Hace décadas, no conocíamos ningún planeta más allá de nuestro sistema solar. No teníamos la tecnología para detectarlos. Al mismo tiempo que prosigue la exploración del sistema solar, ha comenzado la búsqueda de mundos que se encuentran más allá
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00:00In this precise moment, on a planet far, far away,
00:29in a galaxy far, far away,
00:35in a galaxy far, far away,
00:41in a galaxy far, far away,
00:48the dawn gives rise to a new day.
00:52In a galaxy far, far away,
00:59in a galaxy far, far away,
01:05But will there be extraterrestrial eyes that can enjoy it?
01:09In a galaxy far, far away,
01:16in a galaxy far, far away,
01:22Or will it go unnoticed?
01:29Maybe it's like any other lost moment in an immense and sterile universe.
01:42We keep looking for the answer.
01:54Magnificent desolation.
01:56A wonderful view.
01:58System ready.
02:12The Milky Way.
02:26Hundreds of thousands of millions of stars.
02:29Distributed in a space of thousands of light years.
02:40Among them, the Sun.
02:49With eight planets orbiting around it.
02:56Among them, our home.
03:00Until recently, they were the only known worlds,
03:05the only planets we could explore to find signs of life outside the Earth.
03:11When I first started in astronomy, in the 1970s,
03:25we didn't know any planets beyond our solar system.
03:28We didn't have the technology to detect them, even if they did exist.
03:32Our neighborhood was the only place we could look for life.
03:38So we began our search in our closest neighborhood.
03:50In recent decades, we have launched several missions to explore the planets of our solar system.
04:02Also to some of its moons.
04:07But until now, although we continue to search,
04:10we have not found any signs of life in any of those worlds.
04:25The Earth remains something unique.
04:29The Earth remains something unique.
04:37The only planet with life in the solar system.
04:50As we continue to explore the solar system,
04:54the search for worlds beyond our domain has begun.
05:03The wonderful thing about astronomy is that as we develop better technologies
05:08and accumulate more and more knowledge about our universe,
05:12we turn more and more into worlds.
05:18For example, we've known for a long time that Mars is a planet.
05:24But tonight, beyond Mars, we see a constellation called Pegasus.
05:31This is the square of Pegasus.
05:34And we know that around there is a star called 51 Pegasi,
05:39which has a planet orbiting around it,
05:43a gas giant the size of Jupiter,
05:46which revolves every four days around that faint point of light.
05:51It is wonderful to think that throughout my adult life,
05:56in the last 25 years,
05:58we've gone from a universe in which there were no planets outside our solar system
06:04to a universe that we know is full of places where we can search for life.
06:21In the last three decades,
06:23some of the Earth's most powerful telescopes have joined the search.
06:34To the hunt for unimaginably distant planets.
06:41Hidden in the dark.
06:45Planets like 51 Pegasi b.
06:55The first world outside our solar system,
06:58detected in orbit around a star similar to the Sun.
07:1451 Pegasi b. is a gaseous giant.
07:18It is half the mass of Jupiter.
07:23But it is closer to its star.
07:30Let's imagine what that planet would be like.
07:34A world in which titanic winds scratch the sky.
07:46And inside it, a rain of sapphires is cooking.
07:5751 Pegasi b. is a giant.
08:0251 Pegasi b. is a very strange world in every way.
08:10And we will soon discover that the galaxy is full of planets
08:14that are nothing like what we have seen in our solar system.
08:26Planets enveloped by intense radiation.
08:32Planets with maltreated surfaces
08:35and swept away by the stroboscopic light of high energy
08:38that irradiates their star.
08:46Or worlds so cold that their atmosphere has frozen.
09:0251 Pegasi b. is a giant.
09:14Or large, swollen planets.
09:21With the density of polystyrene foam.
09:26And unfathomable atmospheres.
09:35These discoveries prove that, in a way, we are not alone.
09:42There are other worlds waiting to be explored.
09:56We calculate that in the Milky Way there are more planets than stars.
10:02Hundreds of thousands of millions.
10:07That means hundreds of thousands of millions of places to seek life.
10:14But there is a complication.
10:16Not all those worlds are like this one.
10:19Not much less.
10:26The first planets we found seemed too strange, too large.
10:30And often they were too close to their stars
10:33for the survival of living beings.
10:45If we wanted to find worlds in which we could explore,
10:49we would have to go to the Milky Way.
10:52If we wanted to find worlds in which life could exist,
10:56we would have to look for smaller rocky planets
10:59and in orbits farther from their stars.
11:07We needed to look for another Earth.
11:10Four. Three. Two.
11:13Ignition. One. Zero.
11:16And takeoff of the Delta II rocket with the Kepler telescope
11:20in search of planets similar to ours.
11:25The tracking was transferred to space
11:27when NASA launched the Kepler space telescope.
11:33Separation completed.
11:36In search of planets similar to Earth
11:39in the vastness of the galaxy.
11:51Kepler traveled 150 million kilometers in space
11:59until it settled in a stable orbit around the Sun.
12:06Kepler's orbit around the Sun
12:14From there it had a fixed and clear view
12:22of a very precise area of the firmament
12:25in the constellation of the swan.
12:36And it exposed its extremely sensitive photometer
12:46to the light of 150,000 stars.
12:57And it began to look for distant worlds similar to Earth.
13:05Kepler's orbit around the Sun
13:24Kepler doesn't detect planets directly.
13:27They are far too small.
13:29They are too small,
13:32and they don't emit light of their own.
13:35They only glow very faintly
13:37reflecting the ambient light of their stars.
13:43So Kepler has to detect planets indirectly.
13:46Imagine that a moth just flew across the light of the lighthouse.
13:53Now, I wouldn't see the moth,
13:55but if I had such a very sensitive detector
13:58and everything was well aligned,
14:00I would see that the intensity of the light dims.
14:04And that's how Kepler detects planets.
14:07If an alien astronomer in a distant solar system
14:10looked at our Sun with the correct alignment,
14:13he would see the trace of the Earth
14:16crossing in front of our star.
14:19He would see that the light of the Sun dims by one hundredth.
14:23It's very little, but it's enough.
14:26And if they saw that dimming was regular,
14:29and it's all done once every year,
14:32then they would infer that there is a planet
14:35orbiting around the star.
14:57Kepler's photometer is extraordinarily sensitive.
15:04But it only sees a regular darkening of pixels.
15:12Even if it's very little data.
15:19Astronomers have begun to build an image of those worlds
15:23that dim the light of the stars.
15:34Worlds that could somehow look like the monster.
15:47Worlds like Kepler-36b.
15:54This planet was one of the first discoveries of the Kepler telescope.
16:08It orbits around a star similar to ours,
16:11so at first glance it's a world that would be familiar to us.
16:16Its mass is four times the mass of the Earth.
16:20And it was one of the first of a new kind of planet.
16:25A super-Earth.
16:46Kepler's data not only allows us to say
16:49that there is a planet around that star,
16:52it also allows us to capture some of its characteristics.
16:55So by looking at the size, weight, light, phase,
16:58and the rise and fall of the light,
17:01and the time at which it dims,
17:04we can measure the orbit of the planets.
17:07And if there are multiple planets in the system,
17:10we can even estimate their masses.
17:13So astronomers can get an idea of the worlds they discover.
17:30But the more detailed our information about the Kepler-36b planet was,
17:34the less this super-Earth looked like our planet.
17:43Kepler-36b
17:48It orbits very close to its star,
17:51going around every 14 days.
18:01And it has company.
18:07A gaseous giant,
18:11that keeps an orbit exceptionally close to its own.
18:17The proximity of its mother star and its brother planet
18:21allows us to imagine the strange conditions
18:24that could be found on the surface of Kepler-36b.
18:29Kepler-36b
18:39It is possible that the planet has a synchronous rotation,
18:43so that an hemisphere would always be oriented towards the star.
18:53The scorching heat of this hemisphere
18:56would melt the ground,
19:03creating lava rivers that would cross the surface.
19:18The planet could experience violent eruptions
19:21when the gravitational pull of the gaseous giant
19:24triggers an extreme volcanism,
19:34every time it passes by.
19:54Kepler-36b
20:02But Kepler-36b could also be an ice planet.
20:16Due to the synchronous rotation,
20:19the other side would be permanently behind the star.
20:25This leads us to imagine an ice hemisphere
20:28enveloped in an eternal darkness.
20:46For now, it's all speculation.
20:50But at least we have begun to create an image of these worlds.
20:54We imagine a world in which the sun
20:57is always placed at the same point in the sky.
21:00One side of the planet would be submerged in an eternal night,
21:04and the other would live an eternal day.
21:07In fact, the twilight strip between day and night
21:11would also suffer from extreme conditions.
21:20So, Kepler-36b demonstrates that the composition of a planet
21:24is not enough for it to be habitable.
21:27You have to take into account the details of its orbit,
21:31and the nature of the other objects in the solar system
21:35that it orbits around its star.
21:49Kepler-36b
21:58Kepler-36b is just one of the thousands of planets
22:02that the Kepler telescope has discovered.
22:11We know without a doubt that in our galaxy
22:14there is a very varied collection of extrasolar worlds.
22:19Kepler-36b
22:25Each one of the more than 4,000 planets discovered so far
22:29is different from all the others.
22:32They all seem strange and exotic to us.
22:35There is certainly no planet that is identical
22:38to the planets in our solar system.
22:41This shows us a deep truth about the universe.
22:45The laws of nature that have formed the planets
22:48are simple and identical everywhere.
22:51And the fundamental ingredients of which the planets are made
22:55are also simple and identical everywhere.
22:58But the nature of a planet also depends on the history of its formation
23:02and the environment that surrounds the mother star from which it was formed.
23:07And those are all totally and absolutely different.
23:12Each planet tells us a different story.
23:15In a way, they are similar to human beings.
23:18And this wholly unexpected and exciting discovery
23:22certainly complicates the search for life.
23:32We need to limit the search for planets
23:37that are not too far from their mother stars.
23:47Planets at the right distance from their surfaces
23:50so that they are habitable.
23:57Distant worlds with a precious ingredient
24:00that makes the Earth a living planet.
24:06Planetary Science
24:23It would be logical to ask ourselves
24:26if we can apply all our knowledge of life on Earth
24:29to planets elsewhere in the universe.
24:32Well, I would say, yes, we can.
24:35Because the laws of nature are universal.
24:38The laws of physics and chemistry that sustain the biology of the Earth
24:42will affect every planet out there in the universe,
24:46whether we discover it or not.
24:56The chemistry of life is based on a few basic ingredients,
24:59carbon, nitrogen, oxygen, and iron.
25:04And it also requires a fast energy supply of good quality,
25:08coming from the heat of the interior of the planets
25:11or the light of the stars.
25:17But life on Earth depends on an extra ingredient,
25:20which is very important, liquid water.
25:23Liquid water is a deceitfully complicated substance.
25:28It's a great solvent, but inside it has structures
25:31that form and disappear constantly,
25:34structures that act as a kind of snap,
25:37around which biology develops.
25:44Organic molecules are aligned in that snap
25:47so that they can react together.
25:51Now, on Earth, all living beings need liquid water to survive,
25:55and I would say this is a very good assumption,
25:58that every living being anywhere in the universe
26:01will require it as well.
26:26In the universe, there is a lot of water.
26:31In our galaxy, large deposits have been discovered,
26:34among the gas clouds of the giant nebulae.
26:41But the abundance of water does not necessarily mean
26:44that it accumulates on planetary surfaces,
26:47forming oceans.
26:51Of the eight planets in our solar system,
26:54there is only one in which liquid water
26:57flows permanently on its surface.
27:04A marine world in which life began a long time ago.
27:11And there is no doubt that there is a lot of water
27:14on the surface of our planet.
27:20But how long?
27:39Around 4 billion years ago,
27:42life on Earth began in places very similar to this,
27:46where there is geothermal activity,
27:49a source of energy in contact with rich concentrations
27:52of reactive minerals and chemical elements.
27:56But also, and this is the fundamental,
27:59there was a magical solvent, liquid water.
28:03Now, many rocky planets in the galaxy
28:06probably have this,
28:09but very few people would think
28:12that large masses of liquid water on the surface.
28:17So that's why in the astrobiological community
28:20the phrase is repeated,
28:23if you want to find life, look for water.
28:41As life evolved on Earth,
28:46it began to collapse.
28:51At 124 light-years,
28:54in the collapse of a cloud of gas, dust and ice,
29:03a small star was born.
29:07The remains of the whirlpool of the cloud condensed
29:10and formed a new world.
29:21In 2015, the Kepler telescope
29:24found a planet orbiting relaxedly
29:27in the habitable zone of its star.
29:37Kepler's mass multiplies by 8 the mass of the Earth.
29:41K2-18b is a giant.
29:56And it has a huge gravitational attraction.
30:01If the planet is rocky,
30:04that attraction would have allowed it to preserve a tense atmosphere.
30:10K2-18b has all the attributes of an aquatic world.
30:16But it is not only that,
30:19it is also that it has a very strong gravitational force.
30:24K2-18b has all the attributes of an aquatic world.
30:34And a legendary space telescope
30:37had in sight the new discovery of Kepler.
30:46The most powerful of the space telescopes
30:49joined the search.
30:54Hubble inspected the light of the mother star
30:57when K2-18b passed in front of it.
31:04And it detected what could be a weak indicator
31:07of water vapor.
31:16It is possible that we have finally found
31:19proof of the existence of a planet
31:22and more proof of the existence of water
31:25in an extrasolar world,
31:28124 light years from Earth.
31:31This was the first observation of water vapor
31:34in the atmosphere of a planet
31:37that orbits in the habitable zone around its star.
31:40The measurement obtained of the amount of water vapor
31:43is very imprecise.
31:46It oscillates between 0.01 and 50%.
31:49It is very far away.
31:52The important thing is to compare it with Earth,
31:55which only has a small percentage of water vapor in the atmosphere.
31:58The discovery is important for two reasons.
32:01First, it is not zero.
32:04In its atmosphere, there is water vapor.
32:07Secondly, if the measurement is in the lower range
32:10and the percentage is low,
32:13it would be compatible with the possibility
32:16that there are oceans on its surface.
32:25At this moment, there is an intense scientific debate
32:28about the nature of this planet.
32:31It could be a small Neptune,
32:36a gaseous planet.
32:42But we can also dream of an extrasolar world
32:45with sky full of clouds,
32:53where drops of water accumulate
32:57and precipitate,
33:04feeding huge oceans
33:09that cover the surface of a giant planet.
33:16An aquatic world.
33:26A world where the elixir of life abounds.
33:39K2-18b is exciting.
33:42It is the smallest world with atmosphere that we have analyzed.
33:45And we have found that its mass,
33:48its density and its orbit
33:51are consistent with the possibility that it is a world with water.
33:57And it might be a world with oceans on its surface.
34:00We don't know for sure.
34:03We just imagine how that small, far away world could be
34:06orbiting around a faint red star.
34:13Kepler Space Telescope continues to make many more discoveries.
34:30Until in October 2018, it ran out of fuel.
34:43In its nine years of activity,
34:46it found more than 2,500 extrasolar worlds.
34:57And it showed us that planets potentially similar to Earth
35:00could be very common.
35:12We estimate that in our galaxy
35:15there could be about 20 billion worlds
35:18potentially similar to Earth.
35:21That is, rocky planets in the habitable area around the star
35:24are possibilities of housing liquid water on the surface.
35:2720 billion potential homes for life.
35:42What we can't calculate is the probability
35:45that life could begin when the conditions are right on a planet.
35:48We only know the experience of our world.
35:51We know that life on Earth began as soon as it was possible.
35:54The oceans on the surface arose
35:57when the Earth ended up deforming and cooled off.
36:00So that might suggest that although the origin of life
36:03doesn't seem to be inevitable,
36:06despite the fact that life on Earth
36:09is given in the right conditions,
36:12it is reasonably likely.
36:15So I think that there is at least a possibility
36:18that life has begun in some
36:21or in many of the 20 billion worlds
36:24in our galaxy similar to Earth.
36:30But I think there are two questions about life.
36:33One question is the origin and existence of microbes.
36:37In general, when we talk about aliens,
36:40we don't think of microbes,
36:43but of complex and intelligent creatures
36:46with whom we could speak.
36:49We think of civilizations.
36:52What is the probability that there are other civilizations on the Milky Way?
36:55Well, we don't know the answer.
36:58But in our observations,
37:01we find patterns that we also see on the Milky Way.
37:04And that leads us to make certain conjectures.
37:34We don't know exactly how we have become
37:37such complex and intelligent creatures.
37:58But we do know for sure
38:01that life on Earth has not been at this level
38:04from the beginning.
38:07We are the product of a history
38:10that has developed for more than a quarter
38:13of the age of the universe.
38:19From microbes
38:22to a global technological civilization
38:25that wants to contact other civilizations.
38:29At least we remain surrounded by silence.
38:32The messages we have sent to the cosmos
38:35remain unanswered.
38:38And the telescopes we use to scan the space
38:41in search of extraterrestrial signals
38:44remain undetected.
38:47That doesn't mean that there aren't other civilizations.
38:50We may have been looking for what we shouldn't have
38:53in the wrong place.
38:56But the answer is here, on Earth.
38:59Because here 4 billion years of stability were needed
39:02for a civilization to emerge.
39:05That is a vast amount of time.
39:08And when we look at the other worlds on the Milky Way,
39:11we find that stability and time
39:14appear to be very rare commodities.
39:27In 2013, the European Space Agency
39:30launched the Gaia Space Telescope.
39:36Its mission is to probe the stars of our galaxy,
39:39the Milky Way.
39:43It has mapped thousands of millions of stars.
39:50Each star could be the center
39:53on which alien worlds orbit.
39:59And several patterns have already emerged.
40:17Not all stars are alone.
40:24Some have company.
40:34And as strange as it may seem,
40:37the Gaia mission has discovered
40:40nearly a million binary or multiple stellar systems.
40:47We already knew about the existence of binary and multiple stellar systems.
40:51But we didn't know exactly if they were common or not.
40:56But now we have an enormous amount of high-precision data,
40:59including the data from the Gaia mission,
41:02which tells us that around 50% of stars similar to the Sun
41:05are in multiple stellar systems.
41:08And for the most massive stars,
41:11the percentage reaches 80%.
41:21And the prevalence of multiple stellar systems in the galaxy,
41:24how does it affect the possibilities
41:27of finding another Earth?
41:32Could there be planets like Earth
41:35in multiple stellar systems?
41:38And in that case, what could be its future?
41:46In 2020, we found a clue.
41:51We discovered a planet the size of Mars,
41:54moving freely through the galaxy.
41:57Let's call it a rebel planet.
42:02Now, if the planets don't form by themselves
42:05in interstellar space,
42:08where does this planet come from?
42:20The Sun.
42:26The Sunrise.
42:35Illuminated not by one star,
42:42but by two.
42:51Perhaps the rebel planet
42:54was born in a nearby binary system.
43:09Subject to the gravitational force of two stars.
43:21Perhaps its orbit was unstable.
43:32And the two stars fought to control their destiny.
43:36In the systems of a single star,
43:39the weak gravitational interactions between planets
43:42can also alter their orbits.
43:45And in a double stellar system,
43:48they are not only subjected to the gravitational force of others,
43:51but also to the attraction,
43:54the momentary attraction,
43:57of the other planets.
44:00Although a planet enters a stable orbit,
44:03it is very likely that it will not remain in it for a long time.
44:06But when it comes to a double stellar system,
44:09there is a very thin line between order and chaos.
44:18Even the slightest changes in the orbit of a planet
44:21can be seen as a sign of a change in the orbit of a planet.
44:25That is why it is unlikely that the conditions of the surface of a planet
44:28in a double system will remain stable for long enough
44:31for intelligent life to evolve.
44:54And sometimes, changes in the orbit of a planet
44:57may not be precisely subtle.
45:20It is possible that some approach
45:24would give the rebel world the definitive gravitational kick,
45:48throwing it outside the system.
45:54And freeing it from the clutches of its stars,
46:04to wander on its own,
46:11on a journey through the galaxy.
46:24Far from the heat of its stars,
46:29any trace of liquid water that it had
46:36would have frozen.
46:44And the atmosphere that protected it
46:48would freeze on the surface.
46:59The rebel planet would become
47:02a world without the right conditions for life.
47:18A lonely and drifting planet.
47:30To be detected by us
47:33millions of years later.
47:37A small wandering planet
47:40similar to Earth
47:43that will wander through the darkness of space
47:46for all eternity.
47:58This lonely wandering planet
48:01is not a unique case.
48:04Although they are very difficult to detect,
48:07it is estimated that there are more than 100 billion of them in our galaxy.
48:10It is possible that the rebel planets
48:13are the most common type of planet on the Milky Way.
48:16And although we think that most of them
48:19were expelled from their system shortly after their formation,
48:22it is an indicator that stellar systems
48:25are not always stable places where complex life
48:28has possibilities to evolve for billions of years.
48:43The search for another planet with life has just begun.
48:50But we have already learned a lot.
49:00We have found our first rocky worlds.
49:04Some in a habitable area around certain stars.
49:14Some with the possibility of having water in a liquid state on its surface.
49:18Candidate worlds for future missions
49:21in search of life evidence.
49:29We have also found a huge number of strange and mistreated worlds
49:32orbiting around the Milky Way.
49:36And we have also discovered
49:40many rebel planets.
49:44Planets where it seems impossible
49:47to exist what we understand by complex life.
50:10Maybe we will find in those worlds
50:13the explanation why our planet,
50:16for the moment,
50:19is still an exception.
50:39Our planet has been largely free
50:42from the violence, the chaos,
50:45and the constant change so common in the Milky Way.
50:48It has witnessed some kind of massive extinction.
50:51But the chain of life has not been interrupted
50:54at any time since 4 billion years ago.
50:57If that is what is needed
51:00for life to begin and evolve
51:03until it becomes a civilization,
51:06there could be thousands of millions of worlds with life,
51:09but without civilizations.
51:12But that should be a fundamental hypothesis,
51:15an opinion, in a way.
51:18Although given the depth of the question,
51:21it does not matter much the solidity of that foundation.
51:24It would be absurd to stop looking inside and outside
51:27of our galaxy.
51:32Because it is possible that we have first glimpsed
51:35a world beyond the Milky Way.
51:47About 30 million light years
51:50in the spiral arms of the galaxy Remolino,
51:59there is a planet the size of Saturn.
52:05This discovery represents
52:08a progression of our horizon,
52:15the beginning of the search
52:18for extragalactic planets.
52:25I never thought I would see the discovery
52:28of a planet orbiting around a star
52:31in another galaxy.
52:34This opens up the exciting possibility
52:37of exploring not only if we are alone in our galaxy,
52:40but if we are alone in the universe.
52:47The answer to that question
52:50is so far away in the future
52:53that we may never find it.
52:56But by saying that the question of whether we are alone is deep,
52:59I mean that answering it would teach us much more
53:02about what it means to be human.
53:08With each world we explore,
53:11we become a little more human
53:14because of our ability to lay down the foundations
53:17and ask ourselves questions
53:20that we may never ask in our lifetime.
53:23Asking questions for our children or our grandchildren
53:26is a fundamental part of what it means to be human.
53:29It is a fundamental part of what makes us so special
53:32in this little world,
53:35looking at the stars,
53:38whether we are alone or not.
53:59Five, four, three, two, engine start,
54:02one, zero.
54:05Lift off of the Delta II rocket
54:08with the Kepler telescope
54:11in search of planets similar to ours.
54:14The joint work of thousands of people
54:17has become a reality.
54:20Separation complete, Adam.
54:23It was so emotional to see the project
54:26in which they had worked for so many years,
54:29so many decades, finally go to space
54:32and all that hope and promise, hope and promise,
54:35travel between machinery.
54:42The Kepler telescope was an immediate success.
54:45It discovered more than 2,000 new planets
54:48in its first four years of operation.
54:52But in the summer of 2012,
54:55the team faced a challenge that threatened the entire mission.
55:03One of the fundamental elements of the Kepler
55:06is the reaction wheels that rotate
55:09and keep it focused on the targets,
55:12always pointing to the same stars without moving,
55:15and the telescope has four of those wheels.
55:21And we knew that the gyroscopes of the spacecraft
55:24would end up failing,
55:27but we only had a couple of them to spare.
55:32And after all, it failed.
55:35Three months later, the second failed,
55:38and since we needed three,
55:41we were no longer able to maintain the Kepler field of view.
55:44I had hope that they would find a way
55:47to work with two gyroscopes, and they did.
55:52So very clever people, engineers, scientists,
55:55said, we're going to use solar radiation
55:58as if it were the third wheel.
56:01We'll make it reflect sunlight,
56:04and with the other two wheels working,
56:07we'll be able to point to space.
56:14That's some good news, actually.
56:17The Kepler was going to go off,
56:20and we were going to get all kinds of other stars,
56:23and that was a big boost for astronomy.
56:30After four more years of discovery,
56:33they found more than 2,600 planets.
56:37It became our main planet hunter,
56:40until the moment...
56:45The sending of the order of Apagado was a very sad moment.
56:48Now it's asleep.
56:51It's in orbit around the sun, and it will remain in orbit.
56:54But since it was launched from Earth,
56:57the orbit will bring it back to us again.
57:00It will visit us in about 40 years,
57:03and I hope that people will say,
57:06it's a historic telescope.
57:09It taught us a lot about those planets.
57:12They will go up to pick it up and bring it back
57:15to us in a little while.
57:46ESOcast is produced by ESO, the European Southern Observatory.
57:50ESO, the European Southern Observatory, is the pre-eminent intergovernmental science and technology organisation in astronomy designing, constructing and operating the world's most advanced ground-based telescopes.