[ExI] Abiogenesis

[John Clark]

 Stuart LaForge <avant at sollegro.com> wrote:

> *They have found complex chiral organic compounds in the center of the
> galaxy*


They found the chiral molecule Propylene oxide, but as far as I know they
did not find more of the right handed version than the left handed version.

*> they think meteorites brought the chiral molecules to Earth.*


I'm sure that true, with the exception of glycine the simplest amino acid
all of them are chiral and 52 have been found in meteorites, but 33 of
those are not among the 20 amino acids that life uses. And life only uses
left handed amino acids (and right handed sugars) and most meteorites don't
have more left handed amino acids than right, but one was found that did
and it's hard to think how that could be without polarized light:

https://www.nasa.gov/topics/solarsystem/features/life-turned-left.html

However such a asymmetrical meteorite is rare and it shouldn't be if the
light came from the galactic center, so I think it's more likely the
polarized light came from something local and much smaller than the
galactic center, a nearby neutron star perhaps. Or maybe astronomy is not
needed at all to explanation the lopsidedness in the chemistry of the
biosphere; as far as we know right handed molecules would work as well as
left so maybe LUCA, the last universal common ancestor, just happened to use
 left handed amino acids and once such a standard had been established
there was no reason to change it.

Speaking of the galactic center, all galaxies have black holes at their
centers and on average they have about .1% of the mass of the galaxy
they're in. our Milky Way galaxy has the mass of 700 billion Suns so you'd
think its central Black Hole should have a mass of about 700 million suns,
but in fact it's only 4 million. So for some reason Sagittarius A is
freakishly small and that may be a good thing because if a galactic center
where to turn into a full power quasar it sterilize the entire galaxy it
was in.

John K Clark
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