My colonists have been terraforming a planet for centuries. They chose this exo-planet for its many earth-like qualities (size, gravity, Goldilocks zone, volcanos, similar sun). However, it is like the Earth of 400 million-ish years ago. The atmosphere has lots of nitrogen but not much oxygen. Also, a great deal of water is tied up in glaciers though there is some very basic plant life near the equator. The oceans have lots of critters but it is a lot less ocean than Earth. There are “red beds” indicating that all the minerals that could have reacted with free oxygen have already done so.
They have been using solar collectors and mirrors to melt the glaciers. This puts a little oxygen into the atmosphere by splitting the H’s and O’s. Mass plantings of genetically modified organisms have also increased the oxygen. The gardener in me wants there to be legumes to fix the nitrogen in the soil for future use by farmers.
The people live in domes on the moons of this planet, a space station, and domes on the planet surface. They really want to spread out and use this beautiful planet.
My question: Is it plausible that they could get the oxygen level up to 21% (like Earth) in a few centuries. Will they be able to stop it at the right number?
These two articles were helpful in getting at how Earth’s atmosphere developed but so much of the timeline described involves waiting for specific organisms to evolve. The colonists have Earth plants and a talent for GM which should help a great deal.
Evolution Of The Atmosphere: Composition, Structure And Energy http://www.globalchange.umich.edu/globalchange1/current/lectures/Perry_Samson_lectures/evolution_atm/#
The Mystery of Earth’s Oxygen http://www.nytimes.com/2013/10/03/science/earths-oxygen-a-mystery-easy-to-take-for-granted.html?_r=1&&module=ArrowsNav&contentCollection=Science&action=keypress®ion=FixedLeft&pgtype=article