The first steps would be to colonize Mars. See also: Mars Base.
There are several ways in which Mars might be terraformed:
- Inject methane gas, water vapor or other greenhouse gases into the atmosphere to induce an artificial greenhouse effect. Since methane gas is over twenty times more effective at trapping heat than carbon dioxide, the methane gas might raise the surface temperature of Mars to above the melting point of ice. Once the temperature starts to rise, the underground permafrost may begin to thaw out, for the first time in billions of years. As the permafrost melts, riverbeds would begin to fill up with water. Eventually, lakes and even oceans might form again on Mars as the atmosphere thickens. This would release more carbon dioxide, setting off a positive feedback loop. On Mars, methane gas may be a by-product of geologic processes. If one can locate the source of this methane gas, then it might be possible to increase its output and hence alter the atmosphere.
- We could consider mining methane-rich Titan, one of the moons of Saturn, and bringing the methane to Mars. One of the drawbacks of Mars is that it lacks nitrogen which is needed to grow food and to create a breathable atmosphere. Nitrogen and other resources from Titan's atmosphere could be harvested and then transported using spacecraft. We could use Titan's resources to construct a space elevator where spacecraft could be launched from. These spacecraft would carry their payload to Mars and deposit it into Mars' atmosphere. Planets like Jupiter are also nitrogen-rich but it would be a lot easier to work with the low gravity of Titan before gas giant mining becomes common.
- Deflect a comet or asteroid into the Martian atmosphere. If one can intercept a comet far enough away, then even a small nudge by a rocket engine, an impact with a probe, or even the tug of the gravity of a spaceship might be enough to deflect it. Comets are made mainly of water ice and periodically race through our solar system. As the comet gradually gets closer to the surface of Mars, it would encounter friction from the atmosphere, causing the comet to slowly disintegrate, releasing water into the atmosphere in the form of steam. Asteroids are known to contain ammonia, a greenhouse gas.
- Iceteroids (asteroids made of ice) in the Kuiper belt (extending beyond the orbits of Neptune and Pluto) might be considered instead of the asteroids in the inner belt next to Mars which travel at tens of thousands of km/s to remain in orbit around the Sun. In order to change their momentum in a direction towards Mars, an enormous force needs to be exerted on them. The Kuiper belt iceteroids move at a speed of 300 km/s to stay in orbit around the Sun. Thus, much less power and energy would be required to change their momentum in a direction towards Mars. Also, by sending them on a path towards any one of the gas giants (Jupiter, Saturn, Uranus, or Neptune), their high gravity could "sling-shot" the asteroid towards Mars.
- Deflect one of the ice moons of Jupiter or perhaps an asteroid that contains ice, such as Ceres, which is believed to be 20 percent water. Instead of having the comet, moon, or asteroid slowly decay in its orbit around Mars, releasing water vapor, another choice would be to maneuver them into a controlled impact on the Martian ice caps. The polar regions of Mars are made of frozen carbon dioxide, which disappears during the summer months, and ice, which makes up the permanent part of the ice caps. If the comet, moon, or asteroid hits the ice caps, they can release a tremendous amount of heat and vaporize the dry ice. Since carbon dioxide is a greenhouse gas, this would thicken the atmosphere and help to accelerate global warming on Mars. It might also create a positive feedback loop. The more carbon dioxide is released from the ice caps, the warmer the planet becomes, which in turn releases even more carbon dioxide.
- Detonate nuclear bombs directly on the ice caps. The drawback is that the resulting liquid water might contain radioactive fallout. Or we could try to create a fusion reactor that can melt the polar ice caps. Fusion plants use water as a basic fuel, and there is plenty of frozen water on Mars. It is estimated that if the ice caps of Mars were completely melted, there would be enough liquid water to fill a planetary ocean fifteen to thirty feet deep, equivalent to about 20% of Mars' surface.
- Build solar satellites surrounding the planet, reflecting sunlight onto Mars. Solar satellites by themselves might be able to heat the Martian surface above freezing. Once this happens and the permafrost begins to melt, the planet would naturally continue to warm on its own. A soletta is a magnifying device constructed in space for the purpose of amplifying the solar radiation a planet receives, in order to generate power or aid in the process.
Once the temperature of Mars rises to the melting point of ice, pools of water may form, and settlers could begin large-scale agriculture with certain forms of algae that thrive on earth in the Antarctic may be introduced to Mars. They might actually thrive in the atmosphere of Mars, which is 95 percent carbon dioxide. They could also be genetically modified to maximize their growth on Mars. These algae pools could accelerate terraforming in several ways. First, they could convert carbon dioxide into oxygen. Second, they would darken the surface color of Mars, so that it absorbs more heat from the sun. Third, since they grow by themselves without any prompting from the outside, it would be a relatively cheap way to change the environment of the planet. Fourth, the algae can be harvested for food. Eventually these algae lakes would create soil and nutrients that may be suitable for plants, which in turn would accelerate the production of oxygen, an essential ingredient for terraforming Mars.
Biodomes would be built with controlled environments in which to grow oxygen-producing cyanobacteria and algae. Lichen, which is similar to moss, could survive there. Some species of methanogens, microorganisms that produce methane, can survive. Algae and cyanobacteria could be placed in canisters and drilled down into the Martian soil. Water would be added to the canisters, and then instruments would look for the presence of oxygen, which would activate photosynthesis. Farms of this kind could generate oxygen and food.
A type of Genesis Device could be built to introduce bioengineered DNA onto the lifeless planet. The ecology, temperature, soil chemistry, and atmosphere would determine which types of DNA should be introduced. Then, fleets of robotic drones would deposit millions of nano-sized capsules carrying an array of DNA. When these capsules release their contents, the DNA, engineered precisely to thrive in the planet’s environmental conditions, would latch onto the soil and begin to germinate. The contents of these capsules are designed to reproduce by creating seeds and spores on the barren planet and use the minerals found there to create vegetation.
Hundreds of years after successful terraforming, scientists would have to prevent Mars from returning to its prior state. Billions of years ago Mars cooled off and lost its molten core and therefore its magnetic field. This field protects the atmosphere from the solar wind and deflects deadly radiation from space. The lack of a global magnetic field on Mars, coupled with the planet's thin atmosphere, means that high-energy cosmic rays and solar particles shower the Martian surface. One method is to artificially generate a magnetic field around Mars. To do this, we would have to place huge superconducting coils around the Martian equator. Using the laws of electromagnetism, we can calculate the amount of energy and materials necessary to produce this band of superconductors.