Terraformation: Making a Planet
written by Tim Volkert on December 02, 2005 | forum profile | contact me
number of views: 74734 | printable version (text) (PDF)
While humanity has produced great works of engineering before, such as the Great Wall, the Pyramids, and Panama and Suez Canals, very little has been done to consciously remake the planet as a whole. Sure, global warming has certainly had an effect on the planet, scientists now agree on that. But how much was purely human? What did it? Can it be reproduced on another planet, with a different climate, to much more extreme temperatures? Everything human industries have done so far to the climate has only been a byproduct of their efforts; what if those efforts were directed AT the climate?
As with any problem in physics, this one has its "givens," several possible processes, and a desired result. The givens: Mars' present state, the atmospheric pressure less than 1% of Earth's and composed mainly of carbon dioxide, 38% of Earth's gravity, nearly 60% less sunlight, and an average temperature of –63ºC, compared with Earth's 15ºC. Its orbit is more eccentric and a time and a half farther out than Earth's. But for all of the differences, there are many similarities between the worlds. Both are rocky planets composed mainly of silicates, and relatively close to the Sun, warm and snug (compared to, say, Saturn or Neptune). Both have nearly 24-hour days, Mars' longer by only 40 minutes or so; both have inclined orbits around 24º, allowing for seasonal changes. Both have had a geologically active past, replete with volcanoes, escarpments, and crater impacts. Mars is almost inhabitable already, argue supporters of terraformation, it just needs that extra push.
The end result of terraformation varies with the observer. Some say that an exact replica of Earth, or as near as possible, should be the goal. They argue that Mars should have the same atmosphere constituents in the same proportions, with identical pressure at a chosen "sea level," sometimes around –1km, or one kilometer below the mean surface elevation. Others would be content with a colder, thinner atmosphere, with the bare minimum air pressure and oxygen/nitrogen mix needed for humans. Still others contend that a thick, CO2 atmosphere (sometimes 2 or 3 Earth atmospheres!) just to warm the planet to a tropical jungle is ideal, with humans needing air tanks or CO2 filters to be outdoors. And the possible ways to reach all of these are even more numerous!
Despite the general consensus that terraformation is a long ways off, a great many suggestions have been made as to how it should be done. Boosting the temperature enough for plant life is a must, as is finding enough nitrogen for them. If a fully or even partially terraformed Mars is desired, one must choose between a high concentration of CO2 for high heat, or a balanced mix of an atmosphere, relatively thin and cold, and constantly needing to be replenished due to gases escaping at the top of the atmosphere. And the range of time frames these processes could take place in is enormous; conservative estimates have been known to put it between 200 and 10,000 years!
There are some radical ideas to boost the atmosphere. The extreme ideas even include capturing a comet (made mostly of water ice and silicates) via robotic rockets and steering them into a collision course with Mars! Backers of this say that not only would much of the ice burn off into the atmosphere, making it thicker and adding to the hydrogen and oxygen already present, it would also melt permafrost in the ensuing smash. This at the expense of areological explorations of the entire area. Others propose guiding the comet into a "near-miss" with Mars, thus avoiding the cataclysmic impact a direct hit would create while still retaining the benefits the comet could potentially give.
For those who seek a warm Mars, releasing much of the massive amount of carbon dioxide in the Martian regolith is the key. The comets could do the trick, and so could thermonuclear bombs dug deep underground! The radiation would be largely contained, and veritable aquifers of liquid water would be created from the melted permafrost due to the heat. On top of that, explosions near the surface would vaporize the regolith (much of it ferric oxide, common rust, and pure carbon dioxide) into its component parts, releasing enough CO2 and O2 into the atmosphere to begin warming the planet through the greenhouse effect in the same way as on Venus and Earth. (Note the opponents of this scheme point out that Venus is home to a runaway greenhouse effect, and that Earth is not a great example of a controlled atmosphere anymore, either.)
Another way to add heat would be to decrease the albedo, or light reflectivity, of Mars. By making Mars darker, it will retain heat more easily. One proposal on this topic would be to spread black "dust" (possibly the constituents of the mysterious black dunes in the northern hemisphere mistaken by Percival Lowell for vegetation) across the polar ice caps. Both the southern cap's carbon dioxide ice and the northern cap's water ice would retain far more heat than they did previously, and would begin to sublime away. If the atmospheric pressure was increased enough, they might even stand a chance of turning to running water rather than water vapor.
The atmosphere itself would need reworking, as well. Some have suggested that ecopoesis be followed, a moderate, biologically-based solution to let algae and plant life terraform the planet through natural photosynthesis and "accelerated evolution," or genetically engineered organisms. By taking in sunlight and the abundant carbon dioxide gas and making oxygen, they would do the work for us in much the same way as happened on the early Earth. But the early Earth had much more nitrogen, critics point out, whereas Mars has very little to support plant life. And the gases released by plant life alone wouldn't be in the right balance (78% nitrogen, 21% oxygen, or thereabouts), or even be self-sustaining as the solar wind whips away the higher, lighter, and faster particles. Only by actively and continually pumping perfluorocarbons, or PFCs- the same types that have been giving Earth so many problems since the Industrial Revolution- into the atmosphere will the heat actually rise, with ecopoesis playing a more minor role. Large factories with the express purpose of expelling a mix of gases into the Martian atmosphere would be needed.
There are still a great number of problems involved with the terraformation of Mars, not the least of which is the immense complexity of such an operation. The vertical scale of the planet is enormous, a whopping 30 kilometers, trumping Earth's 20 or so kilometers, much of it below sea level. Katabatic winds rushing along the mild geography of Earth can give us a vague idea of the force such winds would have around such titanic areological features as Olympus Mons, a 27-kilometer-tall shield volcano with an 8 kilometer escarpment ringing its southern edge; or Valles Marineris, a relatively shallow, 4000-kilometer-long gash in Mars; or any of the several outflow channels such as Nirgal Vallis or Shalbatana Vallis; or the Great Escarpment itself, the dividing line between the flat, dune-filled northern lowlands and the cratered, chaotic southern highlands. The gravity less than 40% of Earth's might pose issues with the atmosphere we haven't even begun to consider; what if the black dust we sprinkle on the caps is too light and is continually swept away into the upper atmosphere? The solar radiance is much less on Mars, as mentioned previously; could this aversely affect plant life more than we will plan on, even making it impossible for plants to live?
And then there are still unstated proposals: a "soletta," a giant orbital mirror system to reflect more light to the surface; giant open pits dug deep into the crust, about 15 kilometers down and a kilometer wide, called "moholes" for nearly reaching the Mohorovicic discontinuity in the Martian crust; some even farther out of the imagine of rational scientists!
Despite all of the guesswork, speculation, and estimation that makes up the field today, terraforming Mars has astonishingly wide support. In his 1997 book "The Case for Mars," Robert Zubrin details a cheap and effective way to begin exploration of the Red Planet. He is the founder of the Mars Society, an active participant in the space community that supports and even funds research for the exploration and ultimately terraformation and colonization of Mars. Red Colony is an online community (of which the author is an avid member) in support of Mars space programs, also with the goal of Mars' terraformation and colonization. It sponsors articles and short stories written by its members (including the author) about the Red Planet in addition to supplying news regarding the current exploration of Mars and research in technologies that will make it more feasible. Red Colony helped spur the creation of MarsDrive, a combination grassroots advocacy group and taskforce to direct the creative and enthusiastic efforts of its members. All three organizations have helpful and insightful websites that connect people around the world and help organize events in support of the terraformation of Mars. In addition to those, the Planetary Society, co-founded by Carl Sagan, an avid supporter of terraformation, promotes the exploration of the solar system in general, with great success in lobbying for Mars as well as the other planets and minor planets.
The opposition, while probably more logical for the time being, is largely ignored because of the obvious points it makes. NASA's already weak budget and choking bureaucracy impedes any and all planetary exploration operations, it would most certainly slow or even halt terraformation as a process. Refractory congressmen and recalcitrant senators are already hardly willing to spend money on such an obscure concept as space exploration; what were to happen if someone proposed room for "making another Earth" in the budget of 2006 or 2018 or any other year? They'd hear massive protests against "irresponsible spending" and "creating another world to pollute and destroy" when the focus should be on Earth and Earthly problems.
Even ignoring the likelihood of obtaining financial support, and ignoring the sheer immensity of such a task as changing the atmosphere of Mars, and ignoring the possible timeframes of up to 10,000 years before being even near completion, what about the scientific data lost by such a venture? The more radical schemes- detonating thermonuclear bombs in the regolith, slamming comets into the surface, drilling colossal holes into the crust- would immediately obliterate any traces of microorganisms in the area, and make it impossible to tell the areological history there, too. Even the more subtle approaches such as ecopoesis, black dust on the caps, vegetation on the surface, and PFCs pumped into the air, would slowly erode the landscape. The chaotic terrain of the south shows signs of being repeatedly melted by meteor impacts and washed away, only to refreeze in a new context. The outflow channels near Valles Marineris suggest that immense aquifers released by asteroid or comet impacts gushed out several times in the planet's 4.4 billion year history, flowing water, ice and rock pounding away at the channel walls with the force of several nuclear blasts per day, and nearly ten times the flow rate of the entire Amazon river. With the terrain so fragile, and relatively unchanged in the past billion years, this devastation could once again wipe out any traces of our early solar system we might find.
With regards to possible Martian microbes, sterilizing each and every spacecraft that will reach Mars will be expensive, and ultimately dropped altogether. So that if a mysterious microorganism is found in a warm volcanic vent near a Mohole, we may never know whether it is from Earth or a native Martian.
NASA is currently under pressure to have developed and ready a new Crew Exploration Vehicle soon after the shuttle fleet is retired in 2010. At the present rate, we will be without a means of independent space travel from then until 2014 or even later. The International Space Station is just short of an insult to taxpayers, a nearly useless waste of money in low Earth orbit since very little credible research can be done when 50% of an astronaut's time must be spent staying in shape over months. The plans for a human expedition to Mars are many and insufficiently supported for any one to take the forefront and be accepted by the space community. The author sees a hard time for humanity as a whole to even get to Mars, let alone terraform it. But that is an issue for scientists with many degrees and research grants to ponder, not a mere undergraduate.
1) Red Colony
2) Mars Society.
3) MarsDrive Agenda