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  • SciShow is supported by Blue Apron.

  • Right now, Blue Apron is offering $50 off two boxes of meals to the first 50 SciShow

  • Space viewers to sign up.

  • Get fresh ingredients and chef-designed recipes delivered right to your door.

  • Just click on the link in the description to get $50 off your first two Blue Apron boxes.

  • [ ♪ Intro ]

  • These days, it seems like we're closer than ever to transporting humans around the solar system.

  • But getting people into space is one thing; keeping them alive is a whole different ball game.

  • It's the difference between exciting new exploration and just a really expensive way to die.

  • Among a bunch of other things, one of the most important elements to sustaining life

  • beyond Earth is making sure we're really well fed.

  • So far, a lot of thinking has gone into ways to grow food in places like the Moon or Mars,

  • but those are just single locations in the vast solar system.

  • What we really need is a cosmic food court capable of feeding us wherever we go.

  • And for that, we might want to look to the asteroid belt!

  • All this concern about growing food is necessary because of our pesky friend gravity.

  • It takes a ton of energy to escape the Earth's gravitational pull, and even with reusable

  • rockets, getting to space can be pretty pricey.

  • Take SpaceX's new Falcon Heavy rocket, for instance.

  • It's among the most efficient rockets today, but pack it full of food for Mars and you'd

  • be paying more than $5,000 per kilogram.

  • For a one-off trip, maybe that makes sense, but to settle humans on Mars it would cost

  • $5,000 per kilogram per person, for the rest of their lives.

  • That's just not sustainable.

  • Conveniently, though, it turns out we've solved this problem before, like a lot, — and

  • with something really simple: seeds.

  • One obvious example is when Europeans crossed the Atlantic to settle in North America, they

  • didn't bring a lifetime's worth of food with them.

  • Instead, they brought the means to create more food once they got there.

  • They farmed.

  • In that example, North America already had people who were farming, but it's still

  • a good tactic for getting food to space!

  • Once we figure a few things out, this could work for a place like Mars, where settlers

  • could grow food right on the surface.

  • But if we sent people to Jupiter's moon Europa or Saturn's moon Titan, things would

  • get more complicated.

  • Those trips would last for years, and because of their surface conditions, there'd be

  • nowhere to farm right when we got there.

  • That's where asteroids come in.

  • Since they mostly orbit between Mars and Jupiter, they could be a convenient gateway to the

  • outer solar system.

  • They're also a lot smaller than even the Moon, meaning they have dramatically less

  • gravity to escape, which would greatly reduce the food's cost to ship.

  • Ceres, which is often considered the largest asteroid, has about 3% of Earth's surface

  • gravity, and most others have thousands of times less than that.

  • Most importantly, though, some kinds of asteroids may already contain many of the most important

  • nutrients for life.

  • They're called carbonaceous asteroids, or sometimes C-types.

  • C-types are probably the most common kind of asteroid, but they're remarkably difficult

  • to study because of their appearance.

  • They reflect just a tiny percentage of the Sun's light, and probably look more like

  • coal than whatever you're picturing right now.

  • I say probably because we haven't really been able to study carbonaceous asteroids

  • in great detail.

  • Instead, most of what we think we know about them comes from meteorites called carbonaceous

  • chondrites, which are likely chips of C-type asteroids.

  • Based on the name, you might think they're mostly made of carbon.

  • But they only contain a small percentage of carbon at best, along with nitrogen, potassium,

  • and phosphorus.

  • Sounds like fertilizer, doesn't it?

  • Amazingly, deep inside these meteorites, we've also found evidence of some of the same amino

  • acids that are inside our bodies, as well as other organic compounds.

  • To top it all off, some carbonaceous chondrites contain up to 20% of their weight in water.

  • Some of that was surely absorbed here on Earth, but many meteorites contain evidence suggesting

  • they formed in the presence of liquid water, too.

  • These useful elements were even enough for one chemist to grow plants in crushed up meteorites!

  • But hold your space tractors, because we're not ready to start farming just yet.

  • Ironically, the main obstacle to growing plants on an asteroid might be one of its main benefits: microgravity.

  • Space station and Space Shuttle experiments going back decades have tried to grow plants

  • in zero-g with only limited success.

  • Even though the plants often grow well, the seeds they produce rarely create a healthy

  • second generation.

  • Which is obviously key, if you're looking to set up a long-term farming operation.

  • But some recent experiments are finding more success, so it's not all bad news.

  • And, of course, we'd still need to provide the right atmosphere, enough sunlight, and

  • protection from cosmic radiation, so this is an idea for the long haul.

  • But if we can get it right, the dividend could be awesome, in the true sense of the word.

  • One estimate suggests that the total population of C-type asteroids could sustain a billion

  • humans for the rest of the Sun's lifetime -- no matter where they are.

  • Fortunately, we're also about to reach an important milestone in all of this.

  • This summer, Japan's Hayabusa2 spacecraft will reach the asteroid Ryugu, marking the

  • first time we can properly study a C-type asteroid up close.

  • What's more, Hayabusa2 will also scoop up a piece of its surface and return the sample

  • to Earth by late 2020.

  • So, who knows?

  • Maybe that could start the clock towards a future fed by asteroids.

  • Thanks to Blue Apron for sponsoring this video.

  • And for giving me the confidence to cook pork chops for the first time!

  • I did not grow up in a cooking house, so even though I like to try new foods, I don't

  • know how to bring them into being in my kitchen.

  • And it's a problem because my boyfriend is a really good cook and he'll ask me to

  • help him season things and I just panic and put a ton of cumin in EVERYTHING.

  • But the other night I made pork chops with quick pickled cabbage and potato salad with

  • buttermilk dressing.

  • Blue Apron recipes are super straightforward and explain everything, so you're learning

  • to cook while making a really good meal.

  • And, if you get nervous in the kitchen, like I do, it's really comforting to have those

  • step-by-step instructions.

  • I didn't overthink, or over season, anything, and it turned out delicious.

  • So to build your own confidence in the kitchen, check out Blue Apron at the link in the description.

  • Prices start at $7.49 per serving, and the first 50 SciShow viewers to sign up, get $50

  • off your first two weeks!

  • [ ♪ Outro ]

SciShow is supported by Blue Apron.

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搬過來,火星。我們可以在小行星上養殖! (Move Over, Mars: We Could Farm on Asteroids!)

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    林宜悉 發佈於 2021 年 01 月 14 日
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