Posted on September 25, 2015
I’m looking forward to seeing The Martian, but the trailer has caused one question to pop into my mind. Matt Damon’s character plainly says that the soil has no nutrients and won’t grow anything. Then we see that with some water and fertilizer, tiny green sprouts pop out.
Here’s my question: If you add water and nutrients to some dirt and things start to grow in it, what was the dirt for? Why not just use hydroponics?
But that’s not the thing I’ve been thinking about lately when it comes to off-world colonization. Rather, I’ve been wondering what would happen to us if we stepped out of our spacecraft onto the surface of a living world. A world with its own ecosystem.
More and more research lately is redefining the human animal away from a single, distinct creature and more toward a tight coupling of symbiotic organisms. Whether it’s the bacteria in our gut that help with digestion or the viruses that help with reproduction or the cloud of microbes that surrounds us, we can’t live without a lot of help from a lot other species.
When we step onto the surface of a dead planet like Mars, that makes little difference. There’s nothing there to affect our biome and no indigenous biome to be affected. But what happens when we step onto a living planet with its own set of microbes? What happens to our cloud of microbes when it comes into contact with alien microbes?
Suppose you found an Earth-like planet out there that had developed rudimentary life, let’s say grasses. Even just to have grasses, there has to be an entire hierarchy of single celled and multi-cellular animals to build up the food chain and to support and protect life.
You could step out of your spaceship, take one deep breath and drop dead. Or, worse, you could exhale and cause the catastrophic collapse of the alien ecosystem. Life eats to gain energy in order to sustain life. Population is limited by energy availability. If it turned out that your microbes could munch on the indigenous ones with impunity, there might be no curb to their appetite.
One plague later, you’d have a dead planet.