"A rose-red city half as old as time."

It wouldn’t be right, the first night on Mars, to make a loud noise, to introduce a strange, silly bright thing like a stove. It would be a kind of imported blasphemy. There’d be time for that later; time to throw condensed-​milk cans in the proud Martian canals; time for copies of the New York Times to blow and caper and rustle across the lone gray Martian sea bottoms; time for banana peels and picnic papers in the fluted, delicate ruins of the old Martian valley towns. Plenty of time for that. And he gave a small inward shiver at the thought.

Ray Bradbury, And The Moon Be Still As Bright

Hey, let’s terraform Mars.

Yes, I know, all we’ve done is look around via remote, we really haven’t seen the property in person yet, but what the heck, let’s assume that we’ll like it and that we’ll want to take it.  (And after all, I think we all take into account that the realtor’s photos are going to exaggerate things a little bit, make the yard look larger than it really is, that sort of thing.)

We start with a quick trip out to the Oort Cloud* – okay, not THAT quick, it’s about a light year – where we can start grabbing water ice planetoids and throwing them at Mars.  Given that we’re talking about an extended program of what is essentially bombing Mars with meteors, we really want to get this out of the way before we establish any bases on the planet.  Think of it as painting the new house before you move in, it’s just so much more convenient without any furniture.

Bombarding the planet with ice starts to help with the two major shortcomings of Mars:  liquid water and oxygen.  Mars does have a certain amount of water, but it’s mostly tied up in the polar ice caps (the southern ice cap is made up of frozen carbon dioxide – more commonly known as dry ice – but it’s generally accepted that the CO2 covers large deposits of water ice.)  Dropping big ice cubes from orbit starts to fill Mars’ minimal atmosphere with water vapour as well as throwing up a lot of dust, with the goal of jumpstarting the greenhouse effect:  the water vapour and dust create a barrier of clouds that should stop the heat created by the impacts from dissipating into space.

And the other thing you get from clouds?  Rain...

Or will it snow?  After all, the current weather report from the Rover Environmental Monitoring Station (REMS) forecasts a high of -29 C and a low of -114 C, which sounds to me more like snow weather.  On the other hand, the greenhouse effect may raise the temperature enough for water to remain water.

Let's assume that we're going to get rain - and as a result, mud.  There are a few odd components in Martian soil (there's been a lot of discussion about the discovery of perchlorates in some samples) and, unlike terrestrial dirt, there's no real organic component.  Regardless, the presence of nutrients such as sodium, potassium and chloride would suggest that it will be possible to grow plants on Mars.

Water, as always, will seek its own level, even in the reduced gravity of Mars, and the misnamed Martian canals will become rivers that will ultimately create ponds, lakes and oceans.  Depending on the manner in which the components of the Martian soil leach into the water, it may or may not be possible to import sea life as part of the biosphere.

It will undoubtedly be necessary to introduce simple elements such as primitive mosses and lichens which will be able to survive on their own before moving up the evolutionary ladder to grasses, insects and so on.  As more plant life is introduced, we will see the oxygen level increase, but it will be a slow process. Electrolyzing asteroid water into hydrogen and oxygen will help speed things up, although that would require a substantial industrial footprint in order to be effective - all of which would need to come from Earth.

This is all very glib, but there’s an unasked question in all of this:  is this something we should do?  Rorschach images of giant faces aside, there’s no evidence of any sort of advanced life on Mars.  There may or may not be some kind of life at the bacterial level, but there’s certainly been absolutely no sign of anything advanced enough for colonists to take home as pets.  But does that make Mars a blank slate for us to write on?  Or, more accurately, a palimpsest, where we’re writing over the faded words already in place?

Whatever unique lessons we may be able to learn from Mars, we will not be able to learn them by turning the Red Planet into a clone of our own.  There may come a day where it's necessary for whatever reason to undertake the process that I've described above, but as with processes such as strip mining and hydraulic frakking, we will need to take the time to consider all the possible consequences before taking action.  After all, it's not like we'll be able to put everything back to the way it was if we make a mistake.

- Sid

* If you had to Google™ "Oort Cloud", hand in your geek card.