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I would say "Ok", but I have to point out a weakness in your argument. I hope you won't take this as an attack. I greatly appreciate a new perspective, new ideas. But science criticizes everything, every new idea must withstand critical review.
You claim the fact hydrogen has been measured escaping into space is the reason there must be hydrogen vents. That doesn't hold. Yes, there is hydrogen escaping. However, solar wind impacts the upper most atmosphere directly. That imparts enough energy to dissociate water into monoatomic hydrogen and hydroxyl (H+ and OH-). And hydrogen can be accelerated to escape velocity. So the expected source of hydrogen is water. The Earth is bombarded by snowball size ice meteoroids every day. They deliver new water to our planet. Furthermore volcanoes release water. Much of the water is from subduction, but there could be water from the mantle as well. Mars has a lot of meteors; just look at its surface. Orbiters haven't measured meteor impacts, but based on craters its expected there are quite a few. So Mars should get snowball meteoroids just as Earth does. And the frozen pack ice of Elysium Planetia is believed to have come from volcanic eruption of Cerberus Fossae fissures just 2 to 10 million years ago. Most of that water was from melting permafrost, but it still means active volcanism. Volatiles in volcanic eruptions contribute to the atmosphere and hydrosphere.
You're right. I finally looked it up. They are talking about monoatomic hydrogen escaping, not H2.
On the other hand, based on Earth's geochemistry, unless Mars has cooled so much that there is no movement of magma, it should still be venting hydrogen (H2) somewhere. In fact, I could swear I saw a news story less than two weeks ago about this having been confirmed.
Reminds me - these critters are pretty interesting too:
https://en.wikipedia.org/wiki/Iron-oxidizing_bacteria
Iron oxidising bacteria - could we use them on Mars to make oxygen out of iron oxide? Don't know whether it would be a less energy intensive method than others.
Iron oxidizing bacteria consume oxygen, rather than produce it. Oxygenic photosynthesis required at least 1000 million years of oxygen production just to rust away the iron in the earth's crust, before any traces of free oxygen could begin to accumulate in the atmosphere.
The popular misconception that the rise of oxygenic photosynthesis caused an "oxygen catastrophe" mass extinction is proven wrong in the long record of banded iron formations. There was never a sudden rise in oxygen. It was an incredibly slow process.
Admittedly, I never studied Martian geochemistry before.
I guess with no ozone shield, UV has had thousands of millions of years to bring about photooxidation.
It almost sounds hopeless to establish microorganisms, even if you could create liquid water for them, with so much perchlorate around.
There is clear evidence that hydrogen is continuously escaping the Martian atmosphere.
Absent an underground source venting new hydrogen to the surface, all hydrogen should have left the planet thousands of millions of years ago.
Hydrogen can be combined with carbon dioxide to generate methane (methanogenesis) and water, but the organisms that do this can only capture the chemical energy of the components.
Anoxygenic photosynthesis also captures sunlight energy, in addition to the chemical energy of hydrogen oxidation, for even greater growth yield.
Methane isn't so useful as substrate, unless fairly strong oxidant is available.
I suspect that methane is too light to remain in the Martian atmosphere, as is the case with water vapor.
The biggest limiting factor for terraforming Mars is the absence of bodies of liquid water.
Mars still has places where hydrogen vents to the surface, only to be quickly lost from the atmosphere to outer space.
Earth already has species of anyoxygenic photosynthetic bacteria that can turn hydrogen into water, using sunlight
2H2 + CO2 = CH2O (carbohydrate) + H2O
In contrast, oxygenic photosynthesis consumes water
H2O + CO2 = CH2O + O2
More than 3800 million years ago, anoxygenic photosynthetic bacteria consumed hydrogen, creating the chert layers found in banded iron formations.
Hydrogen is the strongest available reductant, but many other pathways of anoxygenic photosynthesis evolved using various forms of sulfur, ferrous iron, arsenic III, and even nitrite as reductant. Oxygenic photosynthesis only evolved as a desperate last resort (relatively low yield) when these reductants were depleted.
So, with just a tiny puddle of water at a hydrogen vent, anoxygenic photosynthetic bacteria can generate more and more water, hopefully faster than it can be lost to the atmosphere. Even beneath an ice sheet.
To find the ingredients for hydroponics, they only need to harvest salts from a dry lakebed.
This would contain the nitrogen, phosphorus, potassium, calcium, magnesium, iron, zinc, copper, nickel, boron, molybdenum, etc., in fairly concentrated form
Anoxygenic photosynthesis evolved on earth more than 3800 years ago.
Although Mars has no surface bodies of liquid water, hydrogen vents could provide the substrate to create water via anoxygenic photosynthesis.
Oxygenic photosynthesis, overall reaction:
H2O + CO2 = CH2O (carbohydrate) + O2
Anoxygenic photosynthesis using hydrogen, overall reaction:
2H2 + CO2 = CH2O + H2O
There are still species of cyanobacteria on Earth that can go both ways. In the presence of hydrogen, they turn off the oxygenic photosystem and use the (far more productive) hydrogen-based photosystem. Without hydrogen, they resort to the (less productive) oxygenic photosynthesis.
So, with sunlight and a small puddle of water at a hydrogen vent, a colony of these cyanobacteria could generate more and more water, limited only by the supply of hydrogen.
Once the puddle grows large enough, these same cyanobacteria could colonize outward, resorting to oxygenic photosynthesis.
Although oxygenic photosynthesis consumes water, the oxygen produced can be used to make more water:
e.g. CH2O + O2 = CO2 + H2O
Robert R. Northup Ph.D. biogeochemist
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