1
00:00:02,535 --> 00:00:06,939
I was just praying with my eyes
closed that this was going to work.
2
00:00:08,541 --> 00:00:11,777
Things, if they're gonna
go wrong, do go wrong.
3
00:00:11,811 --> 00:00:13,645
This thing could fail, you know?
4
00:00:13,680 --> 00:00:16,081
[Scott] If it doesn't work,
it's over.
5
00:00:16,116 --> 00:00:17,616
Lights off.
6
00:00:17,650 --> 00:00:21,253
[narrator] Exploring the Solar
System is not for the faint of heart.
7
00:00:21,287 --> 00:00:26,291
It requires courage,
determination and ingenuity.
8
00:00:26,326 --> 00:00:29,728
[James Garvin] This is like the first
Renaissance voyage over the oceans,
9
00:00:29,763 --> 00:00:32,097
but it's to another planet.
10
00:00:33,333 --> 00:00:36,235
Can we send a spacecraft
through that environment?
11
00:00:36,269 --> 00:00:38,337
There's no question
whatsoever that this is
12
00:00:38,371 --> 00:00:40,950
one of the most difficult
technological jobs
13
00:00:40,974 --> 00:00:42,908
that the human species
has ever tried.
14
00:00:42,942 --> 00:00:46,645
It's a very violent,
dangerous, deadly place.
15
00:00:46,679 --> 00:00:49,848
[narrator] Through failure and
triumph, the people who risked it all
16
00:00:49,883 --> 00:00:53,786
for human exploration
are providing new insights.
17
00:00:54,921 --> 00:00:58,924
- [James] Holy gosh.
- [Fran] I was stunned.
18
00:00:58,958 --> 00:01:00,526
We found the holy grail.
19
00:01:00,560 --> 00:01:04,029
[woman] It's definitely the most
interesting place in the Solar System.
20
00:01:04,064 --> 00:01:07,733
Wouldn't that be cool,
if Pluto has or had life?
21
00:01:07,767 --> 00:01:11,437
We're thinking,
"Holy crap, Batman."
22
00:01:11,471 --> 00:01:13,906
[narrator] These are
the missions that change
23
00:01:13,940 --> 00:01:17,743
how we see the Solar System
and ourselves.
24
00:01:17,811 --> 00:01:22,681
We are the only generation that
will ever explore the Solar System
25
00:01:22,715 --> 00:01:24,650
for the first time.
26
00:01:41,401 --> 00:01:44,403
[Eugene speaking]
27
00:02:02,122 --> 00:02:03,922
[narrator] This prediction
was more accurate than
28
00:02:03,957 --> 00:02:07,526
Eugene Cernan
could have known in 1972.
29
00:02:13,733 --> 00:02:17,769
Fifty years later, for the
first time in human history,
30
00:02:17,804 --> 00:02:22,407
we now have images in stunning
detail of the major planets,
31
00:02:22,442 --> 00:02:25,177
many moons, asteroids
and comets,
32
00:02:25,211 --> 00:02:28,380
taken from space
by manmade machines.
33
00:02:29,983 --> 00:02:33,385
These images bear witness to
the tireless work of the people
34
00:02:33,419 --> 00:02:37,723
who went in search of answers
to humanity's biggest questions.
35
00:02:39,893 --> 00:02:43,328
[Nicola] Humanity, I think, has
a general quest for knowledge.
36
00:02:43,363 --> 00:02:47,666
We tend to just ask questions
and wonder why.
37
00:02:47,700 --> 00:02:50,936
The nature is to look up
and to look around you
38
00:02:50,970 --> 00:02:53,138
and to want to understand
your surroundings.
39
00:02:53,173 --> 00:02:55,541
And so the first thing
anyone looked up
40
00:02:55,575 --> 00:02:57,743
and wondered about was the Sun.
41
00:03:11,157 --> 00:03:15,427
The Sun at the center of the Solar
System is an incredibly hot object.
42
00:03:16,829 --> 00:03:20,232
This hot, raging ball of gas.
43
00:03:21,568 --> 00:03:24,970
In order to be able to truly
see the Sun, the interior,
44
00:03:25,004 --> 00:03:29,007
the surface, the atmosphere,
we have to go into space.
45
00:03:29,042 --> 00:03:31,043
-[mission control] Status check.
-[technician] Go, Delta.
46
00:03:31,077 --> 00:03:35,347
-[mission control] Go, PSP. First stage, propulsion.
-[technician] Go.
47
00:03:35,381 --> 00:03:36,682
- Hydraulics.
- Go.
48
00:03:36,716 --> 00:03:38,417
- Box.
- Go.
49
00:03:38,451 --> 00:03:40,219
[man] This mission has been
a long time coming,
50
00:03:40,253 --> 00:03:43,622
you know, that for 60 years
we tried to do this mission.
51
00:03:43,656 --> 00:03:50,295
We're going to go to the most extreme
environment in our entire Solar System.
52
00:03:50,330 --> 00:03:53,332
We're going to go in and
we're going to touch the Sun.
53
00:03:53,366 --> 00:03:57,336
[announcer]
Eight, seven, six, five,
54
00:03:57,370 --> 00:04:02,808
four, three, two, one, zero.
55
00:04:02,842 --> 00:04:06,278
Liftoff of the mighty
Delta IV heavy rocket
56
00:04:06,312 --> 00:04:08,413
with NASA's Parker Solar Probe,
57
00:04:08,448 --> 00:04:11,116
a daring mission to shed light
on the mysteries
58
00:04:11,150 --> 00:04:13,986
of our closest star, the Sun.
59
00:04:17,357 --> 00:04:20,792
The Sun is a constant in our
lives, it rises every morning,
60
00:04:20,827 --> 00:04:23,829
it sets every night, and yet
when you look at the Sun,
61
00:04:23,863 --> 00:04:26,932
you will see that it is
anything but constant.
62
00:04:26,966 --> 00:04:32,170
It is a continually changing,
incredibly active star.
63
00:04:32,205 --> 00:04:37,876
[narrator] The story of the Sun is
very much the story of the Solar System.
64
00:04:37,910 --> 00:04:42,781
Finding out how it works
is still a work in progress.
65
00:04:42,815 --> 00:04:46,485
That hazy atmosphere that you
see during a total solar eclipse,
66
00:04:46,519 --> 00:04:50,355
the Sun's corona, is hotter
than the surface of the Sun,
67
00:04:50,390 --> 00:04:53,358
and that really doesn't make
sense, it breaks the laws of physics.
68
00:04:53,393 --> 00:04:56,762
[Matthew] And we don't know why.
69
00:04:56,796 --> 00:05:01,867
If it's that hot, why does
the gas stay on the Sun?
70
00:05:02,969 --> 00:05:06,938
Hot materials move really fast.
71
00:05:06,973 --> 00:05:12,277
And if the gas molecules are
traveling faster than escape velocity,
72
00:05:12,312 --> 00:05:17,015
there should be a wind
streaming away from the Sun.
73
00:05:17,050 --> 00:05:22,254
[Lucie] And this radical idea was
predicted by an American astronomer,
74
00:05:22,288 --> 00:05:24,823
Eugene Parker.
75
00:05:27,760 --> 00:05:31,697
[narrator] In 1958, space was
thought to be a hard vacuum.
76
00:05:31,764 --> 00:05:35,534
And while the light and heat from
the Sun could pass through space,
77
00:05:35,568 --> 00:05:37,703
the enormous gravity of the Sun
78
00:05:37,737 --> 00:05:42,908
would prevent any matter
such as gas from reaching us.
79
00:05:42,942 --> 00:05:45,777
But Parker thought differently.
80
00:05:45,812 --> 00:05:48,914
[Parker speaking]
81
00:05:52,352 --> 00:05:55,287
[Lucie] He went through the
mathematics, he went through the physics,
82
00:05:55,321 --> 00:06:00,659
and he predicted the hot atmosphere
of the Sun has a high pressure.
83
00:06:00,693 --> 00:06:03,195
So the gas is wanting
to push outwards.
84
00:06:03,229 --> 00:06:07,232
And there's a really
important consequence of that.
85
00:06:07,266 --> 00:06:10,836
The gas streams out
into the Solar System.
86
00:06:10,870 --> 00:06:15,173
The Sun is literally
expanding into space.
87
00:06:15,208 --> 00:06:17,943
[Parker speaking]
88
00:06:21,948 --> 00:06:26,918
[narrator] Publication of Parker's
radical idea was repeatedly rejected,
89
00:06:26,953 --> 00:06:31,356
but finally he convinced The
Astrophysical Journal to accept it.
90
00:06:31,391 --> 00:06:34,726
But still it's ridiculed.
91
00:06:46,839 --> 00:06:51,009
[mission control]
...three, two, one, zero.
92
00:07:03,189 --> 00:07:05,123
[Lucie] And they did
indeed discover
93
00:07:05,158 --> 00:07:10,228
that the Sun does have this
outflow of gas coming from it.
94
00:07:10,263 --> 00:07:12,364
The solar wind does exist.
95
00:07:22,074 --> 00:07:24,443
[Matthew] This discovery
was... was momentous.
96
00:07:24,477 --> 00:07:29,514
All of a sudden, space is no longer
a void, it's no longer a vacuum.
97
00:07:29,549 --> 00:07:33,885
It's filled with material, it's
filled with this wind from the Sun.
98
00:07:35,188 --> 00:07:40,192
And it has some real,
significant effects on our planet.
99
00:07:42,728 --> 00:07:47,999
[narrator] In 2018, NASA launched a
spacecraft called the Parker Solar Probe.
100
00:07:48,034 --> 00:07:50,635
[announcer] ...two, one.
101
00:07:50,670 --> 00:07:52,938
Liftoff of the mighty
Delta IV heavy rocket...
102
00:07:52,972 --> 00:07:54,906
[narrator] It's the only
spacecraft ever to bear
103
00:07:54,941 --> 00:07:57,375
the name of a living scientist.
104
00:08:01,447 --> 00:08:04,015
[woman] Wow! Go, baby, go.
105
00:08:10,923 --> 00:08:14,059
[cheers and applause]
106
00:08:22,335 --> 00:08:24,836
[narrator] The Parker Solar
Probe would reveal the Sun
107
00:08:24,871 --> 00:08:28,306
to be as dynamic as
Eugene's research predicted.
108
00:08:30,743 --> 00:08:35,013
The strange, powerful phenomena
Parker observed when it touched the Sun
109
00:08:35,047 --> 00:08:37,115
characterized the celestial body
110
00:08:37,149 --> 00:08:41,953
as incomprehensibly hot
and enormously variable.
111
00:08:41,988 --> 00:08:45,991
So it followed that Mercury,
the planet closest to our star,
112
00:08:46,025 --> 00:08:47,993
would be a blistering
world of extremes.
113
00:08:48,027 --> 00:08:49,995
[mission control]
...two, one, and zero.
114
00:08:50,029 --> 00:08:54,900
[narrator] But even here, explorers
would find something that few expected.
115
00:08:54,934 --> 00:08:57,302
[James Green] When I became
the head of Planetary Science,
116
00:08:57,336 --> 00:09:01,840
MESSENGER had launched
and it was on its way to Mercury.
117
00:09:03,910 --> 00:09:07,445
MESSENGER was all about
exploring the full surface
118
00:09:07,480 --> 00:09:09,114
that we had never seen before,
119
00:09:09,148 --> 00:09:12,050
but also we had to really think
about how we develop our technology
120
00:09:12,084 --> 00:09:14,753
to survive this environment.
121
00:09:14,787 --> 00:09:18,723
[narrator] The MESSENGER spacecraft
was designed to travel millions of miles
122
00:09:18,758 --> 00:09:23,528
and survive a temperature range
of over 1,100 degrees Fahrenheit,
123
00:09:23,563 --> 00:09:28,533
and it went into orbit around
Mercury seven years after launch.
124
00:09:28,568 --> 00:09:33,271
What MESSENGER did was it
provided, as its top science priority,
125
00:09:33,306 --> 00:09:38,810
a high-resolution image of
the entire surface of Mercury.
126
00:09:38,844 --> 00:09:42,514
But the mystery was
that there were bright spots,
127
00:09:42,548 --> 00:09:46,117
there were small bright spots.
128
00:09:46,152 --> 00:09:52,123
And then one of the MESSENGER
scientists took all of the bright spots
129
00:09:52,158 --> 00:09:56,094
and laid them down
on the map of Mercury.
130
00:09:57,663 --> 00:10:04,269
Every single bright spot was inside of
a crater that is permanently shadowed.
131
00:10:05,371 --> 00:10:08,840
We have found
what we believe is ice.
132
00:10:08,874 --> 00:10:10,875
Water ice at Mercury.
133
00:10:10,910 --> 00:10:14,779
It's in one of the hottest
regions in our Solar System.
134
00:10:14,814 --> 00:10:17,682
So how did the ice get in there?
135
00:10:20,219 --> 00:10:24,489
[narrator] No-one expected
Mercury to contain water ice.
136
00:10:24,523 --> 00:10:29,327
And water indicates one exciting
possibility to planetary scientists:
137
00:10:29,362 --> 00:10:32,197
the possibility of life.
138
00:10:33,132 --> 00:10:35,533
When you're talking about
where life is
139
00:10:35,568 --> 00:10:39,537
and where the kind of
chemistry and ultimately biology
140
00:10:39,572 --> 00:10:43,074
that might produce something
like us could take place...
141
00:10:43,109 --> 00:10:46,344
At the moment, it's looking
like it might be broader
142
00:10:46,379 --> 00:10:51,650
than just one little planet
at the Goldilocks distance.
143
00:10:55,688 --> 00:10:57,322
[narrator] Extraterrestrial life
144
00:10:57,356 --> 00:11:00,692
is the holy grail
of space exploration.
145
00:11:00,726 --> 00:11:03,428
What it could reveal
about the universe,
146
00:11:03,462 --> 00:11:07,699
Earth and humanity itself
is a powerful incentive,
147
00:11:07,733 --> 00:11:13,171
but knowledge isn't the only
motivator for human activity in space.
148
00:11:13,205 --> 00:11:17,442
We can't deny that we rode to
the Moon and to the other planets,
149
00:11:17,476 --> 00:11:19,711
you know, on the wings of war.
150
00:11:26,952 --> 00:11:29,054
[narrator] Our Solar System
holds the answers
151
00:11:29,088 --> 00:11:31,623
to some of humanity's
greatest questions,
152
00:11:31,657 --> 00:11:36,895
but historically it's been world
politics rather than pure curiosity
153
00:11:36,929 --> 00:11:40,765
that drives innovation in space.
154
00:11:40,833 --> 00:11:44,636
The Cold War led to some
particularly radical science.
155
00:12:16,302 --> 00:12:18,937
Space exploration
has a dark side.
156
00:12:22,608 --> 00:12:27,078
We can't deny that we rode to
the Moon and to the other planets,
157
00:12:27,113 --> 00:12:29,214
you know, on the wings of war.
158
00:12:31,550 --> 00:12:33,818
The reason we have these rockets
159
00:12:33,853 --> 00:12:37,188
that can launch payloads
into orbit and beyond
160
00:12:37,223 --> 00:12:41,860
is because they were developed
to destroy cities.
161
00:12:50,069 --> 00:12:54,639
[narrator] The Cold War made space exploration
a matter of national pride for the U.S.
162
00:12:54,673 --> 00:12:59,210
and the Soviet Union, a
dynamic that ultimately led to
163
00:12:59,245 --> 00:13:04,649
numerous groundbreaking
missions, including Venera 9.
164
00:13:04,683 --> 00:13:09,888
This huge, complex Russian spacecraft
was built to send back the first image
165
00:13:09,922 --> 00:13:11,890
from the surface
of another planet.
166
00:13:13,225 --> 00:13:15,760
The race to Venus was on.
167
00:13:18,364 --> 00:13:21,366
[Anatoly speaking]
168
00:13:38,584 --> 00:13:41,352
[narrator] This component
of the Venera 9 spacecraft
169
00:13:41,387 --> 00:13:45,757
had become the first manmade
object to enter orbit around Venus.
170
00:13:48,093 --> 00:13:50,895
But the mission
was far from over.
171
00:13:52,431 --> 00:13:54,399
The lander began
the long process
172
00:13:54,433 --> 00:13:57,135
of touching down
on the far side of the planet.
173
00:14:17,690 --> 00:14:20,625
[narrator] The heat shield and
a sequence of three parachutes
174
00:14:20,659 --> 00:14:26,598
slowed the lander from 820 feet
per second to 160 feet per second.
175
00:14:27,733 --> 00:14:31,135
During this descent,
the lander's top was ejected
176
00:14:31,170 --> 00:14:34,138
and data collection began.
177
00:14:44,550 --> 00:14:46,618
[indistinct
radio communications]
178
00:14:46,652 --> 00:14:51,055
[narrator] The first parachute
sequence ended when the third detached.
179
00:14:51,090 --> 00:14:54,092
[Anatoly speaking]
180
00:14:59,431 --> 00:15:01,633
[narrator] The lander
would then spend 20 minutes
181
00:15:01,667 --> 00:15:05,136
methodically taking
measurements of the atmosphere.
182
00:15:05,170 --> 00:15:08,806
But its brutal voyage
was not over yet.
183
00:15:10,376 --> 00:15:13,378
[Anatoly speaking]
184
00:15:21,020 --> 00:15:25,023
[David] The atmosphere gets hotter
and hotter and more and more dense
185
00:15:25,057 --> 00:15:30,194
to the point where it's 100 times as
dense as the atmosphere on Earth,
186
00:15:30,229 --> 00:15:33,631
and that means that you're falling
through... It's not quite a liquid,
187
00:15:33,666 --> 00:15:36,701
but it's a gas that is approaching
the properties of a liquid,
188
00:15:36,735 --> 00:15:38,870
and that would slow your fall.
189
00:15:40,472 --> 00:15:42,273
And then
when you get to the surface,
190
00:15:42,308 --> 00:15:45,710
it's almost like going
through the ocean.
191
00:15:45,744 --> 00:15:49,948
[narrator] Venera 9 wasn't the first
lander to get to the surface of Venus...
192
00:15:53,385 --> 00:15:55,954
...but it was the first
to send back pictures.
193
00:15:59,058 --> 00:16:04,595
This was the first image ever taken by
humans on the surface of another planet.
194
00:16:09,068 --> 00:16:12,370
And that was a real triumph
of exploration.
195
00:16:17,776 --> 00:16:22,013
[narrator] This remarkable scientific
accomplishment was just the beginning.
196
00:16:22,047 --> 00:16:25,783
Spacecraft have now sent back
images of numerous other planets,
197
00:16:25,818 --> 00:16:28,386
asteroids and comets,
198
00:16:28,420 --> 00:16:31,422
but few have had
the emotional impact
199
00:16:31,457 --> 00:16:33,658
as our journey to Mars.
200
00:16:37,763 --> 00:16:41,532
[James Green] These rovers
were not inanimate objects to us.
201
00:16:41,567 --> 00:16:45,303
We were part of them
and they were part of us.
202
00:16:46,538 --> 00:16:49,040
[narrator] In 2004, two rovers,
203
00:16:49,074 --> 00:16:50,942
Spirit and Opportunity,
204
00:16:50,976 --> 00:16:54,879
landed on the Red Planet
in search of one thing:
205
00:16:54,913 --> 00:16:57,815
sedimentary rock.
206
00:17:01,020 --> 00:17:03,588
[James Green] When geologists
go out in the field here on Earth,
207
00:17:03,622 --> 00:17:06,190
they want to look for
layers of sediment
208
00:17:06,225 --> 00:17:08,726
that have accumulated over time.
209
00:17:10,763 --> 00:17:15,967
This is literally the historical
pages of the Book of the Earth.
210
00:17:17,503 --> 00:17:20,538
At this level was
where the dinosaurs were,
211
00:17:20,572 --> 00:17:26,277
and at this level they died, and
at this level, new life became.
212
00:17:26,311 --> 00:17:29,247
You can just read
that book of history.
213
00:17:31,383 --> 00:17:33,551
[narrator] Scientists
chose Martian landing sites
214
00:17:33,585 --> 00:17:36,921
based on their likelihood of
containing sedimentary rock.
215
00:17:39,758 --> 00:17:44,729
Spirit landed in an ancient
drainage channel off of Gusev Crater,
216
00:17:44,763 --> 00:17:48,866
but all it found was a vast,
scorched lava field.
217
00:17:50,569 --> 00:17:54,906
[Matt] We were crestfallen
that none of our predictions
218
00:17:54,940 --> 00:17:59,243
about what materials would be there
were... You know, that we were wrong.
219
00:17:59,278 --> 00:18:02,780
[wind blowing]
220
00:18:04,383 --> 00:18:07,685
[Matt] Opportunity was
completely different.
221
00:18:11,557 --> 00:18:13,825
[Rod] Opportunity really
hit the bull's eye
222
00:18:13,859 --> 00:18:16,260
because it landed in a place
called Eagle Crater,
223
00:18:16,295 --> 00:18:19,764
in which Mother Nature has
done you a big favor.
224
00:18:19,798 --> 00:18:23,234
At some point, she slammed a
meteorite into the surface of the planet,
225
00:18:23,268 --> 00:18:27,672
excavating this big hole,
and basically gave you
226
00:18:27,706 --> 00:18:30,508
this archeological dig,
if you will.
227
00:18:30,542 --> 00:18:33,678
[Matt] These were sedimentary
rocks that would have been formed by...
228
00:18:35,781 --> 00:18:39,784
...liquid water, and it was
a classic sedimentary sequence
229
00:18:39,818 --> 00:18:43,254
that we've seen on the Earth
in many places.
230
00:18:45,491 --> 00:18:48,659
And this is where
it really gets interesting.
231
00:18:51,130 --> 00:18:53,631
[James Garvin] We see these
little bead-like things in the soil.
232
00:18:53,665 --> 00:18:55,399
We thought,
"What could these be?"
233
00:18:55,434 --> 00:18:57,702
I mean, people started
conjecturing,
234
00:18:57,736 --> 00:18:59,871
but when we put
the infra-red eyes on them,
235
00:18:59,905 --> 00:19:02,740
we can see iron
and oxygen in them.
236
00:19:02,774 --> 00:19:08,579
We're thinking, "Holy crap,
Batman." We found hematite.
237
00:19:12,217 --> 00:19:18,022
[James Green] Hematite is a mineral
here on Earth that's formed in water,
238
00:19:18,056 --> 00:19:22,927
and a lot of it, in moving water
that allows this mineral to be formed,
239
00:19:22,961 --> 00:19:25,563
and they were
all over the place!
240
00:19:27,499 --> 00:19:31,202
Holy gosh.
We found the holy grail.
241
00:19:38,443 --> 00:19:41,546
[narrator] The rovers were
expected to last 90 days,
242
00:19:41,580 --> 00:19:46,217
but Opportunity's hematite
discovery was just the beginning.
243
00:19:48,587 --> 00:19:53,324
[James] They outdid their
warranty by factors of hundreds.
244
00:19:55,561 --> 00:20:00,798
[Matt] We're several years into the mission
that we had real trouble with Spirit.
245
00:20:03,835 --> 00:20:06,971
Spirit had lost one drive wheel.
246
00:20:08,507 --> 00:20:12,743
In doing so, we got stuck
in a sandy crater,
247
00:20:12,778 --> 00:20:15,446
and that was
the end of Spirit, yeah.
248
00:20:18,650 --> 00:20:22,987
But Opportunity just
shines like a radiant star
249
00:20:23,021 --> 00:20:26,224
because this rover keeps
going and going and going.
250
00:20:31,430 --> 00:20:34,732
[Rod] Then in 2012, a new
rover drops into the party.
251
00:20:35,734 --> 00:20:37,768
Curiosity, equipped with a drill
252
00:20:37,803 --> 00:20:40,204
and carrying an entire
laboratory on its back.
253
00:20:40,239 --> 00:20:42,440
This machine rolled into town
254
00:20:42,474 --> 00:20:45,309
and immediately changed
our view of the Red Planet.
255
00:20:47,512 --> 00:20:53,150
[James Green] As we dug into the
soils and we found, to our delight,
256
00:20:53,185 --> 00:20:58,389
it had carbon, hydrogen, oxygen,
nitrogen, phosphorus and sulfur.
257
00:20:58,423 --> 00:21:02,360
That's everything between
these two fingers.
258
00:21:04,329 --> 00:21:10,501
All the right stuff that life
is made of is on Mars.
259
00:21:17,943 --> 00:21:21,312
[narrator] Opportunity
roamed Mars for 15 years,
260
00:21:21,346 --> 00:21:25,950
exploring more distance than
any other rover in history,
261
00:21:25,984 --> 00:21:29,453
but its journey came to
an end in 2018
262
00:21:29,488 --> 00:21:31,889
when a severe dust storm struck.
263
00:21:31,923 --> 00:21:35,793
It's this unstoppable machine.
It just keeps driving.
264
00:21:35,827 --> 00:21:39,030
And then in June of 2018...
265
00:21:41,333 --> 00:21:43,734
...here's a dust storm
in the distance...
266
00:21:47,606 --> 00:21:50,174
...that turns out
to be a whopper.
267
00:21:53,445 --> 00:21:55,813
[Matt] The Sun was
almost blacked out.
268
00:21:58,050 --> 00:22:02,920
And at that point, there was
no power getting to the panels
269
00:22:02,954 --> 00:22:07,591
and we tried for months and months
and months until there was just nothing.
270
00:22:09,995 --> 00:22:12,063
And at that point,
you've eventually...
271
00:22:12,097 --> 00:22:14,832
you know, you say
that's the end, yeah.
272
00:22:23,108 --> 00:22:27,645
We had one final day where
they called the team out to JPL,
273
00:22:27,679 --> 00:22:30,614
the Jet Propulsion Laboratory,
where anybody that wanted to come
274
00:22:30,649 --> 00:22:33,084
and be there when they sent
the final commands could come.
275
00:22:36,955 --> 00:22:40,291
We had all gathered in this
area called the Dark Room
276
00:22:40,325 --> 00:22:43,928
overlooking mission operations and
we're watching the flight commanders
277
00:22:43,962 --> 00:22:46,130
sending off the last commands
to the rover.
278
00:22:46,164 --> 00:22:48,966
We did, basically,
four final pings.
279
00:22:54,005 --> 00:22:56,073
The, like, time delay
280
00:22:56,108 --> 00:22:58,476
comes and goes,
we got no signal,
281
00:22:58,510 --> 00:23:00,578
and everybody just kind of
sits there in silence.
282
00:23:05,817 --> 00:23:09,153
And then the manager of
the mission, John Callas...
283
00:23:09,187 --> 00:23:14,291
This concludes operations
for MER-1, spacecraft ID 253.
284
00:23:14,326 --> 00:23:18,362
...says, you know, "Thank you
for your 15 years of service."
285
00:23:18,397 --> 00:23:20,097
Thank you.
286
00:23:20,132 --> 00:23:25,469
[Tanya] "But this is the end, so, you
know, this is MER, signing off the net."
287
00:23:25,504 --> 00:23:28,005
MER project, off the net.
288
00:23:31,543 --> 00:23:34,278
In the Dark Room, it was just
silence and everybody's kind of
289
00:23:34,312 --> 00:23:38,649
looking around, and we're like,
"This is it. This is actually the end."
290
00:23:44,022 --> 00:23:46,257
[narrator] Opportunity's
mission was over,
291
00:23:46,291 --> 00:23:49,226
but its dogged pursuit
of knowledge lives on
292
00:23:49,261 --> 00:23:53,864
as scientists strive to learn more
about our mysterious universe.
293
00:23:57,836 --> 00:24:02,273
And where better to look
for answers than comets?
294
00:24:02,307 --> 00:24:05,342
Leftovers from the formation
of the Solar System,
295
00:24:05,377 --> 00:24:08,512
comets contain the
building blocks of our world.
296
00:24:11,750 --> 00:24:14,452
[Mark] To learn more, you want
to go and rendezvous with a comet.
297
00:24:14,486 --> 00:24:16,353
You want to fly alongside it.
298
00:24:16,388 --> 00:24:20,090
And, of course, then the idea comes up you
would want to touch down on the surface.
299
00:24:20,125 --> 00:24:22,560
You want to land there,
sample material.
300
00:24:25,030 --> 00:24:31,335
To do all of that in one
mission is incredibly gutsy.
301
00:24:31,369 --> 00:24:34,572
[countdown in foreign language]
302
00:24:34,606 --> 00:24:39,410
The first time I heard about the
mission, I thought they must be joking.
303
00:24:39,444 --> 00:24:42,847
[countdown in foreign language]
304
00:24:45,917 --> 00:24:48,352
[Paolo] We launched
in March 2004.
305
00:24:51,189 --> 00:24:55,926
The whole travel to the comet,
it was an adventure for Rosetta.
306
00:25:00,765 --> 00:25:05,236
[Mark] So, we did this thing to use
the planets and to use their gravity
307
00:25:05,270 --> 00:25:07,705
to slingshot us through space
308
00:25:07,739 --> 00:25:10,341
on a different trajectory
with more speed
309
00:25:10,375 --> 00:25:12,543
in order to be able to
get to the comet.
310
00:25:13,845 --> 00:25:17,648
After this,
we came back to Earth.
311
00:25:17,682 --> 00:25:20,017
This one gave us
the last big kick.
312
00:25:23,121 --> 00:25:28,659
We were really launched very
fast, but getting very far from the Sun.
313
00:25:36,434 --> 00:25:40,571
We could not keep all
the systems on board active
314
00:25:40,605 --> 00:25:44,942
because the illumination of our
solar panels was getting very weak.
315
00:25:49,948 --> 00:25:53,117
So the decision was made,
in fact, to turn it off.
316
00:25:55,587 --> 00:25:58,088
I hated that concept
from the very beginning.
317
00:25:58,123 --> 00:25:59,723
I've been fighting it for years.
318
00:25:59,758 --> 00:26:04,461
I was convinced we would
never do it. It was too crazy.
319
00:26:04,496 --> 00:26:10,301
[Paolo] Switching off the radio
signal is like cutting a vital link.
320
00:26:10,335 --> 00:26:12,903
[Andrea] You've been flying
a spacecraft for seven years.
321
00:26:12,938 --> 00:26:16,607
It's at hundreds of millions of
kilometers away. And what do you do?
322
00:26:16,641 --> 00:26:18,943
You send a command to switch it
off and wake it up three years later.
323
00:26:18,977 --> 00:26:22,980
This just doesn't make sense.
And this is what we did.
324
00:26:23,014 --> 00:26:27,251
[Paolo] We spent two and
a half years without contact.
325
00:26:27,285 --> 00:26:29,820
And we waited.
326
00:26:33,959 --> 00:26:36,994
[Mark] We couldn't talk to it
while it was in hibernation.
327
00:26:37,028 --> 00:26:41,242
We needed it to wake up,
which it was due to do
328
00:26:41,266 --> 00:26:44,501
on 20th January, 2014.
329
00:26:45,704 --> 00:26:48,205
[mission control]
Three, two, one.
330
00:26:50,875 --> 00:26:53,444
[Paolo] We were sitting
all in the control room,
331
00:26:53,478 --> 00:26:56,213
waiting for the signal to come,
332
00:26:56,247 --> 00:27:01,185
and this was probably the most
tense moment of the mission.
333
00:27:03,355 --> 00:27:05,422
This was everything or nothing.
334
00:27:05,457 --> 00:27:07,558
It was life or death.
335
00:27:08,593 --> 00:27:10,394
"Why it's not coming?"
336
00:27:13,465 --> 00:27:16,567
[murmuring]
337
00:27:16,601 --> 00:27:19,436
[Mark] Everybody was
getting very nervous.
338
00:27:20,605 --> 00:27:23,641
[Paolo] It was
very difficult to bear.
339
00:27:25,777 --> 00:27:28,879
We started really
getting worried.
340
00:27:29,881 --> 00:27:32,716
[Joel] Then suddenly
the signal came.
341
00:27:32,751 --> 00:27:34,785
[cheers and applause]
342
00:27:34,819 --> 00:27:38,022
[Paolo] When the signal came, it
was a big relief for me personally.
343
00:27:38,056 --> 00:27:40,424
There was an explosion of joy.
344
00:27:40,458 --> 00:27:46,063
[Joel] A little blip on a noise
spectrum told us Rosetta was there
345
00:27:46,097 --> 00:27:47,965
and it was calling home.
346
00:27:47,999 --> 00:27:50,267
[applause]
347
00:27:53,805 --> 00:27:57,207
But now the mission starts because
now we have to get to the comet,
348
00:27:57,242 --> 00:27:59,076
fly around the comet,
orbit the comet
349
00:27:59,110 --> 00:28:03,147
and land on the comet,
all within the next 10 months.
350
00:28:03,181 --> 00:28:07,184
[narrator] The Rosetta team had
successfully woken a dormant spacecraft
351
00:28:07,218 --> 00:28:13,157
millions of miles away, but the
real challenge was just beginning.
352
00:28:20,565 --> 00:28:23,701
[narrator] After two and a
half years of radio silence,
353
00:28:23,735 --> 00:28:28,005
Rosetta had come back online
right on schedule.
354
00:28:28,039 --> 00:28:32,209
A decade after launch, the
spacecraft was about to touch a comet
355
00:28:32,243 --> 00:28:34,478
for the first time in history.
356
00:28:37,015 --> 00:28:39,650
[Mark] The comet we ended up
deciding to go to
357
00:28:39,684 --> 00:28:42,453
was 67P/Churyumov-Gerasimenko.
358
00:28:47,692 --> 00:28:50,894
At the beginning, the comet
was just a very small dot.
359
00:28:54,032 --> 00:28:55,866
And then day by day,
the comet was growing
360
00:28:55,900 --> 00:28:58,135
in the field of view
of the camera.
361
00:29:03,408 --> 00:29:08,412
[Joel] You have this spacecraft
visiting an ambassador
362
00:29:08,446 --> 00:29:12,616
from the Solar System
from 4.5 billion years ago.
363
00:29:12,650 --> 00:29:17,087
It's modern technology
visiting an ancient relic.
364
00:29:19,791 --> 00:29:24,728
It's really
profoundly emotional.
365
00:29:30,502 --> 00:29:33,237
[Paolo] We saw
this incredible shape --
366
00:29:33,271 --> 00:29:36,140
Some people have described it
as a rubber duck.
367
00:29:40,178 --> 00:29:43,013
[Joel] It was amazing.
It was beautiful.
368
00:29:43,047 --> 00:29:46,683
Scientists were just stunned
with their mouths open.
369
00:29:54,159 --> 00:29:59,096
[Joel] Comet 67P is about
4 kilometers in size.
370
00:30:03,001 --> 00:30:06,069
If you were standing on
the bottom of the comet,
371
00:30:06,104 --> 00:30:09,840
you might see a flat,
dusty plain.
372
00:30:12,277 --> 00:30:17,314
If you were standing on the head of
the comet, it might look more rocky.
373
00:30:17,348 --> 00:30:19,983
If you were standing
on the neck of the comet,
374
00:30:20,018 --> 00:30:23,020
you would be in
this interesting valley,
375
00:30:23,054 --> 00:30:26,957
kilometer-high cliffs
on either side.
376
00:30:29,260 --> 00:30:34,131
There's so many different
types of surfaces and variety.
377
00:30:34,165 --> 00:30:36,600
You could spend the rest of
your life
378
00:30:36,634 --> 00:30:38,969
exploring every little part
of the comet,
379
00:30:39,003 --> 00:30:41,371
not see the same
type of thing twice.
380
00:30:49,781 --> 00:30:52,049
[narrator] The images
the Rosetta mission returned
381
00:30:52,083 --> 00:30:55,152
are as visually stunning
as they are informative,
382
00:30:55,186 --> 00:30:59,256
and scientists still analyze them
today for anything they can reveal
383
00:30:59,290 --> 00:31:02,125
about comets and their place
in our universe.
384
00:31:04,696 --> 00:31:07,364
But, of course, some of
the most exciting data
385
00:31:07,398 --> 00:31:10,934
space science can provide
isn't visual at all.
386
00:31:14,038 --> 00:31:18,542
In 1995, spacecraft Galileo
arrived at Jupiter
387
00:31:18,576 --> 00:31:24,214
and began recording data that suggests
conditions almost beyond imagination.
388
00:31:28,219 --> 00:31:31,855
The Galileo spacecraft
carried along with it a probe,
389
00:31:31,890 --> 00:31:34,191
and it's sort of, like,
this size
390
00:31:34,225 --> 00:31:36,860
and it had a big heat shield
to protect it around it.
391
00:31:38,496 --> 00:31:40,330
[narrator] There were
no cameras on board,
392
00:31:40,365 --> 00:31:44,601
only sensors designed to withstand
an extremely violent introduction
393
00:31:44,636 --> 00:31:46,503
to Jupiter.
394
00:31:48,373 --> 00:31:52,476
And so, in July 1995,
we launched that probe
395
00:31:52,510 --> 00:31:54,578
and sent it in the direction
of Jupiter.
396
00:31:54,612 --> 00:31:58,582
Now, it didn't have engines, so we
weren't guiding it and saying, "Go there."
397
00:31:58,616 --> 00:32:02,352
We just sort of sent it on
a trajectory towards Jupiter.
398
00:32:11,763 --> 00:32:17,534
[Fran] It was coming in at
something like 130,000 miles an hour,
399
00:32:17,568 --> 00:32:21,405
because it was pulled in by the gravity
of Jupiter, and we had to slow it down.
400
00:32:23,241 --> 00:32:26,710
And so this heat shield
heated up to about three times
401
00:32:26,744 --> 00:32:29,046
the temperature of the surface
of the Sun.
402
00:32:38,890 --> 00:32:42,025
And then eventually we
kicked off that heat shield,
403
00:32:42,060 --> 00:32:44,661
put out some parachutes.
404
00:32:46,864 --> 00:32:53,103
And so as it went down, we were
able to get a sense of what it was like.
405
00:32:53,137 --> 00:32:58,208
What we were expecting was
three separate layers of clouds.
406
00:33:02,313 --> 00:33:05,315
And we went down, it was like,
"Where are the clouds?
407
00:33:05,350 --> 00:33:08,452
Where are the clouds? We're not
seeing the clouds. What's going on?"
408
00:33:08,486 --> 00:33:13,123
[narrator] Ironically, after five months
in space and years of mission planning,
409
00:33:13,157 --> 00:33:18,195
it would take a ground-based
telescope to reveal Jupiter's secrets.
410
00:33:25,737 --> 00:33:29,406
[narrator] When Galileo reached
Jupiter, the probe showed no evidence
411
00:33:29,440 --> 00:33:33,010
of the clouds scientists
expected to find,
412
00:33:33,044 --> 00:33:35,746
and the team was baffled,
413
00:33:35,780 --> 00:33:39,983
but infra-red data taken from ground
telescopes revealed the problem.
414
00:33:40,018 --> 00:33:45,022
The probe had landed in a
particularly dry, hot location.
415
00:33:45,056 --> 00:33:49,793
So I think we realized that our
whole idea of exploring these planets
416
00:33:49,827 --> 00:33:53,497
with single probes is a little bit
susceptible to going into the wrong place.
417
00:33:55,233 --> 00:33:59,870
[Fran] By the time the probe
had got down to about 160km,
418
00:33:59,904 --> 00:34:02,839
something like 23 times
atmospheric pressure,
419
00:34:02,874 --> 00:34:05,742
it was now starting
to get really hot.
420
00:34:05,777 --> 00:34:09,980
And so at that point, the electronics
is just not working anymore
421
00:34:10,014 --> 00:34:12,182
and it stops communicating.
422
00:34:13,651 --> 00:34:16,420
But let's imagine
what it would be like
423
00:34:16,454 --> 00:34:20,390
if you could be in a pressurized
capsule as you get deeper down.
424
00:34:21,659 --> 00:34:24,161
It would get a little calmer,
little less turbulent.
425
00:34:24,195 --> 00:34:27,197
The pressure would
get higher and higher.
426
00:34:28,166 --> 00:34:31,468
[Scott] So hot,
everything's vaporous.
427
00:34:31,502 --> 00:34:34,638
Eventually, get down to material
that are almost like rock clouds,
428
00:34:34,672 --> 00:34:37,207
and they're probably
precipitating.
429
00:34:37,241 --> 00:34:39,042
[Fran] Now, when you get down,
430
00:34:39,077 --> 00:34:41,289
something like 10%
of the radius,
431
00:34:41,313 --> 00:34:44,681
you're now getting to the point
where the pressures are about
432
00:34:44,715 --> 00:34:48,385
a million times
Earth's atmospheric pressure
433
00:34:48,419 --> 00:34:51,688
and the density
is getting really high.
434
00:34:51,722 --> 00:34:55,759
And at that point,
hydrogen changes its phase.
435
00:34:55,793 --> 00:35:01,064
It's no longer molecules, protons
and electrons connected together,
436
00:35:01,099 --> 00:35:04,334
but the protons and the
electrons are moving separately
437
00:35:04,368 --> 00:35:06,670
and it becomes metallic.
438
00:35:06,704 --> 00:35:09,973
That is, it becomes
electrically conducting.
439
00:35:10,007 --> 00:35:13,877
I suspect it would look like
mercury, a glob of mercury,
440
00:35:13,911 --> 00:35:16,246
is what it would
probably look like.
441
00:35:18,116 --> 00:35:22,619
If you existed, you would be, you
know, unbelievably thin, flat-out pancake.
442
00:35:24,088 --> 00:35:27,057
[Fran] You get to the
center of Jupiter, we're talking
443
00:35:27,091 --> 00:35:30,060
four times the temperature of
the surface of the Sun,
444
00:35:30,094 --> 00:35:33,396
50 million atmospheres pressure,
445
00:35:33,431 --> 00:35:35,232
and a density that's denser
446
00:35:35,266 --> 00:35:39,236
than the heaviest metals
that we have on Earth.
447
00:35:41,572 --> 00:35:43,874
[man] ...counting, this is
Titan launch control.
448
00:35:43,908 --> 00:35:47,010
[Hunter] Without any doubt,
the most risky element
449
00:35:47,044 --> 00:35:49,779
of any space mission
is the launch.
450
00:35:49,814 --> 00:35:51,982
[mission control]
T-minus 15 seconds.
451
00:35:52,016 --> 00:35:54,718
When you've put eight years
of your life into designing
452
00:35:54,752 --> 00:35:57,687
and building and testing something
which is going to go into space...
453
00:35:57,722 --> 00:35:59,689
[mission control]
Nine, eight, seven...
454
00:35:59,724 --> 00:36:01,591
[Andrew] And then seeing it
on the top of a rocket
455
00:36:01,626 --> 00:36:04,828
that's being vibrated and
accelerated on its way to Saturn,
456
00:36:04,862 --> 00:36:07,063
it is quite a feeling.
457
00:36:11,769 --> 00:36:15,906
[Andrew] When it did go off, it
created a huge amount of light.
458
00:36:16,941 --> 00:36:19,776
And then the rocket
went behind a cloud.
459
00:36:21,913 --> 00:36:24,848
[Hunter] And then the nose cone
came out and you're going, "Phew!"
460
00:36:35,326 --> 00:36:39,496
[narrator] Exploring a planet such
as Saturn is a very risky business.
461
00:36:39,530 --> 00:36:41,798
The mission called
Cassini-Huygens
462
00:36:41,832 --> 00:36:45,502
was one of the most technically
demanding ever undertaken.
463
00:36:48,472 --> 00:36:51,441
When Cassini was approaching
Saturn for the first time,
464
00:36:51,475 --> 00:36:54,477
our experiment was
systematically scanning
465
00:36:54,512 --> 00:36:56,546
back and forth
on the planet Saturn,
466
00:36:56,581 --> 00:36:59,749
and we were amazed to
discover that the system
467
00:36:59,784 --> 00:37:03,253
was filled with
molecules of oxygen.
468
00:37:05,056 --> 00:37:10,327
And we mapped this out and we
noticed that the peak in the distribution
469
00:37:10,361 --> 00:37:16,499
was just a distance four times Saturn's
radius from the center of the system.
470
00:37:16,534 --> 00:37:22,038
We knew that the moon Enceladus
was orbiting just at that distance.
471
00:37:22,073 --> 00:37:24,307
[narrator] Enceladus is
a tiny moon
472
00:37:24,342 --> 00:37:27,811
just over 300 miles in diameter.
473
00:37:27,845 --> 00:37:32,482
Enceladus originally was on the
itinerary, but only marginally so.
474
00:37:32,516 --> 00:37:34,584
It was another
very interesting Saturn moon.
475
00:37:34,619 --> 00:37:37,954
It's small, very shiny,
very white, very bright,
476
00:37:37,989 --> 00:37:40,557
but other than that,
too small to be interesting.
477
00:37:44,695 --> 00:37:48,465
[Elizabeth] It was in the first close
fly-by that the magnetometer team
478
00:37:48,499 --> 00:37:52,068
detected something interesting
that they didn't expect.
479
00:37:53,137 --> 00:37:55,805
[Earl] It looks like it has
an atmosphere.
480
00:37:55,840 --> 00:37:59,409
Well, anybody that knows anything
about moons says, "That's too tiny.
481
00:37:59,443 --> 00:38:02,812
It can't have an atmosphere. It's
way too small to hold on to anything."
482
00:38:04,949 --> 00:38:08,218
[Elizabeth] If you flew by the south pole,
it looked like there was an atmosphere,
483
00:38:08,252 --> 00:38:10,153
but if you flew by
at the equator,
484
00:38:10,187 --> 00:38:13,023
you didn't see anything at all.
485
00:38:13,057 --> 00:38:16,126
[narrator] Yet Enceladus
had another surprise in store
486
00:38:16,160 --> 00:38:21,731
and what Cassini found would open
up a whole host of new possibilities.
487
00:38:28,606 --> 00:38:31,007
[narrator] When the Cassini
spacecraft showed evidence
488
00:38:31,042 --> 00:38:34,210
of an atmosphere at
Saturn's moon, Enceladus,
489
00:38:34,245 --> 00:38:37,514
the team was shocked,
and what they found next
490
00:38:37,548 --> 00:38:42,018
permanently altered the existing
conceptions of Jupiter's tiny moon.
491
00:38:43,321 --> 00:38:46,189
[Earl] We went back again
and again and all of a sudden
492
00:38:46,223 --> 00:38:48,625
realized that not only
it had an atmosphere,
493
00:38:48,659 --> 00:38:51,828
it was an icy atmosphere,
but it had these plumes
494
00:38:51,862 --> 00:38:53,797
coming out of the southern pole.
495
00:38:58,903 --> 00:39:02,739
And here's water geysers,
you know, on a... on a tiny moon.
496
00:39:07,011 --> 00:39:09,546
And that water that
was coming out of the...
497
00:39:09,580 --> 00:39:12,215
what we've later found out
to be an interior ocean,
498
00:39:12,249 --> 00:39:15,819
not only did it contain water
vapor, but it had traces of
499
00:39:15,853 --> 00:39:20,390
ammonia, methane, H2,
CO2, and then there was
500
00:39:20,424 --> 00:39:24,627
a whole host of organic
compounds that we could also see.
501
00:39:24,662 --> 00:39:27,597
[Larry] And now we can put
all that information together
502
00:39:27,631 --> 00:39:30,467
to get a picture
of the shape of the eruption
503
00:39:30,501 --> 00:39:34,571
and also the material that's being
erupted from inside of Enceladus.
504
00:39:34,605 --> 00:39:36,306
And amazingly enough,
505
00:39:36,340 --> 00:39:40,143
that material has the basic
building blocks of life.
506
00:39:41,779 --> 00:39:44,892
This says to me that would be
a good place to go
507
00:39:44,916 --> 00:39:47,350
and see if there's
any form of life there.
508
00:39:53,858 --> 00:39:56,559
[narrator] It is increasingly
evident that life might exist
509
00:39:56,594 --> 00:39:59,829
in even the unlikeliest
of places,
510
00:39:59,864 --> 00:40:03,133
and where less likely
to find life
511
00:40:03,167 --> 00:40:07,170
than the dwarf planet lingering
at the edge of our solar system,
512
00:40:07,204 --> 00:40:13,009
an average of 3.7 billion
miles from the Sun, Pluto?
513
00:40:13,043 --> 00:40:17,213
As we were flying up to Pluto
and imaging it day after day
514
00:40:17,248 --> 00:40:21,618
and week after week on approach,
we could see this bright feature
515
00:40:21,652 --> 00:40:23,720
on the surface.
516
00:40:26,957 --> 00:40:29,092
One morning,
we got an image back,
517
00:40:29,126 --> 00:40:31,761
and as soon as it came up
on the big screen,
518
00:40:31,796 --> 00:40:35,231
I remember a NASA official
who said,
519
00:40:35,266 --> 00:40:37,734
"Do you see?
That looks like a heart."
520
00:40:40,271 --> 00:40:42,739
And as we got closer
and closer, amazingly,
521
00:40:42,773 --> 00:40:45,975
it looked more and more
like a heart.
522
00:40:47,678 --> 00:40:51,247
I think that's what emblazoned
Pluto into the public mind
523
00:40:51,282 --> 00:40:55,852
as this amazing place at the
frontier of our Solar System.
524
00:40:55,886 --> 00:41:00,423
[narrator] Pluto's heart
measures about 1,000 miles across
525
00:41:00,458 --> 00:41:03,226
and it's composed
of nitrogen ice.
526
00:41:03,260 --> 00:41:06,663
We believe that structure
might be supported
527
00:41:06,697 --> 00:41:09,332
by water underneath the surface.
528
00:41:12,069 --> 00:41:16,206
There could be an ocean
underneath Pluto's surface.
529
00:41:17,541 --> 00:41:20,076
There probably is some kind of
liquid water ocean.
530
00:41:20,110 --> 00:41:23,313
It's very deep down inside,
but we think
531
00:41:23,347 --> 00:41:26,316
there's a pretty good chance
that it's there.
532
00:41:26,350 --> 00:41:28,051
[Marc] It's one of
those things where
533
00:41:28,085 --> 00:41:30,253
if you find water,
is there a chance for life?
534
00:41:30,287 --> 00:41:33,957
Wouldn't that be cool, if Pluto
is actually one of those places
535
00:41:33,991 --> 00:41:37,193
in the Solar System
that has or had life?
536
00:41:37,228 --> 00:41:39,596
That's just mind-blowing,
right there.
537
00:41:45,035 --> 00:41:49,339
[narrator] The exploration of
our Solar System is far from over,
538
00:41:49,373 --> 00:41:52,041
but it has already taught us
what a rich,
539
00:41:52,076 --> 00:41:54,577
varied and strange place it is.
540
00:41:57,515 --> 00:42:03,653
But scientists will agree the
greatest discoveries are yet to come.