# Is it possible to colonize planetoids by using perfluorocarbon lakes?

Is it possible to colonize planetoids using breathable liquid such as perfluorocarbons (PFCs) with dissolved oxygen and filling craters and depressions with it instead of building insulated habitats?

I think this would require much less oxygen than creating a breathable atmosphere and at the same time would not limit the colonists to the inside of their dwellings.

Besides liquid breathing, fluorocarbons have other wonderful properties:

• They are very potent dielectrics unlike water, so no short-circuit.
• They have high weight so they can form an atmosphere where there is not enough gravity to keep an atmosphere of lighter gases.
• For terraforming a planet: PFCs are not photodissociated, having highest lifetime in the atmosphere, they are the most potent greenhouse gases (tetraflourocarbon is 6500 times more potent than CO2), which allows to warm up planets such as Mars (this has been already suggested).
• PFCs can be used as blood substitutes and have anestetic properties. Oxygen-rich PFCs help to heal wounds. They are also used to store living organs for transplantation.
• Some PFCs are extremely hydrophobic

As uhoh suggests in a comment, one scenario for breathable liquid environment is "walking on the ceiling":

if the local gravity were $g′$ and the perfluorocarbon had a density of 1.6 $g/cm^3$ then they'd be walking on the ceiling feeling a "gravity" of 0.6 $g′$.

edit: Here is an example of such a buoyant, inverted "ice walker" - starts at 03:27:

• What about the temperature? – Organic Marble Sep 24 '16 at 1:43
• @uhoh you can make a gas atmosphere of this volume only by building closed compartments. You cannot make it in the open. The puddle can have a layer of water on the top which would be ice in the vacuum and protect the puddle. – Anixx Sep 24 '16 at 13:54
• @uhoh besides liquid breathing, fluorocarbons have other wonderful properties. They are dielectrics unlike water, so no short-circuit. They have high weight so they can be used for artificial atmosphere on bodies that do not keep other gases. They are not photodissociated, having highest lifetime in the atmosphere, they are the most potent greenhouse gases, tetraflourocarbon is 6500 times more potent than CO2, which allows to warm up planets such as Mars (this has been already suggested). If I were writing a computer game, I would express the cost of terraforming in one resource, fluorocarbons – Anixx Sep 24 '16 at 14:56
• "Fluorocarbons as liquid breathing can be used in places like Ceres." But as I've been trying to point out, they'd be utterly impractical in 'puddles'. No ice layer, they boil. Ice layer, too cold for the humans who would naturally float on the dense liquid (and thereby be pressed against the ice layer). You're either over or under thinking this, or both. But in any case, I'm sick of discussing when you obviously don't get the point. Best of luck with your puddles. I'm out of here. – Andrew Thompson Sep 24 '16 at 15:26
• @AndrewThompson the humans are smart - after hitting their heads a few times the humans would rotate and then just walk on the underside of the ice. If the local gravity were $g'$ and the perfluorocarbon had a density of 1.6 $g/cm^3$ then they'd be walking on the ceiling feeling a "gravity"' 0.6 $g'$. Boats would be small crawlers/rovers that sit on the ice with rubber treads. When they want to get into a boat, they get an ice fishing hole maker and cut a hole below the rover. They "jump in" (up) until their legs are in the rover (glued to ice by oozing water) then push their way through. – uhoh Sep 26 '16 at 17:42