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doctordirt

InActive

Registered: 2017-06-22

Posts: 7

let cyanobacteria generate the needed water, exploiting hydrogen vents

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.

SpaceNut

Administrator

From: New Hampshire

Registered: 2004-07-22

Posts: 29,433

Re: let cyanobacteria generate the needed water, exploiting hydrogen vents

This would require some sort of barrier to mars loss, aka dome or some other means to trap what we would want to create via biology.