I have argued to some people that space settlement proponents are marvelous anthropologists. I have done so because in proposing to move humans off planet to other places in the cosmos, to other worlds (be it Mars, the moon, a free space colony, a generation starship), they have to define, describe, and account for “world” – they have to take or make or account for everything that can make a world that humans can live in. In doing so, they must open up what it is that we consider “natural,” what appears to be, simply, there. A modest list, for starters, would go something like this (and perhaps not coincidentally, sounds a bit like Eddie Izzard describing how God made the Earth in seven days — starting at around 2:05): Architecture, Mozart, gravity, microbiomes, radiation, psychology, Jesus, power dynamics, pregnancy, orientation, soil, the internet, shit, macrofauna, growth cycles, photosynthesis, race, gender, up and down, socialization, tea and coffee, the idea of quickly and slowly, kinship, the idea of Europe, exercise, the structure of a staircase, soil, signal latency, how concrete sets, circadian rhythms, sedimentation, flat feet, data, sonar resonances, rotation, cancer, commodities and exchange, electromagnetism, turning, waste, the division of labor, the length of day and night, how ink flows in a pen, relativity, “pests,” kinky sex, AI, apathy, genetics, seasons, the chemical reactions necessary for making chocolate cake, rock, haircuts, jam. And they have to account for the myriad interactions among all these things. They are not producing Earth elsewhere, though they are worlds that necessarily bear a relationship to this planet. But they are different worlds, and worlds in which the difference from Earth is constantly a question. Such worlds are not necessarily anthropocentric — while made by humans and ultimately designed to sustain human life, every element, human and nonhuman (from what we would call pests to grain to intention and anger) would have to be integrated or integrate itself to sustain this new world for humans and for nonhumans alike. There is no order to my list because there can’t be: every element is essential to be thought about, provided, nurtured, accounted for ahead of time and as it emerges, whether ostensibly a noun, verb, adjective, conjunction, article, or adverb. Nature and culture can no longer have secure meaning in planning for a world that isn’t Earthbound. Humans may make these worlds, but humans cannot be the ultimate element because they rely on too many others. This is what is radical about space settlement: the need to define what is in a world, to be explicit about its constitution and its purpose, the need to recognize the value of every element in the maintenance of this world, not simply the predominance of the human because there is no Earth to absorb the mistakes. This is what makes space settlement proponents so profoundly anthropological in their thinking: they must open up every claim about what is “natural” in the world and consider how it might be made. And once it is, it has its own intention, agency, and purpose. I would say that working with space settlement advocates has made me a better anthropologist because they have thrown everything I assume open to question. So, thanks for that!