Andy Weir

So the gravity is going to be high.

Okay, that's something that's worth knowing.

Second off, it's right next to its star.

But I want there to be a biosphere here, which means it needs an atmosphere.

If you're going to have an atmosphere and be right next to a star, then you need a really strong magnetic field or the star will have sandblasted away your atmosphere.

What makes a magnetic field is...

a liquid metal core and the planet rotating.

But this one's got a badass magnetic field.

So I'm just going to say it's rotating really fast.

So that's why Iridians have like a six hour day.

And I'm like, okay, so I've defined something about this planet.

Next up, it's right next to its star.

I mean, it is closer to its star than Mercury is to our star.

And I'm like, so that planet would be hot, really, really hot.

And I want there to be like liquid water for life to be there.

And I said, like, OK, so how do you have oceans on a planet that's like right next to the star?

And I'm like, well, you have an incredibly high atmospheric pressure because the higher the atmospheric pressure, the higher the boiling point of water.

So the oceans are like 210 degrees Celsius, which is like 400 degrees Fahrenheit.

But it's still water because the atmospheric pressure is like 29 atmospheres.

That means the atmosphere is so thick.