For space plant experts, “The Martian” is more science than fiction
When you study space plants for a living, you don’t expect to see yourself reflected in a blockbuster movie. But with the release of “The Martian,” University of Florida researchers Robert Ferl and Anna-Lisa Paul have a big-screen avatar in the title character, a space botanist marooned on Mars.
Here, the minds behind UF’s Space Plants Lab talk about weightlessness, heroic nerds, and why Matt Damon might want to switch to sweet potatoes.
Will you be able to enjoy the movie, or will you be busy checking it for accuracy?
RF: I have no problem enjoying a movie that is 90 percent accurate — 50 percent accurate, even. The celebration for us is that a scientist is the protagonist. The nerd of the group is the hero! For us, the notion of a hit movie celebrating the idea that science can figure it out is just really satisfying.
What are your hopes for the movie?
ALP: I hope it shows people that science can be an adventure. We try to get that concept across, but listening to a bunch of scientists in a room — even if they are wearing flight suits — isn’t the same as seeing it on the big screen.
RF: We’ve been weightless, we’ve been on fighter jets, we’ve been to the Arctic to a mockup of a Mars colony, we have experiments on the International Space Station being tended by astronauts. I’m glad to see a movie where the hero faces a problem and says he’s going to “science the s#!t out of it.” That’s what we do every day. Science is cool.
When Matt Damon’s character is left behind on Mars, he survives by planting potatoes. Would that be your choice for a Mars farm?
ALP: There are other crops that are easier to grow and give you a higher return on food value. Sweet potatoes can be more robust and grow in more adverse environments, and they give more complex nutrition back. There are also some really useful plants in the legume family that have a high fat, protein and carbohydrate content. Super-dwarf wheat would also be a good option. Space plant scientists have identified a nice handful of candidate crops for extraterrestrial colonies.
What has surprised you most in what you’ve learned growing plants off-Earth?
RF: Every plant, every microbe, every person on the surface of the Earth has lived its entire evolutionary history in this terrestrial biosphere. So to take people or plants off the surface of the Earth and have them survive at all? that’s the biggest surprise. We can do this. That means that the solar system really is available to us.
ALP: We’re also seeing that plants can survive at extremely low atmospheric pressures. At a fifth or even a tenth of Earth’s pressure, plants will grow great. That means we could have a Mars greenhouse with pressures much lower than those on Earth, which would use less resources. It also means that a breach probably wouldn’t kill the plants. We know they can recover from temporary exposure to that kind of atmosphere.
When people think about growing plants in space, they think about food. But that’s just part of their purpose, right?
RF: The major source of oxygen on Earth is plants, and the same is true in a small biosphere like a space capsule or Martian colony. Plants produce oxygen as a byproduct of photosynthesis. Plants would be an excellent carbon-dioxide scrubber for your life support system. They would clean both your air and water.
ALP: Plants take everything we get rid of and give it back to us clean.
RF: If you pee into the ground, plants will take that moisture and release clean water into the atmosphere. There is a good reason why plant systems are used to reclaim water on the earth, and would do so on Mars.
ALP: They could also help us pull nutrients out of the Martian soil that we couldn’t otherwise get.
You accompany some of your plants on zero-gravity flights to see how they respond. Do you still get excited about it, or is weightlessness all in a day’s work?
ALP: I’m always excited. It’s something you never get jaded about.
Why did you choose arabidopsis — a type of mustard — for your experiments?
ALP: It’s the model organism for this kind of research — the fruit fly of the plant world. It’s small, easy to grow and the genome is completely sequenced, so we can bring all of modern molecular biology to the task of understanding what’s happening.
You’ve been putting plants in space since 1999. How much closer are we to understanding what we need to know to grow plants off-planet?
RF: We basically know. We know we can successfully grow plants in zero gravity. We can grow them in space ships and planetary colonies. We can grow them in the rocky soils at meteor-impact craters on the earth where the landscape is similar to the moon or Mars. We’re already there for the most part. But we need to get even better at it to count on space agriculture for survival.
What’s left to discover?
ALP: We don’t know about potential toxins in the Martian soil or how much water it would take to leach Martian dirt to a level where plants could survive and use the soil. We can only estimate from the soil analyzed by the rovers. We also don’t know the long-term effects of reduced gravity on plant growth, but suspect they’d be just fine with the 1/3 gravity of Mars.
RF: There’s also the issue of what would change if we found microbes on Mars. Because of our desire to protect any Martian ecology, would we even be allowed to go if we found life there? But if you sent me and Anna-Lisa to Mars and told us we had to live off what we could grow, we could do it. We really could. You could do it too.
ALP: But we’d rather you send us.