Name: How To Terraform Venus (Quickly)
Uploaded: 2022-04-11T23:37:39.000Z
Duration: 12 min 48 s

Leaving earth to find new homes in space is an old dream of humanity and will sooner or

地球を離れ、宇宙に移住するのは 古来からのロマンで

later be necessary for our survival. The planet that gets the most attention is Mars, a small,

人類存続に遅かれ早かれ必要になる

程度の副詞

toxic and energy poor planet that just about seems good enough for a colony of depressed

最も注目されているのは火星で

小さく、有毒でエネルギー不足なこの星は

But what if we think bigger? What if we take Venus, one of the most hostile and deadly

地下都市に憂鬱な人間を すし詰めにするぐらいならできそうだ

places in the solar system and turn IT into a colony? Not by building lofty cloud cities,

視野を広げ、金星はどうだろう？

but by creating a proper second earth? It might be easier than you think.

太陽系で最も過酷で危険な場所の一つを コロニーにするなら？

Venus is by far the hottest planet in the solar system with a surface temperature of

雲上の都市ではなく まさに第二の地球を築くとしたら？

460°C, hot enough to melt lead. This heat is due to the most extreme greenhouse effect

in the solar system. CO2 is great at trapping heat – even a rise from 0.03% to 0.04% in

Earth's atmosphere is heating up our planet right now. Venus's atmosphere is 97% CO2.

表面温度は460℃ 鉛を溶かすレベルだ

Also, Venus's atmosphere is 93 times denser than earth's. Standing on Venus' surface

これは太陽系最強の温室効果によるものだ

would feel like taking a dive about 900 meters deep into the ocean. The pressure would kill

地球の大気中で0.03%から0.04%に上昇しただけで 今まさに温暖化が起きている

It's a truly horrible place! So why should we even bother?

First and foremost, Venus is almost as big as Earth and has 90% of its surface gravity.

Surface gravity is a big problem when colonizing the solar system because it is very likely

金星の地表に立つことは 水深900mに潜るようなものだ

that long stays in low gravity places will have negative health effects.

Venus' size means it could be the second largest habitat in the solar system. A new

home for billions of humans and trillions of animals. With oceans, lush forests and

a beautiful blue sky. A properly terraformed Venus may be the most pleasant place to live

何より重要なのは、金星の重量は地球の90％と ほぼ同サイズなことだ

太陽系への移住において重力は深刻な問題で 長期間の低重力は健康に悪影響だ

While we can't exactly terraform Venus today, a slightly more ambitious future version of

サイズ的に、金星は太陽系で 2番目に大きな居住地になりうる

us COULD take this project on. It will take a few generations to complete and be a huge

数十億の人間、数兆の動物たちの新たな住処だ

challenge – like building the great pyramids was for our ancestors. But then it's not

海と、豊かな森と、美しい空もある

like humans have never started projects that took more than a lifetime to complete.

適切にテラフォーミングされれば 地球を除き最も快適な場所になりうる

Before anything else, we need to cool Venus down and remove the gas that makes up the

未来の人類の野心があれば取り組める

extremely heavy atmosphere. As mentioned, there is a lot of it. Around 465 million billion

完成には数世代を要し、大きな挑戦となる

祖先が巨大ピラミッドに挑んだときのように

How do we do that? There are a few options. We could create giant solar collectors powering

しかし、世代を超えたプロジェクトの前例はあるのだ

a huge array of laser beams, that heat up the atmosphere so much that it is blasted

into space. Although we would need thousands of times the entire power generating capacity

とにかく金星を冷やし 極度に重い大気からガスを取り除くことだ

of humanity and it would still take thousands of years to remove the atmosphere.

先述した通り、その量は膨大で 約46.5京トンだ

Another way is to sequester the atmosphere. Binding the CO2 in different compounds through

どう除去するか？ いくつかの選択肢がある

chemical reactions. We could mine elements like Calcium or Magnesium on Mercury and shoot

巨大な太陽熱収集器からレーザーを照射し 大気を加熱して宇宙に放出させる方法があるが

them at Venus via mass driver systems – Electric rails that make rockets unnecessary on smaller

現人類のエネルギー産生能力の数千倍を要するうえ 大気を除くのに数千年かかる

planets. The metals would combine to bind the CO2 into different carbonates basically

もう一つの方法は大気の隔離だ CO2を化学反応で異なる化合物にする

forever. But the scale makes the whole thing impractical. We would need several hundred

水星でCaやMgを採掘し マスドライバーを介して金星に打ち込む

billion tons of material to sequester the CO2 this way. Seems like a waste of material

ロケットを不要とする電動加速路だ

届いた元素はCO2と結合し 炭酸塩として固定される

An equally ridiculous idea that could actually work is to put Venus in the shade. Literally.

By constructing a huge mirror to blot out the sun to just freeze the atmosphere. The

この方法では数千億トンの材料が必要となる

mirror does not need to be complex or massive, just a very thin foil with a little structural

材料の無駄遣いに思え 時間もかかりすぎる

support. Building such a large flat surface so close to the sun will turn it effectively

同じくらいぶっ飛んだ発想として 「金星を日陰に置く」案がある

into a solar sail and push it out of position, so instead of one giant circular object, our

巨大な鏡を作って太陽を遮断し 大気を凍らせるのだ

mirror will consist of many different pieces.

鏡に複雑さや巨大さは必要なく 薄片に少しの構造的支持があればいい

Annular slats of angled mirrors can reflect sunlight from one set of mirrors to the next.

太陽の近くに巨大な平面を作ると、 ソーラー帆として機能し位置がずれてしまうので

Mirrors would be angled, reflecting light from one to another until the light is redirected

一つの円形の物体にはせず 多くのパーツで構成する

to the back - balancing the force on the front and holding them in position.

環状で角度のついた鏡を複数配置すると 太陽光を反射させあうことができる

After a few years of getting the infrastructure in place, things start slowly and then escalate.

鏡は角度がついており、後方に光を送り出すまで 次々に反射していくことで

For the first few decades, the atmosphere slowly cools down but stays dense and deadly.

前後の力が釣り合い 位置を固定できる

Until, after some 60 years it reaches the critical temperature of 31° Celsius. Suddenly,

数年がかりで整えると 物事は緩やかにはじまり、加速していく

the Great Flood begins on Venus, as CO2 turns to liquid at this pressure and begins to rain

最初の数十年、大気はゆっくり冷えていくが 高密度で生存不能なままだ

down- a constant global rainstorm of unbelievable proportions lasting 30 years. The pressure

そして約60年後 臨界温度の31℃に達する。

and temperature suddenly begin to drop in unison. For almost a century, puddles turn

突如、洪水が始まった CO2が圧力で液化し、雨を降らせ始めたのだ

30年にわたり、金星中で嵐が続く

The surface temperature is now -56° Celsius and the pressure has dropped to only seven

突如、圧力と気温が同時に下がり始める

times the pressure on earth. Finally, at a really unpleasant -81°, the CO2 oceans begin

約1世紀にわたり、水たまりは湖や海になっていく

to freeze and the rain turns into snow. This leaves us with a frozen Venus covered in oceans

地表温度は-56℃ 気圧は地球上の7倍にまで低下した。

as hard as rock and gigantic CO2 glaciers. What remains of the atmosphere is mostly nitrogen,

-81℃に達するとCO2の海が凍り始め 雨は雪へと変わる

at about 3 times earth's surface pressure. If you don't mind freezing and suffocating,

こうして金星は凍り 岩のような海と巨大なCO2氷河におおわれる

you can now take a stroll over Venus' surface.

大気に残るのはほとんどが窒素で 地球の約3倍の圧力がかかっている

But the frozen CO2 remains a bit of a problem. At some point we want to warm up the planet,

凍死や窒息死を厭わないなら 金星の表面を散策するのもいいだろう

but if we do, the CO2 ice will melt and fill up the atmosphere again.

だが凍ったCO2には少々問題もあり

So we need some way to keep it from doing that.

いずれ金星を暖めることになると CO2の氷がとけ、また大気に充満してしまう

One is to simply cover it all with cheap plastic insulation and cover it up with ground-up

venus rock or water oceans. Although some planetary scientists will be very stressed

一つは、安いプラ製の断熱材でCO2の海を覆い さらに金星の岩石や水の海で覆うことだ

out about us building a new planet containing a potential timebomb like that. A few unfortunately

しかし、時限爆弾を抱えた惑星を作ることに 大反対の惑星科学者もいるだろう

timed volcanoes could melt a lot of CO2 at once and ruin everything.

間の悪い噴火が数回あれば 一気にCO2が溶出し全てが台無しになるかも

Another obvious solution is to shoot it all out into space and collect it into a small

もう一つの明確な解決策は、凍ったCO2を全て射出し 小さな月に備蓄しておくことだ

moon for storage and future use. We can make this more efficient by using mass drivers

ロケットでなくマスドライバーが効率的だ

instead of rockets, but moving all that mass will still be a pretty intense challenge that

それでも全ての質量を移動させるのは かなり厳しい課題で、解決には時間がかかる

大気の処理以外にも水の確保が必須だが これは氷の月から得ることができる

Whatever we end up doing with the atmosphere, to move forward we need water, which we could

木星の衛星「エウロパ」には 地球の海の2倍の水がある

get from Ice-Moons. Europa, a moon of Jupiter, has twice as much water as Earth's oceans.

さて、月を捕まえて太陽系内を移動させるのは 容易ではない

Now catching a moon and transporting it through the solar system is not exactly easy.

エウロパの氷を建設用ドローンの編隊で切り取り マスドライバーで金星に撃ち込むほうが簡単かも

So instead it might be easier to cut chunks of ice off Europa with an army of construction

テザーはここでの労力とエネルギーを 大幅に節約するのに役立つ

drones and shoot them at Venus using more of those mass drivers. Space tethers could

テザーの仕組みは他の動画で解説済みだが 簡単に言うと両端にペイロードを搭載できる投石器だ

save us a lot of effort and energy here – we made a whole video explaining how they work,

氷を金星に運ぶプロセスの ほぼ全てはエウロパで行われ

but in a nutshell, they are slings that can take a payload on both ends.

氷が金星側のテザーに当たると 大気中に静かに落とされ、雪となって降り注ぐ

On Europa, they do most of the work needed to catapult our ice to Venus. The ice hits

代わりに、金星側のテザーは打ち上げられた CO2の氷を受け止め、軌道上へと加速する

the Venus tethers, which gently drop it into the atmosphere, where it falls down as snow.

同様に余分な窒素を取り除けば さらに気圧を低下させられる

In exchange, the Venus tethers get to catch CO2 ice shot up from below and accelerate

数十年～数百年後、金星は深さ数100mの 浅い凍った海に覆われており

it into orbit. We can remove excess nitrogen using this same

今とは全く異なる姿になるだろう

method to further lower our atmospheric pressure.

幾つかの大陸と無数の島が形成され 地球に少し似た姿になってきた

After a few decades or centuries, Venus would be covered by a nice, shallow frozen ocean

さて最後にして最も壮大な段階が始まる

a few hundred meters deep. It would look extremely different from today. A few continents and

大気を呼吸可能とし、生命を誕生させるのだ

countless islands have formed. This is beginning to look a bit like our planet!

まずは光で金星を暖めなおす必要がある

Now the last and most magnificent phase of terraforming begins: Making the atmosphere

金星の一日は2802時間で 地球の116日分よりも長い

だから巨大な鏡を外すだけだと 金星の半分が焼かれてしまう

First we need light though and we need to heat the planet up again. A Venus day is 2802

気圧をクリアしても 気温だけで生存不能なレベルだ

hours long. More than 116 Earth days. So if we just remove our giant mirror, we would

昼夜のサイクルを作り エネルギーを取り入れる最も簡単な方法は

grill half of our planet. Even without the massive atmosphere, temperatures would reach

別の鏡を用いて大陸を照らし、海を溶かすことだ

unbearable levels. The simplest way to create a day/night cycle and let some energy in again,

これでエネルギーの量と行き先を 完全に制御できる

is with another set of mirrors to illuminate our continents and melt our water oceans.

この時点で大気はほぼ窒素であり 基本的に酸素はない

Which would let us completely control how much energy we get and where it goes.

だから最初の居住者は 大量のシアノバクテリアになるだろう

The atmosphere is now mostly made up of nitrogen and basically devoid of oxygen. So the first

光合成によって酸素を放出できるからだ

inhabitants will likely be trillions and trillions of Cyanobacteria, which can get photosynthesising

大気の速やかな変化が期待できる

and release oxygen. We know that they can quickly turn around the atmosphere of a planet

何十億年も前、地球の有毒な大気に酸素をもたらし、 高等動物の繁栄を助けたと考えられているのだ