Name: 火星のテラフォーミングはどこまで近づいているのか？ (How Close Are We to Terraforming Mars?)
Uploaded: 2021-01-14T09:58:39.000Z
Duration: 9 min 8 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

WITH TOWERING VOLCANOES, SWIRLING DUST STORMS,

AND PLUMES OF SUBLIMATING DRY ICE AT ITS POLES,

THE SURREAL LANDSCAPE OF MARS HAS CAPTURED THE EARTHLY IMAGINATION FOR CENTURIES.

BUT WHAT WOULD IT TAKE TO MAKE IT HABITABLE?

AS IN, A PLACE WHERE WE COULD BREATHE, WALK AROUND WITHOUT OUR BLOOD BOILING, OR EVEN

THERE HAVE BEEN SOME WILD PROPOSALS ABOUT HOW TO MAKE MARS MORE SUITABLE FOR HUMANS

FROM NUKING THE POLES TO HIJACKING A FLEET OF COMETS

SO, HOW CLOSE ARE WE TO TERRAFORMING MARS?

TERRAFORMING IS A TERM THAT WAS  COINED IN SCIENCE FICTION.

BUT TODAY, THE IDEA IS BEING THROWN AROUND BY A HANDFUL OF ACTUAL SCIENTISTS.

- Terraforming, put simply, is changing the atmosphere and climate of a planet

TO SURVIVE ON MARS, THAT IS, WITHOUT EXTENSIVE EQUIPMENT AND RE-SUPPLY FROM EARTH,

WE'D NEED TO BE ABLE TO DO A FEW SIMPLE THINGS:

BREATHE, STAY CONSCIOUS,  AND NOT FREEZE TO DEATH.

IF WE CAN FIGURE OUT THOSE THREE HURDLES, WE’D HAVE THE LUXURY OF WORRYING

ABOUT LONGER-TERM CONCERNS, LIKE HOW TO GROW FOOD, OR

TRUE, MARS DOESN’T SOUND THAT HOSPITABLE, BUT AFTER MULTIPLE MISSIONS WE’VE FOUND

- We see evidence that there was liquid water

The atmosphere must have been thicker so that greenhouse trapping of heat from the sun would

- Most of Mars' atmosphere escaped to space over the last four billion years.

TO RESTORE IT TO A VERSION THAT’S MORE LIVABLE

FOR HUMANS, WE'D HAVE TO  ADDRESS BREATHING FIRST.

ON EARTH, WE HAVE A DELICIOUS ATMOSPHERE MADE OF AROUND 21% OXYGEN, 78% NITROGEN,

It wouldn't need to be exactly that mix, but we would need a very similar amount of oxygen.

There certainly is enough water locked up in ice on Mars to get some O2 for you.

Unfortunately, there probably isn't enough nitrogen that we could easily get to, to build

up an Earth-like, mostly-nitrogen atmosphere.

If you're willing to wear a gas mask, then the gases could be pretty much anything which

OKAY, FINE – I’LL AGREE TO WEAR A  DJ MARSHMELLO MASK FOR A LITTLE WHILE

SO, THAT BRINGS US TO OUR OTHER GOALS:  STAYING AWAKE AND WARM.

AND IT TURNS OUT, THESE TWO  ACTUALLY GO HAND IN HAND.

IF YOU STEPPED OUTSIDE ON MARS TODAY,  YOU’D PASS OUT INSTANTLY

AND DIE SHORTLY AFTER, AS THE LOW PRESSURE LITERALLY PULLED THE OXYGEN

TEMPERATURES ON MARS SIT, ON AVERAGE, AT A CHILLY −63°C/−81°F.

BUT, IF WE COULD THICKEN THE ATMOSPHERE BY ADDING SOME MASS TO IT, WE MIGHT BE ABLE TO

KICKSTART A GREENHOUSE EFFECT THAT WOULD STABILIZE THE TEMPERATURE,

AND STAVE OFF SOME OF THAT  DEADLY RADIATION, AS WELL.

So the question becomes, is there enough CO2 anywhere on Mars that we can mobilize it

- In terms of the very first sort of  easy baby steps of terraforming Mars,

would be the release of the  easily accessible CO2.

Now, this is the south pole of Mars here.

It's kind of hard to see there, but this is some water ice, but mostly CO2 ice down here…

if you started making the planet warmer, you would sublimate more of it.

- The fast way is to drop thermonuclear weapons over the poles.

- That would only double the atmospheric pressure on Mars.

So we would go from 6% of the  Earth's atmosphere to 12%.

And that's so not enough to heat up the planet.

OTHER SOURCES OF THAT DESIRABLE ATMOSPHERE FOR TERRAFORMING COULD BE HIDING IN MARTIAN

MINERALS AND DUST... BUT THEY’RE  TRICKY TO UNLOCK.

Carbon-bearing minerals have to be heated up to several hundred degrees,

so you'd have to strip mine the planet globally  in order to mobilize that CO2.

So that's about a million billion tons of gas that we would need dug up out of the ground

and then vaporized, or somehow released from those minerals.

And the energy required to do that is staggering.

You'd need the equivalent of running  10,000 gigawatt nuclear power plants constantly

NOW, WE MIGHT BE ABLE TO USE SOMETHING MORE EFFICIENT – A SUPER GREENHOUSE GAS

LIKE HYDROCHLOROFLUOROCARBONS,  FOR EXAMPLE –

BUT WE’D NEED TO BUILD HUNDREDS OF FACTORIES

ON THE PLANET’S SURFACE TO PUMP OUT ENOUGH OF IT TO AFFECT THE CLIMATE.

THEN, OF COURSE, WE’D HAVE TO ADD BACK IN OUR CUSTOM COCKTAIL OF GASES TO ALLOW US TO

TAKE OFF OUR GAS MASKS AND OXYGEN TANKS,  LET ALONE GROW ANY CROPS.

STEALING THE BUILDING BLOCKS OF AN ATMOSPHERE FROM COMETS.

There is a large source of nitrogen, oxygen,

hydrogen, et cetera, in the form of comets.

If you could redirect something like, depending on how big they are, ten thousand to a million

comets, and you were able to crash them into Mars on purpose… that would be possible,

given the distribution of comets  that we have now.

- If you've got a million kilometer-sized objects hitting Mars, that would be pretty damaging.

It would probably devastate the entire surface.

- But really what you would need would be an army

of self-replicating robots that could essentially attach what people call mass drivers, which

would be, let's say, a nuclear power plant on a comet, which could be fed by the water

of that comet and then would use that same water as propellant to act like a rocket,

and over the course of years, redirect those comets to eventually impact Mars.

BUT WITH A NEW GLOBAL ENTHUSIASM FOR SPACE EXPLORATION AT LOWER COSTS,

WE MIGHT SEE SOME OF THE TECHNICAL ADVANCES REQUIRED TO INCH US CLOSER

TO THIS VISION – LIKE AUTONOMOUS NAVIGATION AND IN-SPACE ASSEMBLY OF SPACECRAFT –

BUT EVEN IF WE CAN BUILD AND MASTER  ALL THIS TECHNOLOGY,

字幕リスト動画再生

火星のテラフォーミングはどこまで近づいているのか？ (How Close Are We to Terraforming Mars?)

ultimately

figure

term

enthusiasm