1
00:00:06,000 --> 00:00:08,400
[calm music playing]

2
00:00:14,200 --> 00:00:17,600
[Freeman] Every year
for just a few short months…

3
00:00:17,680 --> 00:00:19,160
[birds squawking]

4
00:00:19,240 --> 00:00:23,160
…fresh water flows
into the Okavango Delta…

5
00:00:27,680 --> 00:00:29,280
creating the perfect home…

6
00:00:31,360 --> 00:00:33,480
for a small family of elephants…

7
00:00:38,000 --> 00:00:42,280
and a playground
for their two young calves…

8
00:00:44,520 --> 00:00:45,600
Bosigo…

9
00:00:46,600 --> 00:00:47,600
[calf whines]

10
00:00:47,680 --> 00:00:50,760
…and her baby cousin, Metsi.

11
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[whining continues]

12
00:00:58,040 --> 00:00:59,360
[elephant trumpeting]

13
00:00:59,440 --> 00:01:03,680
[Freeman] Bosigo and Metsi
are only just beginning

14
00:01:03,760 --> 00:01:05,400
their love affair with water.

15
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[calm music swells]

16
00:01:09,000 --> 00:01:10,320
But from now on,

17
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their lives will be defined by it.

18
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[whooshing, crackling]

19
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This one precious molecule…

20
00:01:19,680 --> 00:01:21,320
[intense music playing]

21
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…delivered to Earth…

22
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[exploding]

23
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…by the astonishing forces
at work in our universe.

24
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[rumbling]

25
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It has transformed this planet…

26
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[whooshing]

27
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…into a haven…

28
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[sizzling]

29
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…for life.

30
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[dramatic music playing]

31
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[tense music playing]

32
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Summer has arrived.

33
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And what was paradise is no more.

34
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The fresh water that flooded the delta…

35
00:02:42,800 --> 00:02:44,760
only stays for a few months.

36
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And water holes are now vanishing.

37
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[crackling]

38
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Fast.

39
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This means only one thing

40
00:03:00,400 --> 00:03:03,640
for the thousands of elephants
who've been living here.

41
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[elephant trumpeting]

42
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It's time to move on.

43
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[pensive music playing]

44
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[elephant grumbling]

45
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[elephant trumpeting]

46
00:03:21,960 --> 00:03:26,120
This has been the only home
Metsi and Bosigo have ever known.

47
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[Metsi whines]

48
00:03:28,720 --> 00:03:32,200
But in a few weeks,
all the water will be gone.

49
00:03:32,280 --> 00:03:33,400
[Metsi grunts]

50
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So they must leave the delta
with the rest of their family.

51
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A herd of females,

52
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sisters, aunts, and cousins,

53
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led by their grandmother,

54
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the great matriarch, Pula.

55
00:03:55,000 --> 00:03:57,400
[pensive music continues]

56
00:03:58,360 --> 00:04:02,440
They're embarking on a journey
along with thousands of other families…

57
00:04:05,160 --> 00:04:06,400
out into the desert…

58
00:04:10,280 --> 00:04:11,600
in search of water.

59
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[whooshing]

60
00:04:16,160 --> 00:04:17,840
[intriguing music playing]

61
00:04:18,840 --> 00:04:20,480
For the next eight months,

62
00:04:20,560 --> 00:04:24,840
they will migrate
from water hole to water hole…

63
00:04:27,320 --> 00:04:30,160
and navigate ancient elephant trails…

64
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[elephant growls]

65
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…using the matriarch Pula's knowledge,

66
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handed down to her through generations.

67
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[zebras yelping]

68
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The trek will put all their lives at risk.

69
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[calf whining]

70
00:04:45,080 --> 00:04:48,720
And they'll need
every one of their exceptional senses…

71
00:04:48,800 --> 00:04:51,120
-[elephant trumpets]
-…to endure the dangers.

72
00:04:51,640 --> 00:04:53,080
[solemn music playing]

73
00:04:55,640 --> 00:04:58,840
Making this journey is not a choice.

74
00:05:04,640 --> 00:05:07,080
Without water, they will die.

75
00:05:11,320 --> 00:05:13,880
Even on our blue planet,

76
00:05:13,960 --> 00:05:16,960
fresh liquid water is scarce.

77
00:05:20,160 --> 00:05:23,400
And if we search beyond the shores
of our own planet…

78
00:05:25,480 --> 00:05:27,000
it's rarer still.

79
00:05:30,320 --> 00:05:32,880
Even the most arid desert on Earth

80
00:05:33,640 --> 00:05:38,240
is nothing compared
to the rest of our solar system.

81
00:05:38,320 --> 00:05:40,760
[pensive music playing]

82
00:05:41,560 --> 00:05:44,080
In the cold outer reaches…

83
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[whooshing]

84
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…the only surface water is ice.

85
00:05:56,880 --> 00:05:59,320
Like Saturn's frozen moons…

86
00:06:01,640 --> 00:06:03,280
where fountains of ice

87
00:06:04,880 --> 00:06:07,400
shoot kilometers into space.

88
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[whooshing]

89
00:06:11,600 --> 00:06:13,440
[ethereal tinkling]

90
00:06:14,520 --> 00:06:17,800
Closer to the Sun on Mars,

91
00:06:18,720 --> 00:06:21,840
water is stripped away
by savage solar winds.

92
00:06:22,360 --> 00:06:23,880
[wind gusting]

93
00:06:27,800 --> 00:06:29,600
[whooshing]

94
00:06:31,080 --> 00:06:32,120
[rumbling]

95
00:06:32,640 --> 00:06:34,240
And on Venus,

96
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it simply boils away.

97
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There's only one world we know of

98
00:06:48,400 --> 00:06:51,800
that has the gift
of liquid water on its surface.

99
00:06:51,880 --> 00:06:54,480
[majestic music playing]

100
00:06:57,120 --> 00:06:59,280
A pale blue dot.

101
00:07:00,920 --> 00:07:02,000
Our home…

102
00:07:08,160 --> 00:07:09,960
where right now,

103
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water is driving one particular family

104
00:07:14,800 --> 00:07:16,840
on a quest for survival.

105
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[majestic music crescendos]

106
00:07:24,600 --> 00:07:26,840
Just a month after leaving the delta,

107
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only a scattering of muddy pools remain.

108
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[solemn music playing]

109
00:07:34,840 --> 00:07:40,120
And they're getting fewer
and farther apart each day.

110
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Pula is using her highly tuned memory
to lead her family to a water hole.

111
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[Pula screeching]

112
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She can remember the exact route,

113
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even decades later.

114
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[elephant grumbling]

115
00:08:03,680 --> 00:08:05,760
It's been a long day's march,

116
00:08:06,480 --> 00:08:09,640
and all of them are desperate for a drink.

117
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[calf whining]

118
00:08:12,000 --> 00:08:13,720
[elephant trumpeting]

119
00:08:13,800 --> 00:08:17,920
But so are the other 130,000 elephants

120
00:08:18,000 --> 00:08:19,600
that live in Botswana.

121
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[playful music playing]

122
00:08:22,080 --> 00:08:23,360
[elephant trumpeting]

123
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[calf purring]

124
00:08:27,760 --> 00:08:29,160
[elephant grumbling]

125
00:08:31,280 --> 00:08:34,800
The dry season has drawn herds
from far and wide…

126
00:08:34,880 --> 00:08:36,520
[elephants roaring, trumpeting]

127
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…to this water hole.

128
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[calf roars softly]

129
00:08:52,160 --> 00:08:56,360
All competing
for the same shrinking resource.

130
00:09:01,280 --> 00:09:03,520
[elephants breathing heavily]

131
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[elephant growling]

132
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[trumpets]

133
00:09:09,520 --> 00:09:10,880
[calm music playing]

134
00:09:10,960 --> 00:09:11,880
[Metsi trumpeting]

135
00:09:15,120 --> 00:09:19,240
The adults teach the young ones
clever survival tricks,

136
00:09:20,000 --> 00:09:23,920
like how to skim a muddy pool
to get the freshest water.

137
00:09:29,240 --> 00:09:34,000
And how to use some muddy water
as refreshing sunscreen.

138
00:09:36,880 --> 00:09:40,800
Their wrinkly skin is perfect
for trapping water and keeping cool.

139
00:09:48,560 --> 00:09:49,400
[Metsi trumpets]

140
00:09:49,480 --> 00:09:53,080
But Metsi and Bosigo are also learning…

141
00:09:56,120 --> 00:09:58,440
mud pools aren't just a place to drink.

142
00:10:00,080 --> 00:10:01,640
They're water parks too.

143
00:10:01,720 --> 00:10:04,600
[calm music continues]

144
00:10:06,400 --> 00:10:08,680
[Bosigo purring]

145
00:10:15,000 --> 00:10:16,960
With so many thirsty elephants,

146
00:10:17,480 --> 00:10:19,720
the water hole has been drained.

147
00:10:24,080 --> 00:10:26,080
[elephant moaning]

148
00:10:26,160 --> 00:10:28,000
Pula's family must press on…

149
00:10:31,840 --> 00:10:37,600
and try to make it to the next water hole
before the blazing sun sucks it dry.

150
00:10:38,200 --> 00:10:40,640
[solemn music playing]

151
00:10:40,720 --> 00:10:44,080
This battle between sun and scorched earth

152
00:10:44,160 --> 00:10:47,280
has raged ever since our world was born…

153
00:10:52,040 --> 00:10:56,000
when our blue planet
was anything but blue.

154
00:10:57,960 --> 00:11:00,280
[tense music playing]

155
00:11:04,160 --> 00:11:06,840
Four and a half billion years ago…

156
00:11:12,600 --> 00:11:15,160
Earth was in its infancy.

157
00:11:16,640 --> 00:11:18,920
A fireball of molten rock…

158
00:11:20,200 --> 00:11:22,400
[rumbling]

159
00:11:23,440 --> 00:11:27,360
…destined to become a dry, barren world.

160
00:11:28,000 --> 00:11:30,280
[tense music continues]

161
00:11:31,440 --> 00:11:34,560
But millions of kilometers
out in the coldest reaches

162
00:11:34,640 --> 00:11:35,880
of the solar system…

163
00:11:41,040 --> 00:11:42,720
water crystals were forming

164
00:11:43,680 --> 00:11:46,760
on the surface of dust particles.

165
00:11:46,840 --> 00:11:48,480
[crackling]

166
00:11:48,560 --> 00:11:50,880
[pensive music playing]

167
00:11:54,480 --> 00:11:59,760
Over time, these grains
of dust clumped together into asteroids.

168
00:12:01,520 --> 00:12:03,920
Millions and millions of them.

169
00:12:06,080 --> 00:12:09,600
And these became the asteroid belt.

170
00:12:11,240 --> 00:12:14,440
A vast expanse of icy rocks.

171
00:12:17,640 --> 00:12:21,880
Yet they've laid tantalizingly out
of Earth's reach.

172
00:12:25,840 --> 00:12:27,680
As luck would have it, however,

173
00:12:28,400 --> 00:12:30,160
a giant was on the move.

174
00:12:31,680 --> 00:12:34,080
[tense music playing]

175
00:12:39,080 --> 00:12:40,160
Young Jupiter.

176
00:12:41,160 --> 00:12:43,120
A monster of a planet.

177
00:12:48,080 --> 00:12:50,920
Forces within
the turbulent inner solar system

178
00:12:51,640 --> 00:12:55,520
were slowly pulling it in toward the Sun.

179
00:13:00,760 --> 00:13:03,880
A flight path that brought it
into a collision course

180
00:13:04,760 --> 00:13:06,440
with the asteroid belt.

181
00:13:08,120 --> 00:13:09,480
[crashing]

182
00:13:13,680 --> 00:13:16,080
[tense music continues]

183
00:13:22,080 --> 00:13:24,560
As it thundered through the asteroids…

184
00:13:25,760 --> 00:13:28,400
[crashing, rumbling]

185
00:13:28,480 --> 00:13:30,800
…its massive gravitational force

186
00:13:31,800 --> 00:13:34,000
flung rocks in every direction.

187
00:13:34,080 --> 00:13:36,800
[tense music continues]

188
00:13:41,880 --> 00:13:46,160
And yet,
from all this chaos and destruction

189
00:13:46,240 --> 00:13:49,040
came the ultimate cosmic gift.

190
00:13:49,120 --> 00:13:50,880
[tense music crescendos]

191
00:13:52,880 --> 00:13:55,040
[ethereal music playing]

192
00:13:55,120 --> 00:14:00,760
Icy, water-rich rocks
were hurled towards the Earth…

193
00:14:02,160 --> 00:14:06,280
[elephants trumpeting]

194
00:14:06,360 --> 00:14:11,360
…bringing the promise of life
one step closer.

195
00:14:15,720 --> 00:14:17,280
Over billions of years,

196
00:14:17,360 --> 00:14:21,480
asteroids were woven
into the fabric of Earth as it formed.

197
00:14:25,680 --> 00:14:29,240
Caught in the turmoil wrought by Jupiter…

198
00:14:29,320 --> 00:14:30,840
[dramatic music playing]

199
00:14:30,920 --> 00:14:34,120
…driven deep into the Earth by asteroids,

200
00:14:35,800 --> 00:14:39,800
water molecules did not have
an easy journey getting here.

201
00:14:41,400 --> 00:14:42,680
[exploding]

202
00:14:42,760 --> 00:14:45,160
And they still had a long way to go,

203
00:14:46,320 --> 00:14:49,320
imprisoned for millions of years,

204
00:14:50,200 --> 00:14:52,640
locked within Earth's molten core…

205
00:14:55,640 --> 00:14:57,400
waiting for another miracle…

206
00:15:00,600 --> 00:15:01,960
to set them free.

207
00:15:12,040 --> 00:15:15,960
Today, much of Earth's water
is still trapped underground.

208
00:15:19,600 --> 00:15:21,080
[intriguing music playing]

209
00:15:21,160 --> 00:15:22,800
[elephants trumpeting]

210
00:15:23,880 --> 00:15:28,120
So elephants have evolved special skills

211
00:15:28,200 --> 00:15:29,240
to find it.

212
00:15:29,320 --> 00:15:31,000
[elephant moaning]

213
00:15:32,600 --> 00:15:34,680
[snorting]

214
00:15:39,400 --> 00:15:41,960
Even the muddy pools are empty.

215
00:15:43,240 --> 00:15:46,120
This dry season
has become a full-on drought.

216
00:15:49,560 --> 00:15:51,880
But Pula has a superpower.

217
00:15:51,960 --> 00:15:53,440
[Pula roaring]

218
00:15:54,200 --> 00:15:55,720
Her incredible trunk,

219
00:15:57,240 --> 00:15:59,880
packed with millions of sense receptors…

220
00:16:02,000 --> 00:16:04,440
can smell water from kilometers away…

221
00:16:09,040 --> 00:16:12,880
and pinpoint its sources deep underground.

222
00:16:12,960 --> 00:16:15,680
[Pula snorting]

223
00:16:23,720 --> 00:16:25,080
But you have to dig for it.

224
00:16:25,160 --> 00:16:26,160
[Pula snorts]

225
00:16:27,080 --> 00:16:28,320
[grumbles]

226
00:16:33,880 --> 00:16:35,640
Metsi isn't a big digger.

227
00:16:35,720 --> 00:16:37,080
[Metsi trumpets]

228
00:16:40,840 --> 00:16:43,080
But Bosigo is a natural.

229
00:16:51,520 --> 00:16:54,680
And Metsi is offered a seat at the bar.

230
00:17:00,360 --> 00:17:02,640
These few sips won't last them long.

231
00:17:02,720 --> 00:17:05,240
[mysterious music playing]

232
00:17:05,320 --> 00:17:06,400
[Metsi whining]

233
00:17:07,280 --> 00:17:09,880
But if water
had stayed trapped in the Earth,

234
00:17:11,520 --> 00:17:13,240
there would be none to drink.

235
00:17:17,800 --> 00:17:19,680
There would be no elephants.

236
00:17:23,200 --> 00:17:25,280
No life at all.

237
00:17:27,920 --> 00:17:29,400
[whooshing]

238
00:17:31,600 --> 00:17:34,000
[mysterious music continues]

239
00:17:36,440 --> 00:17:37,720
[crashing, rumbling]

240
00:17:37,800 --> 00:17:41,160
After water
was delivered here by asteroids

241
00:17:41,240 --> 00:17:43,480
and consumed by the Earth…

242
00:17:45,640 --> 00:17:48,280
it was locked into the rock as crystals

243
00:17:50,200 --> 00:17:51,800
deep inside the planet.

244
00:17:51,880 --> 00:17:54,840
[tense music playing]

245
00:17:57,560 --> 00:18:00,160
It stayed buried for millions of years,

246
00:18:01,160 --> 00:18:04,360
beneath a vast sea of magma.

247
00:18:04,880 --> 00:18:07,280
[crackling]

248
00:18:11,880 --> 00:18:12,840
[sizzling]

249
00:18:12,920 --> 00:18:17,880
Until slowly but surely, Earth cooled.

250
00:18:21,360 --> 00:18:25,880
And its surface hardened to a thick crust.

251
00:18:26,480 --> 00:18:28,520
[whooshing]

252
00:18:29,680 --> 00:18:34,240
Then, finally,
the boiling interior broke through.

253
00:18:35,760 --> 00:18:37,600
[explosion rumbles]

254
00:18:41,440 --> 00:18:42,640
[thunder crashing]

255
00:18:43,720 --> 00:18:45,600
Enormous volcanoes

256
00:18:47,080 --> 00:18:50,880
blasted gas and vapor
kilometers into the sky.

257
00:18:53,280 --> 00:18:54,600
[exploding]

258
00:18:58,720 --> 00:19:01,520
At last, water molecules…

259
00:19:01,600 --> 00:19:02,920
[exploding]

260
00:19:03,000 --> 00:19:04,200
…were set free…

261
00:19:05,960 --> 00:19:07,080
[exploding]

262
00:19:11,080 --> 00:19:13,800
…and formed the first clouds.

263
00:19:13,880 --> 00:19:16,920
[energetic music playing]

264
00:19:18,480 --> 00:19:21,080
Growing and building
for millions of years,

265
00:19:21,600 --> 00:19:23,400
becoming laden with water…

266
00:19:24,040 --> 00:19:25,880
[wind howling]

267
00:19:25,960 --> 00:19:27,120
[thunder crashes]

268
00:19:28,320 --> 00:19:31,120
…until the temperature
dropped just enough…

269
00:19:31,640 --> 00:19:34,080
[thunder crashing]

270
00:19:38,920 --> 00:19:41,480
…for the very first raindrop…

271
00:19:41,560 --> 00:19:44,520
[ethereal tinkling]

272
00:19:46,920 --> 00:19:50,560
…to form and fall.

273
00:19:50,640 --> 00:19:53,400
[ethereal music playing]

274
00:19:57,320 --> 00:19:59,600
[sizzling]

275
00:20:00,200 --> 00:20:03,600
[raindrops pattering, sizzling]

276
00:20:03,680 --> 00:20:06,440
[dramatic music playing]

277
00:20:08,800 --> 00:20:11,000
What followed was a deluge…

278
00:20:16,240 --> 00:20:18,640
that lasted thousands of years.

279
00:20:30,040 --> 00:20:32,080
Puddles turned into rivers.

280
00:20:39,880 --> 00:20:41,440
[wind whistling]

281
00:20:41,520 --> 00:20:42,720
Lakes…

282
00:20:42,800 --> 00:20:44,320
[thunder rumbles]

283
00:20:44,400 --> 00:20:45,760
…became seas.

284
00:20:46,800 --> 00:20:49,240
[dramatic music continues]

285
00:20:53,480 --> 00:20:57,560
And great oceans flooded Earth's surface.

286
00:21:15,920 --> 00:21:20,120
And here, water gave rise
to something magical.

287
00:21:21,000 --> 00:21:22,680
-[gurgles]
-[ethereal tinkling]

288
00:21:25,320 --> 00:21:26,840
The first life.

289
00:21:28,600 --> 00:21:31,000
[ethereal tinkling continues]

290
00:21:31,080 --> 00:21:33,680
From these first cells

291
00:21:35,000 --> 00:21:38,040
sprang every living thing.

292
00:21:40,640 --> 00:21:43,960
Water is the fundamental ingredient

293
00:21:44,040 --> 00:21:48,000
of every cell of every creature on Earth.

294
00:21:48,080 --> 00:21:51,240
[dramatic music continues]

295
00:21:57,360 --> 00:21:58,440
And today…

296
00:22:01,320 --> 00:22:06,400
the herd still carries
this ancient water within them.

297
00:22:06,920 --> 00:22:07,800
[elephant snorts]

298
00:22:07,880 --> 00:22:10,200
[intriguing music playing]

299
00:22:12,080 --> 00:22:13,480
[elephant grumbles]

300
00:22:13,560 --> 00:22:16,480
[ethereal tinkling, whooshing]

301
00:22:18,040 --> 00:22:20,240
It transports nutrients and oxygen.

302
00:22:20,320 --> 00:22:22,680
[intriguing music continues]

303
00:22:22,760 --> 00:22:24,640
-[whooshing]
-[elephant trumpets]

304
00:22:24,720 --> 00:22:27,080
[grumbling]

305
00:22:27,640 --> 00:22:29,400
[whooshing]

306
00:22:30,200 --> 00:22:32,000
It powers every heartbeat.

307
00:22:32,080 --> 00:22:34,280
[heartbeat thumping]

308
00:22:35,240 --> 00:22:37,000
[elephant roars]

309
00:22:37,080 --> 00:22:38,840
[whooshing]

310
00:22:38,920 --> 00:22:41,160
And drives every breath.

311
00:22:41,240 --> 00:22:43,000
[breathing heavily]

312
00:22:46,640 --> 00:22:49,240
Life evolved because of water,

313
00:22:51,000 --> 00:22:54,960
which is why no life
can survive without it.

314
00:22:56,000 --> 00:22:58,280
[wind gusting]

315
00:22:58,360 --> 00:23:00,760
[solemn music playing]

316
00:23:01,920 --> 00:23:05,480
In Botswana,
the drought is only getting worse.

317
00:23:06,360 --> 00:23:08,080
[fire crackling]

318
00:23:11,080 --> 00:23:13,880
The elephants' world is on fire.

319
00:23:15,920 --> 00:23:17,160
[elephant grumbles]

320
00:23:19,400 --> 00:23:20,560
[trumpets]

321
00:23:22,600 --> 00:23:25,520
The herd manages
to escape the burning forest…

322
00:23:29,040 --> 00:23:31,320
but walks straight into a new threat.

323
00:23:31,400 --> 00:23:32,560
[elephant huffs]

324
00:23:34,240 --> 00:23:36,000
[lion growling]

325
00:23:37,560 --> 00:23:40,360
In this drought, everyone is suffering…

326
00:23:40,440 --> 00:23:41,720
[lion continues growling]

327
00:23:43,680 --> 00:23:46,160
…from thirst and hunger.

328
00:23:49,680 --> 00:23:52,520
[elephant grumbling]

329
00:23:52,600 --> 00:23:56,960
And for lions,
baby elephants would satisfy both.

330
00:24:00,000 --> 00:24:02,400
[ominous music playing]

331
00:24:04,320 --> 00:24:06,480
[Metsi trumpeting softly]

332
00:24:11,200 --> 00:24:12,640
[lion growls]

333
00:24:14,200 --> 00:24:17,320
The adults rally around Metsi and Bosigo.

334
00:24:23,360 --> 00:24:24,640
[lion growling]

335
00:24:24,720 --> 00:24:26,960
It's enough to keep the threat at bay.

336
00:24:27,040 --> 00:24:29,480
[growling continues]

337
00:24:30,680 --> 00:24:32,880
But lions are patient creatures.

338
00:24:36,880 --> 00:24:40,400
And the herd still has to cross
an unforgiving wasteland…

339
00:24:42,600 --> 00:24:44,280
before the next water hole.

340
00:24:45,680 --> 00:24:48,440
[wind gusting]

341
00:24:48,520 --> 00:24:50,680
They need a lifeline.

342
00:24:50,760 --> 00:24:52,840
[calm music playing]

343
00:24:53,760 --> 00:24:56,040
And the Earth provides it

344
00:24:57,720 --> 00:25:00,120
in the most unexpected of places.

345
00:25:03,840 --> 00:25:05,240
[birds chirping]

346
00:25:05,320 --> 00:25:08,000
The acacia tree is a beacon of hope.

347
00:25:13,880 --> 00:25:16,800
And a haven for creatures of all kinds.

348
00:25:18,320 --> 00:25:21,000
[calm music continues]

349
00:25:24,880 --> 00:25:28,320
Its long roots reach
much deeper underground

350
00:25:28,400 --> 00:25:30,400
than an elephant could ever dig…

351
00:25:30,480 --> 00:25:32,680
[crackling softly]

352
00:25:41,240 --> 00:25:43,360
…drawing water up to its branches…

353
00:25:47,360 --> 00:25:48,520
and leaves.

354
00:25:59,560 --> 00:26:00,920
[elephant trumpeting]

355
00:26:01,000 --> 00:26:04,480
It's just enough water to keep them going.

356
00:26:06,040 --> 00:26:08,200
[elephant grumbling]

357
00:26:08,280 --> 00:26:10,840
Especially vital for Metsi's mother,

358
00:26:12,720 --> 00:26:14,320
still nursing her baby.

359
00:26:18,320 --> 00:26:21,800
But this is so much more
than just a local oasis.

360
00:26:25,360 --> 00:26:28,480
It's the vital link
in water's eternal cycle.

361
00:26:28,560 --> 00:26:30,520
[elephant grumbling]

362
00:26:32,720 --> 00:26:36,800
The acacia tree connects ground and sky…

363
00:26:37,320 --> 00:26:39,520
[whooshing softly]

364
00:26:39,600 --> 00:26:41,320
[intriguing music playing]

365
00:26:43,600 --> 00:26:46,080
…breathing oxygen and vapor into the air.

366
00:26:48,560 --> 00:26:50,920
[whooshing softly]

367
00:26:53,480 --> 00:26:54,920
[thunder crashes]

368
00:26:55,000 --> 00:26:56,480
Feeding clouds

369
00:26:56,560 --> 00:26:59,320
and powering water's journey
around the planet.

370
00:26:59,400 --> 00:27:01,040
[wind gusting]

371
00:27:01,120 --> 00:27:03,480
[ethereal tinkling]

372
00:27:04,760 --> 00:27:06,480
[sizzling]

373
00:27:07,400 --> 00:27:08,880
Ever since rain

374
00:27:10,120 --> 00:27:12,400
fed the first green shoots…

375
00:27:16,320 --> 00:27:18,840
and gave life to the first tree…

376
00:27:21,800 --> 00:27:24,040
[birds chirping]

377
00:27:24,120 --> 00:27:27,720
…plants have made our planet habitable…

378
00:27:28,920 --> 00:27:31,200
[majestic music playing]

379
00:27:35,280 --> 00:27:37,680
…bringing a once barren ball of rock

380
00:27:39,440 --> 00:27:40,280
to life.

381
00:27:45,880 --> 00:27:48,760
But the gifts our universe bestows

382
00:27:50,320 --> 00:27:52,760
can also be taken away.

383
00:27:52,840 --> 00:27:55,400
[solemn music playing]

384
00:28:01,280 --> 00:28:02,760
A long time ago,

385
00:28:04,080 --> 00:28:05,680
there was another planet

386
00:28:06,680 --> 00:28:09,480
whose surface was covered in liquid water.

387
00:28:18,080 --> 00:28:20,600
A water world just like ours.

388
00:28:22,680 --> 00:28:25,040
[solemn music continues]

389
00:28:25,720 --> 00:28:28,440
The same forces
that delivered water to Earth

390
00:28:29,440 --> 00:28:32,000
also gave it to Mars.

391
00:28:35,200 --> 00:28:37,440
With an atmosphere in place,

392
00:28:37,520 --> 00:28:38,640
clouds formed,

393
00:28:40,480 --> 00:28:41,480
rain fell,

394
00:28:43,000 --> 00:28:44,440
rivers flowed.

395
00:28:45,000 --> 00:28:47,480
[calm music playing]

396
00:28:48,800 --> 00:28:52,160
And an ocean surged across its surface.

397
00:28:57,240 --> 00:28:59,520
It was a world of possibility.

398
00:29:00,040 --> 00:29:02,320
It had the potential for life.

399
00:29:06,600 --> 00:29:08,080
But it didn't last.

400
00:29:13,720 --> 00:29:19,080
Because not far away
was a raging nuclear inferno.

401
00:29:19,600 --> 00:29:20,960
[fire roaring]

402
00:29:21,040 --> 00:29:22,040
Our Sun.

403
00:29:24,120 --> 00:29:27,520
It unleashes torrents
of high-energy particles

404
00:29:27,600 --> 00:29:29,800
so powerful and deadly…

405
00:29:29,880 --> 00:29:32,400
[fire continues roaring]

406
00:29:32,480 --> 00:29:34,480
…they can devastate planets.

407
00:29:35,920 --> 00:29:38,400
[solemn music playing]

408
00:29:42,840 --> 00:29:43,880
[wind gusting]

409
00:29:43,960 --> 00:29:47,840
This solar wind streams through space…

410
00:29:52,320 --> 00:29:55,640
at 400 kilometers per second.

411
00:29:57,680 --> 00:29:58,880
[whooshing loudly]

412
00:30:00,480 --> 00:30:03,160
And it ripped through
the Martian atmosphere,

413
00:30:04,640 --> 00:30:06,800
tearing water molecules apart.

414
00:30:15,040 --> 00:30:16,520
Bit by bit,

415
00:30:16,600 --> 00:30:18,160
over millions of years,

416
00:30:19,600 --> 00:30:24,480
the planet's protective layer
was stripped away by the Sun's fury…

417
00:30:24,560 --> 00:30:26,680
[solemn music playing]

418
00:30:29,680 --> 00:30:31,640
…until its ocean evaporated…

419
00:30:37,640 --> 00:30:41,040
and its water was lost to space.

420
00:30:43,480 --> 00:30:46,000
[solemn music continues]

421
00:30:48,600 --> 00:30:52,400
Mars became a desolate, frozen shadow

422
00:30:52,920 --> 00:30:54,280
of its former self.

423
00:30:58,800 --> 00:31:00,480
[thunder crashes]

424
00:31:00,560 --> 00:31:02,680
[wind gusting]

425
00:31:03,360 --> 00:31:05,920
Consumed by dust storms.

426
00:31:12,520 --> 00:31:14,480
Any chance of complex life…

427
00:31:16,480 --> 00:31:18,280
gone forever.

428
00:31:19,480 --> 00:31:22,280
[wind continues gusting]

429
00:31:27,560 --> 00:31:29,640
This could have been our story too.

430
00:31:29,720 --> 00:31:32,080
[solemn music continues]

431
00:31:33,200 --> 00:31:35,680
[elephant grumbling]

432
00:31:37,080 --> 00:31:38,440
[trumpeting]

433
00:31:44,360 --> 00:31:46,640
But somehow, on Earth,

434
00:31:47,560 --> 00:31:51,280
water and life
have found a way to cling on.

435
00:31:51,360 --> 00:31:52,600
[elephant moaning]

436
00:32:06,320 --> 00:32:07,960
In Botswana,

437
00:32:08,040 --> 00:32:10,640
after 200 days in the burning sun…

438
00:32:11,160 --> 00:32:12,760
[wind gusting]

439
00:32:12,840 --> 00:32:15,000
…there is no water to be found.

440
00:32:19,000 --> 00:32:20,240
[solemn music continues]

441
00:32:20,320 --> 00:32:23,600
[elephants howling]

442
00:32:23,680 --> 00:32:26,040
Violent winds whip the scorched earth

443
00:32:26,120 --> 00:32:27,600
into a dust bowl.

444
00:32:33,160 --> 00:32:35,520
[wind continues gusting]

445
00:32:42,280 --> 00:32:43,280
[elephant huffs]

446
00:32:45,320 --> 00:32:49,440
And the elephants' struggle
hasn't gone unnoticed.

447
00:32:49,520 --> 00:32:52,200
[ominous music playing]

448
00:33:02,920 --> 00:33:06,800
In daylight,
adults can usually protect their young.

449
00:33:13,680 --> 00:33:15,720
[elephants moaning]

450
00:33:18,240 --> 00:33:19,800
But when night falls…

451
00:33:19,880 --> 00:33:21,080
[sniffing]

452
00:33:22,600 --> 00:33:25,400
[elephant grumbles, huffs]

453
00:33:25,480 --> 00:33:26,920
…it's a different story.

454
00:33:30,240 --> 00:33:33,560
[lion breathing heavily]

455
00:33:36,240 --> 00:33:37,440
[elephants trumpeting]

456
00:33:37,520 --> 00:33:40,400
Lions are masters of chaos and confusion.

457
00:33:41,160 --> 00:33:42,240
[elephant trumpeting]

458
00:33:44,560 --> 00:33:47,200
[elephant roaring]

459
00:33:47,280 --> 00:33:49,760
[trumpeting]

460
00:33:52,280 --> 00:33:53,360
[Bosigo squeals]

461
00:33:53,440 --> 00:33:55,880
They pick the most vulnerable target…

462
00:33:59,080 --> 00:34:00,720
[Bosigo trumpeting]

463
00:34:00,800 --> 00:34:02,120
…working as a pack…

464
00:34:02,200 --> 00:34:05,040
[Bosigo continues trumpeting]

465
00:34:08,200 --> 00:34:10,280
…until there's nowhere left to run.

466
00:34:10,360 --> 00:34:12,480
[Bosigo squealing]

467
00:34:13,880 --> 00:34:14,960
[moans]

468
00:34:16,480 --> 00:34:19,520
[lions growling]

469
00:34:27,240 --> 00:34:29,600
Without the entire herd as protection,

470
00:34:30,960 --> 00:34:34,080
the lions overwhelm their prey.

471
00:34:34,160 --> 00:34:36,800
[lions continue growling]

472
00:34:36,880 --> 00:34:40,600
The drought and endless search
for food and water

473
00:34:41,440 --> 00:34:44,880
have taken their ultimate toll on Bosigo.

474
00:34:47,480 --> 00:34:49,600
[somber music playing]

475
00:34:49,680 --> 00:34:50,680
[elephant cries out]

476
00:34:52,480 --> 00:34:53,680
[grumbles]

477
00:34:55,040 --> 00:34:58,240
Elephants form deep emotional bonds.

478
00:34:58,320 --> 00:35:00,040
[elephant grumbles, huffs]

479
00:35:09,920 --> 00:35:13,080
All the family mourn Bosigo's loss.

480
00:35:14,360 --> 00:35:16,640
[elephant moaning]

481
00:35:23,600 --> 00:35:25,680
[Metsi cries out]

482
00:35:25,760 --> 00:35:28,080
[somber music continues]

483
00:35:30,480 --> 00:35:32,840
The herd gathers to comfort Metsi,

484
00:35:34,680 --> 00:35:36,960
who feels it hardest of all.

485
00:35:48,480 --> 00:35:50,720
The never-ending fight to survive

486
00:35:50,800 --> 00:35:52,480
plays out every year,

487
00:35:54,280 --> 00:35:55,720
across the Okavango…

488
00:35:58,000 --> 00:35:59,280
across our planet…

489
00:36:01,960 --> 00:36:03,040
and beyond.

490
00:36:07,080 --> 00:36:09,560
But in this battle for survival,

491
00:36:10,440 --> 00:36:12,000
Earth got truly lucky…

492
00:36:14,000 --> 00:36:17,440
with a secret guardian that protects it.

493
00:36:17,520 --> 00:36:19,200
[whooshing]

494
00:36:24,360 --> 00:36:25,480
Deep within…

495
00:36:26,200 --> 00:36:27,440
[whooshing continues]

496
00:36:28,520 --> 00:36:32,280
…the planet's raging molten furnace burns

497
00:36:32,920 --> 00:36:33,920
and churns…

498
00:36:34,440 --> 00:36:36,600
[ethereal music playing]

499
00:36:37,840 --> 00:36:40,240
…generating a powerful magnetic field

500
00:36:41,920 --> 00:36:44,360
that extends from the heart of the planet…

501
00:36:44,440 --> 00:36:46,080
[ethereal humming]

502
00:36:46,160 --> 00:36:50,680
…65,000 kilometers out towards the Sun.

503
00:36:52,600 --> 00:36:55,880
A vital force field defending Earth…

504
00:36:56,400 --> 00:36:58,240
[fire hissing]

505
00:36:58,320 --> 00:37:01,040
…from the same savage solar winds

506
00:37:02,080 --> 00:37:04,040
that stripped water from Mars.

507
00:37:07,080 --> 00:37:09,160
[ethereal music continues]

508
00:37:10,480 --> 00:37:13,920
Defeating them
before they hit our atmosphere.

509
00:37:26,520 --> 00:37:28,760
Safeguarding our essential water.

510
00:37:30,520 --> 00:37:34,160
Hugging every drop close to our planet.

511
00:37:34,240 --> 00:37:36,760
[ethereal whooshing]

512
00:37:41,040 --> 00:37:43,960
This is what makes our pale blue dot

513
00:37:44,480 --> 00:37:46,160
unlike anywhere else.

514
00:37:49,520 --> 00:37:52,920
A place where life can thrive.

515
00:37:53,000 --> 00:37:55,480
[majestic music playing]

516
00:37:56,960 --> 00:37:59,080
Bringing relief to the elephants.

517
00:38:01,600 --> 00:38:04,880
Ensuring rains return each year
without fail.

518
00:38:05,400 --> 00:38:08,320
[thunder crashing]

519
00:38:09,680 --> 00:38:14,000
In the distance,
storm clouds are building.

520
00:38:14,080 --> 00:38:15,880
[Metsi grunts, moans]

521
00:38:21,680 --> 00:38:22,600
[moans]

522
00:38:26,600 --> 00:38:29,120
[elephant huffing]

523
00:38:29,200 --> 00:38:33,800
Elephants can detect
the low-frequency rumble of thunder

524
00:38:33,880 --> 00:38:36,480
from 240 kilometers away.

525
00:38:36,560 --> 00:38:37,480
[thunder rumbling]

526
00:38:37,560 --> 00:38:38,920
[elephant grumbles]

527
00:38:39,000 --> 00:38:40,120
[trumpets]

528
00:38:43,400 --> 00:38:47,880
And it's telling them it's time
to return to the Okavango.

529
00:38:48,440 --> 00:38:51,400
[ethereal music playing]

530
00:38:56,600 --> 00:38:58,440
From the highlands of Angola,

531
00:39:00,200 --> 00:39:03,080
water is weaving its way through Botswana…

532
00:39:09,280 --> 00:39:10,800
[whooshing]

533
00:39:12,000 --> 00:39:14,280
…to rejuvenate the delta…

534
00:39:22,640 --> 00:39:24,720
with the kiss of life.

535
00:39:28,960 --> 00:39:31,600
[dramatic music playing]

536
00:39:34,480 --> 00:39:37,480
Every step
that brings the herd closer to home…

537
00:39:40,760 --> 00:39:45,280
is a continuation
of a much larger cosmic odyssey.

538
00:39:51,640 --> 00:39:57,280
From tiny molecules hitching a ride
on dust beyond Jupiter…

539
00:40:03,000 --> 00:40:05,800
to surviving the crushing heat
of early Earth.

540
00:40:05,880 --> 00:40:07,560
[rumbling]

541
00:40:09,280 --> 00:40:12,280
[whooshing]

542
00:40:13,680 --> 00:40:16,160
Imprisoned in the planet's core…

543
00:40:16,240 --> 00:40:18,120
[dramatic music swells]

544
00:40:18,200 --> 00:40:19,880
…then set free…

545
00:40:19,960 --> 00:40:21,160
[thunder crashes]

546
00:40:21,240 --> 00:40:23,080
…to sow the seeds of life…

547
00:40:23,160 --> 00:40:25,440
[elephant moaning]

548
00:40:25,520 --> 00:40:27,280
-[exploding]
-[thunder crashes]

549
00:40:27,360 --> 00:40:31,880
…every drop of water
has an amazing tale to tell.

550
00:40:34,640 --> 00:40:36,000
Every molecule…

551
00:40:36,080 --> 00:40:39,120
-[water gurgling]
-…a link in an unbroken chain…

552
00:40:39,200 --> 00:40:40,360
[elephant trumpets]

553
00:40:40,440 --> 00:40:43,400
…cycling over tens of thousands of years…

554
00:40:43,480 --> 00:40:44,960
[dramatic music continues]

555
00:40:46,480 --> 00:40:47,800
…through air…

556
00:40:50,840 --> 00:40:51,800
oceans…

557
00:40:55,680 --> 00:40:56,560
rocks…

558
00:41:01,880 --> 00:41:03,440
[dramatic music crescendos]

559
00:41:04,800 --> 00:41:05,960
…and elephants.

560
00:41:06,560 --> 00:41:08,880
[pensive music playing]

561
00:41:11,680 --> 00:41:16,040
After eight months
and hundreds of kilometers,

562
00:41:17,720 --> 00:41:21,520
Metsi and her family have finally reached

563
00:41:21,600 --> 00:41:24,960
the life-giving waters of the delta.

564
00:41:25,040 --> 00:41:27,200
[majestic music playing]

565
00:41:33,280 --> 00:41:34,480
[elephant trumpeting]

566
00:41:38,040 --> 00:41:41,640
It's well past time to drink…

567
00:41:43,880 --> 00:41:45,080
and play.

568
00:41:46,400 --> 00:41:47,360
[elephant trumpets]

569
00:41:47,440 --> 00:41:50,160
And then, drink some more.

570
00:41:50,720 --> 00:41:52,200
[elephant grumbles]

571
00:41:55,240 --> 00:41:58,000
[elephants trumpeting]

572
00:41:59,560 --> 00:42:02,040
And show the newest member of the family…

573
00:42:02,120 --> 00:42:03,800
[elephants continue trumpeting]

574
00:42:06,360 --> 00:42:09,200
…how they do things in the delta.

575
00:42:11,080 --> 00:42:12,280
[elephant trumpets]

576
00:42:15,640 --> 00:42:18,080
[elephant grumbling]

577
00:42:19,480 --> 00:42:22,280
[calm music playing]

578
00:42:22,360 --> 00:42:25,360
Metsi and her new baby cousin

579
00:42:25,440 --> 00:42:28,240
are the latest in a long line

580
00:42:28,320 --> 00:42:31,560
to benefit from water's miraculous arrival

581
00:42:32,800 --> 00:42:33,720
on this planet.

582
00:42:33,800 --> 00:42:34,680
[calf whines]

583
00:42:37,720 --> 00:42:40,240
[calm music continues]

584
00:42:44,480 --> 00:42:46,440
They will forever be connected

585
00:42:46,520 --> 00:42:47,880
to the universe

586
00:42:48,800 --> 00:42:52,280
that gave our planet this magic ingredient

587
00:42:54,040 --> 00:42:59,920
and gave us the ability
to preserve and treasure it.

588
00:43:08,440 --> 00:43:10,760
[intense music playing]

589
00:43:10,840 --> 00:43:15,120
Next, the story of our universe concludes…

590
00:43:15,200 --> 00:43:16,200
[rumbling]

591
00:43:16,280 --> 00:43:22,160
…with the force that brings everything
we've seen so far together.

592
00:43:23,560 --> 00:43:26,320
The great sculptor of the cosmos,

593
00:43:26,960 --> 00:43:27,800
gravity.

594
00:43:29,160 --> 00:43:32,520
It's a force of attraction
that built our planet.

595
00:43:32,600 --> 00:43:33,960
[intense music crescendos]

596
00:43:34,560 --> 00:43:35,480
[penguin squawks]

597
00:43:35,560 --> 00:43:39,160
And we'll bring two penguins together
at Earth's southern pole.

598
00:43:39,240 --> 00:43:40,960
[majestic music playing]

599
00:43:41,040 --> 00:43:44,120
But when did gravity
start exerting its influence?

600
00:43:45,680 --> 00:43:50,080
How does it create both order and chaos?

601
00:43:52,920 --> 00:43:57,640
And why does it make ours
the perfect planet for life…

602
00:43:57,720 --> 00:43:59,840
[chick chirping]

603
00:43:59,920 --> 00:44:00,920
…and love?

604
00:44:01,800 --> 00:44:03,080
[penguin moaning]

605
00:44:06,280 --> 00:44:08,920
[dramatic music playing]