RobertDyck wrote:
I have to make a correction. I keep running into people who claim terraforming can't be done, it's too difficult. Within the Mars Society many people claim terraforming Venus can't be done, or at best is very difficult. Both statements are untrue. Terraforming is a big job, but can be done. Venus does have water, not as much as we would like but its cloud layer is entirely water. Terraforming Venus is the reverse of terraforming Mars in several key areas: Mars requires mechanical/chemical means, Venus requires biological technology.
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Hi Robert.
Venus' atmosphere has:
CO2...........96.3 %
N2.............03.5 %
SO2...........~150 ppm (parts per million)
H2O...........~100 ppm
Ar..............~100 ppm
COS...........<40 ppm
H2S............<40 ppm
O2..............<30 ppm
H2..............<25 ppm
CO..............~30 ppm
Ne..............~14 ppm
He..............~12 ppm
Kr...............~1.5 ppm
HCl.............~0.4 ppm
HF...............~5 parts per billion
There are strong indications that there were massive volcanic resurfacing of Venus 500 million years ago with much vulcanism since then. Given this, the tiny amount of water remaining now is disturbing. (On Earth volcanic gasses are typcially 75% water.) If all the water on Venus were to condence on the surface the water would only be ~5cm giving it even less water than Mars.
The clouds are made up of aerosol particles <10 micrometers in diameter of sulfuric acid 85% pure by weight.
Fogg (page 339) wrote:
"Sulfuric acid is generated photo-chemically, starting with the action of ultraviolet radiation on sulfur dioxide above the clouds (a simular proces converts SO2 to H2SO4 on Earth - See equations 4.11). It then becomes incorported in aerosol droplets which, after about a year, sink to the base of the cloud layer where they evoporate. Ultimately the heat of the lower atmosphere dissociates H2SO4 to SO3, which then undergoes thermochemical reduction by reacting witht eh CO back to SO2. The Venusian clouds are maintined in a dynamic, sulfur - cycling steady state and have little in common with terrestrial clouds, being more akin to photochemical smog in mode of formation and composition."
As for seeding the atmosphere with algea, there are many problems with this.
-- First, we know of no cyanobacteria that can live in sulfuric acid.
-- Second we know of no cyanobacteria that can live in the upper atmosphere (or indeed have positive boyancy).
-- Third, the upper atmosphere is totally lacking in Sodium, Magnesium, Potassium, Calcium, Phosphorus, Selenium, Iron, Copper, Zinc, Iodine and many other trace elements needed to form cells. (This is the same reason why it is unlikely we will find life floating in Jupiter's atmosphere.)
-- Fourth, all known life requires liquid water. None (I know of) grows in micrometer (which are smaller than bacteria) sized droplets of water (let alone concentrated sulfuric acid).
If you postulate engineering magical nano-tech you can do anything. If you postulate engineering magical blue green algae you can also do anything.
In my judgment, creating a new species that have the properties that I've listed above can't be done or (at a VERY generous best) is very difficult. Note that the engineering techniques discussed for terraforming Mars do not require the wholesale creation of wildly unique species. Or if that you postulate the ability to gene-engineer your Venus bacteria why not say that Mars is trivial to terraform by creating psychrophilic, hypobaric bacteria that produce PFC's? THAT is an easier species to create and Mars already has water.
My data comes from:
- "Terraforming: Engineering Planetary Environments" by Martyn J. Fogg and "Moons and Planets" by William K. Hartmann.
- "Extremophiles for Ecopoiesis: Desirable Traits for and Survivability of Pioneer Martian Organisms" by David J Thomas, et all (7 authors).
I feel that the very brief summary that I gave in the FAQ was fair. If you wish to argue these points further, the posts should likely be moved into the Venus thread.
Warm regards, Rick.