Terraforming
From Future
- Terraforming is the transformation of inhabitable planets into the form and shape of Earth-like planets (Terra means Earth). For example, carbon dioxide (if present) is changed into oxygen using algae or other simple plants, which allows more advanced organisms including Earth animals and humans to thrive and reproduce.
- (Rough) plans exist for terraforming Mars.
- Venus could also be terraformed if the plans were altered (i.e., cool the planet with oxygen instead of heating it with carbon dioxide).
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[edit] Challenges
There are many obstacles to terraforming that need ot be overcome.
- The fact that Mars appears to have large reserves of underground water-ice is a hugely exciting discovery. Water is central to life, and can also be split to yield Hydrogen and Oxygen.
- In the absence of water, some proposals have suggested diverting an ice-comet in deep space, where a relatively small course adjustment could bring a colision course with the planet to be terraformed.
- Possible lack of Carbon and Nitrogen may require that materials be brought from Earth. The material would need to be harvested from high orbit to reduce the 'lifting cost'.
[edit] Albedo Manipulation
- A planet's albedo (the fraction of incident sunlight it reflects) is a value between 0.0 and 1.0. It can be radically changed using relatively little material. It is easier to reduce the albedo than increase it. Furrows in the ground as made by ploughing decrease the albedo, making the planet appear darker. The darker planer captures more solar energy, causing it to warm up.
[edit] Timescale
- Timescales for Terraforming a planet such as Mars using only biological methods are likely to be measured in thousands of years. This is based on considerations of the amount of Oxygen that a rain forest turns over per year (see discussion on Talk:Terraforming)
[edit] Mars
In the future people may want to colonize Mars. Terraforming Mars would make it a more habital planet. One way this could happen is if humans harvested water from Europa. Mars's axis is highly unstable it is also reasonable that humans would take one of Jupiters moons to stablize it.
Robert Zubrin, the founder of the Mars Society, likes to point out that Columbus encountered similar resistance from noobs when he pointed across the Atlantic. But Zubrin isn’t a seafarer—he's a scientist, with calculations that say people could create an oxygen atmosphere on Mars in just over 1,000 years. Compare that with other scientists’ predictions of 20,000 or 100,000 years, and he might seem like he's peddling interplanetary snake oil, but there’s no denying that his scheme for “terraforming” is thoroughly conceived.
- Thursday 15th March 2007: WASHINGTON (Reuters) - A spacecraft orbiting Mars has scanned huge deposits of water ice at its south pole so plentiful they would blanket the planet in 36 feet of water if they were liquid, scientists said on Thursday. The scientists used a joint NASA-Italian Space Agency radar instrument on the European Space Agency Mars Express spacecraft to gauge the thickness and volume of ice deposits at the Martian south pole covering an area larger than Texas. The deposits, up to 2.3 miles thick, are under a polar cap of white frozen carbon dioxide and water, and appear to be composed of at least 90 percent frozen water, with dust mixed in, according to findings published in the journal Science.
[edit] Steps to Terraforming
In the medium term, the steps towards terraforming are perhaps more interesting .
- We would need to show that we can reclaim deserts, right here on Earth. One fairly successful approach is to bury irrigation pipes underground to feed the roots of plants directly - so minimising evaporative losses. Mixed plantings with varying height of plant and root depth do best.
- Long before terraforming is achieved we would like to be able to live in closed environments, e.g. domed structures with their own ecosystem. This is a challenging goal, and many of the challenges are similar, but it is on a much more manageable scale. With a presence on the planet, we are in a much better position to adapt our terraforming strategy in the light of experience gained.
