Life transforms environments, creating ecosystems where there was once only rocks. The evolution of photosynthetic bacteria billions of years ago created the atmosphere we have today, paving the way for the evolution of larger, oxygen-breathing organisms. We humans obviously transform our environment in countless ways, but can we also engineer barren environments to be hospitable to life? Can we create new living, self-sustaining ecosystems in hostile places? Can we turn lifeless planets into second Earths through the clever introduction of life forms?

Terraforming is the (currently theoretical) idea about doing just that, turning Mars or Venus into pleasant ecosystems by seeding them with communities of extremophiles or engineered microorganisms. Could hardy photosynthetic algae absorb the carbon dioxide on Venus and turn it into oxygen, creating a breathable and much cooler atmosphere with fewer greenhouse gasses? Could dark colored, cold-tolerant microorganism colonize Mars, increasing the temperature by absorbing light from the sun?

This kind of micro/macro-scopic landscape architecture is a fun thought exercise for biological engineers who like how biology can have big, hopefully positive impacts. NASA scientists have over the past few years been thinking about turning this stuff of science fiction novels into a "viable research area" and there have even been two iGEM teams (as far as I know, sorry if I missed you!) that have worked on designing organisms specifically for terraforming Mars, Valencia this year and Tokyo Tech last year.

i-90e662654d566bbde05bba6c52e3e3d2-_48935350_e6800173-spl.h-thumb-200x200-55420.jpgColonization of a human-friendly transformed Mars is, if it ever happens, obviously very far in the future, but small-scale "terraforming" here on Earth has been shown to be possible. A recent BBC article tells the story of Ascension, a tiny volcanic island in the Atlantic Ocean that was transformed from a "cinder" of an island into a lush tropical oasis during a much earlier colonial period (ht Camille!). Charles Darwin was inspired on his 1836 visit to turn the rocky island into a "Little England" for the benefit of its inhabitants. With the help of his friend Joseph Hooker he set in motion a project to plant many different species of trees high up on the island over the next several decades as the Royal Navy made the trips back and forth to the strategic island. The new plants, never before seen together in nature, captured moisture from the air, making the island more hospitable to other plants, starting a feedback loop of ecosystem formation that led to the self-sustaining forest that exists today.

We've done a pretty good job screwing up one planet, so I'm not the hugest fan of starting up on a different one, but I am hopeful that a better understanding and ability to engineer ecosystems and microbial communities at small scales can have a positive impact on our environment. At the smallest, most achievable level this can be as simple as composting and planting a garden but as the scales and stakes grow, so too must our understanding of the benefits and potential (although often unpredictable) risks. The adaptability and feedback that makes terraforming--and biology in general--so interesting can also make it scary. Learning from how we have changed ecosystems both positively and negatively in the past, with stories like that of Ascension but also of the introduction of invasive species and the much longer story of climate change perhaps we can solve some of our problems with a new and more thoughtful terraforming.

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"The Earth destroys its fools, but the intelligent destroy the Earth." -Khalid ibn al-Walid Usually, when we talk about terraforming, we think about taking a presently uninhabitable planet and making it suitable for terrestrial life. This means taking a world without an oxygen-rich atmosphere, with…
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At the very simplest, you can argue that using belts of trees and scrub to reduce soil erosion is terraforming.

By stripey_cat (not verified) on 04 Sep 2010 #permalink

Watching television the other night and saw a program on Earth's moon which claimed that its gravity keeps the planet's axis stable. A comparison was made to Mars, whose axial tilt can apparently vary radically and chaotically due to its interactions with Jupiter.

If this is true, wouldn't any terraforming project's progress be utterly derailed by a period of extreme axial tilt?

By Proper Gander (not verified) on 04 Sep 2010 #permalink

Was enjoying that until your human hating comment. They should not be there. Besides, life is not some sort of pastoral symphony. :@

By Richard Mitton (not verified) on 04 Sep 2010 #permalink

There used to be a bumper sticker around that said, "Earth First!!! (We'll screw up the other planets later)"

It certainly would be nice to have other human-habitable planets around - from a human-centric point of view, at least - but my understanding is that the biggest problem with attempting to terraform Mars or the Moon into something that humans could live on is the absence of an intrinsic magnetic field, which is needed to keep the solar wind from stripping away any atmosphere that might form. (Presumably this already happened to both bodies; Mars used to have liquid water on its surface, which would have required a more substantial atmosphere than it presently enjoys)

I have wondered if the difference between Earth and Venus isn't due to life also. The interesting thing about Venus is how dry it is. That dryness extends all the way through the crust and into the mantle. That dryness greatly increases the viscosity of magma and so slows down a lot of geological processes and also makes the crust a lot stiffer and thicker.

Venus has plate tectonics too, so just like on Earth the surface gets subducted and recycled. An interesting thing about silicate glasses is that a little bit of water increases their density over anhydrous glass of the same composition. If the subducted stuff that melted and became magma then differentiated according to its density, the denser water-bearing magma would sink and the anhydrous and lighter magma would float. Over geologic time that might tend to bury all the water deep under the crust.

However, on Earth there was more than just damp sediments being subducted, there was also organic carbon. When organic carbon is heated along with damp sediments it tends to form methane. Methane is not appreciably soluble in molten silicates and would not be carried down by them. Methane due to subducted organic carbon may have been a mechanism by which the hydrogen in subducted water was recycled to the surface on Earth.

When iron containing sediments are heated along with organic carbon, the iron can be reduced to metal. Liquid iron is much denser than silicates and would tend to flow downward, carrying reducing equivalents with it and leaving behind the CO and CO2 from the iron oxides. We know there are gigantic banded iron formations from when the Earth's atmosphere went from reducing to oxidizing. What happened when they were subducted along with the biomass generated by the iron oxidizing bacteria?

In science fiction, the two themes for dealing with not really habitable planets is terraforming or adaptaman. Adaptaman is the idea of genetically modifying humans to live and work in the harsh environments. Terraforming sounds more politically correct.

By Jim Thomerson (not verified) on 05 Sep 2010 #permalink

Richard- "We've done a pretty good job screwing up one planet" isn't a human-hating comment so much as a statement of raw fact. I mean, what humans do as a matter of course constitutes an extinction-level event. You can love your species while acknowledging its faults. If you don't acknowledge the faults, you can't find a way to overcome them. And if we can't overcome our natural tendencies, we will become extinct sooner than later.

By CS Shelton (not verified) on 05 Sep 2010 #permalink

I am just trying out your new predictions platform.
This is interesting for Collective intelligence purposes and well done.
Could I have more background information on that project? Having worked at Yahoo!
Answers, Flickr and Community products out of Canada, I like to discover interesting projects like this.

@ 4 and 6

Yes, to terraform a planet, you need to have a large moon present (for moons obviously it isn't a problem). Also, a reasonable day is required, between 8 to 46 hours every rotation.

Surprisingly enough, gravity actually isn't a problem down as far as .08th of Earth's. The REAL stripper of atmospheres is of course, the solar and cosmic winds. However, magnetic fields are not necessary, a thick atmosphere is, coupled with great, salty oceans. The atmosphere will quickly develop stratification, an ozone layer and most importantly, an ionosphere. These alone are enough to prevent atmosphere loss for a very long time. Cancer and electronic failure rates will be somewhat higher than on earth, but by then, tech ought to be able to take care of that. Not only that, but terraforming will probably result in greatly increased geologic activity, and the already nascent magentic fields would probably be strenghtened along with new tectonic plate activity within a million years or so of the terraforming.

By questioning (not verified) on 05 Sep 2010 #permalink

Thanks for the Valencia link! Yeast on Mars sounds interesting, I wonder whether that would be more or less viable than bacteria on Mars.

Tokyo tech did quite well last year, I know they managed to make the melanin where we failed. :)

The "terraforming" of Ascension Island is rather exaggerating the condition of the island before the colonials introduced trees.

There was already an ecosystem in place. The addition of shrubby and tree species was not difficult because the first pioneer plants had done a lot of the work. "Although Ascension Island was discovered in 1501 it was not until 1815, when Napoleon Bonaparte was held on St Helena, that the Island was settled. At that time there was only vegetation on the higher slopes of Green Mountain - mostly ferns, mosses and some grasses."

25 species of native plant, 10 endemic. Perhaps 75 native invertebrate species. Caves have endemic blind spiders and springtails that must have been there for quite a while. Landcrabs that "occasionally win a fight with a rat."


Hooker commented on "the rich carpet of ferns that clothed the top of the mountain when I visited it" http://liveweb.livjm.ac.uk/BIE/greenmt.pdf That was despite the introduction of goats some time before and their "great herds" described in 1798. In 1771 a visitor remarked on "a prodigious quantity of purslane". The reference I gave above seems to have ignored the 30 native species of moss, 20 lichens and 10 liverworts. There were masses of nesting seabirds, even after the rats and cats were introduced.

Monthly shipments of hundreds of species of live plants (each with insects and fungi and bacteria and at least ten species of agricultural weeds) and 700 packets of seed in one month alone. The majority of species did not survive.