Re: In looking for life on mars, what are we looking for?

Hello Gareth,

  The "easy" answer to your question is that you are absolutely right.  We 
(humans) tend to filter our discoveries based on our 'narrow' but accepted 
views about life.  

  We are looking for "things" that we associate with life here on the 
Earth.  "Things" can mean chemicals (e.g., amino acids or complex organic 
molecules) or active or fossilized cellular structures.  A very limited 
viewpoint dominates the question of extraterrestrial life; i.e., we 
believe that things should be similar to our familiar Earth.  Examples 
include the belief that an oxidizing atmosphere and water and complex 
carbon backbone molecules are required to support and define "life".
 
  You have posed a very interesting and controversial question for which 
there is no fully satisfying answer.  These questions require much more 
study by persons willing to see beyond the limitations of our present 
chemical and biological knowledge.  This research costs money.  An 
unfortunate aspect of research funding is that it is easier to get moneys 
for projects that support the currently accepted viewpoints.

  Opinions expressed above are mine and may not agree with those of my 
employer.
John Haberman