Penelope Boston: Life on Mars? Let's look in the caves

ペネロープ・ボストン「火星に生命はいるのか？」

翻訳: Yusuke Yanagita 校正: Akira Kan

The career that I started early on in my life

私はキャリアの始めの頃は

was looking for exotic life forms in exotic places,

珍しい場所で珍しい生物を探しました

and at that time I was working in the Antarctic and the Arctic,

当時 私は南極 北極 各地の砂漠で

and high deserts and low deserts.

探索を行いました

Until about a dozen years ago, when I was really captured by caves,

10数年前 洞窟に興味を持ってから

and I really re-focused most of my research in that direction.

私は研究の方向を洞窟に変えました

So I have a really cool day job-- I get to do some really amazing stuff.

毎日の研究はとても楽しく とても驚くような仕事ができました

I work in some of the most extreme cave environments on the planet.

地球上で最も過酷と言われる洞窟にも行き

Many of them are trying to kill us from the minute we go into them,

生命の危険も感じました

but nevertheless, they're absolutely gripping,

しかし洞窟はどれも非常に魅力的で

and contain unbelievable biological wonders

信じられない程の生物学的神秘があり

that are very, very different from those that we have on the planet.

まるで地球上とは思えない程です

Apart from the intrinsic value

生物学 鉱物学 地質微生物学

of the biology and mineralogy and geo-microbiology that we do there,

本来の目的を探究する他に

we're also using these as templates

私たちは研究成果を

for figuring out how to go look

他の惑星の生命の探索に

for life on other planets.

活用しています

Particularly Mars, but also Europa,

特に火星や木星の小さな衛星で

the small, icy moon around Jupiter.

氷で覆われたエウロパに注目しており

And perhaps, someday, far beyond our solar system itself.

そしておそらく将来は我々の 太陽系外も対象になります

I'm very passionately interested in the human future,

私が情熱を注いでいるのは 月や火星

on the Moon and Mars particularly,

他の太陽系惑星における

and elsewhere in the solar system.

人類の未来です

I think it's time that we transitioned

今は人類が太陽系全体の

to a solar system-going civilization and species.

文明や生命に目を向ける時代です

And, as an outgrowth of all of this then,

そしてこれらの調査結果は

I wonder about whether we can, and whether we even should,

地球上の生命を他の惑星に送り込めるか

think about transporting Earth-type life to other planets.

送り込むべきか 思案させるのです

Notably Mars, as a first example.

特に火星は注目に値します

Something I never talk about in scientific meetings

私が学会で話さないのは

is how I actually got to this state

どのようにして現在に至り

and why I do the work that I do.

なぜ普通の仕事をせずに

Why don't I have a normal job, a sensible job?

この研究をしているかです

And then of course, I blame the Soviet Union.

それはもちろん ソ連のせいです

Because in the mid-1950s,

1950年代半ば

when I was a tiny child,

私はまだ小さな子供でした

they had the audacity to launch

ソ連は大胆にもスプートニクという

a very primitive little satellite called Sputnik,

初歩的な小さな衛星を打ち上げました

which sent the Western world into a hysterical tailspin.

それを目の当たりにした西側諸国は大いに狼狽し

And a tremendous amount of money

そして莫大な額の資金が

went into the funding of science

科学の振興と 子供たちの

and mathematics skills for kids.

数学教育に注ぎ込まれました

And I'm a product of that generation,

私は他の同僚と同じように

like so many other of my peers.

その時代の産物なのです

It really caught hold of us, and caught fire,

私たちは本当に焚き付けられました

and it would be lovely if we could reproduce that again now.

また再現できれば素晴らしいと思います

Of course, refusing to grow up --

もちろん成長するのを拒んだり

-- even though I impersonate a grown-up in daily life,

日常は大人のふりもできます

but I do a fairly good job of that --

実際そのように振る舞っています

but really retaining that childlike quality

それでも他の人の意見ばかり気にせず

of not caring what other people think

童心を忘れないようにすることは

about what you're interested in, is really critical.

とても大事なことです

The next element is the fact that

他の要素として

I have applied a value judgment

私の価値基準は

and my value judgment is that the presence of life

単純に生命が存在することは

is better than no life.

存在しないことよりも良く

And so, life is more valuable than no life.

存在自体に価値があるのです

And so I think that that holds together

このような姿勢は

a great deal of the work

この会場にいる皆さんにも

that people in this audience approach.

共通するものだと思います

I'm very interested in Mars, of course,

もちろん私は火星にとても関心があります

and that was a product of my being a young undergraduate

バイキング着陸船が火星に降り立ったのは

when the Viking Landers landed on Mars.

私が学部生の頃のことです

And that took what had been

火星は空に浮かんでいる

a tiny little astronomical object in the sky,

ほんの小さな天体でしかなく

that you would see as a dot,

点にしか見えなかったのが

and turned it completely into a landscape,

スクリーン上に初めて描写される

as that very first primitive picture

おぼろげな映像を通して

came rastering across the screen.

現実の景色となったのです

And when it became a landscape,

火星の景色は

it also became a destination,

目標にもなり

and altered, really, the course of my life.

私の人生を変えました

In my graduate years I worked with

私が大学院生の時

my colleague and mentor and friend, Steve Schneider,

同僚 師 友人である

at the National Center for Atmospheric Research,

アメリカ大気研究センターの スティーブ・シュナイダー博士は

working on global change issues.

地球変動を研究していました

We've written a number of things on

私たちはガイア理論の役割について 多くの論文を執筆しました

the role of Gaia hypothesis --

私たちはガイア理論の役割について 多くの論文を執筆しました

whether or not you could consider Earth as a single entity

地球を個別の存在として見なすべき

in any meaningful scientific sense,

科学的論拠を検証しました

and then, as an outgrowth of that,

その後派生した研究の中には

I worked on the environmental consequences of nuclear war.

核戦争がもたらす環境破壊があります

So, wonderful things and grim things.

素晴らしい研究や ぞっとする研究です

But what it taught me was to look at Earth as a planet

しかし研究のおかげで地球を棲み家でなく

with external eyes, not just as our home.

一つの惑星として見ることを学びました

And that is a wonderful stepping away in perspective,

生命を育む地球の惑星としての特性を

to try to then think about the way

考察するうえで

our planet behaves, as a planet,

素晴らしい発想の転換を

and with the life that's on it.

得ることができました

And all of this seems to me to be

私にはこれらは歴史の

a salient point in history.

転換点に見えます

We're getting ready to begin to go

私たちは母星を離れて

through the process of leaving our planet of origin

太陽系とその彼方に出発する

and out into the wider solar system and beyond.

準備を始めようとしているのです

So, back to Mars.

火星の話に戻りましょう

How hard is it going to be to find life on Mars?

火星で生命の発見は どの位困難か?

Well, sometimes it's really very hard for us to find each other,

地球上ですら お互いを

even on this planet.

探すのはとても困難です

So, finding life on another planet

他の惑星で生命を見つけるのは

is a non-trivial occupation

簡単な仕事ではありません

and we spend a lot of time trying to think about that.

検討には多くの時間を費やします

Whether or not you think it's likely to be successful

発見できるかどうかは

sort of depends on what you think about

宇宙に生命がいる可能性を

the chances of life in the universe.

どう考えるか次第でしょう

I think, myself,

私が考えるのは

that life is a natural outgrowth

生命は長年にわたり物質が高度に

of the increasing complexification of matter over time.

進化した自然な結果だということです

So, you start with the Big Bang and you get hydrogen,

ビッグバンから始まり 水素が生まれ

and then you get helium, and then you get more complicated stuff,

ヘリウム さらに複雑な物質が生まれ

and you get planets forming --

惑星が誕生します

and life is a common, planetary-based phenomenon, in my view.

生命も同様に惑星の現象の 一つだと私は考えます

Certainly, in the last 15 years,

この15年間で

we've seen increasing numbers of planets

我々は太陽系以外でも

outside of our solar system being confirmed,

多くの惑星を発見してきました

and just last month, a couple of weeks ago,

そして 昨月 数週間前のことですが

a planet in the size-class of Earth

地球と同程度の大きさの惑星が

has actually been found.

見つかりました

And so this is very exciting news.

非常に驚くべきニュースでした

So, my first bold prediction is that,

私が言う最初の大胆な予測は

is that in the universe, life is going to be everywhere.

この宇宙には生命があふれているのです

It's going to be everywhere we look --

生命を維持できそうな惑星系では

where there are planetary systems that can possibly support it.

至る所で生命を発見できるでしょう

And those planetary systems are going to be very common.

そのような惑星系は普通にあります

So, what about life on Mars?

では火星に生命はいるでしょうか?

Well, if somebody had asked me about a dozen years ago

もし10数年前に誰かが私に

what I thought the chances of life on Mars would be,

火星に生命がある可能性を尋ねたら

I would've probably said, a couple of percent.

数%と答えたことでしょう

And even that was considered outrageous at the time.

それでも当時としては無謀な意見でした

I was once sneeringly introduced

私は以前NASAの職員に

by a former NASA official,

火星に生命があると考える

as the only person on the planet

地球上唯一の人間だと

who still thought there was life on Mars.

皮肉っぽく紹介されました

Of course, that official is now dead, and I'm not,

その職員は亡くなりましたが私は健在です

so there's a certain amount of glory

自分の反対者より長生きすることは

in outliving your adversaries.

ある意味 名誉なことですね

But things have changed greatly

しかしこの10数年で

over the last dozen years.

状況が大きく変わりました

And the reason that they have changed

理由は新しい情報を

is because we now have new information.

入手したからです

The amazing Pathfinder mission that went in '97,

1997年のパスファインダー計画と

and the MER Rover missions

現在まさに火星で活動中の

that are on Mars as we speak now

火星探査車計画

and the European Space Agency's Mars Express,

そして欧州宇宙機関のマーズ・エクスプレスから

has taught us a number of amazing things.

様々な驚くべきことを学びました

There is sub-surface ice on that planet.

火星には地表下に氷があります

And so where there is water,

水がある場所では地球に似た

there is a very high chance of our kind of life.

生命がいる可能性が高いです

There's clearly sedimentary rocks all over the place –

地表は堆積した岩で覆われています

one of the landers is sitting in the middle of an ancient seabed,

太古の海底に到達した着陸船があります

and there are these amazing structures called blueberries,

そこには「ブルーベリー」と呼ぶ奇妙な構造があり

which are these little, rocky concretions

その小さな岩の塊は

that we are busy making biologically

私の研究室で生物的に

in my lab right now.

作成するのと似ています

So, with all of these things put together,

あらゆる発見を考慮すると

I think that the chances of life

生命存在の可能性は

are much greater than I would've ever thought.

かつてない程高まっています

I think that the chance of life having arisen on Mars, sometime in its past,

火星で過去に生命が存在した確率は

is maybe one in four to maybe even half and half.

25％〜50％程度と私は考えています

So this is a very bold statement.

とても大胆な見解です

I think it's there, and I think we need

生命はいます 探すべきです

to go look for it, and I think it's underground.

探すべきは地下です

So the game's afoot, and this is the game that we play in astro-biology.

これはいわば宇宙生物学のゲームです

How do you try to get a handle on extraterrestrial life?

どうすれば地球外生命を 解明できるのでしょうか

How do you plan to look for it?

探索の計画は？

How do you know it when you find it?

生命の発見をいかに認識できるのか?

Because if it's big and obvious, we would've already found it --

大型で判り易い生命なら既に 発見したはずですが そうはいきません

it would've already bitten us on the foot, and it hasn't.

大型で判り易い生命なら既に 発見したはずですが そうはいきません

So, we know that it's probably quite cryptic.

つまり 判り難いのです

Very critically, how do we protect it,

重要なことは 発見した際に

if we find it, and not contaminate it?

いかに守り 汚染を防ぐのか

And also, even perhaps more critically, because

さらに重要なことは

this is the only home planet we have,

私たちの唯一の母星である地球を

how do we protect us from it, while we study it?

地球外生命から守りながら 研究を継続できるか?

So why might it be hard to find?

発見が困難な理由は何でしょうか?

Well, it's probably microscopic, and it's never easy

非常に微小だからです 微小物の研究は常に困難です

to study microscopic things,

非常に微小だからです 微小物の研究は常に困難です

although the amazing tools that we now have to do that

最新の機器を用いて

allow us to study things in much greater depth,

さらに深く より小さい物質も

at much smaller scales than ever before.

調査できる今日でも困難です

But it's probably hiding, because if you are out

生命は隠れているはずです

sequestering resources from your environment, that makes you yummy,

もし誰かが目立った存在ならば

and other things might want to eat you, or consume you.

格好の獲物になってしまうでしょう

And so, there's a game of predator-prey

つまり生物界における捕食者と獲物の

that's going to be, essentially, universal, really,

関係はどこの生態系でも通用する普遍的な

in any kind of biological system.

仕組みなのです

It also may be very, very different in its fundamental properties –

化学的成分や大きさ等の根本的な性質は

its chemistry, or its size.

全く異なることでしょう

We say small, but what does that mean?

ではどの位小さいのでしょうか

Is it virus-sized? Is it smaller than that?

ウイルス位? もっと小さい?

Is it bigger than the biggest bacterium? We don't know.

最大のバクテリアよりは大きい?

And speed of activity, which is something that we face

生物の活動速度は?

in our work with sub-surface organisms,

地中で調査する生物は

because they grow very, very slowly.

大変ゆっくり成長します

If I were to take a swab off your teeth

もし私が誰かの歯をガーゼで拭い

and plate it on a Petri plate,

それをペトリ皿に入れたとします

within about four or five hours, I would have to see growth.

4−5時間経てば細菌の成長を観察できます

But the organisms that we work with,

私たちが研究する生物は

from the sub-surface of Earth,

数ヶ月 数年の 期間を経てようやく

very often it's months -- and in many cases, years --

数ヶ月 数年の 期間を経てようやく

before we see any growth whatsoever.

成長を観察できます

So they are, intrinsically, a slower life-form.

これらの生物は成長が遅いのです

But the real issue is that we are guided by

しかし根本的な問題は

our limited experience,

私たちの経験が浅いため

and until we can think out of the box of our cranium and what we know,

発想を変えて 今ある知識を捨てない限り

then we can't recognize what to look for,

何をどう探せばよいか

or how to plan for it.

見当つかないことです

So, perspective is everything

発想の視点が全てです

and, because of the history that I've just briefly talked to you about,

今お話した私自身の経験から

I have learned to think about Earth

地球を一つの惑星として

as an extraterrestrial planet.

考えるようになりました

And this has been invaluable in our approach to try to study these things.

これは私の研究において 非常に重要な点です

This is my favorite game on airplanes:

飛行機でよくする遊びです

where you're in an airplane and you look out the window,

機内から窓の外を眺めると

you see the horizon.

地平線が見えますね

I always turn my head on the side,

そして頭を横に倒すと

and that simple change makes me go from

地球が私たちの母星ではなく

seeing this planet as home,

一つの惑星のような

to seeing it as a planet.

感覚になります

It's a very simple trick, and I never fail to do it

簡単な遊びで窓際に座ると

when I'm sitting in a window seat.

いつもしています

Well, this is what we apply to our work.

これを研究にも応用しました

This shows one of the most extreme caves that we work in.

ここは最も過酷な洞窟の一つ

This is Cueva de Villa Luz in Tabasco, in Mexico,

メキシコ タバスコ州の ヴィラ・ルース洞窟で

and this cave is saturated with sulfuric acid.

洞窟内は硫酸が充満しています

There is tremendous amounts of hydrogen sulfide

火山やこの洞窟を形成する

coming into this cave from volcanic sources

炭酸塩のミネラル分である

and from the breakdown of evaporite --

石膏の分解により

minerals below the carbonates in which this cave is formed --

大量の硫化水素が洞窟内に流入し

and it is a completely hostile environment for us.

非常に過酷な環境です

We have to go in with protective suits and breathing gear,

防護服と防護マスクは欠かせません

and 30 parts per million of H2S will kill you.

30ppmの硫化水素でも死に至りますが

This is regularly several hundred parts per million.

ここでは数百ppmを超えます

So, it's a very hazardous environment,

一酸化炭素等の有毒ガスもあり

with CO as well, and many other gases.

非常に危険な環境です

These extreme physical and chemical parameters

この極端な物理的 化学的環境で

make the biology that grows in these places very special.

育つ生命は生物学的にとても特殊です

Because contrary to what you might think, this is not devoid of life.

実はここは生命と無縁ではありません

This is one of the richest caves

ここは私たちが発見した中で最も

that we have found on the planet, anywhere.

豊かな洞窟の一つで

It's bursting with life.

生命で溢れていました

The extremes on Earth are interesting in their own right,

地球上のへき地が興味深い

but one of the reasons that we're interested in them

理由の一つは他の惑星で

is because they represent, really,

遭遇する平均的環境を

the average conditions that we may expect on other planets.

再現していると思えるからです

So, this is part of the ability that we have,

このようにして私たちは

to try to stretch our imagination,

想像力をかき立て

in terms of what we may find in the future.

将来の発見に備えるのです

There's so much life in this cave,

この洞窟には多様な生命があり

and I can't even begin

今日紹介するのは

to scratch the surface of it with you.

ほんの一部だけです

But one of the most famous objects out of this

ここで最も有名な生物は

are what we call Snottites, for obvious reasons.

「スノティテス」と呼ばれます

This stuff looks like what comes out of your two-year-old's nose when he has a cold.

まるで風邪をひいた２歳児の 鼻から流れ出るものと同じです

And this is produced by bacteria who are actually

この物体は実際に硫酸を作り出す

making more sulfuric acid,

バクテリアにより生成され

and living at pHs right around zero.

pH0に近い状態で生息します

And so, this stuff is like battery acid.

まるで蓄電池の鉛酸です

And yet, everything in this cave has adapted to it.

あらゆる生物がこの洞窟に適応しています

In fact, there's so much energy available

実際この洞窟には生物の

for biology in this cave,

エネルギーに満ち溢れており

that there's actually a huge number of cavefish.

たくさんの洞窟魚もいます

And the local Zoque Indians

現住民のソケ族は

harvest this twice a year,

年に二回 イースターと聖週間に

as part of their Easter week celebration and Holy Week celebration.

この魚を収穫しています

This is very unusual for caves.

洞窟では非常に稀です

In some of the other amazing caves that we work in --

他に研究したことがある洞窟では―

this is in Lechuguilla cave in New Mexico near Carlsbad,

ニューメキシコ州 カールズバッド 近郊にあるレチュギヤ洞窟は

and this is one of the most famous caves in the world.

世界で最も有名な洞窟の一つです

It's 115 miles of mapped passage,

長さは180Kmあり

it's pristine, it has no natural opening

開口部がない 手つかずの空間です

and it's a gigantic biological,

生物学 地質微生物学の

geo-microbiological laboratory.

いわば巨大な研究室です

In this cave, great areas are covered by

洞窟内の大半は この赤い物質で

this reddish material that you see here,

覆われており

and also these enormous crystals

非常に大きな石膏の水晶が

of selenite that you can see dangling down.

吊り下がっているのが見えます

This stuff is produced biologically.

これらは生物学的に生成されたもので

This is the breakdown product of the bedrock,

微生物が岩盤を

that organisms are busy munching their way through.

捕食した結果です

They take iron and manganese minerals

岩盤から鉄とマンガンの成分を 取り出し酸化させます

within the bedrock and they oxidize them.

岩盤から鉄とマンガンの成分を 取り出し酸化させます

And every time they do that, they get a tiny little packet of energy.

その際 非常に微量なエネルギーを発生します

And that tiny little packet of energy is what they use, then,

その微量なエネルギーがこの微生物の

to run their life processes.

糧となっているのです

Interestingly enough, they also do this

面白いことに この微生物は

with uranium and chromium, and various other toxic metals.

ウランやクロム等 毒性の金属も 同様に消費します

And so, the obvious avenue

このような微生物は

for bio-remediation

生物学的修復を確立する

comes from organisms like this.

明らかな基盤です

These organisms we now bring into the lab,

研究室に持ち帰った

and you can see some of them growing on Petri plates,

これらの微生物をペトリ皿で培養し

and get them to reproduce the precise biominerals

洞窟にあるのと全く同じ生体鉱物を

that we find on the walls of these caves.

生成させようとしています

So, these are signals that they leave in the rock record.

これらが微生物たちが岩盤に残した印です

Well, even in basalt surfaces in lava-tube caves,

火山活動の副産物である溶岩洞の

which are a by-product of volcanic activity,

玄武岩の壁面が

we find these walls totally covered,

銀 ピンク 赤 金色等に

in many cases,

美しく輝く膜で

by these beautiful, glistening silver walls,

完全に覆われているのを

or shiny pink or shiny red or shiny gold.

数多く発見しています

And these are mineral deposits

これらはバクテリアが

that are also made by bacteria.

作った鉱床なのです

And you can see in these central images here,

中央に見える画像は

scanning electron micrographs of some of these guys --

このバクテリアの培養液の

these are gardens of these bacteria.

電子顕微鏡写真です

One of the interesting things about these particular guys

興味深いのはこれらのバクテリアは

is that they're in the actinomycete

放線菌群に属しており

and streptomycete groups of the bacteria,

私たちが抗生物質を作る際に

which is where we get most of our antibiotics.

使う菌種と同じです

The sub-surface of Earth

地球の地下は生命の

contains a vast biodiversity.

多様性に満ちています

And these organisms,

これらの微生物は

because they're very separate from the surface,

地表から隔絶されているため

make a vast array of novel compounds.

非常に多くの新しい混合物があります

And so, the potential for exploiting this

この分野を医薬や

for pharmaceutical and industrial chemical uses

工業化学へ応用するのは

is completely untapped,

全く手付かずの状況ですが

but probably exceeds most of the rest

地球上の他の生物多様性よりも

of the biodiversity of the planet.

大きな可能性があります

So, lava-tube caves--

溶岩洞について話します

I've just told you about organisms that live here on this planet.

地球の洞窟の生物はお話しました

We know that on Mars and the Moon

火星や月にも似たような構造が

there are tons of these structures.

非常に多くあります

We can see them.

見てみましょう

On the left you can see a lava tube forming

左の写真は最近のシチリア島のエトナ火山が

at a recent eruption -- Mount Etna in Sicily --

噴火した際に溶岩洞が形成される様子を

and this is the way these tubes form.

示しています

And when they hollow out,

ここに空洞ができ

then they become habitats for organisms.

生物が発生するのです

These are all over the planet Mars,

火星の至る所にも溶岩洞があり

and we're busy cataloguing them now.

私たちは今それらを分類中です

And so, there's very interesting cave real estate

火星には同様な種類の

on Mars, at least of that type.

興味深い洞窟が多くあります

In order to access

これらの調査対象の

these sub-surface environments that we're interested in,

地下環境に到達するための

we're very interested in developing the tools to do this.

機器を現在開発中です

You know, it's not easy to get into these caves.

容易なことではありません

It requires crawling, climbing,

這って進んだり 登ったり

rope-work, technical rope-work

ロープを使ったりと

and many other complex human motions

到達するには様々な複雑な人間の動きが

in order to access these.

要求されます

We face the problem of, how can we do this robotically?

この動作をロボットにどう仕込むかが問題です

Why would we want to do it robotically?

ロボットを使う理由は何か?

Well, we're going to be sending

有人計画よりも前から

robotic missions to Mars

ロボットを火星に送って

long in advance of human missions.

探査をするからです

And then, secondly, getting back to that earlier point that I made

そして既に話したとおり火星で

about the preciousness of any life that we may find

発見するであろう貴重な生命を

on Mars, we don't want to contaminate it.

汚染したくありません

And one of the best ways to study something without contaminating it

対象を汚染することなく調査するには

is to have an intermediary.

媒介を使うのが最善です

And in this case, we're imagining

この場合にはロボットが

intermediary robotic devices

媒介になり 発見できた

that can actually do some of that

生命を保護しながら

front-end work for us,

私たちの研究の下準備を

to protect any potential life that we find.

実際にすることになります

I'm not going to go through all of these projects now,

今回は計画の全てはお話しませんが

but we're involved in about half-a-dozen robotic development projects,

私たちは現在様々な研究グループと共同で

in collaboration with a number of different groups.

数件のロボット開発計画に携わっています

I want to talk specifically about the

本日特にお話したいのは

array that you see on the top.

写真上部の機器です

These are hopping microbot swarms.

これは超小型の飛跳ねるロボット群です

I'm working on this with the Field and Space Robotics Laboratory

私はMITロボティックス研究所の

and my friend Steve Dubowsky at MIT,

ドヴォースキー教授と共同開発しています

and we have come up with the idea

人工筋肉を付けた

of having little, jumping bean-like

豆のような小さくて

robots

飛跳ねるロボットを

that are propelled by artificial muscle,

考案しました

which is one of the Dubowsky Lab's specialties --

ドヴォースキー研究室の専門はEPAM (電場応答高分子型人工筋肉)

are the EPAMs, or artificial muscles.

つまり人工筋肉です

And these allow them to hop.

これで飛跳ねることができます

They behave with

昆虫の群れを真似て

a swarm behavior,

お互いに連携しながら

where they relate to each other,

群れで行動します

modeled after insect swarm behavior,

そして何より

and they could be made very numerous.

非常に多くの個体を作れます

And so, one can send a thousand of them,

一度に千個を送ることができ

as you can see in this upper left-hand picture,

左上の画像にあるように

a thousand of them could fit into the payload bay

千個を貨物室に収めて

that was used for one of the current MER Rovers.

現在の火星探査計画でも使用しています

And these little guys -- you could lose many of them.

たくさんの個体を失っても構いません

If you send a thousand of them,

千個も送ることができれば

you could probably get rid of 90 percent of them and still have a mission.

90％を失っても計画は遂行できます

And so, that allows you the flexibility

そして探索したい場所の

to go into very challenging terrain

非常に困難な環境でも

and actually make your way where you want to go.

柔軟に対応できます

Now, to wrap this up, I want to talk for two seconds

最後に私たちの洞窟での研究の延長線として

about caves and the human expansion beyond Earth

他の惑星の洞窟と移住の可能性を

as a natural outgrowth of the work that we do in caves.

お話したいと思います

It occurred to us a number of years ago

だいぶ前に気付いたのですが

that caves have many properties

洞窟には人類や他の生物が

that people have used

棲み家に利用するのに適した

and other organisms have used as habitat in the past.

条件が揃っています

And perhaps it's time we started to explore those,

将来の月や火星の探査を考える時

in the context of future Mars and the Moon exploration.

その条件を考慮すべき段階に来ているでしょう

So, we have just finished a NASA Institute for Advanced Concepts Phase II study,

私たちはちょうど NIAC の第2期研究を完了しました

looking at the irreducible set of technologies

その中で月や火星の

that you would need in order to

溶岩洞で人間が生活するのに

actually allow people to inhabit lava tubes

必要不可欠な技術は

on the Moon or Mars.

何かを研究しました

It turns out to be a fairly simple and small list,

結果は非常に単純で短い項目で

and we have gone

比較的従来の技術で

in the relatively primitive technology direction.

対応しうる内容です

So, we're talking about things like inflatable liners

例えば洞窟の内部の

that can conform to the complex topological shape

対応して自在に脹らむことができる

on the inside of a cave,

裏地膜であったり

foamed-in-place airlocks to deal with this complex topology,

複雑な形状に合わせてエアロックを作ったり

various ways of getting breathing gases

内部固有の物質を利用して呼吸する

made from the intrinsic materials of these bodies.

空気を生成する技術等です

And the future is there for us

将来火星の溶岩洞を

to use these lava-tube caves on Mars.

活用するのは現実的です

And right now we're in caves, and we're doing science and recreation,

私たちは今洞窟を科学や娯楽で使用しています

but I think in the future we'll be using them

しかし将来 地球外洞窟は

for habitat and science on these other bodies.

居住地や科学目的で活用されるでしょう

Now, my view of what the current status

さて 火星の生命の可能性について

of potential life on Mars is

現状の私の意見では

that it's probably been on the planet,

おそらく存在したことがあった

maybe one in two chances.

確立は50%と見ます

The question as to whether

火星の生命と地球の生命には

there is life on Mars that is related to life on Earth

何らかの関連があるという仮説が

has now been very muddied,

議論を呼んでいます

because we now know,

火星からの隕石が

from Mars meteorites that have made it to Earth,

地球に到達して二つの惑星間で

that there's material that can be exchanged between those two planets.

物質の交換があることが既に判明しています

One of the burning questions, of course, is

最大の関心事の一つは

if we go there and find life in the sub-surface,

もし火星の地下で 私たちが望むとおりに

as I fully expect that we will,

生命を発見したら それは

is that a second genesis of life?

「第二の生命の誕生」なのか?

Did life start here

地球で生命が誕生し

and was it transported there?

火星に移住したのか

Did it start there and get transported here?

それとも火星から地球にやってきたのか?

This will be a fascinating puzzle as we go into the next half-century,

これは非常に心躍る話題です 今後50年に渡り

and where I expect that we will

より多くの火星探査計画を通して

have more and more Mars missions to answer these questions.

この問いの答えが明らかになるでしょう

Thank you.

ご清聴ありがとうございました