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alfchemist
2005-Mar-16, 10:12 PM
Now, this might have been asked for nth time but I was prmpted to ask (again?) because of this rover's find in atacama desert. It detected chlorophyll, DNA, proteins, and other visual images that would suggest "life". Isn't this being biased? If you were the lead scientist searching for life on mars using a rover with instruments at your disposal, what would you look for and how would you look for it? What if life on mars is not based on purine and pyrimidine bases or amino acids or any other biological molecule common here on earth? What would you look for then?

piersdad
2005-Mar-17, 07:21 AM
If having established what sorts of chemicals do exist on mars with the two rovers there now. I would ask my brightest chemists to look for any sort of life form that could use these chemicals.
bearing in mind the temperature and all other conditions and design an instrument that will detect a by product most likely to indicate life.
Also have a back up experiment possibly programmable from earth that get more possible proof.

One of earths earliest life forms did nothing more that turn iron to iron oxide leaving huge deposits in outback australia some where.

We are finding life forms in some funny places on earth so this will enable us to keep a completely open mind to extra terrestal life

alfchemist
2005-Mar-18, 05:08 AM
Now you're talking, Piersdad! :D all lifeforms here on earth are carbon-based and there's an abundance of carbon here on earth. What if you consider that the most abundant mineral on the crust which is silicate (correct me if i'm wrong). Why aren't we made up of silicon or at least, is there any known lifeform that's silicon-based?

Life will try to survive by propagating and this requires transfer/holder of information thru something like DNA. Now, I think, the key is finding a pattern regardless of the chemical composition. What do you think? :rolleyes:

Nereid
2005-Mar-18, 10:30 PM
Life will try to survive by propagating and this requires transfer/holder of information thru something like DNA. Now, I think, the key is finding a pattern regardless of the chemical composition. What do you think? rolleyes.gif
I think baryonic matter is the scum of the universe; only when we understand how dark matter creatures are able to extract energy from tapping into neutrino oscillations will we begin to appreciate what life is all about ;)

piersdad
2005-Mar-18, 10:48 PM
What if you consider that the most abundant mineral on the crust which is silicate (correct me if i'm wrong). Why aren't we made up of silicon or at least, is there any known lifeform that's silicon-based?

hi alfchemist

If on another planet with abundant silicon there was an oxidiser that reacted well with silicon then i would be devising and experiment it will prove something in that way.

on earth carbon oxygen and a great many other minerals all react with each other both ways according to the conditions.
if another mineral, found in abundance, would do this for instance under extreem heat or cold then this would be an area to explore for some sort of self replicating combination of chemicals that utilises the various chemical reactions for its own selfish reasons ie a predator.

alfchemist
2005-Mar-19, 03:35 AM
hello, Nereid! Unless they can establish the existence of dark matter creatures, I think it's prudent to talk along the lines of something tangible.

Hello, Piersdad! So far, I'm impressed. It's the abundance and chemistry of the substance(s) available. But somehow, I feel that this is incomplete. Maybe you still have something up your sleeves? :D What about "matrix", or pattern? Maybe symmetry or assymetry?

piersdad
2005-Mar-19, 04:56 AM
Nothing up my sleeve Alchemist

Just a lateral thinking inventor sort of person.

I would have to look up the elements periodic tables to work out the ins and outs of what reacts with what and how.
A degree in chemistry would be needed.

There is a programme for computors that was originally developed to do this sort of thing and it was originally used to develop superglue.
An friend of mine was the developer of this programme and used it on what was one of the worlds bigest computor then (1/2 meg memory I think)
It will have been very much enhanced by now.
Essentially it worked out what chemicxals would attack what ones and under what conditions so that in the case of super glue they got as super hydroscopic polymer that hardned as soon as it came into contact with certain materials and in the presence of just molecules of water hence instant stick fingers.

So after sensing the conditions on a planet then a computor programme could be adapted to see what might happen there and from this a series of experiments arranged to see if there was some aberations that would indicat a life form was present
I E a smelly patch of poos would be a dead giveaway

filrabat
2005-Mar-21, 12:35 AM
My mom, who has an MA in microbiology (though she earned it way back in the 1960s), says silicon doesn't form long enough chains to offer a wide variety of molecules when compared to carbon. While I'm still open to the possibility of silicon-based life, I think carbon-based with water is more likely (though I understand substituting ammonia for water could work, given high enough atmospheric pressures -- at 1 Earth Atmospheric Pressure, ammonia has a liquidity range of only 44 C, compared with 100C for water).

All and all, were I to place my bets on alternative life forms, I'd go with Carbon and Ammonia (given sufficient atmospheric pressures, of course)

piersdad
2005-Mar-21, 06:42 PM
You are correct filrabat
the best bet is for a reactive element such as carbon so be aware of surprises but look for carbon bases life

alfchemist
2005-Mar-23, 05:47 PM
Hello Piersdad and filrabat! It was my birthday last 21st and got more than a hundred of students to make grades for so I was away from the pc for a while. Well, majority of elements in the periodic table can react with each other with the right chemistry and conditions. However, if we would just consider Mars environment, it is not very extreme as compared to Earth so I guess we are limited to a few elements. Carbon-based is still the most probable form of life out there. I'd agree with you on that. What's exciting could be their enzymes. If thermophiles have polymerase, bacteria in very cold temperature and low atmospheric pressure must have enzyme system very much different from what we normally see