I know water would be out of the question, but what about liquid nitrogen or liquid hydrogen, Would silicon work instead of carbon?

  • $\begingroup$ Silicon, or anything else with a similar combining power will work. Not sure about hydrogen/nitrogen as then most gases couldn't be breathed as they would be liquid. $\endgroup$ Feb 26, 2016 at 20:38
  • $\begingroup$ Possibly helpful. $\endgroup$
    – HDE 226868
    Feb 26, 2016 at 23:13
  • $\begingroup$ According to recent news reports, at one time Pluto had lakes of liquid nitrogen, and perhaps could have them again depending on variations in orbital parameters (akin to Earth's Milankovitch cycles). Don't know about Charon. $\endgroup$
    – jamesqf
    Apr 2, 2016 at 17:54

1 Answer 1


Non-carbon based biochemistry implies the ability to create long molecular chains. The more common alternative mentioned is often silicon (silanes), but other candidates may exist : boranes, sulfur...

The liquid necessary for life support could be ammonia, sulfuric acid, formamide, hydrocarbons, or liquid gas (nitrogen, supercritical fluid hydrogen).

None of these alternatives have however be observed, and carbon-based chemistry seems to be the best competitor : longer chains, fast reactions, etc.

From projectrho, here is an exemple of macromolecule/solvent combination (at 1 ATM, temperature in °C).

  • Fluorosilicones in Fluorosilicones 400° to 500°C
  • Fluorocarbons in Molten Sulfur 113° to 445°C
  • Proteins in Water 0° to 100°C
  • Proteins in Liquid Ammonia -77.7° to -33.4°C
  • Lipids in Liquid Methane -183.6° to -161.6°C
  • Lipids in Liquid Hydrogen -253° C to -240° C

You scan find several sources of information on this topic online.


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