Mars Future: Terraforming
Preliminary Report - G14 Alysha Holmes Mike Jordan Date: 2/8/00
Why do we spend so much money and invest so much technology in the exploration of Mars? There are many reasons Mars is of interest, from satisfying our natural curiosity of the unknown, to harvesting resources that are in limited abundance on earth. However, Mars potentially provides a greater resource than any precious metal - inhabitable space.
The thought of humans one day colonizing Mars has been a scientific consideration since before the first Mars mission. Since discoveries have been made about the climate and the elements present on Mars the idea of humans one day being able to live on Mars is becoming an increasing possibility.
Although the conditions on Mars are not currently suitable for human life, there is the possibility of “Terraforming” Mars.
terraform /'teraform/ v.t. M2O. [f. TERRA + FORM v.] Chiefly Sci. Fiction. Transform (a planet, environment, etc.) into something resembling the earth, esp. as regards suitability for human life
Terraforming may seem like an unbelievable concept, however consider that when the earth was born, its atmospheric and temperature conditions were too harsh to support life. Over time these conditions changed and the climate became more temperate. Consider that Terraforming on Mars is changing the climate in much the same way Earth changed just speeding up this process.
There are five necessary objectives in the terraforming of Mars (Fogg):
1.) The mean global surface temperature must be increased by approximately 60 K.
At the present time, the current black body temperature of Mars is 213.5 K. An
increase of 60 K would make the temperature similar to Earth’s at sea level (273 K).
2.) The mass of the atmosphere must be increased.
Mars’ atmospheric pressure is between 6 and 10 mBar. The pressure on Earth is
1000 mBar.
3.) Liquid water must be made available.
There is frozen H2O at the polar regions of Mars. Warming up the atmosphere will
melt these polar ice caps and form a water supply.
4.) The UV ray and cosmic ray flux must be reduced.
A thicker atmosphere can protect against these harmful rays that would normally
penetrate the present thin Martian atmosphere.
5.) The O2 and N2 portions of the atmosphere must be increased.
The N2 will be necessary in the introduction of plant life. And in time, the plants can
convert the CO2 presently found on Mars, into the precious O2 needed for the full
Terraforming process to take place. The most important step in attaining these goals is to raise the temperature of
Mars. By raising the surface temperature, the CO2 found frozen at the poles will enter the atmosphere and contribute to the greenhouse effect. This will increase the temperature a little more, thus sublimating more CO2 from the poles, thickening the atmosphere, and adding to the greenhouse effect. This runaway CO2 greenhouse effect will hopefully continue on this cycle, autonomously, until the atmosphere is rich enough to support the establishment of the five objectives listed above (Fogg). But how will we increase the surface temperature of Mars? There are a few theories on how to do this.
Large solar mirrors could redirect sunlight to Mars. Aimed
towards the south pole, a solar mirror could aid in the runaway
greenhouse effect. A 125 km in diameter solar sail-mirror
could be positioned 214,000 km away in Mars’ orbit, sending an additional 27 TW of illumination to the south pole (Fogg). While this sounds like a huge undertaking, the amount of aluminum (200,000 tons) needed to produce this mirror is produced on Earth every 5 days
(Fogg). The problem would be trying to export all of this aluminum from Earth to the Martian orbit. Not only would the expense be astronomical, but also the time period would be quite lengthy. The best solution may be to mine and manufacture the mirror in space (Fogg). Another option is to propel asteroids, rich in ammonia, into Mars. The advantage of this is two-fold. Ammonia is a powerful greenhouse gas, which would aid in raising the planet’s temperature, as well as thickening the atmosphere; and increase the nitrogen content in the atmosphere—an element necessary for plant growth (Zubrin). According to Zubrin, “If one such mission were launched per year [for forty years], within half a century or so most of Mars would have a temperate climate, and enough water would have been melted to cover a quarter of the planet with a layer of water 1 m deep.” By using nuclear thermal rocket engines to advance these asteroids, they could be redirected towards Mars, letting the planet’s gravitational pull do the rest of the work (Zubrin).
Zubrin continues that it may be possible to set up a bacterial ecology on Mars’ surface that metabolizes water and nitrogen to produce ammonia, eliminating the need for further impacts.
Possibly the most feasible method of terraforming Mars would be to introduce halocarbons into the atmosphere. The very gases that threaten the Earth with global warming are the same gases that could turn Mars into a safe haven for humans. PFC’s
(perflourocarbons—similar to CFC’s, but more potent) could be introduced into the atmosphere to start the warming of the surface temperature.
While it would be impractical to ship PFC’s from earth, it would be advantageous to produce them on the surface of Mars. First these gases could be produced chemically, then biologically by microorganisms (McKay). PFCs such as CF4, C2F6, and SF6, (McKay) would be ideal because they will start the greenhouse effect, reduce solar radiation, and will last long in the atmosphere. Carbon, fluorine, and sulfur are all abundant on Mars—offering the opportunity to have machines extract these elements from the soil, turn them into the desired compounds, and pumped into the atmosphere.
How long would all these processes take before humans could utilize the results?
It is estimated that after 50 to 60 years of runaway greenhouse
effect (Zubrin, McKay), the atmosphere will have developed
enough so that pressure suits would not be necessary for human
habitation. Only breathing apparatus would need to be worn
by humans on the planet’s surface. The global surface
temperature would be tolerable for humans and plant life.
Possibly the atmosphere would block most of the harmful radiation coming from the sun and the cosmos. Liquid water would be an available resource. Colonization could boom, and humankind could survive on what was once a dry, inhospitable, planet. With plant life flourishing, the continued process of turning carbon dioxide into breathable oxygen would set the stage for a day when humans and animals can breathe the air. Current estimates say that time may not arrive for another 1000 years (Zubrin). But when it comes, Earthlings—now Martians—will thrive on what was once known as the Red
Planet.
There are ethical dilemmas that surround the issue of terraforming. Should we introduce life into another planet? Consider that countless times in human history we have transformed the earth to make it inhabitable to allow human existence – what makes
Mars any different? Also consider that the population of the earth right now is approximately 6 billion people, an in 2050 it is projected to rise to between 7.6 and 11.5 billion. At this exponential rate of growth, can we afford not to look for other inhabitable places beyond earth?
The above images project the stages of development of Mars Terraforming
Bibliography
1. Zubrin, Robert M. Technological Requirements for Terraforming Mars. 1 Feb 2000
2. Fogg, Martyn J. Terraforming Mars: A Review Of Research. 1 Feb 2000
3. McKay, Christopher P. “Bringing Life to Mars.” Scientific American. Mar 1999: 1 Feb 2000,