BBC Focus Magazine

[Thinker]

I know of no organism that can exist from birth to death without water. And as far as a google search is concerned, neither does anyone else!

[Isee]

Tardigrades anyone? Or Water Bears if you prefer, been around for some 530 million years (so they have survived a few major extinctions) and apparently capable of tolerating temperatures from +151 to -328 degrees Centigrade whilst being immune to most levels of radiation considered harmful to other life forms along with the ability to survive 1000 times more UV, they have even been exposed to the vacuum of space at 260 kilometres altitude and survived.
Tough little multi-celluar critters if you ask me.

That kind of answers the question is there life out there other than on earth, non?

If we have already contaminated non terrestial systems with organisms. how long until we contaminate a non solar system in this way and it happens to have acceptable to life conditions (I am not saying perfect, just acceptable. water inliquid form and an energy source). This is nigh on certainty right now. Leave the contamination alone for another billion years and presto- complex life. Maybe even complex enough to build a rocket and contaminate another solar system or a galaxy?

It doesn't answer where the original life came from but in my opinion makes the odds of other active/alive life out there are .99

[MikeG]

About a year ago (maybe more) a Science story claiming a new arsenic based life form was discovered. This is now disputed. The new study claims that the bacteria just lives in an arsenic rich environment (as opposed to arsenic comprising part of its DNA genetic makeup). Whatever the case may be, its certainly indicative that life is more robust than we previously believed.

http://www.nature.com/news/study-challe ... ife-1.9861

[Gabriel]

If astronomers find life on Mars, it wold be such as we known here in Earth? It is necessary water? As Isee asked, it is possible to be produced in sulfuric acid or ammonium or whatever? If are the conditions produced to the emergency of a living being, a living being emerge (Maturana,2009). At least, we can answer two things. Yes and no. If we focus in the organization of living systems, this means processes and relations among processes realized by means of its components (water for example) (Maturana & Varela, 1997), properties of components can be obviated, structure can change in the conservation of organization (Maturana & Mpodozis, 2000). According to this, I dare to say that water is not necessarily a condition sine qua non of life. On the other hand, as Villee (1996) shows as, water is an essential component of living matter, because all of the properties that Flakkarin mentioned us. So, its a very difficult question to solve. Personally, it`s very difficult to me try to imagine life without water, but who knows?¡, maybe science can surprises us again in the future .
Literature Cited
Maturana, H.(2009) Interview in: http://www.youtube.com/watch?v=UW9iXJOUfs8, recovered on June, 1st, 2012.
Maturana, H.,Mpodozis,J.(2000) The origin of species by means of natural drift. Rev Chil Hist Nat;73(2):261-310.
Maturana, H., Varela, F.(1997) De Máquinas y Seres Vivos, autopoiesis de la organización de lo vivo, 2nd Ed.: Universitaria.
Villee,C.(1996) Biología (R. Espinoza, Trad.), 8th Ed.: McGraw-Hill.

[M Paul Lloyd]

Very simple lifeforms, such as bacteria, algae and fungus have been found in extremely hostile environments on Earth and in my own experience one in particular cladosporium resinae the so called kerosene fungus
http://nzetc.victoria.ac.nz/tm/scholarl ... dy-d4.html
survives quite well inside aircraft fuel tanks but they only do so by occupying the narrow margin between the fuel and any water which exists in the tank.

There are a number of alternatives to water and in theory ammonia could replace water as suggested here
http://www.daviddarling.info/encycloped ... alife.html

And then again, "What is Consuming Hydrogen and Acetylene on Titan?"
http://www.nasa.gov/topics/solarsystem/ ... 00603.html

And then again Stephen Hawking has a few ideas to throw into the pot.
http://www.dailygalaxy.com/my_weblog/20 ... -life.html