Terraforming Mars Not as Easy as Once Thought

There's not nearly as much CO2 in the ice caps as previously thought.

This Twitter thread has a good breakdown of some of the flaws in Musk's arguments.



Given Musk's plans to capture and mine asteroids, however, I don't think that it'd be all that difficult for him to capture comets and send them to Mars in order to boost its atmosphere above what could be done otherwise.

NASA is probably right about the difficulty. I mean, it's NASA, after all. But yeah, there's plenty of "stuff" knocking around the solar system that could be used to terraform Mars, at least if you assume a very long-term project. Comets, asteroids, various moons that could be mined, etc. Probably not worth the incredible cost, tho. It would probably be easier to build domed cities or underground colonies or some such.

I love the notion of terraforming being "not as easy as we thought."

It was never going to be and will never be easy. It may never even be possible as a practical matter. Even when it becomes technologically possible, it will likely remain economically daunting.

I guess it isn't quite as bad as the boundless optimism over warp drive. That NASA guy at Eagleworks says "We can do this," but it looks to me like they haven't been able to achieve the necessary physical effect on even a microscopic level, let alone to demonstrate that the effect could be scaled to propel a spacecraft.

Some great technological advances will soon be here, but I wouldn't hold out much hope for things like terraforming Mars.

I can't ever recall anyone saying it would be easy.

Anyway I now think it's actually kinda dumb to colonize Mars.

Fuck that. Let's just get to work building O'Neil Cylinders. Plenty of material in the belt we can use.

I thought impacting (or having them burn up in the atmosphere) so called "iceteroids" on Mars was going to be a required part of terraforming Mars in any case.

I have a feeling this is environmentalists believing we shouldn't mess with the "pristine" (so called) Mars environment.

Meh, I've said before if we plan to colonise the solar system we need to meet the host planet's environment half way.

We're going to have to genetically engineer colonists. They'll need skin that both insulates and allows for survival against the reduce Martian air pressure, likely embedded with choroplasts modified to be efficient in the Martian light to provide a baseline amount of energy to reduce the need for food supplies and blood with a changed disassociation curve for O2 to make breathing more efficient.

I still think Mercury would be the best initial attempt, underground colonies with access to almost limitless solar energy would be able to generate pretty much everything they need. We know how to make water and oxygen, and we also know they need power, and Mercury has it's own nuclear fusion reactor on its doorstep... Plus, underground negates the need for radiation protection.

We'd need to know more about its geology to be sure though. And the initial journey and getting underground would be perilous to say the least.

This calls for an increase in the number, and Musk still seems fixated on Zubrin's plan to melt the caps, and this study refutes the feasibility of it by pointing out that there isn't nearly enough CO2 to accomplish this.

Oh, yeah, the guys who did this:


Are worried about keeping the planet "prisine."

If you follow the Twitter thread I posted (just click on the picture, it'll take you right to it), you'll see the data that they used was all publicly available, and the math (which isn't terribly complicated) all checks out. Thanks to there being both US and ESA missions to Mars which have returned data, you can verify that the data used in the study isn't from a group with an agenda. Unless, of course, you think that there's a conspiracy between the space agencies to block human colonization of Mars. Which seems unlikely, because many people got involved with the space program (in the US, if not Europe) because they want to see humans walk on Mars! They just made that job a little harder to accomplish (in some sense, while at the same time ensuring that any manned mission is more successful), which is not something that you'd expect them to do, if they were going to manipulate data to fit an agenda.

Mercury's fate is to be eventually collided with Callisto and moved to orbit Venus. Serving as a "moon" for a terraformed Venus while combining the water from Callisto will eventually give Mercury a life bearing ecosphere as well.

Seriously. Concept outlined in the book "New Earths". Eventually the idea is that you get SIX life supporting worlds in the inner solar system. Three planet/moon pairings.

Mercury/Callisto and Venus, the Earth and the moon (Terra/Luna), and Ganymede and Mars.

If we develop the necessary technology to achieve that in a reasonable timeframe, and without scattering a load of debris on unpredicatable orbits, we'll have the technology to just terraform and build moons in situ by distilling mass from solar energy.

Seriously, whacking Callisto into Mercury will cause both bodies to become molten and it'll be a few million or so years before they cool off enough to think about setting up shop on the planet. If you've got the kind of power that you can move an object bigger than the Earth's moon out of the gravitational field of freakin' Jupiter, you can mine the friggin' Oort Cloud for stuff and use that to build a Dyson Sphere in a lot less time.

What about a low speed collision?

it's one of those ideas that sounds great until you start looking at even the basic logistics, at which point it becomes apparent it's fucking dumb.

*looks at room*

*Must not make old woman joke, must not make old woman joke*

*shit*

Well, for starters, once you pointed the two objects at one another, their mutual gravities would pull them at one another at increasing speed, so you'd have to find a way to slow them down. Not only does this involve a lot of energy, but you've got to find a way to do it so that you're not burning a hole in the middle of the other body (thrust needs to go through the central mass of an object if you want it to remain on course). Even if you manage to somehow do all of that, you end up with a giant pile of rubble, floating in space, completely unsuitable for life, even if it has a breathable atmosphere, because of all the bodies slowly compacting themselves into larger pieces. Gradually, they'll start to heat up, become molten, and require millions of years to cool down. So by making it a low-speed collision, all you've really done is extend the time it takes for the place to solidify.

I'm sure we'll find a way. At any rate it makes a lot more sense than a stupid "dyson sphere".

Low speed collision?

If you've got the ability to do that why bother? Like others have said, if you've got the power to move something that big like it's a toy you don't need too. You can build whatever you need.

And there is no such thing as a Dyson Sphere. Dyson himself never said anything about a sphere. People misinterpreted what he said and he had to correct them. "A solid shell or ring surrounding a star is mechanically impossible. The form of 'biosphere' which I envisaged consists of a loose collection or swarm of objects traveling on independent orbits around the star." - Dyson

A Dyson Swarm is a better idea.

That's like someone in 1865 talking about sending telegrams to the Moon. By the time we had the ability to put a telegraph operator on the Moon, technology had advanced to the point that telegrams were nothing more than a quaint idea. If a civilization can put together the kind of energies needed to send a moon of Jupiter to smack into another planet, and then move that mass to the orbit of Venus (or move, then smack, doesn't matter the order) to create a livable planet in a "reasonable" time frame (say ~1,000) years, they'll have no need to do such things. Not only would they be able to surround, for example, Ganymede with some kind of giant enclosure that keeps an atmosphere in and Jupiter's radiation out, but they'll be capable of interstellar travel, regardless if we can find a workaround for the speed of light limit or not. Assuming, of course, we're still human at that point and need planets to live on.

While @Zombie is correct, I used the term "Dyson Sphere" since it is better known. Technologically speaking, we are potentially 100-200 years away from building such things (less, if we as a species, were willing to devote significant resources), while what you're proposing is probably, at the most optimistic, at least 1,000 years away.

Fine. That'll be Plan B.

Why would a Dyson Sphere be stupid? Ignoring the technical issues of having a sold shell around a star, you have the capacity to capture 99.9% of a stars output for energy and a significantly greater surface area for a population.

Moreover, if a regular material was ever found to support to support the stresses of such an arrangement, construction could be automated relatively easily.

The only downside would be having to live on the outside of the sphere, and so having to find some way to emulate night and day (which I'm assuming to have a lower energy cost than kitting out a surface area of close to a quintillion square meters with artificial gravity)

What about gravity?

What about it? Mars' gravity is approximately 38% of Earth's.

My point is that you couldn't generate any kind of gravity in the overwhelming majority of the inside of a Dyson sphere.

*cough*

The inside of the sphere would have no gravity, assuming a perfect sphere, however the exterior would experience gravity. I think the exterior of a hollow body would generate the same gravity of a solid object of the same mass (not size), which gives us boundaries for the amount of mass usable in such a construct (and the density of the material then gives us boundaries for the depth of the shell)

Gravity isn't the issue with a Dyson Sphere, stopping collisions - with the star and incoming material - would be the big problem, and handling the materials yield strength.

For a construction material, you'd be wanting degenerate matter. Given the overall mass, condensed electron-degenerate gas would suffice - basically go mine a white dwarf.

Where's Ray Palmer when you need him?

Edit: Thinking about it, given the mass of white-dwarf matter, you'd probably end up with a shell a few nanometers thick, cover it with fluid, so the continents you stuck in it didn't collide at speed. You might even have to use a non-Newtonian fluid, I've not got the tools to model how the surface would behave.

There's a Dr Who tale. A giant planet made of white dwarf matter and custard...

The idea of a Dyson Sphere is to live on the INSIDE of it not the OUTSIDE which would make no sense at all.

No, the image science-fiction has provided is to live on the inside, primarily to take advantage of the light and heat from the star, but they tend to assume the surface will - inexplicably - maintain a constant distance from the star and hope no one mentions night.

The idea of a Dyson Sphere is to provide the ability to capture the entirety of the surrounded object's energy output as well as plentiful living space.

There are pros and cons to living on either side, however living on the inside requires artificial gravity and some mechanism to generate night, living on the outside requires artificial heat and light. Two things we had licked by Roman times, whilst we've not even the fundamentals on how to generate artificial gravitational fields today.

A dyson sphere doesn't have to be a solid object, tho. You could come close to the same performance with a large swarm of independent bodies (a dyson swarm is the actual term, IIRC) in various orbits, each outfitted however you wanted, and either leave them uninhabited, basically just big solar collectors, or build in some kind of artificial gravity.

At Earths distance from the sun the suns gravitational pull is such if you weren't orbiting and were stood on a platform suspended above the sun it would still feel to a human pretty much no different to free fall. For the surface of a rigid Dyson Sphere to have a significant gravitational pull it would need to be much closer to the star than we are, or have many times more mass than our own sun.

That said however, as has been pointed out by a few people a rigid Dyson sphere isn't what the concept is about anyway.

If a civilization had access to enough energy to build a Dyson sphere (or swarm) then they really would never need to do so in the first place.

Unless they are using solar power as their energy source.

Barring some plan for concentrating energy for solar-sail interstellar probes or the like, it's unlikely any such mega-structure would be built with an intended purpose, the swarm would probably just build up over time as the civilisation expanded and needed increasing amounts of energy.

On the inside as the gravity at any single point is cancelled out by the pull from the surrounding mass. On the exterior you would experience the same level of gravity as the same mass as a solid sphere - I did a bit of searching to see if my recollection was correct and the math (thankfully we're not in the RR...) can be found here.

Oh I know, it was Dayton stating the very concept was stupid compared to playing billiards with moons, and I was curious as to if his view originated from any rational view.

My curiosity is now sated