Planetary Terraforming Strategies
In order to forge new worlds under alien suns, we’ll need to be both patient and clever, but billions and billions of planets could be made into new homes for humanity if we can master our terraforming strategies. We recently were looking at strategies we might use for interstellar colonization, and that was such a big topic we decided to save discussing what we did when we arrived in a solar system for a second installment, and today we’ll be talking about how an interstellar colony arriving in another solar system might go about making it a new home. As of today we know of no life on other planets, and while there may well be many habitable worlds out there in the galaxy, the odds aren’t good any of them will be fully compatible with us and our own terrestrial flora and fauna. Even if the perfect new planet were out there, it might not be wise or ethical to colonize such a world, just considering how damaging invasive species can be here on Earth, just from one continent to another.
Terraforming a rocky planet to be like Earth is not the only option our colonists will have, as we’ll discuss today, indeed doing something like this will likely be a later operation. Once your ship or fleet has arrived in a new solar system, your first goal must be resupply. You’ve probably been traveling through space for decades or even centuries without a pit stop and, while in theory you could have carried all you need to establish your colony and more, I think we have to assume no interstellar colony mission would ever be sent unless we were already pretty experienced with in situ production of equipment from locally available raw materials. I feel like that’s a safe bet considering it would be tantamount to cruel experimentation to send colonists out except in grave desperation without the ability to manufacture things from local materials when they arrive. Barring some desperate attempt at a first interstellar colony in the next century or two because of some solar system wide catastrophe like an inbound rogue black hole, I just can’t imagine anyone sending out interstellar colony fleets until we have had some practice on the various planets, moons, and asteroids of our own solar system. Furthermore there are billions of stars in the galaxy awaiting to be colonized,
so we might imagine a handful of first attempts being done with limited knowledge and skill, but this episode isn’t on our first interstellar colony, but rather general strategies. And even if we send a colony ship out tomorrow, we still have a long time before it arrives to figure out how to do some in situ mining and manufacturing on arrival. This assumes no FTL, faster than light travel, and we will keep this assumption for the rest of the episode, but as an example, if tomorrow someone knocks out a portal device in their garage like we see in Peter Hamilton’s Commonwealth Saga, so we can just step onto new planets right from Earth, Stargate style, then we can expect to see a lot of reckless, half-baked colonies get attempted. However, from there they can just ship you what you need through a portal right from Earth, possibly even a perpetual portal with railroads, cables, and pipelines running through it, so things get easier. Indeed much easier, instantaneous transfer of material doesn’t just make shipping in gear cheaper and at-need, but it also opens doors to options like terraforming a desert planet by opening wormholes up to some water planet or frozen moon and draining it onto that other planet. Or warming a planet by opening a
wormhole directly next to a star on one end and in a 24-hour orbital period above the target planet so that it had a sun and normal Earth-like day. Even merging two planets together for added mass, or the targeted addition of matter with high momentum to increase or decrease a planet’s angular momentum to change its day length or year length become viable with portals. Options like this, often overlooked in sci fi, are reasons why I always say the Fermi Paradox, the big question of where all the aliens are, is only exacerbated by faster than light travel options, as they just make endless space colonization so much easier and faster that it’s hard to imagine why someone doesn’t do it, let alone why everyone doesn’t. Those sort of options are cool to contemplate but I just don’t see FTL being in the cards. However,
there are other technologies which would seem outside the realm of known physics now, but which might not be and which might be very handy for terraforming. As an example, we tend to assume gravity manipulation options are limited to either ignoring real gravity and simply replicating it with spin or creating the sort of gravity we want with lots of dense mass. Instead, we may get artificial gravity of the sort ubiquitous in science fiction on board space ships that just “pulls you down” as if you were on the surface of the Earth. And while we have no idea how to do it, it would seem like stimulating the emission of a graviton should be in the realm of the possible, much as it is for photons or other particles. But even without that option, we might be able to make a micro-black hole and place it in a hollowed out chamber inside an asteroid, and to give it Earth-like gravity we could feed it on some cheaper source of matter like ultra-abundant hydrogen or helium. Or maybe even dark matter, which at the moment appears to have little use as a material except for generating gravity. Indeed
given that what little we know about dark matter implies it doesn’t even interact with itself, it’s a material that should be able to be made ultra-dense if you learn any way to manipulate it, making it ideal for adding mass to smaller bodies like Moons or Asteroids to raise the gravity. Such tricks can also be employed to raise or lower gravity in a local area, as we discussed more in our episode Moon: Mega City. The degree of the technology available to a civilization definitely controls what sort of colonization strategies they will be using. For instance if they can open wormholes to entirely separate Universes and suck matter and energy out of them, they might mass manufacture planets and stars, simply because they have infinite access to matter and energy, even if seemingly more economical options like rotating space habitats apparently made more sense. There’s also a lot of question marks on what
humans, and our various plants, microbes, and critters, actually need in terms of a planet. We tend to assume life will do well on planets that are decently like Earth in Gravity, Temperature, and Day Length. This assumption is partially justified since our Sun was a good deal dimmer when life began on Earth and the atmosphere and day length was a lot different too. We believe the Earth used to have a day that might have been as little as 4 hours long, until being smashed into by another smaller planet and the Moon forming from part of the scattered debris. As the Moon
coalesced and slowly tidally locked to always show Earth the same side, Earth’s own day slowed too. One of the better models I’ve seen suggests that when basic life emerged, earth’s day was 12 hours long, 18 hours long when photosynthesis emerged and allowed life to directly use sunlight to fuel itself, and only 21 hours long 2 billion years later when eukaryotic cells emerged. All of this implies that life can handle different day lengths, since it used to, and we already know some lifeforms can thrive in low pressure or zero gravity. But we should take this all with a grain of salt, or maybe an entire ocean of saltwater, because most ecologies are a fragile balance constantly at risk of sliding out of that balance from minor changes. A specific
lifeform - and therefore life at all - might be able to handle a slight change in ocean salinity but an entire ecosystem where that happened might rapidly crash as this or that organism inside it gains an advantage -- or hindrance -- that allows it to become a super-predator eating all its food supply and killing it off, removing a feeding base for other life forms. This is another reason why you need to resupply on day 1 as you enter a new system, because in order to start getting ecosystems going, you’re going to need large spaces to start generating rotating habitats precisely calibrated to mimic Earth where you can put those ecosystems. Rotating habitats are going to be way better than trying to spawn new ecosystems under domes on some planet you’re in the process of terraforming. Terraforming is inherently destructive to the local planet, even modest terraforming efforts on the typical planet would make a nuclear war, dino-killer asteroid, or CO2 rises look rather embarrassingly minimalist. You can do some serious terraforming using atomic explosions or redirected asteroids and comets but those aren’t trivial uses of materials either. As we discussed in Nuking Mars, where we looked at using nukes to terraform the planet, that would require far more megatons worth of explosions than the peak warhead supplies of the Cold War. Redirecting mountain-sized blocks of rock or ice isn’t easy either. Nor are options
like producing a few billion square kilometers of solar mirrors or shades to adjust a planet’s temperature to a higher or lower level. Though in that case there are some simpler options. You might only need a lens or dish at a Lagrange point as you may already have deployed some vast amount of solar mirrors or collectors as part of your slow down maneuver on entering the solar system, and to allow follow up manned missions or robotic supply ships to come at far higher speeds than your ship came in, cruising along vast interstellar laser highways. The power supply from that could be redirected in whole or part, or part-time, to warming up your planet or powering your initial industries. Everything is very dependent on your goals, your technology, and the specific star system you are in, but by and large the most probable strategy tends to converge toward deploying a large laser and power beaming array near your sun and selecting a gas giant or ice giant with a large numbers of moons as your initial landing point for your colony fleet. An outer moon with plenty of ice and rock which is safely outside
any radiation belts of the planet and most of that planet’s own gravity well. Such moons, even bigger ones, really don’t have much of a gravity well to worry about, especially for anyone able to make interstellar spaceships, so it would also be quick and cheap to ship materials back and forth from those neighboring moons, or to any Trojan Asteroids that planet had. Our solar system is the only one we can really speak to in terms of asteroids and moon masses, the normal may range by whole orders of magnitude different from this, to moons as big as Earth that are habitable themselves, to systems almost devoid of any asteroids we could use for raw materials.
Our own asteroid belt combined wouldn’t add up in mass to any of our ten largest moons, and all ten of those combined wouldn’t come close to the mass of Earth. Or close to the mass needed to make a planet like Mars have Earth-like gravity by adding them in. So on the one hand, even a star system with a very modest supply of moons and asteroid is more than sufficient for some extreme levels of industry that will let you tackle colonizing a solar system, while on the other hand it is still limiting for options like copying Earth when there’s no planet already present that’s pretty close to begin with.
What you need early on is energy and cheap sources of raw materials, and smaller moons and asteroids are optimal for the latter. Energy is trickier as it depends on what your best technology for energy is. Your best energy source might not be your cheapest or most technologically advanced. You might have excellent artificial fusion reactors yet opt for solar collectors anyway simply as being easier to mass produce and maintain per watt of energy. Or you have fusion but the reactors are so big that for most applications you often prefer small modular fission reactors running on uranium, plutonium, or thorium. Or you might have black hole generators, ones you can feed mass into, and that might make it preferable to park that generator in orbit of a gas giant and just slowly siphon matter off to generate power as it falls in and beam that out to the nearby moon as needed. Indeed in those sorts of cases of massive power abundance, you might even decide the best way to get an Earth-like Planet is to make some, by stripping the gasses of a gas giant until only the core remained to be cooled and turned into a rocky planet, or creating black holes to just under Earth mass and building a shell world around each, using the methods discussed in our episodes Mega-Earths and Colonizing Black Holes. Abundant cheap energy offers some impressive avenues,
and should never be ignored for discussing interstellar colonization, as opposed to early interplanetary efforts in our native solar system, since interstellar colony ships are potentially so insanely energy intensive themselves. The arrival of a colony fleet around a distant star strongly implies they’ve not got a problem generating lots of energy when they want to, so we definitely want to contemplate it in today’s discussions, whereas other technologies are less strongly implied. The same will hold true of a great knowledge of genetics and biology, and advanced automation. In all probability, they’ve got all of the above, or wouldn’t be colonizing space, though we examined the slow and low tech option in our episode Crawlonizing the Galaxy.
Once you start mining up the local asteroids and moons, which likely relies on advanced automation to help build and run the machines your colonists use for this, you can start building the shells for rotating habitats and preparing them to be your incubators for local ecosystems. You may or may not have had vast zoos and ecologies on your ship during the trip but odds are even if you did it was still kept as small as viable and relied on lots of frozen or digitally stored DNA and samples. We often talk about how nice rotating habitats are for mimicking Earth, places where the gravity and day and temperature can be made exactly like Earth’s, but they can also mimic a planet that might be a candidate for terraforming. For instance, if you had one with a 26 hour day and 81% of Earth’s gravity, you could use a rotating habitat to test how a specific ecosystem from Earth might handle those conditions, and potentially do hundreds of isolated experiments at once, each on a cylinder habitat of its own, to test combinations of terrestrial organisms or those we’ve slightly modified genetically. They then become a great place to serve as nurseries for you to bring in organisms from as your terraforming of that planet progresses.
Since your telescopes likely told you what that planet’s mass, day and year length, and temperature were before you even boarded the ship to leave Earth, it’s possible we might run simulations on rotating habitats back here too, and have good results before the ship arrived at its destination, or that you might have additional habitation drums on your colonial spaceships set to mimic those conditions. You could also mimic its forecasted future conditions, when you add in a large array of solar shades at the L1 to cool the planet down a bit, and begin beaming gigatons of hydrogen at the planet from the star to combine with local oxygen liberated from its own rocks to form oceans, which is probably how we’ll handle terraforming Venus. None of these is a fast process either, and little with terraforming moves quickly. Creating an Earth-like planet, even with the aid of energy ultra-abundance and smart self-replicating machines is likely to be a process of millennia. So a colony that arrived with ten thousand members in the year 2400 AD, after leaving with just five thousand from earth in 2300 AD, might number a hundred million by the time that planet was really suitable for humans to live on as a New Earth in the year 4400 AD. In the meantime those cylinder habitats were a great place to live too, and not a hard adjustment considering their ancestors were probably living in similar habitation drums on board their colony ship for the decades or centuries of flight time there, and indeed for most future interstellar colonies beyond our initial first hundred or so, it would be very likely most immigrants out from our solar system weren’t coming directly from Earth but had come from some rotating habitat built into an asteroid or moon or orbiting Earth.
Which begs the question of whether terraforming copies of Earth is really going to be the normal strategy even in systems which have pretty good basic copies of Earth to work from, which most probably don’t. We also shouldn’t ignore that while we keep talking about making artificial gravity by spin, many future humans might be adjusted to far lower gravity, or even micro-gravity, and indeed settlers out from Earth might not be human. I don’t just mean options like post-human cyborgs or artificial intelligence either. Consider, it is entirely possible we will experiment with, and succeed, in making human-intelligent dogs, dolphins, chimps, cats, whichever. Or hybrids of, like a werewolf, or
something more arcane like a brilliant jellyfish or squid. What then? I won’t say genocide would be off the table, or sterilizing them or controlling their numbers and rights, but I’d like to think more ethical options would be pursued instead. Albeit it’s rather debatable if an ethical society would even perform such experiments in the first place, but if we did, would not that eventually result in colony ships not just containing humans but such uplifted animal or abhuman members? Or entirely composed of them? Indeed they might be fleeing us if we turned out to be cruel to them and thus not able to draw on vast supplies of knowledge, technology, and resources when they reached their unpopulated new haven as refugees The colonization strategies pursued by a race of smart dolphins or a race of humanoids with wings who can fly in a low gravity atmosphere like our Moon might one day offer would vary from what you or I would like, and the same for a race of uploaded humans whose colony is really just a lot of construction and maintenance drones tending to the computers and power collectors that run their vast virtual worlds orbiting some new star. There would be a different style of terraforming too, because it’s all simulated, which doesn’t imply easy either. Being a world designer, be it virtual or classic terraforming, is going to be a job where the Devil is in the details and untold millions of positive and negative feedbacks can wreck your system. And in reality it’s never really a lone planet you’re focused on forging here, but an entire star system. Whatever your colonists wanted
when they left Earth, odds are good it mutated by arrival time, and if not, a few dozen generations of birth and growth is likely to see you get arranged into number of different cultures and emerging civilizations with different interests, and a fairly obvious way of avoiding conflict is to avoid conflicting interests by spreading out. An entire planet is pretty spacious for a growing space colony, but a solar system makes that look tiny. Remember that our own solar system, for all that we talk of having 8 planets, actually contains millions of minor planets and sufficient resources and options for energy production to support many millions of times our current population. Which will be the case for most other star systems too. The dimmest red dwarf may only be able to support a million times our current numbers, several quadrillion people, while the larger giants may be able to support trillions of trillions of people, especially with improvements to efficiency. We often consider such new planets as the birthplace of such greater K2 civilizations once seeded around new stars, but it is entirely possible that the civilization will have grown to trillions living around all those moons and asteroids and other minor planets long before the planet they were planning on terraforming is ready for habitation. With that in mind, there are ways to expedite terraforming, though we need to be aware these will often have limits too. We can talk about grey-gooing a planet with smart
self-replicating machines to just turn it into some instant-paradise, and we know that path is viable since that’s what already happened on Earth, and repeatedly considering how many extinction and replacement events happened. I often call that an example of green-gooing, though the first wave of life on Earth wasn’t photosynthetic and thus presumably wasn’t green, and later got itself wiped out by those, who in turn got wiped out by future iterations. We might think of mechanical machines as being better but evolution already works to minimalize things around the idea of spreading life quickly, so don’t assume anything we design is going to automatically be orders of magnitude better in terms of speed of replication and action or durability. Even super-duper nanotech still has heat issues, as we’ve discussed before, some little robot like that isn’t going to be very durable and a planet can only radiate away heat produced while changing it so fast. As we’ve noted in discussion of terraforming Mars, there’s limits to how fast you can even add water by dropping frozen comets as the gravity of the world will be superheating them as they drop so that the planet would boil if you tried to give it oceans in mere decades. Such problems might have their own workarounds too, some easy way to remove heat from planets is a technology that an advanced civilization would certainly covet and pursue any plausible scientific leads to it. So if it can be done,
they’ll figure out how, but wishing a thing true tends not to work and for the moment at least, science tells us the heat removal issue is a serious bottleneck on terraforming planets along with bottlenecking so many other things too. Hence, no insta-planet. No insta-habitats either but the parameters involved on something like an O’Neil Cylinder or smaller habitat do let them move heat out a lot quicker than your typical planet. You also can minimize a lot of that heat with extensive use of space elevators, space towers, orbital rings, or tethered rings, as those let you recapture a lot of your energy entering a planet’s gravity well as opposed to shedding it as raw heat the way a spaceship aerobraking does, like during the shuttle or capsule re-entries. Again the advantage goes to those who set up their space-based infrastructure before their planet, rather than landing on some planet and then building your space infrastructure like we did. And we must remember, these colonists are principally coming from a
spacefaring civilization, so even if they want a planet of their own as a daughter of Earth, they’re not going to just bypass all that orbital and solar infrastructure and industry, especially given how useful it would be for terraforming. As an example of that, while you can create a huge network of solar shades and mirrors down the road, at first, if you want a home on some frozen planet for instance, a handful of modest parabolic dishes and lenses in orbit targeting your early domes provides warmth and power. Not to mention mapping, after all this is a whole new planet, so an array of satellites providing imaging, mapping, communications, and GPS is certainly handy. We noted earlier that since terraforming is so destructive you don’t really want to live on the planet while it’s going on, but you probably could have some permanent facilities. On an airless world, odds are an equatorial mountain is your preferred alpha site, and I think that will generally hold though I could imagine worlds with thinner existing atmospheres might opt for a valley where things could be sealed up and pressure could be maintained higher and air could be made of a composition we could breathe. You want a place that’s going to be resilient when the time comes to start overhauling the planet, so tectonically active spots aren’t a great pick nor places that might mudslide once you introduce oceans and atmosphere, long before you get to put in organic anti-erosion options, like grasses and tree roots. Though you may mass produce artificial erosion control barriers that emulated roots.
Needless to say, our terraforming options also vary on our biology and culture. For instance, a space colony fleet might contain a faction of the Amish, or a parallel to a different set of technologies. Which can vary a lot. Many Amish families near my farm, for instance, have solar panel arrays to power lighting and will use a credit card at the store but will not use a computer, or car nor own a bicycle, but are also fine with riding in a van they do not own or drive themselves. Insofar as they generally make for polite and trustworthy neighbors, I could easily imagine them coming along as contingents on various colonial expeditions.
It doesn’t matter if they can make technology, just if they’re comfortable with the products. My first thought was they’d prefer planets but they may be as happy as citizens on a O’Neill Cylinder someone else builds and maintains as on a planet, and as general case, it is very easy for me to imagine lots of culture or splinter factions migrating away from Earth with differing opinions on what technologies they were comfortable with and in what fashions. That said if you have a world that’s got an atmosphere at a pressure and mix that would kill you or I dead and half-again Earth’s gravity, it is entirely possible you’d have factions of humanity that were adapted to handle such conditions and just preferred to move in as-is and skip on terraforming. Saves on effort, money, and competition for the space. My guess is that by the time our first colony ships arrive around other solar systems, humanity will already include a lot of cyborg or transhuman clades and there’s a good chance they’ll be highly advantaged and proactive in space colonization of strange new worlds.
So too, we might engineer humans to live on a planet without changing it, by changing them – what we call bioforming. Given that we would also need to do that to all the critters and plants we brought along, my guess is that we will tend to do terraforming more than bioforming, but also that each case will be a little bit of column A and a little of column B, and probably varying not just by the specific planet but amongst the various factions there. There would be those aiming to adapt the world while others focused more on adapting to the world. Which
might lead to some interesting and not always peaceful conflicts as a planet was settled. In the end it is hard to say for sure how other solar systems and their planets will be colonized and what strategies will work best. For now, while we can speculate and make some informed guesses, the best way to find out what truly works is to get out there and explore and see what it takes to start new civilizations on all those strange new worlds out among the stars. So today’s episode is a partial sequel both to our recent episodes on interstellar Colonization Strategies and Asteroid Ships, but also to our episode Planets versus Megastructures that we released as a bonus video last year exclusively on our subscription streaming service, Nebula, if you want to see that our any of our other bonus content. Episodes on Nebula come out 3 to 4 days earlier than they premiere on youtube, but they also come out ad and sponsor read free, and around a quarter of them come out either with extended editions several minutes longer or with a companion episode, like Planets versus Megastructures was for our Megastructure Compendium last year, or Conformal Cyclic Cosmology was for last month’s episode, The Omega Point. Nebula’s a great place for creators to experiment with content without getting penalized by Youtube’s algorithms. If you like the idea of
seeing, or listening, to all that bonus content, by myself and many other creators, and of getting SFIA’s episodes a few days early and without ads, then you can join Nebula for just a few dollars a month, and gain access to all that ad-free, early, and bonus content, while supporting this channel and other independent creators. We also now have Nebula Classes, no additional charge, from many of your favorite educational shows. If you’d like to join Nebula today, just click the link in the episode description, https://go.nebula.tv/isaacarthur. So that will wrap us up for today but we’re just getting started for February, and next Thursday, February 9th, we’ll discuss a surprising candidate for possibly hosting alien life, large oceanic worlds with massive hydrogen atmospheres, or Hycean Planets. And don’t forget
to join us after that for the mid-month Scifi Sunday episode, on February 12th, where we’ll look at the concept of Super Soldiers. Then in two weeks will continue our discussion from last fall about Time Wars with a look at Multiversal Warfare and the implications of some of the crazier aspects of Quantum Mechanics. If you’d like to get alerts when those and other episodes come out, make sure to hit the like, subscribe, and notification buttons. You
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2023-02-05 05:48
