some quick questions on exobiology

RYBICKI, ED ED at molbiol.uct.ac.za
Thu Jul 21 02:46:48 EST 1994


> What processes give rise to comets. Are they formed 
catastrophically and would
> any life survive this? Or are they formed slowly by stuff 
attracting other stuff, and why would one expect life on space 
stuff?

I think the bottom line is that comets are *old* - they formed by 
very slow accretion of material out there in the so-called Oort 
Cloud (which, it has to be understood, is probably a less dense 
environment than the solar system) - and they are *cold* (being as 
there isn't too much sunlight out there).  So, yes, why would anyone 
expect life out there, let alone life anything like what we know and 
sort of understand?

> Finally, a virus as I understand it is not a free living organism. 
So to 
> postulate space viruses one must presumably postulate "higher" 
cells as well, out there.
> I'm very sceptical that a bit of the very simplest amino acids on 
a ball of 
> cometary ice is evidence for life in even the weakest sense.

Seconded!  Amino acids and even nucleotides do not an organism make, 
not without a pressure-cooker environment, and far more concentrated 
reagents.  Just dirty ice, I'm afraid....but making a pretty good 
few holes in Jupiter right now (fragment Q1, live, courtesy of the 
South African Astronomical Observatory and the SABC: 
spectacular...and just in time to commemorate Neil and Buzz).
  _________________________________________________________________
 | Ed Rybicki, PhD          |         Well, I tip my hat           |
 | (ed at micro.uct.ac.za)     |      To the new constitution         |
 | Dept Microbiology        | Take a bow for the new revolution... |
 | University of Cape Town  |  Then I get on my knees and pray     |
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 | 7700, South Africa       |                                      |
 | fax: xx27-21-650 4023    |      - Pete Townshend, 1972          |
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