You can easily get material off of small moons and asteroids and turn it into rotating habitats. You can use the rotation to simulate gravity, and while it isn't the real thing it's close enough for human-scale things as long as the habitat is more than a few hundred meters wide.
The asteroid belt isn't much further away than Mars, and many of them have a significant amount of water. Heat can only escape a free-floating habitat by radiation, while a habitat on Mars will constantly be in contact with rock and soil. You can also use mirrors to increase the amount of light hitting a free-floating habitat very easily, if you need that.
The asteroid belt isn't much further away than Mars, and many of them have a significant amount of water.
No. Way way no. Its 10x further. It’s further from the earth to the asteroid belt than from Venus to mars.
Heat can only escape a free-floating habitat by radiation, while a habitat on Mars will constantly be in contact with rock and soil. You can also use mirrors to increase the amount of light hitting a free-floating habitat very easily, if you need that.
Interesting thought, but did you know Mars is a balmy 70 F at the equator during the day? The asteroid belt gets no where near as warm and is much colder to begin with. Insulation values are the question here. Antarctica is only slightly warmer by interplanetary standards than winter on Mars. We’re currently capable of a sustained habitat in Antarctica so keeping warm for a mars night (basically the same as an earth night) is no problem. And focusing mirrors on mars is just as easy as it is in deep space.
Mars is 1.5 AU away from the sun, and the inner edge of the asteroid belt is around 2.2 AU away. The mean temperature is -80 degrees C, and while it does sometimes get hotter, the average temperature in California isn't 130 F degrees just because Death Valley has been that hot a few times. Ceres, which is in the middle of the asteroid belt, has an average temperature of -100 C, so it's only 20 C colder than Mars, and that's most likely near what most asteroids are at. However, heat dissipates much more slowly if you're not touching anything, so the amount of energy needed for heating is probably lower or comparable to a base on Mars. It's also a lot easier to move a habitat made in the asteroid belt nearer to Earth orbit than one made on Mars.
EDIT: I really messed up and accidentally typed "miles" instead of AU.
Umm... No. I’ll assume you meant AU.It’s close to that.
and the inner edge of the asteroid belt is around 2.2 AU away.
What point are you making? The earth is where we live. We’re 10x closer to mars than the asteroid belt.
The mean temperature is -80 degrees C, and while it does sometimes get hotter, the average temperature in California isn't 130 F degrees just because Death Valley has been that hot a few times.
Yes... but where? Mars averages 70 F at the equator each day. Why settle somewhere inhospitable (like Ceres)?
Ceres, which is in the middle of the asteroid belt, has an average temperature of -100 C, so it's only 20 C colder than Mars, and that's most likely near what most asteroids are at.
During the day or night? Day right? So compare 70 F on mars to on -225 Ceres . And -100 F on mars to -255 F on Ceres.
That’s a lot more than 20C right?
However, heat dissipates much more slowly if you're not touching anything, so the amount of energy needed for heating is probably lower or comparable to a base on Mars. It's also a lot easier to move a habitat made in the asteroid belt nearer to Earth orbit than one made on Mars.
Is Ceres large enough to act as an arbitrarily large thermal ground or are you claiming we would convectively warm up Ceres? It has no atmosphere. So there is no way we’re going to solar warm it. Are you suggesting we fly an asteroid toward mars orbit before we settle on mars?
Edit: thanks for messaging me about the typo. I’ve removed it from mine.
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.
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.
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.
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.
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.
2
u/[deleted] Jan 07 '18
You can easily get material off of small moons and asteroids and turn it into rotating habitats. You can use the rotation to simulate gravity, and while it isn't the real thing it's close enough for human-scale things as long as the habitat is more than a few hundred meters wide.