ABOUT THE SPEAKER
James Green - Space physicist
James Green leads NASA's solar system exploration and astrobiology research.

Why you should listen

Dr. James Green began his career at NASA 35 years ago at the Marshall Space Flight Center, where he developed and managed the Space Physics Analysis Network. It provided scientists all over the world rapid access to data and resources. As NASA's Director of Planetary Science he leads NASA's solar system exploration and astrobiology research.

Green received his Ph.D. in Space Physics from the University of Iowa in 1979 and began working in the Magnetospheric Physics Branch at NASA's Marshall Space Flight Center (MSFC) in 1980. At Marshall, Green developed and managed the Space Physics Analysis Network that provided scientists all over the world with rapid access to data, to other scientists, and to specific NASA computer and information resources. In addition, Green was a Safety Diver in the Neutral Buoyancy tank making over 150 dives until left MSFC in 1985.

From 1985 to 1992 Green was the head of the National Space Science Data Center (NSSDC) at Goddard Space Flight Center (GSFC). The NSSDC is NASA's largest space science data archive. In 1992, he became the Chief of the Space Science Data Operations Office until 2005, when he became the Chief of the Science Proposal Support Office. While at GSFC, Green was a co-investigator and the Deputy Project Scientist on the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) mission. He has written over 100 scientific articles in refereed journals involving various aspects of the Earth's and Jupiter's magnetospheres and over 50 technical articles on various aspects of data systems and networks.

In August 2006, Green became the Director of the Planetary Science Division at NASA Headquarters. Over his career, Green has received numerous awards. In 1988, he received the Arthur S. Flemming award given for outstanding individual performance in the federal government and was awarded Japan's Kotani Prize in 1996 in recognition of his international science data management activities.

More profile about the speaker
James Green | Speaker | TED.com
TED Talks Live

James Green: 3 moons and a planet that could have alien life

James Green: 3 lúas e un planeta poden albergar vida alieníxena

Filmed:
1,837,212 views

Hai vida máis alá da Terra? Únete ao director de ciencias planetarias da NASA James Green para saber que lugares do noso sistema solar teñen máis posibilidades de albergar vida alieníxena.
- Space physicist
James Green leads NASA's solar system exploration and astrobiology research. Full bio

Double-click the English transcript below to play the video.

00:12
Is there life beyond Earth
in our solar system?
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Existe vida máis alá da Terra
no noso sistema solar?
00:17
Wow, what a powerful question.
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Vaia, que pregunta máis poderosa.
00:20
You know, as a scientist --
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Saben, coma científicos,
00:22
planetary scientist --
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científicos planetario,
00:23
we really didn't take that
very seriously until recently.
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non nos tomamos isto moi en serio,
até fai pouco.
00:28
Carl Sagan always said,
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Carl Sagan sempre dicía:
00:30
"It takes extraordinary evidence
for extraordinary claims."
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"Alegacións extraodinarios esixen
probas extraordinarias".
00:36
And the claims of having life beyond Earth
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E as probas de que existe vida
máis alá da Terra
00:41
need to be definitive,
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teñen que ser definitivas,
00:43
they need to be loud
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teñen que ser claras
00:45
and they need to be everywhere
for us to be able to believe it.
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e teñen que estar en todas partes
para que o poidamos crer.
00:50
So how do we make this journey?
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Entón, como facemos isto?
00:54
What we decided to do
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Primeiro, o que deicimos facer
00:55
is first look for
those ingredients for life.
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é procurar os ingredientes da vida.
01:00
The ingredients of life are:
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Os ingredientes da vida son:
01:02
liquid water --
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auga en estado líquido,
01:04
we have to have a solvent,
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temos que ter un solvente,
01:05
can't be ice, has to be liquid.
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non pode ser xeo, ten que ser líquido.
01:08
We also have to have energy.
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Tamén precisamos enerxía.
01:10
We also have to have organic material --
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Amais, necesitamos material orgánico,
01:13
things that make us up,
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cousas que nos compón,
01:16
but also things that we need to consume.
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mais tamén cousas que precisamos consumir.
01:19
So we have to have these elements
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Entón, necesitamos ter estes elementos
01:22
in environments for long periods of time
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en ambientes e
durante longos periodos de tempo
01:25
for us to be able
to be confident that life,
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para estar seguros de que a vida,
01:28
in that moment when it starts,
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no momento no que comeza,
01:31
can spark and then grow and evolve.
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pode xurdir e entón crecer e evolucionar.
01:35
Well, I have to tell you
that early in my career,
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Ben, teño que lles dicir
que nos comezos da miña carreira,
01:39
when we looked at those three elements,
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cando procurabamos estes 3 elementos,
01:41
I didn't believe
that they were beyond Earth
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non cría
que estivesen máis alá da Terra
01:44
in any length of time
and for any real quantity.
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en calquera tempo
nin en calquera cantidade.
01:48
Why? We look at the inner planets.
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Por que? Mirabamos para
os planetas interiores.
01:50
Venus is way too hot -- it's got no water.
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Venus é moi quente, non ten auga.
01:53
Mars -- dry and arid.
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Marte: seco e árido.
01:55
It's got no water.
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Non ten auga.
01:57
And beyond Mars,
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E máis alá de Marte,
01:58
the water in the solar system
is all frozen.
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a auga no sistema solar está xeada.
02:03
But recent observations
have changed all that.
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Mais observacións recentes
mudaron todo isto.
02:07
It's now turning our attention
to the right places
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Agora a nosa atención
está posta nos lugares correctos
02:11
for us to take a deeper look
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para que miremos máis a fondo
02:13
and really start to answer
our life question.
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e poidamos comezar a responder
as nosas preguntas sobre a vida.
02:18
So when we look out into the solar system,
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Así, cando observarmos
o noso sistema solar,
02:21
where are the possibilities?
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cales son as posibilidades?
02:23
We're concentrating our attention
on four locations.
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Centramos a nosa atención
en catro lugares.
02:27
The planet Mars
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O planeta Marte
02:29
and then three moons of the outer planets:
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e tres lúas de planetas externos;
02:33
Titan, Europa and small Enceladus.
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Titán, Europa e a pequena Encélado.
02:38
So what about Mars?
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E que ten Marte?
02:40
Let's go through the evidence.
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Vexamos as evidencias.
02:43
Well, Mars we thought
was initially moon-like:
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Pensamos que Marte era
coma a Lúa inicialmente:
02:47
full of craters, arid and a dead world.
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cheo de cráteres, árido
e un mundo sen vida.
02:52
And so about 15 years ago,
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Entón, hai uns 15 anos,
02:55
we started a series
of missions to go to Mars
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comezamos unha serie de misións a Marte
02:58
and see if water existed
on Mars in its past
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para verificar se existiu auga en Marte
03:03
that changed its geology.
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que mudou a súa xeoloxía.
03:05
We ought to be able to notice that.
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Deberiamos poder advertir isto.
03:08
And indeed we started
to be surprised right away.
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E de feito comezamos
a sorprendernos de novo.
03:11
Our higher resolution images
show deltas and river valleys and gulleys
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As imaxes de alta resolución amosaban
deltas e vales de ríos e cañóns
03:16
that were there in the past.
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que estiveron aí no pasado.
03:19
And in fact,
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E de feito,
03:20
Curiosity --
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Curiosity,
03:21
which has been roving on the surface
now for about three years --
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que se está a mover pola superficie
dende hai uns tres anos,
03:26
has really shown us that it's sitting
in an ancient river bed,
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amosounos que está
no antigo leito dun río,
03:31
where water flowed rapidly.
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onde a auga discorría rapidamente.
03:34
And not for a little while,
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E non durante pouco tempo,
03:35
perhaps hundreds of millions of years.
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talvez durante centos
de milleiros de anos.
03:39
And if everything was there,
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E se existiu algo aí,
03:40
including organics,
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incluíndo material orgánico,
03:41
perhaps life had started.
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talvez comezara a vida.
03:43
Curiosity has also
drilled in that red soil
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Curiosity tamén furou o chan vermello
03:46
and brought up other material.
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e ensinou outros materiais.
03:48
And we were really excited
when we saw that.
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Emocionámonos moito
cando vimos isto.
03:51
Because it wasn't red Mars,
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Porque non era vermello Marte,
03:53
it was gray material,
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era material gris,
03:54
it's gray Mars.
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era gris Marte.
03:56
We brought it into the rover,
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Trouxemos isto,
03:57
we tasted it,
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testámolo,
03:59
and guess what?
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e adiviñade que?
04:00
We tasted organics --
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Estabamos a testar material orgánico:
04:02
carbon, hydrogen, oxygen,
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carbono, hidróxeno, osíxeno,
04:05
nitrogen, phosphorus, sulfur --
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nitróxeno, fósforo, xofre,
04:07
they were all there.
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estaban aí.
04:09
So Mars in its past,
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Entón, Marte, no pasado,
04:11
with a lot of water,
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con moita auga,
04:13
perhaps plenty of time,
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talvez con moito tempo,
04:15
could have had life,
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puido ter vida,
04:16
could have had that spark,
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puido ter esa chispa,
04:18
could have grown.
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puido crecer.
04:20
And is that life still there?
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E aínda está esa vida aí?
04:22
We don't know that.
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Non o sabemos.
04:24
But a few years ago
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Mais hai uns anos
04:26
we started to look at a number of craters.
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comezamos a mirar
a unha serie de cráteres.
04:29
During the summer,
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Durante o verán,
04:30
dark lines would appear
down the sides of these craters.
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aparecían unhas liñas negras
baixo estes cráteres.
04:34
The more we looked,
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Canto máis mirabamos,
04:36
the more craters we saw,
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máis cráteres viamos,
04:37
the more of these features.
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e máis as tiñan.
04:38
We now know more than a dozen of them.
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Agora coñecemos máis dunha ducia deles.
04:42
A few months ago the fairy tale came true.
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Hai uns meses o conto de fadas
convertiuse en realidade.
04:46
We announced to the world
that we know what these streaks are.
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Anunciamos ao mundo
que descubrimos que eran esas liñas.
04:50
It's liquid water.
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É auga, líquida.
04:53
These craters are weeping
during the summer.
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Eses cráteres pingan
durante o verán.
04:56
Liquid water is flowing
down these craters.
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Auga líquida flúe
nesos cráteres.
05:00
So what are we going to do now --
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Entón, que imos facer agora,
05:02
now that we see the water?
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agora que vemos a auga?
05:04
Well, it tells us that Mars has
all the ingredients necessary for life.
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Ben, dinos que Marte ten
todos os ingredientes para a vida.
05:09
In its past it had perhaps
two-thirds of its northern hemisphere --
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No pasado probablemente
dous terzos do hemisferio norte,
05:14
there was an ocean.
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eran océano.
05:15
It has weeping water right now.
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Ten auga goteando agora mesmo.
05:17
Liquid water on its surface.
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Auga líquida na súa superficie.
05:19
It has organics.
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Ten materia orgánica.
05:21
It has all the right conditions.
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Ten todas as condicións necesarias.
05:24
So what are we going to do next?
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Entón, que imos facer agora?
05:26
We're going to launch a series of missions
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Imos lanzar unha serie de misións
05:28
to begin that search for life on Mars.
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para comezar a buscar vida en Marte.
05:32
And now it's more appealing
than ever before.
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E agora é máis atractivo que nunca.
05:35
As we move out into the solar system,
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Cando avanzamos
no noso sistema solar,
05:38
here's the tiny moon Enceladus.
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aquí está a pequena lúa, Encélado.
05:41
This is not in what we call
the traditional habitable zone,
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Non é o que chamaría unha
zona habitable tradicional,
05:44
this area around the sun.
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esta área redor do sol.
05:46
This is much further out.
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Iso está moito máis afastado.
05:48
This object should be
ice over a silicate core.
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Este obxecto debería ser
xeo sobre un núcleo de silicato.
05:54
But what did we find?
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Mais que atopamos?
05:55
Cassini was there since 2006,
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Cassini estivo aí dende 2006,
05:58
and after a couple years
looked back after it flew by Enceladus
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e despois duns anos mirou cara atrás
despois de voar de Encélado
06:03
and surprised us all.
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e sorprendeunos a todos.
06:04
Enceladus is blasting sheets of water
out into the solar system
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Encélado está a tirar láminas de auga
ao noso sistema solar
06:10
and sloshing back down onto the moon.
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e rebotando de novo cara a lúa.
06:13
What a fabulous environment.
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Que ambiente tan fabuloso.
06:15
Cassini just a few months ago
also flew through the plume,
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Hai uns meses, Cassini tamén
voou sobre sobre unha columna,
06:20
and it measured silicate particles.
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e mediu as partículas de silicato.
06:23
Where does the silica come from?
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De onde provén o sílice?
06:25
It must come from the ocean floor.
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Debe provir do chan do océano.
06:28
The tidal energy is generated by Saturn,
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Saturno xera a enerxía mareomotriz,
06:31
pulling and squeezing this moon --
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empurrando e presionando esta lúa
06:34
is melting that ice,
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está derretendo o xeo,
06:35
creating an ocean.
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creando océanos.
06:37
But it's also doing that to the core.
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Mais tamén está a facer iso co núcleo.
06:40
Now, the only thing that we can think of
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Agora, o único que podemos imaxinar
06:42
that does that here on Earth
as an analogy ...
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que ten unha analoxía aquí na Terra...
06:46
are hydrothermal vents.
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Son os respiradeiros hidrotérmicos.
06:49
Hydrothermal vents deep in our ocean
were discovered in 1977.
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Os respiradeiros hidrotérmicos
descubríronse en 1977 no noso océano.
06:55
Oceanographers were completely surprised.
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Os osceanógrafos estaban moi sorprendidos.
06:58
And now there are thousands
of these below the ocean.
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E agora hai miles destes baixo o océano.
07:03
What do we find?
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Que atopamos?
07:04
The oceanographers, when they go
and look at these hydrothermal vents,
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Os oceanógrafos, cando observan
estes respiradeiros hidrotérmicos,
07:07
they're teeming with life,
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están cheos de vida,
07:09
regardless of whether the water
is acidic or alkaline --
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e non importa se a auga é
aceda ou alcalina,
07:13
doesn't matter.
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non importa.
07:15
So hydrothermal vents are
a fabulous abode for life here on Earth.
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Entón, os respiradeiros hidrotérmicos son
unha fabulosa morada para a vida na Terra.
07:20
So what about Enceladus?
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Entón, que pasa con Encélado?
07:23
Well, we believe because it has water
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Ben, cremos que como ten auga
07:26
and has had it for
a significant period of time,
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e tívoa durante moito tempo,
07:29
and we believe it has hydrothermal vents
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e cremos que ten
respiradeiros hidrotérmicos
07:33
with perhaps the right organic material,
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e quizais o material orgánico axeitado,
07:36
it is a place where life could exist.
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pode ser un lugar onde existiu a vida.
07:40
And not just microbial --
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E non só microbiana,
07:42
maybe more complex
because it's had time to evolve.
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talvez máis complexa
porque tivo tempo de evolucionar.
07:47
Another moon, very similar,
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Outra lúa, moi parecida,
07:50
is Europa.
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é Europa.
07:52
Galileo visited Jupiter's system in 1996
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Galileo visitou
o sistema de Xúpiter en 1996
07:58
and made fabulous observations of Europa.
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e fixo observacións fabulosas de Europa.
08:01
Europa, we also know,
has an under-the-ice crust ocean.
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Tamén sabemos que Europa
ten un oceáno de cortiza baixo o xeo.
08:06
Galileo mission told us that,
but we never saw any plumes.
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A misión Galileo amosounos isto,
máis nunca vimos ningunha columna.
08:11
But we didn't look for them.
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Máis tampouco as buscabamos.
08:13
Hubble,
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Hubble,
08:14
just a couple years ago,
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hai só uns anos,
08:16
observing Europa,
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cando observaba Europa,
08:19
saw plumes of water
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viu columnas de auga
08:21
spraying from the cracks
in the southern hemisphere,
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que saían das fendas
no hemisferio sur,
08:24
just exactly like Enceladus.
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exactamente coma Encélado.
08:29
These moons,
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Estas lúas,
08:31
which are not in what we call
a traditional habitable zone,
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que non están no que normalmente chamamos
unha zona habitable,
08:35
that are out in the solar system,
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que están fóra no sistema solar,
08:37
have liquid water.
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teñen auga líquida.
08:39
And if there are organics there,
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E si hai material orgánico aí,
08:41
there may be life.
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pode haber vida.
08:43
This is a fabulous set of discoveries
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É unha serie de descubrimentos fabulosos
08:45
because these moons
have been in this environment like that
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porque estas lúas estiveron
neste ambiente así
08:50
for billions of years.
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durante miles de millóns de anos.
08:53
Life started here on Earth, we believe,
after about the first 500 million,
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A vida comezou na Terra, cremos,
despois dos primeiros 500 millóns,
08:58
and look where we are.
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e mira onde estamos.
09:01
These moons are fabulous moons.
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Estas lúas son fabulosas.
09:04
Another moon that we're
looking at is Titan.
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Outra lúa á que observamos é Titán.
09:08
Titan is a huge moon of Saturn.
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Titán é unha lúa xigante de Saturno.
09:10
It perhaps is much larger
than the planet Mercury.
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É, quizais, moito máis grande
que o planeta Mercurio.
09:14
It has an extensive atmosphere.
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Ten unha atmosfera enorme.
09:17
It's so extensive --
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É moi grande,
09:18
and it's mostly nitrogen
with a little methane and ethane --
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e é na súa maioría nitróxeno
cun chisco de metano e etano,
09:23
that you have to peer
through it with radar.
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que se precisa dun radar
para observala.
09:25
And on the surface,
Cassini has found liquid.
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E na superficie,
Cassini atopou líquido.
09:29
We see lakes ...
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Vemos lagos...
09:32
actually almost the size
of our Black Sea in some places.
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Case do tamaño do mar negro
nalgúns lugares.
09:36
And this area is not liquid water;
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E esta área non é auga líquida;
09:39
it's methane.
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é metano.
09:41
If there's any place in the solar system
where life is not like us,
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Se hai algún lugar no sistema solar
onde a vida non é coma nós,
09:47
where the substitute of water
is another solvent --
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onde o sustituto da auga
é outro solvente,
09:50
and it could be methane --
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e poida ser o metano,
09:52
it could be Titan.
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podería ser Titán.
09:54
Well, is there life beyond Earth
in the solar system?
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Ben, hai vida máis alá da Terra
no noso sistema solar?
09:58
We don't know yet,
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Aínda non o sabemos,
10:00
but we're hot on the pursuit.
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máis sempre estamos na busca.
10:02
The data that we're receiving
is really exciting
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Os datos que recibimos nos entusiasman
10:04
and telling us --
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e nos din,
10:06
forcing us to think about this
in new and exciting ways.
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fannos pensar nesto en novos xeitos.
10:10
I believe we're on the right track.
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Creo que estamos no camiño correcto.
10:13
That in the next 10 years,
we will answer that question.
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Que en 10 anos
responderemos esa pregunta.
10:17
And if we answer it,
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E se a respondemos,
10:19
and it's positive,
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e é un si,
10:21
then life is everywhere
in the solar system.
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significará que a vida
está en todo o sistema solar.
10:25
Just think about that.
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Pensen nisto.
10:27
We may not be alone.
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Talvez non estamos sós.
10:30
Thank you.
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Grazas.
10:31
(Applause)
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(Aplausos)
Translated by Lúa Cruz Fernández
Reviewed by Elena Pérez Gómez

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ABOUT THE SPEAKER
James Green - Space physicist
James Green leads NASA's solar system exploration and astrobiology research.

Why you should listen

Dr. James Green began his career at NASA 35 years ago at the Marshall Space Flight Center, where he developed and managed the Space Physics Analysis Network. It provided scientists all over the world rapid access to data and resources. As NASA's Director of Planetary Science he leads NASA's solar system exploration and astrobiology research.

Green received his Ph.D. in Space Physics from the University of Iowa in 1979 and began working in the Magnetospheric Physics Branch at NASA's Marshall Space Flight Center (MSFC) in 1980. At Marshall, Green developed and managed the Space Physics Analysis Network that provided scientists all over the world with rapid access to data, to other scientists, and to specific NASA computer and information resources. In addition, Green was a Safety Diver in the Neutral Buoyancy tank making over 150 dives until left MSFC in 1985.

From 1985 to 1992 Green was the head of the National Space Science Data Center (NSSDC) at Goddard Space Flight Center (GSFC). The NSSDC is NASA's largest space science data archive. In 1992, he became the Chief of the Space Science Data Operations Office until 2005, when he became the Chief of the Science Proposal Support Office. While at GSFC, Green was a co-investigator and the Deputy Project Scientist on the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) mission. He has written over 100 scientific articles in refereed journals involving various aspects of the Earth's and Jupiter's magnetospheres and over 50 technical articles on various aspects of data systems and networks.

In August 2006, Green became the Director of the Planetary Science Division at NASA Headquarters. Over his career, Green has received numerous awards. In 1988, he received the Arthur S. Flemming award given for outstanding individual performance in the federal government and was awarded Japan's Kotani Prize in 1996 in recognition of his international science data management activities.

More profile about the speaker
James Green | Speaker | TED.com