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  • Thanks to LEGO City Space for sponsoring this episode of SciShow Space.

  • You were born to explore the universe,

  • and LEGO wants to inspire the next generation of space experts through building and play!

  • [♪ INTRO]

  • More people than ever are looking forward to the day we send humans to Mars.

  • But if those first explorers are going to spend much time there,

  • they'll need a lot of supplies.

  • Food, water, air, and shelter are critical components of any expedition,

  • but the problem is, they're also heavy.

  • Some estimates suggest it might take as much as 225 kilograms of fuel

  • to send one kilogram of stuff to Mars.

  • And the more fuel you need, the more expensive your mission becomes.

  • So, what if instead of bringing everything with them, astronauts could live off the land?

  • It sounds like sci-fi, but it could be possible thanks to the Sabatier reaction.

  • It's a chemical process we've known about for more than a hundred years,

  • and it promises to create nearly everything a Martian explorer might need, literally out of thin air!

  • This reaction was discovered in the late 1800s

  • and, in 1912, it earned one of its discoverers the Nobel Prize.

  • Its chemical equation says that if you combine carbon dioxide and hydrogen

  • at several hundred degrees Celsius, you produce methane, water, and energy.

  • Originally, this was just cool from a chemistry standpoint,

  • and because methane is the primary component of natural gas, so being able to make more is handy.

  • But in the near future, it could also transform Mars exploration,

  • because this reaction is almost perfect for living on the Red Planet.

  • For one, you wouldn't even need to bring one of the ingredients.

  • The Martian atmosphere is more than 95% CO2,

  • so it naturally supplies all the carbon dioxide you could ever need.

  • Unfortunately, there's far less hydrogen on Mars,

  • so you would have to bring that from Earth, which could get tricky.

  • But if nothing else, hydrogen is literally the lightest element in the universe,

  • so you at least wouldn't have to worry about it weighing down your rocket too much.

  • And besides, dragging that hydrogen around would be totally worth it,

  • because if you have methane, water, and energy, you have almost everything you need for a Mars colony.

  • The energy produced through this reaction could be turned into electricity or heat,

  • or could be used to keep the Sabatier process going.

  • The methane could be used directly as rocket fuel when combined with liquid oxygen.

  • And finally, the water produced could be used for drinking, farming, or rehydrating stored food.

  • Astronauts aboard the International Space Station

  • actually use a Sabatier system to provide drinking water, so this part isn't just theoretical.

  • Still, on Mars, the water wouldn't be just for drinking or agriculture:

  • It could also be used in other chemical reactions to produce an even wider range of substances.

  • For example, we could use water for electrolysis, a process that uses electricity to break apart molecules.

  • In this case, it would break water into pure hydrogen and oxygen.

  • The oxygen might be used to create a habitat's breathable air,

  • while the recovered hydrogen could start another round of the Sabatier reaction.

  • Alternatively, we could combine the water with more carbon dioxide from the atmosphere.

  • If you add some electricity to that mix, you get ethylene gas.

  • Ethylene has many industrial uses,

  • but Martian explorers might be especially interested in its agricultural properties,

  • where it could be used to promote plant growth and help fruit ripen.

  • This gas could also be compressed into a solid form,

  • and is called polyethylene and is the world's most common form of plastic.

  • So yeah, with CO2 from the atmosphere and hydrogen from home, you can ultimately make plastic.

  • Because this reaction is the best.

  • Unsurprisingly, plastic would have almost unlimited use when setting up a habitat on Mars,

  • after all, with the help of a 3-D printer, it can be turned into nearly anything!

  • But it would also be especially useful for building the habitat itself.

  • A major obstacle to long-term habitation on Mars is the radiation environment.

  • Because the planet has a much thinner atmosphere and lack's Earth's protective magnetic field,

  • a mission to Mars would expose the crew to up to ten times more radiation than on the ISS.

  • So the crew would need to take steps to protect themselves.

  • On the atomic level, radiation is often blocked not by physical collisions,

  • but by electromagnetic interactions.

  • Because of that, the best radiation shields have the most electrical charge in their nucleus

  • relative to their weight.

  • That's where polyethylene comes in.

  • Hydrogen atoms have the highest charge-to-mass ratio of any substance,

  • so because polyethylene is full of hydrogen, it effectively absorbs radiation.

  • And that makes it an ideal building material for the Martian surface.

  • So, as long as you bring a bunch of hydrogen from Earth,

  • there's a lot you can make for yourself on Mars.

  • You can get water to drink, air to breathe, fuel for your rockets, energy to power your equipment,

  • ethylene to help with agriculture, and plastic to build almost anything.

  • That's a pretty sweet deal.

  • And one of the most encouraging things is that we could start doing something like this

  • if we send people to Mars today.

  • There are some things that would require bulky, specialized technology, like plastic production,

  • and there are some efficiency problems to work out since the Martian atmosphere is pretty thin.

  • But none of this is technologically impossible.

  • If we have the will to do it and the resources, we could probably get it done.

  • And it's never too early to inspire the engineers who will one day do the job.

  • This episode was brought to you by LEGO City Space,

  • who wants to help do just that through building and play.

  • LEGO City Space is a great way to celebrate past space accomplishments,

  • like the Moon landing, and look forward to future goals, like moving on to Mars!

  • We don't know what's ahead, but we can prepare to build on everything that's come before.

  • We used kits like the Space Research & Development People pack, Deep Space Rocket and Launch Control,

  • and the Rocket Assembly and Transportation sets to help envision life on the red planet.

  • Click the link in the description to start exploring mars with LEGO City Space.

  • Let's go!

  • [♪ OUTRO]

Thanks to LEGO City Space for sponsoring this episode of SciShow Space.

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B1 hydrogen lego martian reaction water methane

This Reaction Could Let Us Live on Mars

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    林宜悉 posted on 2020/03/30
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