Are water and oxygen absolute universal neccessities for the existence of life?

Question

life somehow eventually developed here on earth under the "circumstances". wouldn't it be just as likely and as possible for it to develop elsewhere, under different circumstances? just because we need water and other elements such as oxygen here on earth in order to survive, does that neccessarily mean that life forms that may exist on other planets or moons in other parts of the universe need the same elements in order to thrive, or are we being arrogant in assuming that life forms elsewhere must be just like we are here on earth?

Answer 1

Molecular oxygen is not essential for life. In fact, the earliest bacteria were poisoned by it as many are today (obligate anaerobic bacteria). There are even bacteria that use sulpher in many reactions where oxygen is used in humans (and most other living things).

Water is a very unusual compound. Its ability to form hydrogen bonds allows it to dissolve a great number of other chemicals and so to provide a medium for the reactions of life. The only other chemical that even comes close is ammonia. But to have liquid ammonia requires low temperatures. That means the basic reactions would be rather slow. Whether that would make it difficult for life to form or not can't be answered with our knowledge at this point.

The only other substitution that is discussed with any frequency is silicon for carbon as the structural element for life. The main difficulty with silicon is that it does not like to form double or triple bonds. This drastically reduces it's ability to form the type of chemicals that carry the information needed for life.

Once you get away from the elements and start looking at larger compounds, it seems likely that other life could be based on other amino acids, or on a genetic material other than DNA, or even something as simple as a mirror image chemistry (using amino acids that are mirror images of those in life on earth).

Answer 2

Water and oxygen are necessary for most forms of life as we know it, but that isn't to say that there might be something out there that evolved a completely different biology from what we're familiar with. There is some speculation that there might be silicon-based life out there somewhere, since it falls in the same group as carbon on the periodic table and therefore exhibits some of the same properties. It would create similar chemical compounds, but more crystalline (I think) than those with a carbon backbone. Living rocks? Why not?

It is indeed rather small-minded to think that if there is life elsewhere in the universe that it must necessarily be just like us. Personally, I'd be a little spooked if I were a human space traveller who just journeyed thousands of light years away from Earth to explore the universe, only to step out of my spaceship and be greeted by a guy named Ed Torkelson who speaks in something eerily like a Jersey accent.

At any rate, this is a question that is bandied about from time to time at places like NASA and the ESU -- as we progress in our exploration of our own solar system, and hopefully outwards to other stars, how will we recognize life when we see it? It may very well be SO alien that we don't even realize it's alive when we meet it.

Answer 3

at the same time as that's real that existence will be in accordance to at least some thing except the carbon/oxygen/water foundation we've for existence right here on earth, it really is the in reality style of existence we've any information of, so perchance it really is style of less demanding to apply those criteria all of us understand and understand, a minimum of partly. The researchers do not characteristic the potential for existence completely to water and oxygen, yet as I stated above, it really is the existence gadget we maximum appropriate understand (or the in reality one we understand). at the same time as there are transformations which will be conceivable, it quite is conjecture. there have been numbers of technology fiction memories with different existence bases, yet all of us understand our personal. gazing Alien video clips and examining sci-fi is reliable leisure, and could be a foundation for some conjecture, yet it really is about it. I agree that if hydrogen and oxygen are present day in an ecosystem, there will be water. again, although, water vapor, or ice do not instantly help existence as we understand it -- our existence varieties desire liquid water. understanding hydrogen and oxygen are present day ought to symbolize water, yet area state is significant too. because the landers have taken Mars' temperature, we've a lot a lot less desire there, and Venus is way too warm, as far as we are able to surmise.

Answer 4

It is essential here on earth, but that doesn't mean that it is for life on planets other than earth. If there is life somewhere where there isn't any water or oxygen then who ever or what ever lived there probably just adapt to live without them.

Answer 5

It seems that water is more of a neccesity than oxygen. In fact, oxygen is toxic to many types of bacteria. It's thought that the first microbes that were able to live in an oxgenated environment did so only because they were able to evolve a compound which binded to the oxygen and removed it from their systems. It's also thought that the hemoglobin in our bodies evolved from this compound.

Answer 6

oxygen is not required for life, but water may be. even on our own planet, we have found microorganisms living in all sorts of strange environments and using all kinds of food. There are microorganisms that live deep in the sea, some near volcanoes, others in high salt conditions, acidic or basic conditions, you name it and they have found it. Its unlikely more complex organisms would evolve without oxygen, but it might happen. Water seems to be important however because of its unique properties. It is still conceivable that life may exist without water, but I don't think its likely.

Answer 7

There is no doubt that theory has sound argument. We are limited in our knowledge of what constitutes life on this planet alone. We have no basis in fact to suggest life in any other form, does not exist, somewhere.

Answer 8

yes for all carbon-base life,and some plants live without oxygen,but the carbon-based life needs water, because water is a polar molecule, which makes it an excellent solvent and therefore an ideal medium for chemistry.But the scientist said that life coud be in Si-based molecules, who knows what do they need for living,maybe some carbon-molecules ...
:)))

Answer 9

Mathematician....you might also add the fact that the very oxygen we breath is killing us, oxygen is what causes the aging process in the human body....ironic isnt it?

Answer 10

Some bacteria can live with no oxygen.