Really, I blame Dr Who for this one. I was watching a special episode, where David Tennant as The Doctor goes to Mars. He finds the first humans on Mars, including a biodome. The biodome included food-producing and other plants. For pest control, they had also introduced animals, including birds.
And then, I saw an job ad for a Lunar Soil Geologist. They are to head a team looking at soil on the Moon. Of course, I could do nothing except think about extraterrestrial soils, terra-forming and if I ever was luck enough to get a job there, if I got to go to the Moon. Zoe said it was unlikely. She had heard an interview with a lady who had dedicated her life to water on the Moon, and she had never been. How am I supposed to classify soils properly if I can't look at them in-situ?!?! Geesh!
Later that day, I was waiting for an appointment when I picked up a copy of Cosmos. It was the special edition on SETI with Frank Drake (is he a relative?). Someone/thing (?!?) was trying to tell me to think about the realities of terra-forming. As I gave the coincidences some thought, I realised that terra-forming on Mars and the Moon may not be just science fiction. In fact, current science can help guide us towards extraterrestrial gardens, and even my own research can answer some of the current questions regarding terra-forming.
What is Terra-Forming?
Terra-forming is a word use by many science fiction writers to explain a process of making an extraterrestrial world habitable for humans. Terra-forming uses a planets resources, such as frozen water and ground, and manipulates it through ecology and technology to make it habitable for humans and other species. A famous fiction series on terra-forming includes Red, Green and Blue Mars by Kim Stanley Robinson. Once upon a time, I would have left the idea of growing plants on Mars to science fiction. Now I am not so sure. Is it possible to grow plants on Mars or the Moon?
What do we need to live?
Before we think of extraterrestrial living, lets think of our own life on Earth. What things does Earth provide us so we can live
* Atmosphere with oxygen
When we think about terra-forming another planet, we know we need to consider these things to make it habitable for human life.
How can we use current science?
Many planets we have identified, like Mars, are too far from the sun to have the same lifeforms we have on Earth. Distance from the sun is crucial for water and for photosynthesis: both keys to life. Water needs to be in liquid and vapor form for biology to utilise. Distance from the sun regulates temperature and light, and thus affects the growth of plants.
Both the Moon and Mars are known to have frozen water (NASA Mars Program and National Geographic NASA Moon Crashes).
Regolith materials are weathered rocks, which aid in the formation of soils. You can find weathered rock on Mars and the Moon. Regolith can be used to grow plants and produce food. Soil amelioration, or adding nutrients and chemicals to the soil, is often undertaken on our own soils to help plants grow. Ameliorants can be also be used on Lunar and Martian materials to aid in plant growth.
The interaction between plants, animals, water, land and distance from the sun regulate the atmosphere. We need an atmosphere that contains Oxygen for us to survive. Recreating similar conditions to what we have on Earth needs to consider these things.
How do we grow food then?
On the Moon and Mars we have water, regolith materials, but limited light and an atmosphere not like our own. Suppose we want to build a permanent space station, and they must be able to grow their own food. What can we do to make things grow?
Just like in Dr Who, we can consider artificially constructed domes. This includes things like the Montreal Biodome. The biodome manipulates the environment, including temperature, atmosphere and light, along with plants, animals and even microbiology and fungi to create its own ecosystem! Using domes in an extraterrestrial environment is called paraterraforming. Domes are kind of cheating the whole terra-forming thing. Domes artificially create an ecology, whereas real terra-forming implies the construction of an ecosystem which will make an atmosphere suitable for human life. Is there a way we can do it without using a fake-environment?
What do you mean terra-forming is related to your research...
Pretend we are on Mars. We have frozen water, different atmosphere to our own, regolith materials (Martian Soil), and that we are able to create a better light source for the planet (you know, those big mirrors you see in movies...). We have everything we need to undertake terra-forming via land rehabilitation.
We can use principles of land rehabilitation when we consider terra-forming. Some of my recent research (Drake et al 2010) and principles founded by David Tongway, discuss that all ecosystems have 4-key features: Landscape, Functions, Structure and Composition. These four features are interlinked to form an ecosystem. Conversely, when you don't have an ecosystem, you can use these 4-features to help build an ecosystem. An example is in mine rehabilitation. A mined landscape is pretty similar to the moon; both have very little life, and are often bare regolith/rock materials. We have to build an ecosystem where there is nothing, and these 4-features help guide processes to engineer an ecosystem.
We start with finding a stable landscape, and then helping functions. This includes using ameliorants or microbiology (you know, they found extinct life on Mars! Perhaps they are dormant?) to recreate water and nutrient cycling. Once we have good water and nutrient cycling, we can then add plants, animals and habitat features. Together, the 4-features form a natural ecosystem which is adapted to the conditions on the mine site/planet, is able to look after itself and is resilient to changes. So, if we consider land rehabilitation principles, we can potentially build an ecosystem on another planet!
Is terra-forming complete? Well, the combination of light, plants, animals, water will create an atmosphere, possibly even one similar to our own. The only way we will be able to tell is to try, to learn more about rehabilitation on earth, and to monitor changes and adaptively manage our terra-forming practices.
So, I suppose I can say that by researching mine-rehabilitation, that I am also potentially improving our knowledge on how to grow food on Mars! Pretty rad.
Terra-forming is so complex! Understanding each intricate detail would take hundreds (possibly thousands) of years of research. We still have many unanswered questions regarding space travel, let alone the ability to utilise a planet to make it habitable for human life. Besides all of the science questions, there are other questions too: ethics, political and economic. However, just thinking about how real science could potentially used to grow plants on Mars is pretty cool!
For more on Scientists exploring terra-forming and growing plants on other planets/Moons, have a look at some of the links below:
ScienceBlogs: Could we garden on Mars?
Pruned: Fake Moon Dirt
Technovelgy: Space Mirrors Could Create Mars Pocket Eden
Mars Homestead Project
For copies of my papers, please email me!
Want to know more about land rehabilitation? Leave me a comment!