Hello, SFIA audio listeners. In this month's Nebula exclusive, big alien theory,

we're asking the reason alien civilizations might be rare is because most aliens are huge.

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check out go.nebola.tv slash Isaac Arthur and use my code, Isaac Arthur.

One day people will travel to Mars, hopefully soon, and perhaps come to live there,

which means they'll need to grow their own food, and that isn't easy on a planet that's more barren

than any desert or tundra.

Yeah. Probably one of the best science fiction films I've seen the last decade is The Martian,

starring Matt Damon, and based on the excellent novel by Andy Weir.

And while it generally got great reviews, it was often criticized for a lack of realism about the astronauts' emergency potato farming on Mars.

As far back as we could see Mars, even when we thought it had canals, we had discussed

agriculture on the red planet, both in terms of terraforming the world and in terms of

building domes and greenhouses.

I thought today we would walk through the challenges and how we can address them so that

future visitors or colonists to Mars don't have to import all their food and drink.

And speaking of food and drink, we will be here for a bit so you might want to grab a drink

and a snack, possibly some potato chips, and don't

forget to hit the like and subscribe buttons while you're at it.

Now there's three obvious problems right out the door for agriculture on Mars, and that's

the general lack of air, water, and sunlight. Mars does have all three, but its sunlight is

weaker than we get, it has precious little water, and its atmosphere barely counts as one.

It's a cold world whose highest recorded temperature is 70 Fahrenheit or 21 Celsius, while its

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