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So there's a sci-fi fantasy that as an astrophysicist and a trekkie, I've been watching percolate all my life.

And in the last decade, it feels like it's become more than fantasy.

Strap yourselves in. We're going to Mars.

Not just a few astronauts, thousands of people are going to colonize

Mars, and I am telling you that they're going to do this soon.

I would love to see, you know, a trillion humans living in the solar system.

Now the next Mars launch window opens in 2026. At the rate we're going here, you wouldn't rule out seeing some sort of mission there in a couple of years' time.

Some of you will end up working on projects on Mars, and I guarantee that some of your children will end up living there.

One path is we stay on Earth forever, and then there will be some eventual extinction event.

The alternative is to become a space-baring civilization and a multi-planet species.

But I've always wondered, what would a space colony actually look like?

So the vision for a successful space settlement would require that you have essentially

families living on the surface of Mars, and that those people are able to have careers

that, you know, give them the money that they need to sustain themselves and that they're also

able to have children, and those children can successfully grow up and have their own children.

That's Kelly Weenersmith. She's a biologist and science writer. And she and her partner,

Zach Weenersmith, spent four years researching space settlement for a book called City on Mars.

And in it, they get into everything it would take to do this.

They talk about the key real estate.

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