04:41
TED2009

Carolyn Porco: Could a Saturn moon harbor life?

カロリン・ポロコ:土星の衛星は生命を抱くのか?

Filmed:

カッシーニ探査機が土星の衛星の一つ、エンケラドスを通過した際にもたらされた驚くべき新発見について、カロリン・ポロコ氏が語る。衛星にある氷の間欠泉から採集されたサンプルは、地下にある海が生命を抱いている可能性があることを示している。

- Planetary scientist
As the leader of the Imaging Team on the Cassini mission to Saturn, Carolyn Porco interprets and shares the pictures coming back from this fascinating planet, its rings and its moons. Full bio

Two years ago here at TED
二年前、ここTEDで
00:18
I reported that we had discovered
我々が発見したことをお話ししました
00:20
at Saturn, with the Cassini Spacecraft,
土星について、カッシーニ探査機が発見したことは
00:22
an anomalously warm and geologically active region
異常に暖かく、地質学的に活発な地域が
00:25
at the southern tip of the small Saturnine moon
土星の小さな衛星の南端にあるということでした
00:28
Enceladus, seen here.
その衛星、エンケラドスです
00:31
This region seen here for the first time
この地域が初めて観察されたのは
00:33
in the Cassini image taken in 2005. This is the south polar region,
カッシーニによって2005年に撮影された写真によるものです これは南極地域です
00:35
with the famous tiger-stripe fractures crossing the south pole.
有名な、タイガーストリップの裂け目が南極を横切っています
00:40
And seen just recently in late 2008,
そして、最近、2008年の後半になって
00:43
here is that region again,
再び、その地域が撮影されました
00:47
now half in darkness because the southern hemisphere
半分が闇に覆われているのは、南半球が
00:49
is experiencing the onset of August
八月の始め頃
00:52
and eventually winter.
つまり、冬であったためです
00:55
And I also reported that we'd made this mind-blowing discovery --
目を疑うような発見がなされたことについてもお話ししました
00:57
this once-in-a-lifetime discovery
まさに一生に一度の大発見です
01:00
of towering jets
高々と噴き上がるジェットは
01:02
erupting from those fractures at the south pole,
南極にある裂け目から噴出されていますが
01:04
consisting of tiny water ice crystals
水が凍ってできた小さな結晶によって形成されており
01:07
accompanied by water vapor
水蒸気も含んでいます
01:09
and simple organic compounds like carbon dioxide and methane.
また、炭素やメタンのような単純な有機化合物も存在します
01:12
And at that time two years ago
二年前、
01:16
I mentioned that we were speculating
我々の予想についてお話ししました
01:18
that these jets might in fact be geysers,
このジェットは間欠泉である可能性があり、
01:20
and erupting from pockets
地上のくぼみ、あるいは
01:22
or chambers of liquid water underneath the surface,
地下にある液体の水の貯水池から、噴出されているのではないか、と
01:24
but we weren't really sure.
しかし、確証はありませんでした
01:26
However, the implications of those results --
一方、我々が得た成果から
01:28
of a possible environment within this moon
予想された、この衛星の環境は
01:31
that could support prebiotic chemistry,
前生物化学、あるいは
01:34
and perhaps life itself --
生命そのものをサポートことができる可能性があり、
01:36
were so exciting that, in the intervening two years,
興味が非常に高まりました そして、この二年間にわたって
01:39
we have focused more on Enceladus.
さらにエンケラドスを注目してきました
01:41
We've flown the Cassini Spacecraft
カッシーニ探査機によって
01:43
by this moon now several times,
この衛星をなんども探査しました
01:46
flying closer and deeper into these jets,
ジェットへさらに近く、さらに内側まで
01:48
into the denser regions of these jets,
さらに濃度が高いところまで
01:51
so that now we have come away with some
そして、今回、
01:53
very precise compositional measurements.
その組成を詳細に計測することができました
01:55
And we have found
その結果、
01:57
that the organic compounds coming from this moon
この衛星から放出されている有機化合物は
01:59
are in fact more complex than we previously reported.
以前に報告されたものより、複雑なものであることが分かりました
02:02
While they're not amino acids,
アミノ酸ではありませんでしたが、
02:05
we're now finding things like
我々は
02:07
propane and benzene,
プロパンやベンゼン
02:09
hydrogen cyanide, and formaldehyde.
シアン化水素、ホルムアルデヒドを検出しました
02:11
And the tiny water crystals here
そして、小さな水の結晶は
02:13
now look for all the world
非常に
02:16
like they are frozen droplets of salty water,
凍った塩水のしずくと似通っていたのです
02:18
which is a discovery that suggests
この発見から予想できることは
02:21
that not only do the jets come from
ジェットが
02:23
pockets of liquid water,
液体の水がたまった窪みから噴出しているだけでなく
02:25
but that that liquid water is in contact with rock.
その液体の水は岩盤との接触があるということです
02:27
And that is a circumstance
そして、この状況においては
02:30
that could supply the chemical energy
生命の維持に必要な化学的エネルギーおよび
02:32
and the chemical compounds needed to sustain life.
化合物が供給されている可能性があります
02:34
So we are very encouraged by these results.
非常に喜ばしい成果を得ることができました
02:37
And we are much more confident now than we were two years ago
我々は、二年前よりさらに確信を深めています
02:40
that we might indeed
つまり
02:43
have on this moon, under the south pole,
この衛星の、南極の地下において
02:45
an environment or a zone that is hospitable to living organisms.
有機体に適した環境、地域が存在している可能性があるのです
02:48
Whether or not there are living organisms there, of course,
もちろん、実際に有機体が存在しているかどうかは
02:52
is an entirely different matter.
まったく別の問題です
02:55
And that will have to await the arrival,
それに関しては、再び
02:57
back at Enceladus,
エンケラドスに
02:59
of the spacecrafts, hopefully some time in the near future,
探査機が接近するのを待つべきでしょう それが近い将来であり、
03:02
specifically equipped to address that particular question.
探査機がその疑問に答えるための装備を備えていることを望みます
03:05
But in the meantime I invite you to imagine the day
それまでの間は、想像をしてみようではありませんか
03:09
when we might journey to the Saturnine system,
土星系まで旅をして
03:12
and visit the Enceladus interplanetary geyser park,
エンケラドスの惑星間間欠泉公園を訪れる日のことを
03:15
just because we can.
それは可能なのですから
03:19
Thank you.
ありがとうございます
03:21
(Applause)
(拍手)
03:23
Translated by Kazuyuki Shimatani
Reviewed by MaYoMo com

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About the Speaker:

Carolyn Porco - Planetary scientist
As the leader of the Imaging Team on the Cassini mission to Saturn, Carolyn Porco interprets and shares the pictures coming back from this fascinating planet, its rings and its moons.

Why you should listen

Planetary scientist Carolyn Porco studies and interprets the photos from NASA space missions like the renowned Voyager mission to the outer solar system in the 1980s and the Cassini-Huygens mission to Saturn. She leads a team of scientists from the US and Europe that has been analyzing the images Cassini has sent back since it left Earth in 1997. At Saturn, they have found new phenomena everywhere they've turned their cameras … in the planet’s atmosphere, within its rings and on the surfaces of its many moons. And they've produced spectacular images and animations of these marvels in the process.

Back in the early-1980s, while still working on her doctorate, Porco was drafted onto the Voyager imaging team to assist in crunching the mountains of data coming back from Voyager’s fly-by of Saturn. Her work on the planet's rings and their relation to its moons cemented her connection with Saturn. After Voyager had flown by Neptune and was nearing conclusion, she worked together with Carl Sagan in planning Voyager’s celebrated Pale Blue Dot picture of Earth.

Her ongoing work at the Cassini Imaging Central Laboratory for Operations (CICLOPs) has two goals: to process, interpret and archive Cassini’s images for other scientists, and to make sure the images -- in all their breathtaking poetry and mystery and sheer Save-Image-As-Desktop awesomeness -- connect with the general public. She is an advocate for the exploration and understanding of planetary space, and her frequent talks (as well as her "Captain's Log" memos on the CICLOPS website) speak to everyone, scientist and nonscientist alike. Her advocacy extends to Hollywood, where she was the character consultant on the 1997 movie “Contact,” and a consultant on the 2009 Paramount Pictures re-boot of “Star Trek.” In 2012, she was named one the 25 most influential people in space by TIME magazine.

Finally, in a twist on the Pale Blue Dot theme, it was she who conceived the idea to invite the people of the world to smile while Cassini imaged the Earth on July 19, 2013 in an event called “The Day the Earth Smiled.”

For more information: 

Solar System Portrait: Earth as 'Pale Blue Dot'

BBC: Saturn snapped as Earth smiled

The Atlantic: The Carl Sagan of Our Time Reprises the 'Pale Blue Dot' Photo of Earth

The Day the Earth Smiled: Image

Library of Congress: Portraits of the Solar System: Talking with Carolyn Porco About Carl Sagan  

More profile about the speaker
Carolyn Porco | Speaker | TED.com