That said, as a moon base it has a lot of things going for it, but I'm not sure if there are significant advantages of going there as a stopping point before going elsewhere, when you can achieve many things in orbit with some advantages of not having to take off again.
Mars has a magnetosphere but it's much weaker since its core is cooler and slower and smaller.
If we nuked the polar ice caps (or similar method to warm + evaporate them) it would generate enough of an atmosphere for the external pressure to be livable - maybe even breathable.
Since the magnetosphere is still weak, this atmosphere would be eroded over time, but we're talking tens of thousands of years or more.
That would be a far cheaper and less disruptive way of keeping an atmosphere on Mars.
edit: Here you go: http://www.orionsarm.com/eg-article/4851d85e0791b
Source?
Even granted that would be possible, it would be an enormous waste. Let's say it's possible to use the polar ice caps to create a breathable atmosphere, why do it for the whole planet instead of using it strategically to pressurize domes where people actually live? Added bonus: The domes provide partial shielding for the radiation on Mars. If you believe the ice on Mars can sustain a breathable global atmosphere for ten thousand years, how long will it last when used in closed systems like domes?
what's wrong with Zubrin's plan?
> not enough gravity.
what's gravity got to do with it?
ADDED: if you're going to tell me the gravity is necessary to hold onto the atmosphere, great, i'm actually familiar with that mechanism. i assert that mars' proclivity for losing the lighter atmosphere over millions of years isn't relevant, and that it'll hold onto everything important for Long Enough.
When the speed of molecules in the atmosphere (thermal, and thus dependent on molecular weight) approaches escape velocity for the body, the atmosphere starts to leak that component. Gasses like N2 (molecular weight 28) and oxygen (32) will "stick" to Earth where Helium (4) won't. Mars can hold CO2 (44) but not O2.
and only hydrogen and helium are currently prone to jeans escape on mars. the current dominant mechanism for atmospheric loss is the solar wind. which eats away ~1/3 megaton/century. mars has teratons of atmosphere remaining. and it can be added faster than that rate of loss.
(once warmed up, oxygen may begin to escape the atmosphere again. not necessarily faster than it can be replaced, though.)
Gravity got the following to do with it: Lower gravity makes it easier for the atmosphere to escape to space, especially since Mars has a very weak magnetosphere. Second, to have a human-breathable atmosphere you need not only the right composition, but also the right pressure, and to get that pressure on Mars you'd require an atmosphere more than 2,5 times the mass of Earth's. Where are you going to get it from? Even if it was available to you, using it to make Mars globally breathable would be an ENORMOUS waste compared to simply pressurizing domes and bunkers instead.
On the other hand, the moon has a lot going for it for manufacturing. It's at the top of Earth's gravity well and has low gravity itself without being microgravity. That lets you move massive things around easily and shoot them out of launchers to get back to earth without all the problems that come with "zero-g" conditions. It's also a lot closer to the sun than Mars is, so solar panels give you up to 50% more power for the same area. You also don't have to contend with dust storms (though moonquakes could be an issue).
A side hat doesn't face terrestrial cameras for example. taps glasses, pushes tinfoil hat slightly back
In either case, the technological breakthroughs we would need in order to actually generate a useful atmosphere are large enough that I would be very excited to just see the byproducts of such breakthroughs.
that's excessive. certainly neither one has even the pressure to keep a human alive for any amount of time.
mars has got teratons of carbon dioxide, which is useful stuff. little bits of some other handy gases. the moon has got 10 tons of atmosphere, total.
Not sure I agree with all intents and purposes. Maybe just some of them? Like say if the intent is to extract CO2 or N2 from the atmosphere, then you'd find more on Mars. Those two things are pretty important for growing things and breathing.
Another intent and purpose could be to airo-break the space craft as it flies in for a landing. Though it is probably more annoying than it helps, in the sense that Mars has enough atmosphere that you need to deal with it, but not enough to be helpful in the final descent phase.
Might have problems long-term though.
This is one of those cases where I am not sure if it was sarcasm or not.
Musk managed to fly about a dozen missions to the ISS, launched an object into an orbit around the sun, and had about 20 successful launches just last year. It would seem when it comes to the space travel domain, if we should put any stock anywhere, putting it on what Musk says is a good bet...?
I know which one I can count on.
That said, I don't disagree that it matters, just not in quite the way you put it, that's a fantasy to me, a way to avoid the responsibility we actually do have, the responsiblity that is actually real. At the very least, mining asteroids beats scouring for ever more elusive resources on Earth. But humans living in hollowed asteroids isn't a solution to overpopulation and pollution. We can't build housing on Earth, but it's going to be so different once "we're in space". Yeah, right. Prove you can do it here or I don't believe it for a sec.
That said, I don't know _anyone_ who would advocate for colonizing Mars is a better solution that tweaking what we already have. It's a different solution addressing a different problem.
We should _absolutely_ be improving and addressing the problems that we have on Earth. I 100% agree with that. I don't see how that precludes us from _also_ starting the process of colonizing another planet.
It sounds like we agree at any rate.
Eventually, we should become a space-faring civilization if it is actually possible (big IF) there.
Not in our lifetimes, maybe. But if we colonize mars in the next 3 decades it seems likely that in 1,000 years human life on Mars could be largely self-sustaining.
When talking about creating planetary redundancy for human life 1,000 years is a small time-scale. We're guarding against 1/10,000,000 year kinds of extinction events on earth. It's unlikely that such an extinction event will happen on earth before a Mars colony could become reasonably self-sustaining.
That said, it's important that we do it _eventually_, because over 100,000,000 years the odds of that earth wide extinction event goes way up.
Would you like to see the most stars ever viewed by a human on the dark side of the moon? Ride a rover to the top of Mount Olympus? Learn if microbial life ever thrived in the ancient waters of Mars? Witness the development of new advanced technologies that raise the quality of life for all humans living back on Earth? I sure as hell would.
But it would be “cheap” once established because cooling would be easy.
I would imagine that if you put a datacenter in orbit or on the moon (or pretty much anywhere else in space), cooling would actually be significantly more difficult, if for no other reason than that in a vacuum the only way of getting rid of heat is via radiation. On earth, you can at least dump the heat out (much more efficiently) via convection into the atmosphere or conduction into a large body of water, or something similar.
- Much lower g ~1/6th g
- 2 week long nights and days.
- Extremes in temperature: -280 to +260F
- Questionable mineral deposits and water is more isolated.
- Much smaller surface area.
- Zero potential for terraforming.
- Zero atmosphere.
- Aesthetically homogenous.
- Very poor 'weather' - in that it practically rains asteroids on the moon. Granted this is all over the moon, and so any given individual or building's chances of getting hit are extremely low, but as we increase the number of people/buildings, getting hit by asteroids will be a regular occurrence.
- Plant growth would need to be 100% driven by external support.
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Mars:
- 1/3rd g
- Day and night cycle near identical to Earth
- Reasonable temperature ranges. About -100 to +70 F, varying depending on the seasons - which it also has 4 of, like Earth.
- Extremely rich mineral deposits. The most evident being the planet's color, which is caused by iron oxide - rust.
- Water everywhere. The soil is moist containing about a liter of water per cubic foot. Something "The Martian" accidentally got wrong, as this was a major discovery of Curiosity, after the book had been written.
- Surface area oddly near identical to the land area of Earth.
- Huge potential for terraforming - from creating magnetic fields in various ways to simply nuking the poles, which are made of dry ice (CO2), and letting it thicken up the atmosphere
- A thin atmosphere, but an atmosphere comprised mainly of handy CO2. For instance the Sabatier Reaction can be used to create methane with a byproduct of water from hydrogen and CO2 - both widely available on Mars.
- Aesthetically diverse - at one time orders of magnitude more. We'll be exploring and discovery Mars' secrets for decades and perhaps centuries once we get feet on the ground. Our rovers and probes have only scratched the surface, figuratively and literally.
- Excellent weather. Hit by relatively minimal asteroids and the thin atmosphere makes even the worst storm on Mars feel like a slight breeve - the one key thing "The Martian" faked. Come to think of it, a hard sci fi book having to rely on an impossible event to trigger a catastrophe on Mars is a pretty good sign.
- Martian soil actually contains everything that's needed to natively grow plants! [1] Sourcing this point since it borders on unbelievable.
[1] - https://www.nasa.gov/feature/can-plants-grow-with-mars-soil
- create whatever level g you want
- create whatever day-night cycle you want
- create whatever atmosphere and temperature range you want
- create as much surface area as you want, potentially millions of Earth's worth
- no need to terraform: build the habitat you want from the start
- solar power continuously available
- wide variety of mineral deposits available
- plenty of water available
It raises more interest. Mars is farther, thus sounds bigger, it also is bigger. The idea is more ambitious. It's appealing to the audience.
If this is true, it seems the moon has a lot going for it which is quite surprising given Elon has been so bullish on Mars. Can someone explain what advantage colonizing Mars has compared to Moon?