[X] My Assistant

[Paolo Amoroso]

I have just read a short story by Alex Saragosa published on issue 1067 (29 Aug 2008, pag. 61) of the italian magazine "il venerdì", a Friday supplement of the major national newspaper la repubblica. The story, titled "I batteri terrestri hanno invaso il pianeta rosso" (terrestrial bacteria have invaded the red planet), claims a group of JPL bilogists analyzed samples from the room where Phoenix was assembled and found 26,000 bacterial cells per square meter from 100 different species, including highly radiation resistant Bacillus pumilis. According to the story, these bacteria may have survived the trip to Mars.

I have never heard anything similar from reliable sources (i.e. anything but la Repubblica) . Any info?


Paolo Amoroso

[dvandorn]

But... how are we currently looking (or have any idea how to look for) non-DNA-based life?

Gets back to my earlier post. It appears that every life-detection experiment is *only* looking for life identical to that found on Earth -- DNA-based, made of organic molecules, using the ADP-ATP cycle to generate chemical energy. It's almost a slam-dunk that any life such sensors *do* detect is a result of contamination... isn't it?



-the other Doug

[djellison]

It appears that every life-detection experiment is *only* looking for life identical to that found on Earth

But the simple fact is that's the only form of life we understand. It's the only form of life we know of, it's the only form of life that, as of now, we know to exist. At some point, we simply end up having a debate about what constitutes life, would we be able to recognize life significantly different to 'ours'. Sulphur based or Silicon based or whatever-based life - we don't know what reactions that might involve. Will it have something like DNA, will it have something like respiration, will it have something like photosynthesis, what will it do instead of proteins, what will it 'eat', what will it 'poop' - we have absolutely no idea. We've been unable to make carbon based life in the lab - so we're a long long way from perhaps making silicon or some other chemistry based life which we could then observe, measure and understand to the point of knowing how to detect them.

Essentially - we can do the instrument measurements we know of - Xray spec, Mass Spec etc etc ( MSL is very very well equipped in that regard ),we can do that basic elemental and mineralogical characterisation - or we can look for life as we understand it using things such as the Life Marker Chip from here in Leicester. But how can we be expected to identify a different type of life that we've never seen, never measured, have no baseline for, and have no grasp of how it might work.

That's like asking me to find a cow - if I'd never ever seen a cow or heard one described or seen a picture of one. I'd walk straight past the big black and white tree with four legs stood in a field - because I don't know it's a cow.