> 00:23:29,540
because Jupiter is the most massive
of all the planets.
232
00:23:29,580 --> 00:23:32,880
It's about 320 times the mass
of the Earth.
233
00:23:32,920 --> 00:23:36,180
That's why it was so destructive
in the past.
234
00:23:36,220 --> 00:23:39,860
And we see the power of
that gravitational field today
235
00:23:39,900 --> 00:23:45,020
in its influence on the closest
of Jupiter's largest moons, Io.
236
00:23:58,660 --> 00:24:01,940
Io is the most volcanic
world in the solar system.
237
00:24:07,060 --> 00:24:10,940
Its surface covered with hundreds
of active volcanoes...
238
00:24:16,140 --> 00:24:18,020
and lakes of molten lava.
239
00:24:24,620 --> 00:24:27,800
The largest, known as Loki Patera,
240
00:24:27,840 --> 00:24:31,020
is more than 200km in diameter.
241
00:24:40,220 --> 00:24:43,980
A million times the area
of any lava lake on Earth.
242
00:24:45,700 --> 00:24:49,140
Its surface tormented by waves
of molten rock.
243
00:25:01,940 --> 00:25:03,980
Io is a vision of hell...
244
00:25:09,740 --> 00:25:13,020
created by the moon's proximity
to Jupiter.
245
00:25:32,100 --> 00:25:36,500
Volcanism here on Earth
is powered by the internal heat
246
00:25:36,540 --> 00:25:38,260
down below the surface.
247
00:25:38,300 --> 00:25:40,320
Now, much of that is residual heat
248
00:25:40,360 --> 00:25:42,340
left over from the Earth's
formation
249
00:25:42,380 --> 00:25:46,020
four-and-a-half billion years ago,
about half of it, and the other half
250
00:25:46,060 --> 00:25:50,780
is down to radioactive decay of
elements around the Earth's core.
251
00:25:50,820 --> 00:25:53,180
Now, on Io it's different.
252
00:25:54,180 --> 00:25:55,820
Io's a much smaller world
253
00:25:55,860 --> 00:25:59,140
and so it didn't retain
much residual heat.
254
00:25:59,180 --> 00:26:03,060
So, there, the volcanoes are powered
by a different process.
255
00:26:03,100 --> 00:26:05,100
It's known as tidal heating.
256
00:26:11,860 --> 00:26:14,580
The energy that drives Io's
volcanism
257
00:26:14,620 --> 00:26:17,980
doesn't come from heat
stored within the moon.
258
00:26:21,340 --> 00:26:23,060
It's generated by gravity...
259
00:26:26,020 --> 00:26:29,280
because Io orbits just 350,000km
260
00:26:29,320 --> 00:26:32,580
from the tops of Jupiter's clouds.
261
00:26:48,980 --> 00:26:53,060
Io orbits at about the same distance
from Jupiter
262
00:26:53,100 --> 00:26:54,820
as our moon orbits the Earth.
263
00:26:54,860 --> 00:26:57,500
But because Jupiter is so much more
massive,
264
00:26:57,540 --> 00:26:58,860
Io goes around much more quickly.
265
00:26:58,900 --> 00:27:02,340
In fact, it goes around once every
42 hours.
266
00:27:02,380 --> 00:27:05,060
Now, if Io were Jupiter's only
moon,
267
00:27:05,100 --> 00:27:07,220
that orbit would be circular,
268
00:27:07,260 --> 00:27:08,500
but it isn't.
269
00:27:12,300 --> 00:27:17,100
The next moon out - Europa - goes
round Jupiter precisely once
270
00:27:17,140 --> 00:27:19,100
for every two orbits of Io...
271
00:27:23,580 --> 00:27:26,080
which means that every second
orbit,
272
00:27:26,120 --> 00:27:28,620
Io and Europa fall into
alignment.
273
00:27:30,780 --> 00:27:34,020
It's what's known as an orbital
resonance.
274
00:27:35,820 --> 00:27:38,100
That gives it a gravitational kick
275
00:27:38,140 --> 00:27:41,260
and that moves Io's orbit
into an ellipse.
276
00:27:41,300 --> 00:27:43,900
Now, that means that the
gravitational force's on Io
277
00:27:43,940 --> 00:27:47,060
are constantly shifting and changing
278
00:27:47,100 --> 00:27:50,060
and that stretches and squashes the
moon,
279
00:27:50,100 --> 00:27:54,820
and heats it up - by friction.
Now, that is called tidal heating
280
00:27:54,860 --> 00:27:58,180
and that is the origin of
Io's volcanoes.
281
00:28:10,540 --> 00:28:13,820
This process raises the temperature
in Io's interior,
282
00:28:13,860 --> 00:28:16,360
which would otherwise be frozen
solid,
283
00:28:16,400 --> 00:28:18,900
to more than 1,000 degrees
Celsius...
284
00:28:22,180 --> 00:28:23,940
creating its lava lakes...
285
00:28:27,380 --> 00:28:30,060
and powering immense volcanic
plumes...
286
00:28:32,900 --> 00:28:36,700
that rise up to 300km
from the moon's surface...
287
00:28:38,420 --> 00:28:40,060
and out into space.
288
00:28:45,180 --> 00:28:49,100
Io provides the solar system
with a vivid reminder...
289
00:28:50,500 --> 00:28:52,460
of the giant planet's power.
290
00:29:07,220 --> 00:29:10,100
Jupiter's intense gravitational
field...
291
00:29:12,260 --> 00:29:15,620
is the source of Io's
volcanism today.
292
00:29:15,660 --> 00:29:18,620
But we don't feel that gravitational
pull here on Earth,
293
00:29:18,660 --> 00:29:21,060
because Jupiter is so far away,
294
00:29:21,100 --> 00:29:24,140
but four-and-a-half billion years
ago,
295
00:29:24,180 --> 00:29:28,140
Jupiter was migrating inwards
towards the inner solar system,
296
00:29:28,180 --> 00:29:32,140
approaching the region where
Mars and Earth were forming.
297
00:29:38,260 --> 00:29:42,420
After passing through what would
become the asteroid belt...
298
00:29:43,860 --> 00:29:46,140
Jupiter entered the inner
solar system...
299
00:29:51,420 --> 00:29:54,940
continuing its journey, spiralling
towards the sun.
300
00:30:03,060 --> 00:30:06,580
Back then, the area where Mars
and Earth orbit today
301
00:30:06,620 --> 00:30:09,660
was densely packed with gas and
rock.
302
00:30:17,820 --> 00:30:21,460
But as Jupiter approached,
it wrought havoc...
303
00:30:23,820 --> 00:30:27,300
scattering the rocky material
in all directions...
304
00:30:29,900 --> 00:30:32,500
some sent careering into the
sun...
305
00:30:41,340 --> 00:30:44,900
others thrown out
into interstellar space.
306
00:30:52,300 --> 00:30:56,940
And it's this that may explain our
solar system's unusual structure.
307
00:30:59,980 --> 00:31:01,540
Here's the solar system today.
308
00:31:01,580 --> 00:31:05,680
The sun, the four inner rocky
planets, the asteroids and Jupiter.
309
00:31:05,720 --> 00:31:10,170
And what we think may have happened
is Jupiter made it inwards
310
00:31:10,210 --> 00:31:14,660
through where the asteroids
are, as far in as the orbit of Mars.
311
00:31:14,700 --> 00:31:17,380
And that would have cleaned out
quite a lot of the material
312
00:31:17,420 --> 00:31:21,900
in the inner solar system, leaving
less for the formation of planets.
313
00:31:21,940 --> 00:31:25,820
And that's why we don't see
super-Earths in our solar system.
314
00:31:25,860 --> 00:31:27,820
Those big massive rocky worlds
315
00:31:27,860 --> 00:31:31,560
that we see in orbit around so many
other stars.
316
00:31:31,600 --> 00:31:35,260
This also might explain
why Mars is so small.
317
00:31:35,300 --> 00:31:39,020
See, if Jupiter was orbiting
in the region that Mars was forming,
318
00:31:39,060 --> 00:31:41,740
there would have been much less
material here.
319
00:31:41,780 --> 00:31:44,460
And that might explain why Mars
320
00:31:44,500 --> 00:31:48,140
is only a tenth of the mass
of Venus and Earth.
321
00:31:58,620 --> 00:32:00,860
Had Jupiter continued to move
inwards,
322
00:32:00,900 --> 00:32:03,900
it would have had a similar effect
on the Earth...
323
00:32:06,260 --> 00:32:09,700
meaning the world we inhabit
might never have formed.
324
00:32:16,380 --> 00:32:20,980
But just as it looked as if Jupiter
would sweep everything away,
325
00:32:21,020 --> 00:32:24,460
something stopped the giant
planet in its tracks...
326
00:32:31,620 --> 00:32:35,780
because in the shadows of the
outer solar system,
327
00:32:35,820 --> 00:32:37,740
another planet was forming.
328
00:32:42,420 --> 00:32:45,020
The solar system's second gas
giant...
329
00:32:46,780 --> 00:32:48,180
Saturn...
330
00:33:00,620 --> 00:33:03,340
and its birth changed everything.
331
00:33:08,180 --> 00:33:11,540
When a planet forms in a disk
of material around a star,
332
00:33:11,580 --> 00:33:14,340
as Jupiter did in our solar system,
333
00:33:14,380 --> 00:33:18,620
it tends to clear out a gap in the
disk.
334
00:33:18,660 --> 00:33:21,940
Now, the material tends to fall
inwards towards the star.
335
00:33:21,980 --> 00:33:23,700
It's called the accretion
336
00:33:23,740 --> 00:33:26,440
and that drags the whole thing
inwards.
337
00:33:26,480 --> 00:33:29,140
And that's what happened to Jupiter.
338
00:33:29,180 --> 00:33:34,100
But, then, a less massive planet,
Saturn, formed further out.
339
00:33:34,140 --> 00:33:36,420
It cleared out its own disk
340
00:33:36,460 --> 00:33:39,940
and it too fell inwards
towards the sun,
341
00:33:39,980 --> 00:33:42,740
but more quickly than Jupiter.
342
00:33:42,780 --> 00:33:46,340
That meant that Saturn got
into a resonance with Jupiter.
343
00:33:46,380 --> 00:33:49,300
It went round once in orbit around
the sun
344
00:33:49,340 --> 00:33:51,500
for every two orbits of Jupiter
345
00:33:51,540 --> 00:33:55,580
and that has the effect of cleaning
out the whole region
346
00:33:55,620 --> 00:33:57,440
between the two planets.
347
00:33:57,480 --> 00:33:59,260
And that has the effect,
348
00:33:59,300 --> 00:34:03,460
through a series of complicated
gravitational interactions,
349
00:34:03,500 --> 00:34:05,700
of slowing and stopping the in-fall
350
00:34:05,740 --> 00:34:10,340
and eventually causing the two
planets to move back out again.
351
00:34:10,380 --> 00:34:15,380
And that is what happened to Jupiter
and Saturn in our solar system.
352
00:34:23,500 --> 00:34:25,820
Saturn caused Jupiter to retreat...
353
00:34:26,940 --> 00:34:29,020
leaving behind just enough
material
354
00:34:29,060 --> 00:34:31,540
from which the inner planets could
form.
355
00:34:35,020 --> 00:34:36,500
Mercury.
356
00:34:39,180 --> 00:34:40,460
Venus.
357
00:34:43,340 --> 00:34:44,700
Mars.
358
00:34:50,540 --> 00:34:52,780
And our home...
359
00:34:52,820 --> 00:34:54,220
the Earth.
360
00:35:00,580 --> 00:35:04,300
By preventing the formation of much
larger super-Earths,
361
00:35:04,340 --> 00:35:07,260
Jupiter allowed our planet to grow.
362
00:35:21,900 --> 00:35:26,900
And even as Jupiter's reign of
terror was drawing to a close,
363
00:35:26,940 --> 00:35:30,820
it provided one last parting
gift to our world.
364
00:35:45,180 --> 00:35:48,700
The young Earth formed in an arid
region of the inner solar system.
365
00:35:48,740 --> 00:35:52,060
There was very little water
that close to the sun,
366
00:35:52,100 --> 00:35:55,820
but as the Earth was forming,
Jupiter was already tacking back
367
00:35:55,860 --> 00:35:58,180
outwards again into the outer solar
system
368
00:35:58,220 --> 00:36:02,220
through the region that we now call
the asteroid belt,
369
00:36:02,260 --> 00:36:06,980
a region populated by many icy,
water rich comets and asteroids.
370
00:36:07,020 --> 00:36:09,660
And they were scattered back inwards
again,
371
00:36:09,700 --> 00:36:12,380
bringing water back into the inner
solar system.
372
00:36:12,420 --> 00:36:15,060
So, I think it is quite a wonderful
thought,
373
00:36:15,100 --> 00:36:19,540
that Earth is a water world today
because of the motion inwards
374
00:36:19,580 --> 00:36:24,020
and then back outwards again
of the massive planet Jupiter.
375
00:36:30,260 --> 00:36:34,660
This idea does seem quite
contrived, almost fantastical,
376
00:36:34,700 --> 00:36:39,100
but the more we learn about
the formation of solar systems,
377
00:36:39,140 --> 00:36:42,820
and the more we try to model
a system like ours,
378
00:36:42,860 --> 00:36:46,700
with four terrestrial, water-rich
planets close to the star
379
00:36:46,740 --> 00:36:49,460
and then the gas giants further out,
380
00:36:49,500 --> 00:36:53,920
the more we learn that perhaps all
these things had to happen,
381
00:36:53,960 --> 00:36:59,250
these unlikely movements and
interactions between the planets,
382
00:36:59,290 --> 00:37:04,580
in order to produce a system like
ours and a planet like ours.
383
00:37:04,620 --> 00:37:08,700
So, places like this may
be extremely rare.
384
00:37:23,900 --> 00:37:27,240
Today, Jupiter has settled
into a regular orbit
385
00:37:27,280 --> 00:37:30,620
back beyond the far edge
of the asteroid belt...
386
00:37:33,540 --> 00:37:37,620
its days of marauding through
the solar system at an end.
387
00:38:20,860 --> 00:38:23,540
Jupiter has been established
in a stable orbit
388
00:38:23,580 --> 00:38:25,620
for almost four billion years.
389
00:38:25,660 --> 00:38:28,760
If I was to sit here on Earth 3.8
billion years ago
390
00:38:28,800 --> 00:38:31,860
when life began and look
up into the night sky,
391
00:38:31,900 --> 00:38:35,500
I would have seen it shining
there as a point of light
392
00:38:35,540 --> 00:38:39,620
the same as it looks today,
distant and seemingly detached.
393
00:38:39,660 --> 00:38:43,660
And it's remained that way for the
vast expanse of time it's taken
394
00:38:43,700 --> 00:38:45,900
for evolution by natural selection
395
00:38:45,940 --> 00:38:51,380
to transform those first populations
of organisms into all this,
396
00:38:51,420 --> 00:38:54,940
to transform the Earth into an oasis
of life
397
00:38:54,980 --> 00:38:57,060
in the desert of the solar system.
398
00:39:07,500 --> 00:39:11,780
But Jupiter's influence over the
Earth remains to this day...
399
00:39:16,100 --> 00:39:19,980
and that's because, despite its
great distance from us...
400
00:39:21,340 --> 00:39:25,020
it retains a vice-like grip
over the asteroid belt.
401
00:39:39,980 --> 00:39:41,980
It's easy, I think quite natural,
402
00:39:42,020 --> 00:39:44,540
to think of the asteroid belt
as a single structure.
403
00:39:44,580 --> 00:39:47,100
A sort of ring of rock surrounding
the sun.
404
00:39:47,140 --> 00:39:49,780
But that's not
what it's like at all.
405
00:39:49,820 --> 00:39:53,780
In reality, each one of those
millions and millions of pieces
406
00:39:53,820 --> 00:39:57,860
of rock is following its own
individual orbits.
407
00:39:57,900 --> 00:40:00,220
And this remarkable animation
408
00:40:00,260 --> 00:40:03,940
is made up of ten years
of astronomical observations.
409
00:40:03,980 --> 00:40:07,980
And every point you see
on this animation...
410
00:40:08,020 --> 00:40:11,540
is a single asteroid,
apart from all the planets.
411
00:40:11,580 --> 00:40:15,820
And so you see Earth and Mars
and Venus whizzing around the sun.
412
00:40:15,860 --> 00:40:19,080
But the interesting one
is Jupiter...
413
00:40:19,120 --> 00:40:22,340
orbiting just outside the asteroid
belt.
414
00:40:23,540 --> 00:40:26,660
What you can see is that the
asteroid belt
415
00:40:26,700 --> 00:40:28,620
dances to Jupiter's tune.
416
00:40:28,660 --> 00:40:31,740
It's the conductor of the asteroid
belt, if you like.
417
00:40:31,780 --> 00:40:36,020
There are complex patterns
here, but there's also structure.
418
00:40:37,980 --> 00:40:41,580
And the reason for that is
the delicate interplay
419
00:40:41,620 --> 00:40:44,200
between the gravitational pull
of the sun
420
00:40:44,240 --> 00:40:46,820
and the gravitational force from
Jupiter.
421
00:40:48,700 --> 00:40:49,980
Now, what can happen is that
422
00:40:50,020 --> 00:40:52,820
perhaps because of an interaction
between two asteroids,
423
00:40:52,860 --> 00:40:54,940
perhaps they collide with each
other,
424
00:40:54,980 --> 00:40:58,620
or perhaps on their orbit
they line-up perfectly with Jupiter
425
00:40:58,660 --> 00:41:00,780
and get an extra gravitational kick,
426
00:41:00,820 --> 00:41:03,700
those asteroids can be disturbed
from this structure
427
00:41:03,740 --> 00:41:06,620
and be sent
inwards to the inner solar system.
428
00:41:06,660 --> 00:41:11,820
And by that mechanism, Jupiter
has a profound influence
429
00:41:11,860 --> 00:41:14,220
on the planets closer to the sun.
430
00:41:24,220 --> 00:41:26,980
Around 100 million years ago,
431
00:41:27,020 --> 00:41:31,420
an asteroid 10km across was ejected
from the asteroid belt.
432
00:41:35,900 --> 00:41:38,900
Dislodged by Jupiter's gravity,
433
00:41:38,940 --> 00:41:42,420
it was set on a collision
course with the Earth.
434
00:42:01,700 --> 00:42:05,300
When it struck, it generated
a fireball so hot,
435
00:42:05,340 --> 00:42:10,540
anything within a 1,000km
radius would have died instantly.
436
00:42:19,260 --> 00:42:22,940
The impact threw 300 billion
tonnes of sulphur
437
00:42:22,980 --> 00:42:24,260
into the atmosphere.
438
00:42:33,340 --> 00:42:36,620
And during the nuclear winter
that followed,
439
00:42:36,660 --> 00:42:41,700
75% of all species were wiped
from the face of the Earth.
440
00:42:49,540 --> 00:42:51,540
In one fell swoop,
441
00:42:51,580 --> 00:42:55,100
Jupiter changed the course
of our planet's history.
442
00:43:07,500 --> 00:43:09,980
There are a few places on Earth
today
443
00:43:10,020 --> 00:43:12,980
where you can catch a glimpse
of lost worlds,
444
00:43:13,020 --> 00:43:16,660
you can see Earth as it was millions
of years in the past
445
00:43:16,700 --> 00:43:20,460
and perhaps glimpse the Earth as it
might have been.
446
00:43:20,500 --> 00:43:21,980
And this is one of them.
447
00:43:22,020 --> 00:43:24,340
Today, this is the Colorado Plain,
448
00:43:24,380 --> 00:43:25,980
over a kilometre in altitude,
449
00:43:26,020 --> 00:43:29,660
south of Denver close
to the Rocky Mountains,
450
00:43:29,700 --> 00:43:33,300
but 200 million years ago,
this was at sea level.
451
00:43:33,340 --> 00:43:37,940
It was an ancient lake and the
ghosts of those lost worlds,
452
00:43:37,980 --> 00:43:40,500
the imprints of the past, can be
seen over there,
453
00:43:40,540 --> 00:43:44,780
because there are literally
thousands of dinosaur footprints.
454
00:44:10,740 --> 00:44:13,580
And here they are, the dinosaur
footprints.
455
00:44:13,620 --> 00:44:16,660
I find this absolutely remarkable.
456
00:44:16,700 --> 00:44:19,860
This is the footprint
of a sauropod dinosaur.
457
00:44:19,900 --> 00:44:23,380
That's one of the big ones. The big
herbivores with the long necks.
458
00:44:23,420 --> 00:44:26,620
This animal would have weighed
about 30 tonnes.
459
00:44:26,660 --> 00:44:29,820
It was tall enough to peer
over a two-storey house.
460
00:44:29,860 --> 00:44:33,620
What happened here is, probably
a herd of them, a group of them
461
00:44:33,660 --> 00:44:37,020
came lumbering across this lake bed
and, then,
462
00:44:37,060 --> 00:44:40,420
perhaps that same afternoon,
predators came,
463
00:44:40,460 --> 00:44:42,860
maybe following the herd.
464
00:44:42,900 --> 00:44:45,060
And that's these footprints here.
465
00:44:45,100 --> 00:44:47,860
The allosaurus', these three-toed
footprints.
466
00:44:47,900 --> 00:44:51,220
Much smaller animal, maybe
about twice the height of me,
467
00:44:51,260 --> 00:44:54,420
about two tonnes, very nimble and
agile.
468
00:44:54,460 --> 00:44:59,220
So, you see a whole story
played out here, frozen in time.
469
00:45:13,380 --> 00:45:16,580
Today, just their traces remain...
470
00:45:22,020 --> 00:45:24,060
but were it not for Jupiter...
471
00:45:25,500 --> 00:45:27,140
they might still be here.
472
00:45:44,900 --> 00:45:46,820
There are so many chance events,
473
00:45:46,860 --> 00:45:49,300
not only throughout the history of
Earth,
474
00:45:49,340 --> 00:45:53,020
but also spanning the entire history
of the universe
475
00:45:53,060 --> 00:45:56,740
for 13.8 billion years, without
which we wouldn't exist.
476
00:45:56,780 --> 00:45:59,140
There's an unbroken chain of life
stretching back
477
00:45:59,180 --> 00:46:01,640
four billion years here on this
planet.
478
00:46:01,680 --> 00:46:04,140
You interrupt or interject
at any point
479
00:46:04,180 --> 00:46:06,860
and life on Earth is different.
480
00:46:06,900 --> 00:46:10,620
But having said that, there are
major events that affected life.
481
00:46:10,660 --> 00:46:14,380
And one of them is the asteroid
that wipes out the dinosaurs.
482
00:46:14,420 --> 00:46:17,540
And, in that sense, it is certainly
true to say
483
00:46:17,580 --> 00:46:20,500
that without Jupiter, we wouldn't be
here.
484
00:46:37,500 --> 00:46:40,300
The godfather of the planets
paved the way for us
485
00:46:40,340 --> 00:46:41,980
to inherit the Earth.
486
00:46:47,780 --> 00:46:49,740
And although it occasionally
flings rocks
487
00:46:49,780 --> 00:46:51,620
from the asteroid belt our way...
488
00:46:52,780 --> 00:46:55,220
it also protects us...
489
00:47:01,660 --> 00:47:04,400
because for objects heading
towards the Earth
490
00:47:04,440 --> 00:47:07,140
from the far reaches of the solar
system,
491
00:47:07,180 --> 00:47:10,740
Jupiter's gravitational
field acts as a shield.
492
00:47:16,180 --> 00:47:20,440
Around a century ago, a lump
of rock and ice
493
00:47:20,480 --> 00:47:24,740
4km across and weighing
17 billion tonnes...
494
00:47:26,340 --> 00:47:29,500
was hurtling towards the inner
solar system...
495
00:47:33,980 --> 00:47:37,060
until Jupiter intervened.
496
00:47:39,860 --> 00:47:44,900
Five, four, three, two, one...
497
00:47:44,940 --> 00:47:47,580
We have ignition and lift off of
Atlantis
498
00:47:47,620 --> 00:47:50,260
and the Galileo Spacecraft
bound for Jupiter.
499
00:47:51,540 --> 00:47:55,860
70 years later, we witnessed
just how effective a shield
500
00:47:55,900 --> 00:47:57,500
Jupiter can be.
501
00:48:06,420 --> 00:48:08,980
Onboard the space shuttle
Atlantis...
502
00:48:10,300 --> 00:48:11,780
the Galileo orbiter.
503
00:48:21,620 --> 00:48:23,980
Three years after Galileo launched,
504
00:48:24,020 --> 00:48:28,980
comet Shoemaker-Levy-9 had been
captured by Jupiter's gravity.
505
00:48:38,020 --> 00:48:40,900
Locked in the giant planet's
embrace...
506
00:48:42,780 --> 00:48:45,940
tidal forces now began to tear
it apart.
507
00:48:53,300 --> 00:48:55,260
Its journey cut short...
508
00:48:56,340 --> 00:48:58,860
the comet now faced annihilation.
509
00:49:10,380 --> 00:49:12,980
After crossing the inner
solar system,
510
00:49:13,020 --> 00:49:15,980
Galileo passed through the asteroid
belt...
511
00:49:19,380 --> 00:49:21,780
approaching the spots from where
it would witness
512
00:49:21,820 --> 00:49:23,660
the comet's final moments.
513
00:49:34,460 --> 00:49:39,500
On July 16th, Galileo saw the first
fragments of the comet
514
00:49:39,540 --> 00:49:42,260
enter Jupiter's southern hemisphere.
515
00:49:54,380 --> 00:49:56,780
Pieces of comet Shoemaker-Levy-9
516
00:49:56,820 --> 00:50:00,020
struck Jupiter over the course of
six days.
517
00:50:04,020 --> 00:50:07,780
It was the first time a comet strike
had ever been witnessed.
518
00:50:28,900 --> 00:50:32,080
The most destructive impact released
energy
519
00:50:32,120 --> 00:50:35,300
equivalent to six million megatons
of TNT...
520
00:50:37,060 --> 00:50:42,420
leaving behind a giant dark
cloud 12,000km across.
521
00:50:51,820 --> 00:50:56,220
By capturing objects
and incinerating them on impact...
522
00:50:56,260 --> 00:51:00,660
Jupiter sweeps up bodies
from the outer solar system...
523
00:51:00,700 --> 00:51:03,580
that might otherwise collide
with Earth.
524
00:51:16,460 --> 00:51:18,300
Jupiter,
525
00:51:18,340 --> 00:51:21,260
the oldest and largest of
the planets,
526
00:51:21,300 --> 00:51:24,220
is the godfather of our
solar system.
527
00:51:27,900 --> 00:51:28,940
In youth...
528
00:51:29,980 --> 00:51:31,660
it went on the rampage.
529
00:51:40,220 --> 00:51:43,180
For some young planets, it spelt
disaster.
530
00:51:48,580 --> 00:51:51,180
But for others, like our own
world,
531
00:51:51,220 --> 00:51:53,820
it cleared the way for their
formation.
532
00:52:02,460 --> 00:52:05,300
And in adulthood, it created
the conditions
533
00:52:05,340 --> 00:52:07,020
that allowed us to rise...
534
00:52:11,860 --> 00:52:15,060
so we owe Jupiter a great debt.
535
00:52:16,820 --> 00:52:19,980
But as the dinosaurs found
to their cost,
536
00:52:20,020 --> 00:52:23,620
it's a debt that could be recalled
at any time.
537
00:52:28,500 --> 00:52:29,700
To the naked eye,
538
00:52:29,740 --> 00:52:33,440
Jupiter is one of the brightest
points of light in the night sky,
539
00:52:33,480 --> 00:52:37,180
and through a small telescope, it is
a beautiful banded world.
540
00:52:37,220 --> 00:52:39,580
But it feels distant, eternal,
541
00:52:39,620 --> 00:52:43,420
disconnected from events
here on Earth.
542
00:52:43,460 --> 00:52:47,340
But the more we've understood about
the history of the solar system,
543
00:52:47,380 --> 00:52:51,120
the more we've come to understand
that that is not the case.
544
00:52:51,160 --> 00:52:54,900
Jupiter has played an important
and perhaps decisive role
545
00:52:54,940 --> 00:52:58,360
in the stories of all the planets,
including Earth.
546
00:52:58,400 --> 00:53:01,820
So, the solar system is just that.
It's a system.
547
00:53:01,860 --> 00:53:05,900
Complex, interconnected and
interdependent.
548
00:53:05,940 --> 00:53:09,980
So, next time you see Jupiter,
just hold your gaze.
549
00:53:10,020 --> 00:53:15,220
Maybe think for a minute, because it
is so much more than just a point
550
00:53:15,260 --> 00:53:17,260
of light, or a planet, even.
551
00:53:17,300 --> 00:53:20,700
It is the great sculptor
of the solar system,
552
00:53:20,740 --> 00:53:23,620
the destroyer and creator of worlds.
553
00:54:05,100 --> 00:54:07,180
I think people are drawn
in by Jupiter
554
00:54:07,220 --> 00:54:10,020
because it's very mysterious.
555
00:54:10,060 --> 00:54:13,540
It's covered by clouds that hide
what's underneath.
556
00:54:13,580 --> 00:54:14,860
It's very violent.
557
00:54:16,500 --> 00:54:18,620
And it's very intimidating.
558
00:54:20,740 --> 00:54:22,540
It's also very beautiful.
559
00:54:23,540 --> 00:54:26,080
It has all these things going on
560
00:54:26,120 --> 00:54:28,620
and it's hard not to be taken in.
561
00:54:28,660 --> 00:54:34,020
T-minus ten, nine, eight, seven,
six...
562
00:54:34,060 --> 00:54:36,340
Such is Jupiter's mystique,
563
00:54:36,380 --> 00:54:39,420
it's been a recurring
target for space exploration.
564
00:54:39,460 --> 00:54:46,260
And lift off of the Atlas V with
Juno on a trek to Jupiter.
565
00:54:46,300 --> 00:54:50,900
In 2011, Nasa launched its latest
mission - Juno.
566
00:55:00,100 --> 00:55:02,300
When we launched the Juno spacecraft
567
00:55:02,340 --> 00:55:05,260
away from the Earth out towards
Jupiter,
568
00:55:05,300 --> 00:55:10,460
we didn't have enough speed to get
away out of the gravity of the sun,
569
00:55:10,500 --> 00:55:13,420
so we actually had to come back
to Earth,
570
00:55:13,460 --> 00:55:15,820
get a gravity assist from Earth,
571
00:55:15,860 --> 00:55:17,740
and then go out to Jupiter.
572
00:55:22,100 --> 00:55:25,940
After travelling for five
years, Juno finally arrived.
573
00:55:30,420 --> 00:55:34,460
This is a mission that goes closer
to the planet in its orbit
574
00:55:34,500 --> 00:55:36,380
than any other mission ever has.
575
00:55:36,420 --> 00:55:41,060
Only a few thousand kilometres from
the cloud tops and very, very fast.
576
00:55:41,100 --> 00:55:43,340
We go from pole to pole in two
hours,
577
00:55:43,380 --> 00:55:46,580
slipping between the radiation belts
in the cloud tops,
578
00:55:46,620 --> 00:55:49,820
getting the data as fast as we can
and getting out.
579
00:55:51,940 --> 00:55:54,540
So, in every way, Juno is breaking
new ground
580
00:55:54,580 --> 00:55:58,980
and that's allowed us to see things
that we couldn't have ever imagined.
581
00:56:03,740 --> 00:56:07,780
Juno's mission is to explore
the planets inside and out.
582
00:56:10,180 --> 00:56:13,500
And amongst the many scientific
instruments it has on board
583
00:56:13,540 --> 00:56:16,420
is its camera, JunoCam.
584
00:56:18,540 --> 00:56:23,300
You see all these swirls, you see
all sorts of spots coming up.
585
00:56:23,340 --> 00:56:29,140
You see all these vortices, you see
dramatic storm systems interacting.
586
00:56:34,700 --> 00:56:37,600
It's mind-blowingly beautiful
pictures
587
00:56:37,640 --> 00:56:40,540
that this little camera
has been taking.
588
00:56:43,220 --> 00:56:46,700
JunoCam was able to see
the Great Red Spot from up close.
589
00:56:48,380 --> 00:56:50,620
We can see height to the clouds.
590
00:56:50,660 --> 00:56:53,300
We can see features that look
like storms.
591
00:56:53,340 --> 00:56:57,660
Maybe it's hailing or snowing
ammonia on Jupiter.
592
00:57:01,060 --> 00:57:06,420
And the most startling thing that we
saw from JunoCam's imagery
593
00:57:06,460 --> 00:57:09,460
was that the poles of Jupiter
are actually blue.
594
00:57:13,300 --> 00:57:15,780
They are nothing like the orange
and white planet
595
00:57:15,820 --> 00:57:18,620
that we grew up thinking about as
children.
596
00:57:23,780 --> 00:57:27,660
Juno has just begun to unlock
Jupiter's secrets.
597
00:57:30,500 --> 00:57:32,340
And so, at last,
598
00:57:32,380 --> 00:57:36,020
the godfather of the planets
has begun to talk.
599
00:57:51,220 --> 00:57:55,260
A planet that began life
as an unremarkable rocky world...
600
00:57:56,860 --> 00:58:01,100
but transformed into one
of the jewels of the solar system...
601
00:58:02,620 --> 00:58:07,700
where shimmering rings of ice
harbour a potential home for life.
602
00:58:10,380 --> 00:58:11,580
Saturn.
603
00:58:15,340 --> 00:58:17,780
Journey through our solar system
with this free poster
604
00:58:17,820 --> 00:58:19,940
produced by the Open University
605
00:58:19,980 --> 00:58:22,780
and discover more about its planets
and moons.
606
00:58:27,420 --> 00:58:31,780
Order your free
copy by calling...
607
00:58:31,820 --> 00:58:37,340
Or go to...
608
00:58:37,380 --> 00:58:40,540
and follow the links
to the Open University.
609
01:08:29,740 --> 01:08:33,020
Journey through our solar system
with the Open University
610
01:08:33,060 --> 01:08:36,340
and discover more about its planets
and moons.
611
01:08:38,460 --> 01:08:41,900
Explore this and more with our
academic experts.
612
01:08:44,220 --> 01:08:47,300
Go to...
613
01:08:49,140 --> 01:08:51,660
and follow the links
to the Open University.
51607
Can't find what you're looking for?
Get subtitles in any language from opensubtitles.com, and translate them here.