Long a staple in  SciFi, terraforming is the hypothetical process by which the properties of another celestial body are changed, allowing it to support terrestrial plants and animals.  While terraforming isn’t within our current capabilities, it’s not as far off as you might think.

There are several good reasons for developing this technology; exploration, adventure, advancement, over-crowding on Earth, and survival.  Yes, survival.  Eventually the Earth will no longer be able to support life.  That’s a given.  Further down the line of the Sun’s lifespan, it will expand.  It might not completely engulf the Earth (the Earth will be pushed away some as the Sun expands), but it will certainly get too close for life.

More than likely, the Moon will be our first destination for colonization, but not for terraforming.  Not only is its mass too low to easily retain an atmosphere, it’s too close if we’re trying to buy some time to get away from the expanding Sun.  Still, we’ll need that moon colony to be able to launch manned missions to Mars that will also be transporting equipment.

Terraforming Mars - artistic impression - image by Doein Ballard

The mass of Mars, in the absence of plate tectonics, may also be too low to effectively hold a viable atmosphere (viable for us, that is).  It does look feasible to build up enough of an atmosphere that we could survive with a little help, like protected enclosures, breathing apparatuses, and protective clothing.  That’s not much, when you compare it to living inside sealed, pressurized domes, wearing pressurized suits, and having clothing that must withstand sub-Arctic temperatures.  This is “living on the summit of Mt. Everest”, compared to “living at the bottom of the ocean”.

Our first challenges with Mars will be (A) to build up the atmosphere, (B) keep the atmosphere from escaping into space, and (C) keeping the planet – or at least parts of it – warm.  We already know a low-mass planet with no plate tectonics can hold heat through greenhouse gas effects (Venus), but it’s extremely arid.  Some scientists think we could get around that problem by manipulating the orbit of a celestial body with an abundance of water to “join” Mars (i.e. crash Ceres into Mars).  I’m not kidding.

(Hmmmm. Maybe not.)

It just got so quiet out there I can hear crickets chirping.

Okay, not as flashy but much safer is the idea of artificially raising the temperature of the Martian South Pole a few degrees, which would cause the CO2 stored there as “dry ice” to sublimate, releasing CO2 into the atmosphere.  CO2 is a greenhouse gas.  This should raise the temperature enough to have areas of liquid water released from the permafrost below the surface.  Next, you introduce basic plant life like plankton, and critters which produce oxygen as a waste product of metabolism.  The beauty of this plan is it doesn’t take much for sublimation to occur; we see it all the time on Earth.  Think about when a pile of snow gets smaller and smaller, but isn’t melting.  Or when ice cubes in the freezer shrink over time.  That’s sublimation.  Matter goes from a solid to a gas without passing through a liquid form.

Once the process gets a toe-hold, there is much we can do to speed things along.  We could make Mars less “shiny” (reduce the albedo) by seeding it with lichens, algae, and a whole zoo full of cyanobacteria.  This would make it so the surface would retain more heat, and add a bit more oxygen to the mix.

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While we’re on the path to having the ability to terraform Mars, there’s still the question of whether or not we have the right.  There are people who feel that we have no business spreading our microbes to any other environment, even ones we consider to currently be devoid of life.  That’s the school of thought that says humanity is an infectious disease to the rest of the solar system… and that’s a discussion I’ll save for another day.