User:Charliea1919/Planetary engineering

Terraforming
Terraforming is the process of modifying the atmosphere, temperature, surface topography or ecology of a planet, moon, or other body to be similar to the environment of Earth to make it habitable by Earth-like life.

Technologies
Terraforming is the process of making other planets be habitable with conditions similar to Earth, and is a form of planetary engineering. To terraform Mars, humans would need to essentially create a new atmosphere, since Mars has a high carbon dioxide concentration with a low atmospheric pressure. This would be possible by introducing more greenhouse gases to increase the temperature of the planet. To terraform Venus, carbon dioxide would need to be converted to graphite. This process is only possible if the greenhouse effect is removed with the use of 'high-altitude absorbing fine particles' or a sun shield, creating a more habitable Venus.

NASA has defined categories of new and necessary habitability systems technologies for terraforming to be feasible. These topics include creating power-efficient systems for preserving and packaging  food for crews, preparing and cooking foods, dispensing water, and developing facilities for rest, trash and recycling, and areas for crew hygiene and rest.

Plausibility
A variety of challenges stand in the way of hypothetical terraforming efforts. The atmospheric terraforming of Mars, for example, would require “significant quantities of gas” to be added to the Martian atmosphere. This gas has been thought to be stored in solid and liquid form within Mars’ polar ice caps and underground reservoirs. It is unlikely, however, that enough CO2 for sufficient atmospheric change is present within Mars’ polar deposits, and liquid CO2 could only be present at warmer temperatures “deep within the crust”. Furthermore, sublimating the entire volume of Mars’ polar caps would increase its current atmospheric pressure to 15 mbar, where an estimated 1 bar is required for habitability.

Environmental Considerations
Locations for Seeding must be chosen based on their temperature, pressure, exposure to harmful radiation, and availability of natural resources such as water and other compounds essential to life. Mars is the primary subject of discussion for terraforming and seeding.

Necessary Technology
Natural or engineered microorganisms must be created or discovered that can withstand the harsh environments of Mars. The first organisms used must be able to survive exposure to ionizing radiation and the high concentration of CO2 present in Mars's Atmosphere. Later organisms such as multicellular plants must be able to withstand the freezing temperatures, withstand high CO2 levels, and produce significant amounts of O2.

Microorganisms provide significant advantages over non-biological mechanisms. They are self replicating, negating the needs to either transport or manufacture large machinery to the surface of mars. They can also perform complicated chemical reactions with little maintenance to realize planet-scale terraforming.