Would you like to inspect the original subtitles? These are the user uploaded subtitles that are being translated:
1
00:00:01,560 --> 00:00:04,800
Is the cost of spaceexploration really worthwhile?
2
00:00:05,360 --> 00:00:07,600
It's a question that crops up regularly.
3
00:00:08,120 --> 00:00:10,240
Could the money be better spent elsewhere?
4
00:00:10,800 --> 00:00:15,440
Even if it were, one space programwould still have to remain in place.
5
00:00:16,080 --> 00:00:18,240
That's the planetary defense program,
6
00:00:18,320 --> 00:00:23,280
to locate identify and deflectany wayward asteroid from hitting Earth,
7
00:00:23,360 --> 00:00:25,600
and destroying our civilization.
8
00:00:26,200 --> 00:00:30,680
At the last count, there were 15,000potentially dangerous candidates
9
00:00:30,760 --> 00:00:32,000
close to Earth.
10
00:00:32,080 --> 00:00:37,080
♪♪
11
00:01:21,880 --> 00:01:24,600
It's now over two yearssince the Rosetta mission
12
00:01:24,680 --> 00:01:27,720
reached it's target rendezvous, 67P.
13
00:01:48,080 --> 00:01:51,960
It's been an audacious mission,gaining unprecedented forensic knowledge
14
00:01:52,040 --> 00:01:56,280
of the comet’s surface, interiorstructure, composition and history.
15
00:02:07,720 --> 00:02:12,280
We’ve noticed
that there is not ice on the surface.
16
00:02:12,360 --> 00:02:16,080
We would be able to see that...
at least not large patches of ice.
17
00:02:16,160 --> 00:02:19,280
You don’t have skating rinks
on this comet.
18
00:02:20,080 --> 00:02:23,440
Uh, and we also see gas in the coma.
19
00:02:23,520 --> 00:02:28,120
We see evidence of
carbon monoxide and carbon dioxide
20
00:02:28,200 --> 00:02:32,160
and the elements themselves,
carbon and oxygen,
21
00:02:32,720 --> 00:02:34,520
in different parts of the coma.
22
00:02:36,960 --> 00:02:39,720
And we discovered that this carbon
23
00:02:39,800 --> 00:02:44,360
was actually a very complex material,
very complex carbon,
24
00:02:44,440 --> 00:02:48,800
very different from the simple molecules
that we would expect to find there,
25
00:02:48,880 --> 00:02:51,360
so we don’t see amino acids or alcohol or this kind of molecules
which is observed in the gas.
26
00:02:54,000 --> 00:02:56,600
But we see something much more complex,
27
00:02:56,680 --> 00:03:01,440
and very rich in carbon
and poor in nitrogen or hydrogen
28
00:03:01,520 --> 00:03:04,200
compared to these other materials.
29
00:03:06,560 --> 00:03:08,880
In particular what we have observed
30
00:03:08,960 --> 00:03:12,080
is that the nucleus is composed of
a mixture of materials, like minerals,
like silicates and sulfides
31
00:03:16,000 --> 00:03:21,600
which have been formed in the inner part
of the solar system, close to the sun.
32
00:03:21,680 --> 00:03:24,960
Because the comet is kept
in a very cold environment,
33
00:03:25,040 --> 00:03:27,840
we don’t expect it
to have very high temperature phases
34
00:03:27,920 --> 00:03:32,080
so it can be that this material
was formed closer to the sun,
35
00:03:32,160 --> 00:03:34,760
and was then was brought
to the comet later.
36
00:03:34,840 --> 00:03:37,800
And this for us was a surprise
because we knew it for the minerals
37
00:03:37,880 --> 00:03:39,200
but not so much for the organics.
38
00:03:39,280 --> 00:03:43,240
So it seems that the organics
also can be transported
39
00:03:43,320 --> 00:03:45,440
over large distances in the solar system.
40
00:03:48,880 --> 00:03:52,320
The most prominent,
the most exciting change on the surface,
41
00:03:52,400 --> 00:03:57,760
I believe it is still the big drop in the
Imhotep plateau which was three meters
42
00:03:57,840 --> 00:04:02,040
and 100 meters in height
and 100 meters in radius.
43
00:04:02,600 --> 00:04:04,320
But we have seen smaller scale features
44
00:04:04,400 --> 00:04:10,480
like a boulder which was
at least 50 meters big, ten tons heavy
45
00:04:10,560 --> 00:04:13,640
which, well on the comet it’s just
a chocolate bar of 100 grams or so,
46
00:04:13,720 --> 00:04:17,920
but still it’s a massive thing
which has moved by 140 meters,
47
00:04:19,840 --> 00:04:22,520
likely due to activity
but we don’t know the real reason.
48
00:04:24,680 --> 00:04:26,960
It was time to decidewhat to do with Rosetta
49
00:04:27,040 --> 00:04:28,480
now its mission was complete.
50
00:04:29,000 --> 00:04:31,960
One option was to land it on the comet.
51
00:04:33,360 --> 00:04:34,360
There were discussions
52
00:04:34,440 --> 00:04:37,840
about what would be the priority
for the end of mission.
53
00:04:38,360 --> 00:04:40,600
So there were several scenarios
put together
54
00:04:40,680 --> 00:04:45,320
and one of the options was to do
those very close flyovers
55
00:04:45,400 --> 00:04:49,160
and, I mean, in terms of
the science objectives,
56
00:04:49,240 --> 00:04:54,000
that was the one that will bring us
the more interesting scientific results.
57
00:04:54,080 --> 00:04:57,720
So it was decided by the science
working team to go for this scenario.
58
00:04:57,800 --> 00:05:02,360
So, yes, that's a very, uh first...
again, another first of Rosetta.
59
00:05:04,000 --> 00:05:07,160
Rosetta's trajectorywas altered to spiral into the comet,
60
00:05:07,240 --> 00:05:09,240
taking photos as it closed in.
61
00:05:13,880 --> 00:05:15,560
Rosetta's blown it all open.
62
00:05:15,640 --> 00:05:19,120
It's made us have to change our ideas of
what comets are, where they came from
63
00:05:19,200 --> 00:05:22,400
and the implications
of how the solar system formed
64
00:05:22,480 --> 00:05:24,200
and how we got to where we are today.
65
00:05:24,680 --> 00:05:28,120
and we've only, like Philae,
just scratched the surface
66
00:05:28,200 --> 00:05:31,800
And it's important to note Rosetta mission
is both the lander and the orbiter.
67
00:05:31,880 --> 00:05:34,560
Together they have made it possible
to do the science,
68
00:05:34,640 --> 00:05:36,200
to make the breakthroughs that we have,
69
00:05:36,280 --> 00:05:38,440
and we have only just scratched
the surface.
70
00:05:39,400 --> 00:05:41,400
We have decades of work to do
on this data,
71
00:05:41,480 --> 00:05:44,200
so the spacecraft may end
but the science will continue.
72
00:05:44,280 --> 00:05:46,560
That's what we're here for.
That's what this mission is for.
73
00:05:47,120 --> 00:05:51,320
We just havehad a loss of signal at the expected time,
74
00:05:51,400 --> 00:05:54,680
which is another outstandingperformance from flight dynamics.
75
00:05:55,320 --> 00:05:59,080
So we'll be listening for the signalfrom Rosetta for another 24 hours,
76
00:05:59,160 --> 00:06:00,600
but we don't expect any.
77
00:06:02,800 --> 00:06:06,880
And so, this is the end of the Rosettamission. Thank you and goodbye.
78
00:06:21,040 --> 00:06:24,240
One major problemfaced by Rosetta and it's Philae lander
79
00:06:24,320 --> 00:06:26,000
was the low gravity.
80
00:06:26,080 --> 00:06:28,960
When the lander's harpoonsfailed to secure it to the comet,
81
00:06:29,040 --> 00:06:33,000
it tumbled and bounceduntil it was lost in the rugged terrain.
82
00:06:33,520 --> 00:06:35,440
But engineers love a challenge,
83
00:06:35,520 --> 00:06:38,840
and they have already come up witha novel answer for next time...
84
00:06:38,920 --> 00:06:41,000
It's called the Hedgehog.
85
00:06:41,800 --> 00:06:43,280
So we said together
JPL and Stanford
86
00:06:43,360 --> 00:06:45,960
have been working
on a totally different rover concept
87
00:06:46,040 --> 00:06:48,880
that is well suited to these environments,
called Hedgehog.
88
00:06:48,960 --> 00:06:50,680
Instead of rolling around on wheels,
89
00:06:50,760 --> 00:06:55,040
the Hedgehog design actually puts
three flywheels on the inside of a cube.
90
00:06:55,120 --> 00:06:59,200
By spinning these flywheels up very slowly
and then very quickly applying a brake,
91
00:06:59,280 --> 00:07:01,680
which transfers all the momentum
from the flywheels,
92
00:07:01,760 --> 00:07:05,680
we're able to cause Hedgehog
to either hop, or tumble,
93
00:07:06,400 --> 00:07:08,240
or perform small adjustments.
94
00:07:08,320 --> 00:07:12,600
We've done many tests here on Earth
in gravity off-loading test beds.
95
00:07:12,680 --> 00:07:16,720
Recently we have flown two
Hedgehog prototypes on a zero-G aircraft.
96
00:07:16,800 --> 00:07:18,760
In these tests, we demonstrated
97
00:07:18,840 --> 00:07:21,320
that we would be able to perform
on a comet or an asteroid.
98
00:07:22,000 --> 00:07:23,600
Hedgehog doesn't have a right way up.
99
00:07:23,680 --> 00:07:27,720
Instead, it can tumble over the surface
and come to rest on any one of its faces
100
00:07:27,800 --> 00:07:29,000
and still work perfectly.
101
00:07:31,520 --> 00:07:34,680
JAXA's sample missionfrom asteroid Itokawa
102
00:07:34,760 --> 00:07:37,440
from the last decadereturned mixed results.
103
00:07:38,160 --> 00:07:41,200
It did, however, teach engineersand designers many lessons
104
00:07:41,280 --> 00:07:45,000
about the difficultiesof collecting samples from asteroids.
105
00:07:45,840 --> 00:07:48,160
Their second attemptis currently underway.
106
00:07:48,720 --> 00:07:52,680
Hayabusa 2 is coastingtowards another asteroid, Ryugu,
107
00:07:52,760 --> 00:07:55,880
and should reach its destinationin the middle of next year.
108
00:08:17,400 --> 00:08:21,480
This new and improved robothas several new capabilities built in.
109
00:08:22,000 --> 00:08:26,000
They include ion engines,navigation and attitude control systems
110
00:08:26,080 --> 00:08:29,200
and an explosive deviceto dig into the asteroid
111
00:08:29,280 --> 00:08:31,560
and return material from within it.
112
00:09:19,600 --> 00:09:23,000
Also on board are a probeand three miniature rovers.A secondary probe launched with Hayabusacalled Procyon
113
00:09:27,280 --> 00:09:30,920
had an engine malfunctionand will not complete its mission.
114
00:09:40,240 --> 00:09:44,160
NASA's attempt at an asteroidsample return is also underway.
115
00:09:44,640 --> 00:09:47,880
OSIRIS-REx was launched fromCape Canaveral Air Force Station's
116
00:09:47,960 --> 00:09:50,200
Space Launch Complex 41,
117
00:09:50,280 --> 00:09:53,840
and is on it's way to interceptthe near-Earth object Bennu.
118
00:09:57,880 --> 00:09:59,720
...2, 1...
119
00:10:02,160 --> 00:10:04,800
...and liftoff of OSIRIS REx.
120
00:10:05,360 --> 00:10:11,720
It's seven year mission... to boldly go
to the asteroid Bennu and back.
121
00:10:24,960 --> 00:10:29,320
Bennu is a B-type asteroidof approximately 500 meters diameter.
122
00:10:29,720 --> 00:10:33,360
It completes an orbit around the sunevery 1.2 years,
123
00:10:33,440 --> 00:10:36,520
and every six yearsit comes very close to Earth.
124
00:10:37,320 --> 00:10:40,720
These close encounters meanthere is a high probability
125
00:10:40,800 --> 00:10:44,720
of Bennu's impacting Earthin the late 22nd century.
126
00:10:45,440 --> 00:10:49,840
Bennu’s size, primitive composition,and potentially hazardous orbit
127
00:10:49,920 --> 00:10:53,440
make it the idealOSIRIS-REx target asteroid.
128
00:10:54,000 --> 00:10:58,560
It will first survey the asteroidto find an ideal touchdown site.
129
00:11:08,160 --> 00:11:10,080
Understanding the shape of asteroid Bennu
130
00:11:10,160 --> 00:11:14,320
is going to be absolutely fundamental
to understanding the geology
131
00:11:14,400 --> 00:11:16,240
and putting it in context.
132
00:11:16,320 --> 00:11:19,840
The other reason you really need to
understand the typography extremely well
133
00:11:19,920 --> 00:11:21,720
is that when we're going in
to take a sample,
134
00:11:21,800 --> 00:11:23,800
it's a very, very fine measurement.
135
00:11:23,880 --> 00:11:27,360
And so if you're coming in, you've got
the sampling head at the end of this arm
136
00:11:27,440 --> 00:11:30,080
that has to come in
perfectly square to the surface.
137
00:11:30,160 --> 00:11:34,400
If you don't understand shape,
sort of at a 30 centimeter scale,
138
00:11:34,480 --> 00:11:36,560
you're not going to be able
to collect a sample.
139
00:11:36,640 --> 00:11:41,120
♪♪
140
00:12:04,720 --> 00:12:08,520
The seven year mission will see ORISIS RExtouch down for only a moment
141
00:12:08,600 --> 00:12:11,360
to retrieve a surface sampleof the asteroid,
142
00:12:11,440 --> 00:12:14,720
then return to Earthto deposit the sample return capsule
143
00:12:14,800 --> 00:12:17,800
somewhere in Utah in 2023.
144
00:12:19,240 --> 00:12:23,880
♪♪
145
00:13:07,440 --> 00:13:13,120
NEOWISE has been a reliable workhorse,operating long past its planned lifetime,
146
00:13:13,200 --> 00:13:16,040
but its mission willeventually come to an end.
147
00:13:23,240 --> 00:13:26,920
Engineers estimate it will moveinto too much sunlight to function.
148
00:13:27,480 --> 00:13:32,680
However, the team is eyeing a new spacetelescope, one with a little more muscle.
149
00:13:33,320 --> 00:13:36,280
The near-Earth Object Camera, NEOCam,
150
00:13:36,280 --> 00:13:39,440
is specifically designedto hunt asteroids.
151
00:13:39,520 --> 00:13:42,880
the proposal has been fundedfor further study by NASA.
152
00:13:45,240 --> 00:13:49,480
♪♪
153
00:13:53,440 --> 00:13:57,640
Undergoing preliminary workis the Asteroid Impact Mission, AIM,
154
00:13:57,720 --> 00:14:00,400
who's launch could come as soon as 2020.
155
00:14:03,520 --> 00:14:09,840
A joint NASA ESA project would see ESAlaunch AIM to a binary asteroid, Didymos,
156
00:14:09,920 --> 00:14:11,880
and its satellite, Didymoon.
157
00:14:12,400 --> 00:14:14,480
They were discovered over twenty years ago
158
00:14:14,560 --> 00:14:17,840
and are part of a group of asteroidscalled the Apollo group,
159
00:14:17,920 --> 00:14:22,400
near-Earth objects that cross Earth'sorbit and are a potential threat.
160
00:14:24,680 --> 00:14:28,200
ESA's part of the missionis to orbit and study the asteroids,
161
00:14:28,280 --> 00:14:30,880
in particular, their orbitsaround each other.
162
00:14:32,560 --> 00:14:37,160
AIM will rendezvous
with asteroid Didymos in June 2022.
163
00:14:37,240 --> 00:14:40,040
The first thing it will do
is to take high resolution images
164
00:14:40,120 --> 00:14:43,080
so that we can reconstruct
a 3D shape of the moon,
165
00:14:43,560 --> 00:14:48,960
and then we will use this data to test
a new optical communications system
166
00:14:49,040 --> 00:14:53,680
with a laser transmitting these images
down to Earth in a very quick way.
167
00:14:54,560 --> 00:14:57,680
After we do these measurements
and we have the 3D model, we will sound the interior structure
of the asteroid
168
00:15:00,960 --> 00:15:03,960
by deploying a small micro lander
on its surface
169
00:15:04,040 --> 00:15:06,120
that will emit small radio waves
170
00:15:06,200 --> 00:15:09,640
that will cached by AIM
and reconstruct the interior structure.
171
00:15:16,320 --> 00:15:18,560
After we have done these measurements,
172
00:15:18,640 --> 00:15:22,640
the spacecraft will move away
about 100 kilometers from the system,
173
00:15:23,320 --> 00:15:26,040
waiting for DART to arrive
and impact the moon.
174
00:15:29,000 --> 00:15:30,560
NASA's contribution DART
175
00:15:30,640 --> 00:15:34,600
is a kinetic impactor traveling atsix kilometers per second.
176
00:15:41,920 --> 00:15:43,560
Once the impact has occurred,
177
00:15:43,640 --> 00:15:47,280
then we will look at the ejecta
and the dynamics of the ejecta cloud,
178
00:15:47,360 --> 00:15:51,880
we'll come closer to the moon
and repeat the same sets of measurements
179
00:15:51,960 --> 00:15:54,920
so that we can understand the changes
in the interior structure,
180
00:15:55,000 --> 00:15:59,520
and the shape and the morphology
of the crater before and after the impact.
181
00:16:00,640 --> 00:16:06,160
AIM is the first mission to test
the kinetic impact deflection technique.
182
00:16:06,240 --> 00:16:11,240
It's the first mission that will prove
deep space optical communication systems,
183
00:16:11,320 --> 00:16:14,920
and it's the first mission to deploy
CubeSats into space
184
00:16:15,000 --> 00:16:19,480
and test inter-satellite
communication systems.
185
00:16:19,560 --> 00:16:22,920
Also, it will be the first mission
to rendezvous with a binary asteroid
186
00:16:23,000 --> 00:16:27,280
and characterize it so that we can
understand how these bodies are formed,
187
00:16:27,360 --> 00:16:31,160
which is highly linked
to the way the solar system was formed.
188
00:16:33,360 --> 00:16:35,560
By measuring Didymoon’sphysical properties
189
00:16:35,640 --> 00:16:39,040
and its orbitbefore and after DART's impact,
190
00:16:39,120 --> 00:16:43,120
scientists will gain valuable knowledgethat can be applied to a real threat,
191
00:16:43,200 --> 00:16:44,640
should it ever occur.
192
00:16:47,680 --> 00:16:52,280
♪♪
193
00:16:52,360 --> 00:16:54,560
NASA is proceeding with long-term goals
194
00:16:54,640 --> 00:16:57,560
such as a mannedsample return from an asteroid.
195
00:16:58,280 --> 00:17:02,200
A robotic spacecraft would locateand capture a small asteroid,
196
00:17:02,280 --> 00:17:04,480
and redirect it into a lunar orbit.
197
00:17:05,000 --> 00:17:07,600
An Orion capsulewould then rendezvous with it.
198
00:17:07,680 --> 00:17:12,600
Astronauts are now training and developingtechniques for such a complex mission.
199
00:17:12,680 --> 00:17:17,200
♪♪
200
00:19:14,040 --> 00:19:17,640
♪♪
201
00:19:22,960 --> 00:19:24,960
There are still many things to be learned
202
00:19:25,040 --> 00:19:28,000
about asteroidsand the dangers they might pose.
203
00:19:41,040 --> 00:19:45,720
As this animation shows, the innersolar system is awash with asteroids.
204
00:19:46,320 --> 00:19:48,400
Many of them are near Earth's orbit.
205
00:19:48,480 --> 00:19:51,320
Some even cross our pathfrom time to time.
206
00:19:51,960 --> 00:19:55,000
All these possible hazardsneed to be identified,
207
00:19:55,080 --> 00:19:59,560
their orbits must be calculated to a highdegree, and their threat assessed.
208
00:20:00,120 --> 00:20:04,800
Finally, we need to develop the technologyto mitigate any danger to our planet.
209
00:20:04,880 --> 00:20:09,480
♪♪
210
00:20:14,680 --> 00:20:18,080
There are several groups of asteroidsbased on where they orbit.
211
00:20:18,600 --> 00:20:22,120
Those within Earth's orbitare Atens and Amors,
212
00:20:22,200 --> 00:20:24,640
while the Apollos cross Earth's orbit.
213
00:20:27,520 --> 00:20:33,680
♪♪
214
00:20:35,000 --> 00:20:38,280
The majority of asteroids residein the main asteroid belt
215
00:20:38,360 --> 00:20:39,960
between Mars and Jupiter.
216
00:20:40,440 --> 00:20:44,680
then there are the Trojans, trappedwithin Jupiter's gravitational pull.
217
00:20:44,760 --> 00:20:48,120
And beyond that, other remnantsof the solar system's formation
218
00:20:48,200 --> 00:20:50,880
can be foundcaught in the orbit of Uranus.
219
00:20:51,680 --> 00:20:54,680
There is a great deal moreto be learned and understood
220
00:20:54,760 --> 00:20:57,080
about these other asteroids.
221
00:21:04,000 --> 00:21:07,440
To this end, two new asteroid missionshave been planned and funded
222
00:21:07,520 --> 00:21:09,320
through the development stage.
223
00:21:09,400 --> 00:21:12,560
They will studytwo very different types of asteroid.
224
00:21:13,240 --> 00:21:17,200
♪♪
225
00:21:24,080 --> 00:21:25,960
The first of those missions is Lucy,
226
00:21:26,040 --> 00:21:31,200
which will visit a target-rich environmentof Jupiter’s mysterious Trojan asteroids.
227
00:21:31,760 --> 00:21:34,400
The mission will launch in October 2021,
228
00:21:34,480 --> 00:21:39,120
and fly by its targetsbetween 2025 and 2033.
229
00:21:47,400 --> 00:21:52,400
In all, Lucy will study six Trojansand one main belt asteroid.
230
00:21:56,760 --> 00:21:59,200
Trojans are fossils of planet formation,
231
00:21:59,280 --> 00:22:04,120
and so will supply important clues to theearliest history of the solar system.
232
00:22:05,480 --> 00:22:08,920
♪♪
233
00:22:14,640 --> 00:22:16,560
The second is Psyche.
234
00:22:16,640 --> 00:22:19,200
This mission will exploreone of the most intriguing targets
235
00:22:19,280 --> 00:22:21,000
in the main asteroid belt:
236
00:22:21,080 --> 00:22:25,080
a giant metal asteroid,
known as 16 Psyche.
237
00:22:25,160 --> 00:22:30,360
♪♪
238
00:22:39,040 --> 00:22:42,200
About three times fartheraway from the sun than the Earth is,
239
00:22:42,280 --> 00:22:46,320
this asteroid measuresabout 210 kilometers in diameter,
240
00:22:46,400 --> 00:22:50,600
and, unlike most other asteroidswhich are rocky or icy bodies,
241
00:22:50,680 --> 00:22:53,760
is thought to comprise mostlymetallic iron and nickel,
242
00:22:53,840 --> 00:22:55,840
similar to Earth’s core.
243
00:23:04,160 --> 00:23:07,720
Psyche could possibly bethe exposed core of an early planet,
244
00:23:07,800 --> 00:23:13,040
which lost its rocky outer layers inviolent collisions billions of years ago.
245
00:23:13,840 --> 00:23:17,480
The mission will help scientistsunderstand how planets and other bodies
246
00:23:17,560 --> 00:23:20,160
separated into their various layers...
247
00:23:20,240 --> 00:23:22,680
cores, mantles and crusts.
248
00:23:23,360 --> 00:23:27,720
Psyche will map features, structure,composition, and magnetic field,
249
00:23:27,800 --> 00:23:31,920
and examine a landscapeunlike anything explored before.
24387
Can't find what you're looking for?
Get subtitles in any language from opensubtitles.com, and translate them here.