With the recent news that there might have recently been water on Mars, people are wondering if that means there is/has been life there, but why does water have to exist for life to exist. Couldn't life on another planet have developed in a manner much different from our own?
2006-12-08 07:07:29 · 11 answers · asked by jcresnick 5 in Science & Mathematics ➔ Biology
Think of life from a different point of view. Propagators of information - genetic information. Since reproduction is a component of life, genetic information, in some form or another is required to be used to encode and pass on characteristics.
There would need to be some way of incorporating the complex information necessary for life for that non-water based lifeform. Currently DNA and/or RNA are the only two things complex enough and replicable, which we know of, which can be used to carry the vast amounts of information needed to propagate even the most simple lifeforms.
DNA and RNA are water based (ribonucleic acid chains).
Perhaps there are other methods of incorporating that complexity, but none with any detail have ever been postulated.
2006-12-08 07:17:03 · answer #1 · answered by Radagast97 6 · 1⤊ 0⤋
Good question.
Water has some nice properties. It has simple formula and
is made of H & O, two of the most common atoms in the universe. Ice floats and if it did not the earth would be very different.
Water has a high heat of vaporization which is useful for
protecting life from temperature changes.
A liquid seems necessary to allow diffusion (i.e. communication of
information, motion of metabolites) without which any life
I can imagine would be impossible. Water is polar and hence good for dissolving ions - if no ions, then there'd be no electrical communication in nerve cells, and no electrical energy
via batteries (which is how energy in
bacteria and mitochondria work, they are batteries really, voltage
difference across their membranes).
What other liquid has all those properties? None that I know of.
To explore some other liquids known to exist and be common
molecules in the universe:
Liquid ammonia is polar, has high heat of vaporization,
and dissolves ions and could perhaps support life somewhere.
(I do not know if solid ammonia floats? Later edit: it doesn't,
as I found with GREAT effort: solid density 0.80 versus liquid 0.68)
It seems the best candidate besides water.
Very cryogenic nonpolar
liquids like liquid H2 or liquid N2 are too cold
to dissolve anything and hence could not support life as we know it.
Hydrocarbons like liquid ethane, benzene,
are nonpolar and hence seem at
a considerable handicap as opposed to water.
Titan was found to have lakes and rains of the stuff, but no life.
CO - carbon monoxide - might possibly be of interest.
Also alcohol. Also HCN. Also H2SO4. But I'm dubious
about all these.
At very high temperatures a lot more things are liquid (e.g, rocks) but complex molecules would be way less stable, probably enough
to prevent life or at least make it less likely.
Another possibility is a supercritical gas, which are common at
high pressure. Supercritical gases are kind of like liquids.
2006-12-08 07:55:39 · answer #2 · answered by warren_d_smith31 3 · 2⤊ 0⤋
Almost all organic reactions need water as a solvent or the medium in which such reactions occur.So far no one could describe other molecule that supports life the way water does even on another planet.
2006-12-08 07:24:15 · answer #3 · answered by Aushbaba 3 · 0⤊ 0⤋
organic matters is made of functional groups (reactive molecules) that are attached on "hydrogen-carbon and sometimes nitrogen as well" backbones. the chemistry of these molecules requires water as a solvent for interactions.
however no other molecules that are able to perform life actions (reproduction, consumption and excretion) can occur spontaneously in the nature.. so probably, life on other planet will also need water.
2006-12-08 08:22:42 · answer #4 · answered by yaz20100 4 · 0⤊ 0⤋
Humans require water to survive. Animals and plants require water to survive. But you are right, what if there is some other form of life that doesn't require water? I think it is assumed because humans assume the whole universe is like them.
2006-12-08 07:17:14 · answer #5 · answered by Bobbie 4 · 0⤊ 0⤋
Well, yeah, I guess our scientists are a bit water centric! But water is the base of all life on earth! I'm sure someone has a better explaination.
2006-12-08 07:19:58 · answer #6 · answered by CruelNails 3 · 0⤊ 0⤋
I agree with u. Just because life on earth need water doesnt mean that life on Pluto would need water.
2006-12-08 07:12:35 · answer #7 · answered by Ethslan 5 · 0⤊ 0⤋
Our bodies are made up of 80% water. That is why water sustains life. I suppose if a living creature was 80% Oreo cookies, then they would need them to survive....duh....
2006-12-08 07:15:36 · answer #8 · answered by valerie s 3 · 0⤊ 0⤋
Water is necessary for life because all cells in our bodies need water in order to do their functions.
2006-12-08 10:05:10 · answer #9 · answered by elizangela r 2 · 0⤊ 1⤋
Absoklutely. As far as i'm concerned, somtehing that can reproduce is alive (and i'm even open to broaden that concept). There could be electrical beeings, magnetic beeings, chemical beeings, beeing that run on oil.....
Anyways, i think wht they mean is that there could have been live as we know it in mars, which could imply that they have the same origin.
2006-12-08 07:15:29 · answer #10 · answered by carlospvog 3 · 0⤊ 0⤋