When I was growing up every kid wanted to be an astronaut. I did too, and not just a ten-day-mission astronaut but a guy who worked full-time in space like the heroes of my favourite SF classics. Maybe on a five-year mission to boldly go…or even to jump on a giant colony ship to be a pioneer in a new star system. Cool! Except I always knew there was one big roadblock that stood in my way (beyond my lack of brains, brawn, courage, and training, of course).

I’d miss the natural Earth way too much. I’m kind of an outdoors guy. Not the hunting and fishing kind so much (as a scuba diver, I enjoy watching them more than catching them), but I love to camp in the bush, go canoeing or hiking, and even when I’m home I go for a daily walk outside our town in the fields and hills. I like the outdoors—I need the outdoors. I don’t think I could stand to be cooped up in a tin can, no matter what the size, or under a dome on the Moon. Or anywhere I couldn’t step outside and feel sunshine and a fresh breeze on my face. Even here on Earth we can be susceptible to “cabin fever” when we’re confined inside. Much as I envied the Star Trek gang, I always felt sorry for the ninety-nine per cent of the crew who never got to join an away team and visit the latest planet. Even if they did, it wouldn’t be Earth. No smell of green grass, trill of bird song, or rustle of the wind through trees.

I love trees. I try to surround myself with them every chance I get. Not much room for trees on a spaceship, though. And who knows what would pass for trees on some other planet? But what about Star Trek holosuites, you ask—a computer simulation of almost any environment? Impressive, but not good enough.

Scientific brain trusts try to solve space travel problems like shielding the crew from cosmic rays, reducing the harmful health effects of zero gravity, ensuring the psychological balance of crewmates to keep them from driving each other crazy. But what about the lack of trees?

I saw an article this week about how the Japanese government has been promoting nature appreciation since the early 80’s for the sake of people’s health. In Japan they call it “forest bathing”—going out in the woods for some peace and quiet for stress relief. But, more than that, a variety of natural oils from trees and other plants, collectively called phytoncide, seems to give a boost to the human immune system. That kind of thing shouldn’t really be a surprise, given our evolutionary history. There have been concerns for some time that we humans, especially children, suffer adverse health effects when they aren’t exposed to the natural world. Researcher Richard Louv coined the term “nature deficit disorder”. No, it’s not officially recognized as a medical disorder, but maybe it soon will be as we continue to keep ourselves locked up in glass towers and brick boxes, surrounded by concrete and asphalt.

So what if we were to leave our natural world entirely and confine ourselves to completely artificial environments for months or years?

There have been experiments to study what happens to humans in closed environments, but mostly, as with the Arizona research facility Biosphere 2, they included miniature ecologies—mini rainforests and savannahs, for instance—as well as people. And the results so far haven’t been all that encouraging. Even so, I do think that we’ll need to take Earth ecologies with us somehow for long-term stays in space. I just don’t think that the human animal could stand spending years at a time in a domed outpost on the Moon or Mars, say, without getting a pathological compulsion to get outside and take a breath of air (a very unhealthy impulse in those circumstances!) But if we can take along some good rich soil, fragrant wildflowers, pungent cedars and pine trees, and blossoming berry bushes, not to mention the birds and the bees…we might be all right.

Personally, I still don’t think I could ever leave the Earth for very long, but for some people, taking a piece of Earth along with them might just be enough.