Re: Planet Densities (actually not, but who cares anyway)

James Rogers (
Thu, 14 Nov 1996 14:55:19 -0800

>> pressure where they live allows liquid water reactions to continue to occur.
>> Even then, there is a soft limit somewhere around 150-170 C for most
>> organics. The absolute hard limit on any planet is somewhere around 375 C
>Certainly for proteins, for aquathermal water is a fierce solute. There
>are lots of organic compounds which can survive hefty temperatures,
>however. NASA uses polymers capable of withstanding 1500 deg C for short
>periods, noticeably lower temps for indefinite time.

Yes, but these polymers are not in a liquid water environment. At that
temperature, I believe liquid water would be required to be supercritical.
Supercritical water doesn't just break down organics, it usually oxidizes
them to the greatest extent possible, with the exception of Nitrogen due to
the relatively low temperature. I've seen supercritical reactors operating
at 550 C that turned ANY organic material into carbon dioxide, water, and
inorganic salts. It is currently gaining very large favor as a new method
of destroying organic waste, toxic and otherwise.

>> since this is where water goes supercritical, although very few organics
>Uh oh, this is a seriously bad customer. Whether sand or gold, it
>dissolves about anything. Many minerals are of geohydrothermal origin.
>Quartz crystals (which are used for computer and clock xtals) are grown
>in autoclaves by a hydrothermal process (specifically: a transport
>reaction in a temperature gradient).
>> would survive even to this point (except maybe some halides and a few
>> proteins). Cells require a pretty broad spectrum of organic compounds to
>I beg to differ, only the biopolymer stuff. I doubt steroids will notice
>much of it. Just remember the hopanes in microfossils.
>> operate, and the number of options decreases rapidly as the temperature
>> increases.
>(A toast of deuterium oxide to that).


-James Rogers