[eru]

The lack of tectonics would only be a problem if you want your terraforming to be 'one and done'.

If you admit that terraforming, even after it's 'done', will require an ongoing maintenance effort, it's simple (but not easy). Eg you can use satellites to spin up an artificial magnetic field to shield against solar wind.

However, I suspect terraforming planets is a waste. Far more bang for your buck to build habitats in space from scratch (eg out of asteroids), than to go down another gravity well. You can spin them for artificial 'gravity'. And you can situate them close to earth where logistics of resupply and communication and trade are much more favourable.

Otherwise, Mercury is the planet to colonise, not Mars.

Mercury gets extremely hot in the sun, and extremely cold at night. So if you dig a bit under the surface it all evens out. Pick the right latitude, and you can get basically any average temperature you feel like, including a comfortable 20C.

(Otherwise, even on the surface it's easy to get comfy temperatures, if you bring retractable parasols. Just don't expect to stroll around outside the base.)

Mercury has the benefit compared to Mars that solar power is extremely plentiful.

[kulahan]

It's worth mentioning that one of the more sane ways to terraform a planet is to redirect specific comets to crash into the planet. It would be "free" in the sense that redirecting an orbit is already actively being studied by NASA for planetary defense reasons. To actually terraform a planet in this method would be unreasonably affordable compared to anything else I've ever heard.

edit: Plus, it's nice to split our eggs into multiple planetary baskets. And I suspect people would feel a bit happier living on the surface of a chilly Mars than to become mole people on Mercury, even if it is easier. Maybe summer and winter homes?

[woopsn]

I didn't think reasonable really has a definition here. The rendezvous with these comets will take centuries or millennia even if we can get out there and kick them the right way (which is much harder than arranging a miss). Only then do we start terraforming, which takes thousands/millions of years in addition. Who/whatever we're preparing the planet for probably wouldn't be "people" anymore. :)

[JumpCrisscross]

> Only then do we start terraforming, which takes thousands/millions of years in addition

The methods we could realistically launch into in our lifetimes would take thousands of years, not millions (but also not hundreds) [1]. Projects of these timescales have precedent in human history, usually with a healthy dose of religious zeal.

[1] https://en.wikipedia.org/wiki/Terraforming_of_Mars

[woopsn]

My impression was that pulverized rock/iron is not actually "soil", so after forming the atmosphere you need lengthy biochemical processes playing out on the surface. I admit though, I don't know too much about this.

[JumpCrisscross]

> pulverized rock/iron is not actually "soil", so after forming the atmosphere you need lengthy biochemical processes playing out on the surface

We're already working on crops that can grow in lunar and Martian regolith [1].

[1] https://pmc.ncbi.nlm.nih.gov/articles/PMC4146463/

[b112]

I think that we should consider "the future". Yes, it's intangible but consider this; go back 2 centuries and ask someone if they could setup a business concern which produced millions of widgets a year.

They'd think you daffy.

Now beyond that, ask them to produce any manner of modern device with the precision and high consistency we have. Again, they'd think you mad, and think that such was impossible.

Yet here we are.

The next stage in our development via LLMs is not about AI helping humans. It's about robotics. Automated assembly. Robots (not Androids) able to interact with the environment and able to problem solve akin to say.. a mouse.

Soon, entire factories will be entirely automated. Many almost are. We don't need Von Neumann machines to see this future, but we will certainly have robots capable of building entire factories, collecting resources and processing them, and further building machines to spec. And those machines will be able to self-drive, self-operat autonomously.

Anyone playing typical resource games knows about bootstrapping, but once in the asteroid field we're basically resource infinite. Building engines to attach to asteroids, mining asteroids, building factories to create more robots and engines, all of it will be automated.

We toil at self-driving cars, yet this same tech enables self-driving robotics of all types.

So I honestly think that once we bootstrap in space, this sort of thing can happen fast, fast, fast. Decades to send hundreds of thousands of ice-rich resources to Mars.

The soil? Ah, genetic engineering. Really, this is an entirely new field, and frankly is beyond the danger yet benefit of nuclear science. We have the bomb, yet we have nuclear energy and medicine. Well genetics can obviously be far more deadly, and research all over the world, and startups, are already working on employing bacteria and organisms as self-replicating machines to do our bidding.

The dangers are in our face, but oh well! So if we presume survival, then once an atmosphere is produced we can seed the planet with organisms which can survive on rock and yet work with a mania to process it. It's OK if we immediately have moss like grass substitute everywhere. As long as it's working its magic, we get continued O2 production, and we can always create a rabbit pet or something that licks moss to survive. Or are tasty.

My point is, there are indeed many barriers. But we need to view them with where we will be in decades, not where we are now.

[eru]

> Yes, it's intangible but consider this; go back 2 centuries and ask someone if they could setup a business concern which produced millions of widgets a year.

To go off on a tangent: two centuries ago was the height of the first industrial revolution (at least in Britain). The first time in history when this actually became realistic.

The Industrial Revolution was the first time we had sustained, broad based productivity growth year after year (even if only around 1%, which is quite low by modern standards).

Weirdly enough, we can see sustained productivity growth in artillery and guns long before the wider industry.

Another weird connection: sometimes people look at a toy 'steam engine' that the ancient Romans had access to (https://en.wikipedia.org/wiki/Aeolipile) and wonder if they could have had an industrial revolution. But, to make a proper steam engine you need a lot more than just the right idea. You need a lot of metallurgy and precise crafting.

Specifically one thing you need is precision crafted cylinders that gas can expand in to move a piston. Well, at the time of the Industrial Revolution, European nations had just spent several hundred years locked in existential competition over who can make precision crafted cylinders that gas can expand in to move a bullet.

[woopsn]

You make a lot of good points. Including that the technology to do all that incredibly dangerous to develop - I still can't see a path to terraforming where in the end it's human people left to take pleasure in Mars.

I had thought due to the eons we'd simply have evolved, but even on shorter time frames there is the transhumanist possibility. When we can engineer rabbit that eats chlorine moss, I don't know what we're aiming for at all. "People" by then could have robust gut culture that just digests the regolith.

There's a difference between considering all this vs thinking it's realistic. It's speculation, as any forecast into the centuries ahead must be.

[eru]

> Plus, it's nice to split our eggs into multiple planetary baskets.

Multiple baskets is good, but why planetary?

[kulahan]

We probably won't get hit by a planet-ending meteor any time soon, but who really knows? Good for that not to be our end.

[eru]

Yes, so? You can have spinning space habitats, instead of needing another planet.

[kulahan]

People would almost certainly prefer a planet.

[baq]

Too many dickheads with a bright idea of putting nuclear warheads on submersibles with a dead man’s switch on this planet.

[Ray20]

Even in the event of a full-scale nuclear war, Earth would still be a more comfortable and safe place to live than Mars.

It's like going to the gladiator pits to fight because someone was robbed and shot on the next street yesterday and you don't think your street is safe enough.

[JumpCrisscross]

> Too many dickheads with a bright idea of putting nuclear warheads on submersibles with a dead man’s switch on this planet

If we're nuking each other on Earth, I find it unlikely we wouldn't aim a nuke or two at that group's colony on Mars.

The only thing a Martian colony is a hedge against is ecological collapse on Earth. Because we did something exceptionally stupid accidentally. Or because a rock came by to say hi.

[ben_w]

> The only thing a Martian colony is a hedge against is ecological collapse on Earth. Because we did something exceptionally stupid accidentally. Or because a rock came by to say hi.

Even then, Mars is colder than the Antarctic, drier than the Sahara, has lower air pressure than the top of Mount Everest, has soil poisoned like a superfund cleanup site, has no meaningful ozone layer, has no magnetosphere protecting against CMEs, has half our solar irradiance level, and occasionally has planet-spanning dust storms, so the bare minimum for colonising Mars must be able to survive worse than any possible thing we can possibly do to Earth and also some of the bigger rocks coming by to say hi.

[eru]

Mostly agreed, though the dust storms aren't really that much of a problem, exactly because the atmosphere is so thin.

[xorcist]

A nuked Earth is still more habitable than Mars, even on their best day.

Wouldn't it be far easier and much more useful to colonize the ocean floor than other planets? It is, after all, 70% of the surface area that just sits there.

[eru]

I think you'd be better off colonising the ocean's surface than the floor.

[eru]

I mean, we can build space habitats, we don't need to settle planets.

[JumpCrisscross]

> If you admit that terraforming, even after it's 'done', will require an ongoing maintenance effort

The Earth hasn't always been hospitale to humans, much less technological civilisation. Chances are, we'll have to do similar "maintenance" at home, too. (Easiest to grasp: deflecting asteroids.)

> I suspect terraforming planets is a waste. Far more bang for your buck to build habitats in space from scratch

This comes down to how biology works in zero and partial g. One of the most useful set of experiments we could be doing right now, in terms of colonisation, is putting lots of rats and whatnot in tiny space stations and letting their life cycles play out.

[elcritch]

Great, and rats will become super adapted to space. Then they'll become endemic to any space habitats humanity builds. Terraforming planets sounds more plausible than not ending up with rats and cockroaches.

[JumpCrisscross]

> and rats will become super adapted to space

That would be great! It would strongly imply humans, over cycles of reproducing in space, would too. I suspect, unfortunately, we'd have to iron out some kinks first [1].

[1] https://pmc.ncbi.nlm.nih.gov/articles/PMC8675004/

[littlestymaar]

> That would be great! It would strongly imply humans, over cycles of reproducing in space, would too.

Animals in their natural habitat and humans (especially with modern healthcare) are responding very differently to environmental pressure: we would need to accept a high infant and child mortality rate to be able to evolve.

And the humans having a much longer lifetime and a much smaller amount of descendant means that even without technology we would evolve orders of magnitude slower than rats.

[eru]

Rats can be pretty tasty.

And: if rats can survive somewhere, it's a pretty small step to make it survivable for humans.

[djmips]

So we'll need responsible stewardship over Earth's Habitability? No problem!

[JumpCrisscross]

> we'll need responsible stewardship over Earth's Habitability

This is just a semantic punt to "stewardship". (Why is habitability capitalised?)

[djmips]

typo. Also I'm being sarcastic.

[eru]

> This comes down to how biology works in zero and partial g.

Why? Just spin the thing.

[JumpCrisscross]

> Why? Just spin the thing

Sure. Let's put rats in centrifuges in space and see if they can reproduce successfully. Maybe there is a coriolis boundary. Maybe something weird happens.

[eru]

If you make your centrifuge big enough, it's fine.

But yeah, sticking rats in a centrifuge is probably a better first step than starting with humans.

[JumpCrisscross]

> If you make your centrifuge big enough, it's fine

We don't know this! We don't know how (or even if) an embryo develops under the Coriolis force, or with a gravity gradient.

[eru]

If you make it big enough, there's no discernible gradient and not much of a Coriolis force.

[zahlman]

> So if you dig a bit under the surface it all evens out. Pick the right latitude, and you can get basically any average temperature you feel like

It seems hard to believe that this would actually work, even though I understand why it should. Although you have to do the digging starting in extreme temperature conditions without an atmosphere.

[mixmastamyk]

The Moon has zones like you describe on Mercury, and is a lot closer to colonize. Lack of large magnetic field probably won’t matter as terraforming either is hopeless.

[eru]

Yes, you can also do a similar strategy on the moon.

You can in principle create artificial magnetic fields. But yeah, you are better off just staying indoors most of the time under a big fat layer of regolith.

[RajT88]

That is some out of the box thinking!

I would say the key thing with Mercury is the ability to dig fast.

[eru]

> That is some out of the box thinking!

Thanks. I'm just parroting some lines I read a decade or so ago on a website that I didn't manage to dig up again. (I wonder if it's still online?)

> I would say the key thing with Mercury is the ability to dig fast.

Why? What are you afraid of?

First, night lasts 88 (earth) days on Mercury. So if you start digging at dusk, you have plenty of time.

Second, Mercury's daytime surface temperature is around 430C (~ 800F ~ 700K). We have plenty of materials, like steel, that can withstand these temperatures easily. Even aluminum only melts at 660C.

So you make a parasol out of steel and span it over your equipment. Important: you make the parasol just big enough to shade your equipment, but otherwise let it see as much of the sky as possible.

Mercury has no atmosphere. So during the day you normally have a small patch of the sky at around 5772K, the sun. The sun has about ~6.6 times the angular area on the sky as from earth. The rest of the sky looks as if it's about 3K in temperature, ie very cold. The effect averages out to Mercury's 700K surface temperature.

The parasol itself will attain the same average temperature as the rest of Mercury's surface (because it's exposed to the same conditions).

But for anyone in the shade under the parasol will replace a patch of sky at 5772K where the sun used to be with one at only 700K where the parasol now blocks the view.

If your parasol is supposed to cover more than just a single point with its shadow, than it needs to be big. From the perspective of each shadow covered point, the parasol will have a bigger angular area than the sun it shades.

So you not only replace some 5772K area with 700K, but also some of the previously 3K area with 700K. Overall, you can probably set up things so that you get something like a balmy 15C on average.

> I would say the key thing with Mercury is the ability to dig fast.

To come back to this: Mercury has lower gravity than earth, so I expect that 'soil' will probably not be as dense?

[Melatonic]

Seems like Mercury could be a good opportunity for automated drones and research