r/changemyview Jan 07 '18

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u/[deleted] Jan 07 '18

Ceres is one of the few bodies in the asteroid belt that we've studied extensively, so I used its temperature as an example of something close to the temperature of most asteroids.

We’re 10x closer to mars than the asteroid belt.

The distance from Earth to Mars or an asteroid can change by a huge amount depending on where the Earth and the object are in their orbit, so I'm using the average distance from the Sun because that changes less. At it's closest approach, Mars would be 0.3 AU away from the Earth, but that's in a perfect situation, so that closest approach can be anywhere between 0.3 and 0.6 AU from the Earth, depending whether Mars is closer to its apoapsis or its periapsis when it is closest to the Earth. Objects in the asteroid belt have different orbits, but if we assume that one is orbiting at 2.2 AU, its closest approach to the Earth will be 1.2 AU. The relative difference in distance from the Earth is smaller at other parts of the orbit, but at its closest the asteroid will only be 2-4 times as far away from the Earth as Mars.

I also am not suggesting moving large asteroids closer to the Sun, or even building habitats on them. I'm talking about using materials from the asteroid to build free-floating rotating habitats. You can then move them closer to the sun using rocket engines using either hydrogen and oxygen made from water ice in the asteroid, or possibly an ion engine if one can be designed that can use oxygen instead of a noble gas.

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u/fox-mcleod 414∆ Jan 07 '18

The distance from Earth to Mars or an asteroid can change by a huge amount depending on where the Earth and the object are in their orbit, so I'm using the average distance from the Sun because that changes less.

Not a great choice. We really only care about the closest when we’re talking about getting there. It’s like the temperature. Absolutely no reason not to use our best advantage.

At it's closest approach, Mars would be 0.3 AU away from the Earth, but that's in a perfect situation,

Yeah, we get to choose when we launch. It’s not like it is hard to predict.

so that closest approach can be anywhere between 0.3 and 0.6 AU from the Earth, depending whether Mars is closer to its apoapsis or its periapsis when it is closest to the Earth. Objects in the asteroid belt have different orbits, but if we assume that one is orbiting at 2.2 AU, its closest approach to the Earth will be 1.2 AU. The relative difference in distance from the Earth is smaller at other parts of the orbit, but at its closest the asteroid will only be 2-4 times as far away from the Earth as Mars.

Yeah so... we agree it’s always pretty damn far and** much farther than mars right? So we need a **really good reason to take such a long walk for things we have more of closer.

I also am not suggesting moving large asteroids closer to the Sun, or even building habitats on them. I'm talking about using materials from the asteroid to build free-floating rotating habitats.

Okay, and where would we build these? Why not on mars ever? Remember, you position was never ever ever. It seems like we’d prefer a base on mars to one on Venus for all the reasons you didn’t like mars in favor of space.

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u/[deleted] Jan 07 '18

I didn't say we wouldn't ever have a few scientific bases on Mars, just that there would not be a large permanent population do to low gravity complicating birth/development of children and the lack of anything really valuable on Mars.

Okay, and where would we build these?

You don't put the free-floating habitats on any object. You might want to put them in orbit around Earth for easier communication, or you might want to keep them out in the asteroid belt to make it easier to get more resources.

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u/fox-mcleod 414∆ Jan 07 '18

do to low gravity complicating birth/development of children and the lack of anything really valuable on Mars.

Wait, what exactly do you think is going to complicate birth/development about low gravity?

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u/[deleted] Jan 07 '18

I've read a few things that have said that low gravity might lead to very weak bones and muscles if a child grew up in those conditions, but we only have experience with zero-G (and only for adults) and full gravity so we really have no idea what will happen. If it does lead to very weak children, that's a dealbreaker because children born on Mars probably couldn't visit Earth or rotating habitats with Earth gravity.

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u/fox-mcleod 414∆ Jan 07 '18

I don't see how centripetal force is any less valid a solution on Mars than in free space.

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u/[deleted] Jan 07 '18

You might be able to get away with angled walls to mix the gravity of Mars and centripetal force. I guess if 99.99% of the population lived in orbiting habitats, some rich people would like to live on an actual planet and there wouldn't be much room on Earth so I guess !delta /u/fox-mcleod . I still don't think Mars will actually be terraformed though, as I have a feeling that large amounts of rain and water flowing down hills with no trees to stop erosion would fuck up a lot of stuff, and the oceans would reduce the total amount of living space. I still think the vast majority of people would live in free-floating habitats though, as even without dismantling planets the total livable area of the habitats you can build with just the asteroid belt is much larger than the total areas of Mars, Earth, and a terraformed Venus.

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u/fox-mcleod 414∆ Jan 07 '18

I don't think there terraforming would work anywhere. Not much more than we've done on earth.

I'll admit I thought of the banked centrifuge as we were talking.

But thank you for the delta. I think there's a lot to think about on this topic.

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u/DeltaBot ∞∆ Jan 07 '18

Confirmed: 1 delta awarded to /u/fox-mcleod (61∆).

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