Brownian Motion

Adapted from an article I wrote for The Tower, the PHS student newspaper.

Pale Blue Dot is a photograph of Earth, taken from a distance of six billion kilometers by the Voyager spacecraft. Described by Carl Sagan as “a mote of dust in a sunbeam,” our home planet barely takes up a pixel of the vast inky seas beyond. We think we have conquered Nature herself as we bend ecosystems to our will; we think we are masters of the laws of physics as we build spires that graze the sky. We have sailed the seven seas, we have summited the highest peaks, and we have mapped the farthest islands. But as that photograph shows, there is so much of the heavens we have yet to explore.

There are those who rationally and logically claim that we should keep ourselves more grounded in reality rather than chasing lofty dreams. First, the practical problems: space is hard. Take a look at plans for bases on Mars, one of science fiction’s favorite places for settlements. You’ll find that many of them look fit for a Hobbit — covered in meter-thick walls of martian regolith as shielding for the scorching cosmic radiation. And it’s difficult to obtain energy — there’s a reason that the Perseverance and Curiosity rovers use nuclear fuel for electrical power. With the added requirements of oxygen, food, and water, keeping humans alive in space is costly and difficult; the ISS costs NASA three billion dollars a year to operate. As it turns out, space really really wants you dead.

And as much as we would like space exploration to be a peaceful endeavor powered by a united human race, politics and greed get in the way. The Outer Space Treaty of 1967 prevents nations from claiming sovereignty over space, but the recent Artemis Accords, a set of guidelines from NASA concerning its plan for a human presence on the Moon, seem to be about asserting American dominance over lunar commercial exploitation. Humans have a terrible track record of agreeing to things — if space resources become commercially exploitable, we will almost certainly fight over them.

Then, the ethical problems: is it right to spoil the pristine environment of space, left untouched for billions of years? When Europeans colonized Australia, they brought many invasive species that destroyed much of its native ecosystem. If there is life on other planets, should we risk damaging it through colonization? And if we accidentally bring along microbes to a planet, how will we know if any life we find is actually native? This potential for contamination is why the Galileo and Cassini probes were deliberately crashed into Jupiter and Saturn respectively (to avoid polluting moons that could support life), but human colonization will likely make contamination inevitable.

Looking at the short term, there are no good reasons to go to space. It’s risky. It doesn’t make economic sense. It could destroy delicate alien life. And with so many problems on our planet, why care about another?

And yet this is the kind of thinking that limits us; in seeking to preserve ourselves we hasten our demise. Perhaps the universe is filled with civilizations with this same mindset, civilizations that rationally decided to keep themselves firmly rooted — their earthen graves remembered by those few that irrationally decided to fly.

We bury our noses in quarterly reports, and fail to see the benefit of space colonization. Start looking at timeframes of decades or centuries, and its usefulness comes into focus. The first settlements on the Moon or Mars can serve as a springboard for the colonization of the rest of the solar system, leading humanity into a multi-planetary future capable of supporting billions more people, reducing the effects of overpopulation. Asteroid mining can satisfy our hunger for precious metals without wounding the surface of the Earth. We can colonize and mine celestial bodies to build magnificent structures to harness the true power of the Sun. A Dyson swarm — a system of solar-power-collecting satellites encircling the Sun — could satisfy our hunger for electricity even as our energy demands rise exponentially. Since only a tiny fraction of the Sun’s light reaches the Earth, such a system would increase our energy budget by a factor of millions. However, it would be impractical or impossible to build and launch a Dyson swarm from Earth, because of its thick atmosphere and comparatively poor metallic resources — but colonies on Mercury or asteroids like Pallas could provide the perfect launch point for such a project.

By spreading to other planets, and eventually, other star systems, we ensure our long-term survival. In an age where human civilization could end in a matter of minutes by an atomic maelstrom, the colonization of the cosmos can ensure the longevity of the human race for millions of years to come.

Even from a philosophical standpoint, exploration has always been a part of what makes us human — that innate curiosity to understand our world, that intrinsic hunger to see what lies beyond the horizon line. Space exploration can answer questions that we have tried searching for since human society arose: who are we? Where did the world come from? Are we alone in this vast expanse?

The colonization of our solar system probably won’t happen in our generation, or the next. But we must set that initial spark alight so that one day, our descendants can look upon the heavens and see a thousand pale blue dots amidst the darkness of the night sky. As Sagan said, “We have lingered long enough on the shores of the cosmic ocean. We are ready at last to set sail for the stars.”