The Repercussions of Planetary Settlement
by Athena Andreadis
Art image: Apollo Dawn, by Chris Butler
Part 1: Why Go at All?
Humans possess two interesting characteristics. The first is our curiosity: we have an insatiable need to know our universe. We’ve investigated our surroundings ever since we became self-aware. That inquisitiveness pushed us out of our original home in an African savanna and drove us to explore and occupy our entire planet, regardless of the local environment. The second is our ability to envision a destination before we actually embark on the quest. As with many of our capabilities, this is a double-edged weapon. It motivates exploration, but it also colors expectations. So it can distort reality, and act as an obstacle to understanding and accepting real discoveries.
Our curiosity and our yearning have fuelled our vision of exploring space. Until now, our dream of space exploration has rested on two deeply embedded but rarely discussed assumptions. One is that humans can overcome everything, given enough technology. This outlook is not surprising, given that the primary movers behind the endeavor have been engineers. Another is that (given our technological prowess) settling on other planets will be about as difficult as it was for our hominid ancestors to expand across the Earth.
Both assumptions are false. Some people advance the argument that humans are really not native to Earth, just to the African savanna. The conclusion is that since we colonized the entire planet, we can do the same with Mars or any other planet we put in our crosshairs. However, there are some fundamental biological limitations that technology cannot address. And these limitations are real enough, since they have prevented us from settling the terrestrial oceans, whose conditions are a distrorted yet faithful mirror of those on Mars — namely, a fatal pressure differential, unfriendly temperature and an unbreathable atmosphere. Contrary to what we like to believe, humans, like all complex systems, are inherently fragile and completely dependent on both external and internal ecosystems.
At first glance, we’re miracles of flexibility. Among advanced mammals, our physique is the least specialized and our brains the least hardwired — at least at birth! With the exception of our manual dexterity, we’re physically mediocre at everything else, jills and jacks of all trades and perfect for none. Our brains, too, can reroute and rewire almost at will, if presented with the crucial information at the right window of opportunity. So, for example, it has come to pass that we click computer mice and drive cars, skills never required of our tree-swinging ancestors.
However, this power of our mind, which made us wish to understand our universe and enabled us to take the first steps towards such a goal, cannot overcome all obstacles. Plainly put, humans are native to this planet in all aspects which matter. Perhaps terrestrial life originally arose from some version of panspermia. It may have arrived from Mars when it was the favorite within the Sun’s habitable zone, dropped out of the sky from contaminated comets or seeded by experimenting aliens. Regardless of origin, the seeds were at most at the bacterial stage. We know this from the fossil record, from the fact that all earth life has the same genetic code and because all terrestrial species are, to a large extent, optimized for this planet.
At this point, humans have overrun the earth, to the point of endangering its miraculously favorable but fragile ecology. If we cannot stabilize our population and do not wish to give up the wasteful first-world living style, our only other choice is to expand outwards. Even if we reach environmental equilibrium, exploring and colonizing other planets is something we must eventually attempt to survive our sun’s evolution into a red giant, regardless of how well these New Worlds can accommodate us.
So when we venture into space long-term, we have to deal with questions beyond the staggering cost and difficulty of the enterprise. Can we bridge the enormous distances between stars without forgetting either our technology or our mission? And can we flourish in a place that is not optimal for us — which, by definition, will be every planet we encounter, as well as the spaceships that take us there?