And we rarely stop to consider the fact that those worlds may well be easier to live in than exotic locales far beyond our own planet.
Catharine Conley, NASA’s planetary protection officer, whose job is to make sure we don’t accidentally infect other planets with Earth-germs, has given this question some thought.
When Scientific American asked her if she thinks we’ll colonize space, she didn’t just say we’ve already colonised it with robots and may well have done so with bacteria too. She also pointed out that humans looking to become permanent citizens of the moon may not want to hold their breath.
“But if the idea is to construct a self-sustaining environment where humans can persist indefinitely with only modest help from Earth … then I’d say this is very far in the future, if it’s possible at all,” she said. She went on to make a thought-provoking comparison: “We haven’t bothered to colonize areas underwater on Earth yet. It’s far more challenging to colonize a place where there’s hardly any atmosphere at all.”
Just as there are a handful of lucky humans who have lived in space, there are a few who have lived underwater. Perhaps the most famous is oceanographer Sylvia Earle, who has spent more than 7,000 hours underwater.
“It was glorious being able to breathe underwater,” Earle said during a public panel earlier this year. Being underwater still requires support, but at least it doesn’t take a rocket to get you there. “The blue part of the planet is accessible to pretty much everyone.”
Conley and Earle both highlight the technical difficulties of being born, living, and dying off our planet.
Earle called Mars “Earth without nature.” Conley points out that we’d need to figure out how to build ecosystems from scratch — strong enough ecosystems that they keep going even when something goes wrong.
But whether or not we ever colonize either space or the ocean, exploring one will help us explore the other.
We know Mars used to have an ocean, one large enough to spawn giant tsunamis we can still see traces of today. And the only permanent underseas lab in the world is used by NASA because they can actually test spacewalk techniques in a fairly realistic environment.
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