What should that definition be? This is a question that still challenges experts and non-experts alike. What constitutes a 'living' organizism on other worlds with different enviroments?
I think that - to be fair - the term LIFE needs to be defined in both a chemical and biological way at the same time. This way, something that can chemically catalyze and biologically interact with other parts of it's enviroment could be a lifeform.
The Viking Mars experiments attempted to find life, and some claim that they did. Other mission scientists have said that it was the chemical make up of the Martian soil that yeilded results, but how could either side know for sure if they weren't sure what they were looking for at the beginning?
NASA should settle on a term that is broad but simple, and gear their missions towards finding a wide array of possible lifeforms based on exotic chemistry. I think that too many of our missions are Earth-centric and ignore that other chemical combinations might be a foundation for life on other worlds.
We need to get past this " Where there is water, there is life " bias and be more open to the prospect of life existing under conditions that aren't always favorable to human beings.
Only by getting beyond that way of thinking will our species truly be able to search the stars with readiness to receive the answers that are out there.
Just one man's thoughts. I'm not a scientist nor a neophyte, just an interested and well-read citizen who dreams that we can do so much more.

Hmm. Interesting yes. However, to me the question should be- What would it take to make us all exicted to find on anohter planet? Bacteria? Plants? Small Animals?

Finding something that can only be seen in a microscope does nothing for me.

Unfortunately it's rather difficult to design an experiment that will detect life without making some kind of assumptions on its form, even more difficult to get someone to fund you to build it and send it into space.

While there may be lifeforms based on exotic chemistry out there, we don't have much idea if that's possible, or what would represent "food" or "lethally dangerous toxin".

I agree with you the current viewpoint is flawed (actually, I suspect there are rather more places with liquid water in the universe which don't have life than that do), and I don't think we're going to get anywhere with chemical tests for life. Maybe a microscope would be more useful to detect whether life exists in the regolith of an alien planet, but getting one of those to Mars/Europa/wherever is quite a challenge.

What we need is some kind of sample/return probe. Again, quite a challenging engineering prospect, but we've got samples from the Moon with such probes.

Excellent points from you both, Tarrifist and chaos.

I enjoy discussions like this because it helps you think 'outside the box' as it involves the search for life. Unfortunately, organizations like SETI are often lampooned in the national media and movies, and this creates a kind of ho-hum attitude by most casual observers when it comes to the question of alien life.

Personally Tarrifist, I would be overwhelmed if we found even microscopic lifeforms on another planet. It would at least confirm that we are not alone in the cosmos as relates to a living world. Actually plant life on another planet would leave me light-headed. Just imagine!

And despite the severe cold - and I know I'm out on a limb here - I believe that Titan might have life despite the lack of Earthlike conditions. Sicentists are more likely to lean towards Enceladus, but I think it's premature to rule out Saturn's largest moon just yet.


Edited by T-Max-C

I am one to dream of beyond this world and life, I quite frequently come to the conclusion in my mind that within all the infinite reaches of the universe, or beyond, that we are most certainly not alone.

The announcement of life found on other planets would more simply help me sleep at night, knowing that mankind is not as alone as we all seem to be.

I agree that more extensive searching and funding should be part of these galactic visions, and that mankind should more commonly think outside of the box of our everyday routine of a normal life.

The big picture is commonly ignored.