It's not impossible to grow plants in seemingly inhospitable environments.
Image: Space Studies Institute
For those of us without a green thumb, growing even the most hardy plants in perfect conditions can seem impossible. How about trying to grow plants on a meteorite? Well, at least one scientist is doing it, with moderate levels of success.
The thinking goes—if we're going to have space colonies, we're going to need some way to eat. Transporting all food from Earth isn't realistic, and neither is bringing tons of bags of topsoil. Photos of asteroids, meteors, and other planets in our solar system look incredibly desolate, but, in fact, some of them contain many of the nutrients necessary to grow plants.
"People have been talking about terraforming, but what I'm trying to do is give some concrete evidence that it's possible to do this, that it's possible to grow in extraterrestrial materials," Michael Mautner, a Virginia Commonwealth University researcher and one of the world's only "astroecologists" told me. "What I've found is that a range of microorganisms—bacteria, fungi, and even asparagus and potato plants—can survive with the nutrients that are in extraterrestrial materials."
Asteroids and meteorites often contain phosphate, nitrates, and even water that plants can feed on. Mautner thinks it's not outside the realm of possibility to directly grow certain plants on other planets, in some sort of protected environment.
An asparagus seedling in meteorite soil. Image: Michael Mautner
He's not simply tossing asparagus seeds onto a meteorite, however—he's grinding up the rock into something more closely resembling soil. His plan is to eventually find several different plants and extraterrestrial soils that make the most sense to farm, and use his experiments to develop a "rating system" for which are likely to fare best—a kind of interplanetary farmer's almanac, if you will.
Of course, Mautner is doing these experiments on Earth, and it's worth taking his results with more than a grain of salt—he's not considering the lack of oxygen on other planets and the different gravity conditions.
"The conditions outside Earth are presumably anaerobic—that's an order of magnitude harder to do," he said. "But, if we can find things that can grow in extraterrestrial materials under Earth conditions, you can start to talk about it. We can maybe start to use those materials in artificial, oxygen-containing environments."
Our best bet for colonizing another planet could be printing humans there—but, if the goal is simply to seed the universe with life and let evolution do its work, Mautner's work could end up being extremely important.
Algae and bacteria living on meteorite soil. Image: Michael Mautner
As the calls for humans to hedge our survivalist bets by spreading out through the universe grow louder, researchers are looking for ways to make "directed panspermia," the purposeful transportation of life from one planet to another, a reality.
Mautner says his work could be used to kickstart a directed panspermia program.
It's an idea that has real scientists thinking about it—including Adam Steltzner, NASA's lead engineer on the Curiosity mission. The most fanciful idea he suggested at the conference was the possibility of "printing" humans on another planet, which you can learn all about here—but there are other ways to go about spreading life through the universe.
"Imagine hurtling durable, terraforming bacteria to other worlds with the idea of shaping that environment," Steltzner said last month at Smithsonian Magazine's Future Is Here conference. "We could send instructions in that bacteria to create descendent organism."
Mautner says that, within our lifetimes, we might be able to create mini ecosystems, "maybe a mixture of more tolerant organisms and extremophiles that can adapt to various conditions," load them into rockets, and shoot them off towards promising planets.
"If we start to manage these plants and microbes, we could help secure life on other planets for millions or trillions of years," he said.