Skip to content

Take an asteroid at least thirty kilometers on its long axis. Any type will do—solid rock, rock and ice, metallic, even iceballs, although each presents different problems.

Attach a self-replicating excavator assembly to one end of the asteroid, and with it hollow out your asteroid along its long axis. Leave the wall at least two kilometers thick at all points except for your entry hole. Assure the interior integrity of the wall by coating it with a dura of suitable strength.

As your assembly hollows the interior, be aware that ejection of the excavated material (best aimed toward a Lagrange salvage point, to collect the salvage fee) will represent your best chance to reposition your terrarium, if you want it in a different orbit. Store excess ejecta on the surface for later use.

When the interior is hollowed out, leaving an empty cylinder of at least five kilometers in diameter and ten kilometers long (but bigger is better!), your excavator assembly will return to the access hole and there reconfigure itself into your terrarium’s propulsion unit. Depending on the mass of your new world, you may want to install a mass driver, an anti-matter “lightning push” engine, or an Orion pusher plate.

Beyond the forward end of the cylinder, on the bow of your new terrarium, attach a forward unit at the point of the long axis. Eventually your terrarium will be spinning at a rotational rate calculated to create the effect of gravity on the inner surface of the interior cylinder, so that when you are inside you will be pulled to the floor as if in a gravity field. This is the g equivalent, or gequivalent. The forward unit will then be connected to the bow of the terrarium by a geared axle, to allow the forward unit not to spin but instead to stay fixed. It will be nearly weightless in this bowsprit chamber, but many functions of the terrarium will go better without the spinning, including docking, viewing, navigating, etc.

It is possible to build an interior cylinder that spins freely inside an asteroid that does not spin—the so-called “prayer wheel” configuration—and this does give you both an interior with g effect and a non-spinning exterior, but it is expensive and finicky. Not recommended, though we have seen some good ones.

When stern and bow are properly installed and configured, and the asteroid is set spinning, the interior is ready to be terraformed. Begin with a light dusting of heavy metals and rare earths, as specified for the biome you are trying to create. Be aware that no Terran biome ever began with the simple ingredients you will be starting with on an asteroid. Biospheres need their vitamins right from the start, so be sure to arrange for the importation of the mix that you want, usually including molybdenum, selenium, and phosphorus. These are often applied in “puff bombs” set off along the axis of the cylindrical space. Don’t poison yourself when you do this!

After that, string the axis of the cylinder with your terrarium’s sunline. This is a lighting element, on which the lit portion moves at whatever speed you choose. The lit portion of the sunline usually starts the day in the stern of the cylinder, after a suitable period of darkness (during which any streetlights overhead will serve as stars.) The lit portion of the line, appropriately bright, then traverses the sunline from stern to bow (or east to west, as some describe it), taking usually the same time as a Terran day, as measured by the latitude of your biome on Earth. Seasons inside your terrarium will be rendered accordingly.

Now you can aerate the interior to the gas mix and pressure you desire, typically somewhere between 500 and 1,100 millibars of pressure, in something like the Terran mix of gases, with perhaps a dash more oxygen, though the fire risk quickly rises there.

After that, you need biomass. Naturally you will have in your spice rack the complete genetic codes of all the creatures you intend to introduce into your biome. Generally you will either be recreating some Terran biome, or else mixing up something new, which hybrid biomes most people call “Ascensions,” after Ascension Island on Earth, the site of the first such hybrid (started inadvertently by Darwin himself!) All the genomes for all the species of your particular biome will be available for print on demand, except for the bacteria involved, which are simply too numerous and too genetically labile to categorize. For them you will have to apply the appropriate inoculant, usually a muck or goo made of a few tons of the bacterial suite that you want.

Luckily bacteria grow very fast in an empty ecological niche, which is what you now have. To make it even more welcoming, scrape the interior wall of your cylinder, then crumble the rock of the scrapings finely, to a consistency ranging from large gravel to sand. Mixed with an edible aerogel, this then becomes the matrix for your soil. Put all of the ice gathered in your scraping aside, except for enough when melted to make your crumbled rock matrix moist. Then add your bacterial inoculant, and turn up the heat to around 300 K. The matrix will rise like yeasted dough as it becomes that most delicious and rare substance, soil. (Those wanting a fuller explanation of how to make soil are referred to my bestselling All About Dirt.)

With a soil base cooked up, your biome is well on its way. Succession regimes at this point will vary, depending on what you are looking for at climax. But it’s true to say that a lot of terraria designers start out with a marsh of some kind, because it’s the fastest way to bulk up your soil and your overall biomass. So if you are in a hurry to occupy, this is often a good way to start.

When you’ve got a warm marsh going, either fresh water or salt, you are already cooking good. Smells will rise in your cylinder, also hydrological problems. Fish, amphibian, animal, and bird populations can be introduced at this point, and should be if you want maximum biomass growth. But here you have to watch out for a potential danger: once you get your marsh going, you may fall in love with it. Fine for you, but it happens a bit too often. We have too many estuarine biomes now, and not enough of the other biomes we are hoping to cook out here.

So try to keep your distance at this point; keep a depopulate marsh, or stay away from it during this part of the process. Or join a trading scheme in which you trade asteroids when they are at the marsh point, so that you come into a new one wanting to change things, unattached to what’s already there.

With the hefty biomass created by a marsh, you can then build up land using some of your excavated materials, saved on the surface of the asteroid for this moment. Hills and mountains look great and add texture, so be bold! This process will redirect your water into new hydrologies, and this is the best time to introduce new species, also to export species you no longer want, giving them to newer terraria that might need them.

Thus over time you can transform the interior of your terrarium to any of the 832 identified Terran biomes, or design an Ascension of your own making. (Be warned that many Ascensions fall as flat as bad soufflés. The keys to a successful Ascension are so many that I have had to pen another volume, How To Mix and Match Biomes!, now available.)

Ultimately you will need to make many temperature, landscape, and species adjustments, to get to the kind of stable climax community you want. Any possible landscape is achievable; sometimes the results are simply stunning. Always the entire landscape will be curving up around you, rising on both sides and meeting overhead, so that the look of the land will envelope you like a work of art—a goldsworthy inscribed on the inside of a rock, like a geode or a Fabergé egg.

Obviously it is also possible to make interiors that are all liquid. Some of these aquaria or oceanaria include island archipelagoes; others are entirely water, even their walls, which are sometimes refrozen transparently so that in the end when you approach them they look like diamonds or water droplets floating in space. Some aquaria have no air space in their middles.

As for aviaries, every terrarium and most aquaria are also aviaries, stuffed with birds to their maximum carrying capacity. There are fifty billion birds on Earth, twenty billion on Mars; we in the terraria could outmatch them both combined.

Each terrarium functions as an island park for the animals inside it. Ascensions cause hybridization and ultimately new species. The more traditional biomes conserve species that on Earth are radically endangered or extinct in the wild. Some terraria even look like zoos; more are purely wilderness refugia; and most mix parkland and human spaces in patterned habitat corridors that maximize the life of the biome as a whole. As such these spaces are already crucial to humanity and the Earth. And there are also the heavily agricultural terraria, farmworlds devoted to producing what has become a very large percentage of the food feeding the people of Earth.

These facts are worth noting and enjoying. We cook up our little bubble worlds for our own pleasure, the way you would cook a meal, or build something, or grow a garden—but it’s also a new thing in history, and the heart of the Accelerando. I can’t recommend it too highly! The initial investment is non-trivial, but there are still many unclaimed asteroids out there.

Take raw Venus. CO2 atmosphere of 95 bar, temperature at surface would melt lead, hotter even than Mercury’s brightside. A hellish place. On the other hand, .09 g, and just a tad smaller than Earth. Two continental rises on the surface, Ishtar and Aphrodite. Earth’s sister planet. There’s real potential here for a great new creation.

Take one Saturnian ice moon—Dione will do fine. Dismantle with Von Neumann self-replicating excavators, cutting into chunks about ten kilometers on a side. Attach mass drivers to the chunks and send them down to Venus.

While doing this, build a round sunshield of lunatic aluminum, very thin material, only 50 grams per square meter and yet still totalling 3 x 1,013 kg, the largest thing ever built by humans. Concentric strips give the sunshield flexibility and allow it to tack up into the solar wind to hold its position at the L1 point, where it will shadow Venus entirely. Deprived of insolation, the planet will cool at a rate of 5 K a year.

After 140 years, the CO2 atmosphere will have rained and snowed to the surface and frozen as a layer of dry ice. Scrape all the dry ice that landed on Ishtar and Aphrodite down to the lowlands, being careful to keep a smooth surface. While clearing off the continents, release another suite of Von Neumann self-replicating chemical factories designed to break oxygen out of the frozen CO2; these will create 150 millibars of oxygen for the atmosphere, in about the same time it takes for all the CO2 atmosphere to freeze. A purely oxygen atmosphere would be too flammable, so add a buffer gas, preferably nitrogen, to make a more stable mix. Titan may be over-subscribed for its excess nitrogen, so be prepared to seek substitutions. Argon mined on the moon would also serve in a pinch.

When you have the oxygen you want, and the dry ice is all flat on the lowlands, cover the dry ice with foamed rock, so that the CO2 is a completely sequestered feature of the lithosphere.

Now take the chunks of Dione you have been saving and crack them against each other in the oxygen-and-buffer atmosphere at the correct height to create steam and rain. This will add back some heat to the planet, which at this point has been taken below the human-friendly range. Possibly some light can be let through the sunshield if needed to help heating. It will only take two years for the greater part of the impact water to rain and snow onto the surface, so be ready to work fast.

The water on the surface after this Dione infusion will be equal to about 10 percent of Earth’s water. It will be fresh water; salt to taste. The water will cover 80 percent of Venus, which is much flatter than Earth, to an average depth of 120 meters. If deeper seas are preferred, but also a maximum amount of land, consider digging an oceanic trench with some of the Dione impactors. Remember this will complicate the CO2 sequestration if you choose to do it, so make adjustments accordingly. If it is done carefully, however, Venus could ultimately end up with about twice the land surface that Earth has.

At this point (140 years freezing and preparation, 50 years scraping and poaching, so be patient!) you might think that the planet is ready for biological occupation. But remember, combining the Venusian year of 224 days with its daily rotation period of 243 days, you get a screwball curve (retrograde motion, sun rising in the west) in which the solar day for any particular point on the planet is 116.75 days. Tests have long since determined that that’s too long for most Terran life forms to survive, tweaked or not. So at this point, two main options have been identified. The first is to program the sunshield so that it lets through sunlight to the surface and then blocks it off again, flexing like a circular Venetian blind to make a more Terran rhythm of night and day. This would make it easy on the new biosphere, but would require that the sunshield work without fail.

The second option would call for another round of impactor bombardments, this time striking the surface of the planet such that their angular momentum spins the planet up to something like a hundred-hour day, which is considered within the tolerance limit for most Terran life-forms. The problem with this option is the way it would delay occupation of the planet’s surface, by its release of a considerable amount of the sequestered dry ice under the foamed rock layer. Biosphere establishment would have to be put off for another two hundred years, effectively doubling the time of terraformation. But there would be no further reliance on a sunshield. And a properly constituted and maintained Venusian atmosphere could handle full sunlight without greenhousing or other spoilage.

Which option you choose is your preference. Think about what you want in the end, or, if you don’t believe in endings, which process you prefer.




the economic model of the space settlements developed in part from their origins as scientific stations. In this early model, life in space was not a market economy; once you were in space your housing and food were provided in an allotment system, as in Antarctic scientific stations. What markets existed tended to be private unregulated individual enterprises in non-essential goods. Capitalism was in effect relegated to the margin, and the necessities of life were a shared commons




exchange between Earth and individual space colonies was on a national or treaty-association basis, thus a kind of colonial model, with the colonies producing metals and volatiles, knowledge useful for Earth management, and later on, food




once the space elevators were in place (first at Quito, 2076) traffic between Earth and space increased by a factor of a hundred million. At that point the solar system became accessible. It was too big to inhabit rapidly, but the increasing speed of space travel meant that over the course of the twenty-second century the entire solar system came within easy reach. It is not a coincidence that the second half of this century saw the beginning of the Accelerando




the space diaspora occurred as late capitalism writhed in its internal decision concerning whether to destroy Earth’s biosphere or change its rules. Many argued for destroying the biosphere, as being the lesser of two evils

one of the most influential forms of economic change had ancient origins in Mondragon, Euskadi, a small Basque town which ran an economic system of nested co-ops organized for mutual support. A growing network of space settlements used Mondragon as a model for adapting beyond their scientific station origins. Cooperating as if in a diffuse Mondragon, the individual space settlements, widely scattered, associated for mutual support and




supercomputers and artificial intelligence made it possible to fully coordinate a non-market economy, in effect mathematicizing the Mondragon. Needs were determined year to year in precise demographic detail, and production then directed to fill the predicted needs. All economic transactions—from energy creation and extraction of raw materials, through manufacturing and distribution, to consumption and waste recycling—were accounted for in a single computer program. Once policy questions were answered—meaning desires articulated in a sharply contested political struggle—the total annual economy of the solar system could be called out on a quantum computer in less than a second. The resulting qube-programmed Mondragon, sometimes called the Albert-Hahnel model, or the Spuffordized Soviet cybernetic model, could be




if everyone had been working in a programmed Mondragon, all would have been well; but it was only one of several competing economies on Earth, all decisively under the thumb of late capitalism, still in control of more than half of Earth’s capital and production, and with its every transaction tenaciously reaffirming ownership and capital accumulation. This concentration of power had not gone away but only liquefied for a while and then jelled elsewhere, much of it on Mars, as GINI figures for the era clearly reveal




in residual-emergent models, any given economic system or historical moment is an unstable mix of past and future systems. Capitalism therefore was the combination or battleground of its residual element, feudalism, and its emergent element—what?




with the success of the Martian revolution and the emergence of its single planetwide social-democratic system, the gates were opened for the rest of the solar system to follow. Many space settlements remained colonies of Terran nations and combines, however, so the ultimate result was a patchwork of systems somewhat resembling anarchy. Much of the space economy came to be dominated by a league of settlements called the Mondragon Accord. The Accord was renewed at a conference every five years, and annually the Accord’s AIs called out its economy, thereafter correcting it frequently (several times a second)




the longer the Mondragon Accord went on, the more robust it got. Confident in its support of the necessities, more and more side deals between individual settlements’ enterprise markets sprang into being, the so-called above and beyonds, all working on the margin. If not for Mars and its




as feudalism is the residual on Earth, capitalism is the residual on Mars




the margin itself grows with prosperity, with growing sophistication and culture




the existence of the marginal economy, semi-autonomous, semi-unregulated, resembling anarchy, filled with fraud, double-dealing, and crime, delighted all free-marketeers, libertarians, anarchists, and many others, some enjoying the bonobo barter and others the machismo of a wild west and wealth beyond need



marginal capitalism is a tough-guy sport like rugby or tackle football, suitable mostly for people slightly overdosed on testosterone. On the other hand, with some rule and attitude changes it has proven it can be an interesting game, even beautiful, like baseball or volleyball. It is a valid project at the margin, a form of self-actualization, not to be applied to the necessities, but on the margin a nice hobby, even perhaps an art form




confining capitalism to the margin was the great Martian achievement, like defeating the mob or any other protection racket.


Excerpted from the novel 2312 by Kim Stanley Robinson. Copyright © 2012 by Kim Stanley Robinson. Reprinted by permission of Orbit, a division of Hachette Book Group, Inc., New York, NY. All rights reserved.