# Does life really REQUIRE water? **URL:** \ **Category:** Factual Questions\ **Created:** [January 19, 2004, 5:31am UTC](https://boards.straightdope.com/t/does-life-really-require-water/225173 "2004-01-19T05:31:06Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![culov](https://avatars.discourse-cdn.com/v4/letter/c/e79b87/32.png) [@culov](https://boards.straightdope.com/u/culov)\ **Post date:** [January 19, 2004, 5:31am UTC](https://boards.straightdope.com/t/does-life-really-require-water/225173/1 "2004-01-19T05:31:06Z")
I was thinking about how scientists claim that finding water on mars would most likely mean that there is some life there… Even if there is no water on mars, why would that rule out the possibility that life exists? Who says that life is dependent on water? How do we know that other creatures outside earth dont get their energy from carbon or something else? Im assuming that not finding water on mars would simply rule out the possibility of familiar life, and not the possibility of every type of life, but why doesnt anyone mention this? thanks, culov ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [January 19, 2004, 5:50am UTC](https://boards.straightdope.com/t/does-life-really-require-water/225173/2 "2004-01-19T05:50:13Z")
The thing is we only _know_ about one life chemistry. As far as we can tell, any form of life is going to need some sort of liquid solvent in which to carry out its reactions. For life on Earth, that solvent is water. Water is simple, plentiful and stable; and it exists in liquid form in a suitable range for a wide variety of reactions to occur, so it’s likely that anywhere there’s sufficient liquid water, there will also be at least the makings of life. ---
**Author:** ![Cervaise](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cervaise/32/16693_2.png) [@Cervaise](https://boards.straightdope.com/u/Cervaise)\ **Post date:** [January 19, 2004, 7:18am UTC](https://boards.straightdope.com/t/does-life-really-require-water/225173/3 "2004-01-19T07:18:54Z")
As **Q.E.D.** says, the organic chemical reactions used by life to, well, live require a solvent. By far the most available and practical is liquid water. Similarly, carbon provides by far the most flexible and useful structural basis for cells and biological architecture. See [this thread](http://boards.straightdope.com/sdmb/showthread.php?t=233557) for some additional discussion. Note that a couple of alternatives to water and carbon are offered (by myself and others), but that for various reasons they are inferior choices. A number of books and other resources are cited in that thread; you can follow up with any of them for more detailed information. The short answer is that water is not _required_, per se, for life to exist (neither carbon), and of course we have but the one ecosphere as an example, but based on everything we know about physics and chemistry, what we have seems to be a hell of a lot more likely than the other hypothetical options. ---
**Author:** ![Matchka](https://avatars.discourse-cdn.com/v4/letter/m/77aa72/32.png) [@Matchka](https://boards.straightdope.com/u/Matchka)\ **Post date:** [January 19, 2004, 6:22pm UTC](https://boards.straightdope.com/t/does-life-really-require-water/225173/4 "2004-01-19T18:22:20Z")
There are cases of life forms that use a concentrated molecular acid in lieu of water, but these have been found to be extremely volatile creatures. They are, in fact, so extremely dangerous to humans as to negate intimate knowledge of their biochemistry. These creatures have been showcased in several 90-odd minute film studies. ---
**Author:** ![Matchka](https://avatars.discourse-cdn.com/v4/letter/m/77aa72/32.png) [@Matchka](https://boards.straightdope.com/u/Matchka)\ **Post date:** [January 19, 2004, 6:22pm UTC](https://boards.straightdope.com/t/does-life-really-require-water/225173/5 "2004-01-19T18:22:35Z")
There are cases of life forms that use a concentrated molecular acid in lieu of water, but these have been found to be extremely volatile creatures. They are, in fact, so extremely dangerous to humans as to negate any value of intimate knowledge of their biochemistry. These creatures have been showcased in several 90-odd minute film studies. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [January 19, 2004, 6:54pm UTC](https://boards.straightdope.com/t/does-life-really-require-water/225173/6 "2004-01-19T18:54:54Z")
> [@Matchka](#): > > There are cases of life forms that use a concentrated molecular acid in lieu of water, but these have been found to be extremely volatile creatures. They are, in fact, so extremely dangerous to humans as to negate any value of intimate knowledge of their biochemistry. These creatures have been showcased in several 90-odd minute film studies. I’m sorry, but this just sounds preposterous. Can you find a cite for me? I’ve looked with no luck. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [January 19, 2004, 7:16pm UTC](https://boards.straightdope.com/t/does-life-really-require-water/225173/7 "2004-01-19T19:16:13Z")
> [@Q.E.D.](#): > > I’m sorry, but this just sounds preposterous. Can you find a cite for me? I’ve looked with no luck. [Whooooooosh!](http://enc.absoluteavp.com/f.html) ---
**Author:** ![kniz](https://avatars.discourse-cdn.com/v4/letter/k/c37758/32.png) [@kniz](https://boards.straightdope.com/u/kniz)\ **Post date:** [January 19, 2004, 7:36pm UTC](https://boards.straightdope.com/t/does-life-really-require-water/225173/8 "2004-01-19T19:36:21Z")
**Q.E.D.** , I don’t think you got “whooshed” on that one. Being whooshed comes from believing a ridiculous “original statement”, not from the proof of a statement being ridiculous. :rolleyes: ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [January 19, 2004, 8:07pm UTC](https://boards.straightdope.com/t/does-life-really-require-water/225173/9 "2004-01-19T20:07:20Z")
> [@kniz](#): > > **Q.E.D.** , I don’t think you got “whooshed” on that one. Being whooshed comes from believing a ridiculous “original statement”, not from the proof of a statement being ridiculous. :rolleyes: Being whooshed comes from not recognizing that a preposterous statement is in fact a joke. By getting **Q.E.D.** to search for cites on creatures with molecular acid in place of blood, **Matcha** indeed whoooshed him. **Q.E.D.** can be excused, however, because such creatures _will_ in fact be discovered in 2112 A.D. (I have cites.) ---
**Author:** ![Cheauvan](https://avatars.discourse-cdn.com/v4/letter/c/b3f665/32.png) [@Cheauvan](https://boards.straightdope.com/u/Cheauvan)\ **Post date:** [January 20, 2004, 4:09am UTC](https://boards.straightdope.com/t/does-life-really-require-water/225173/10 "2004-01-20T04:09:28Z")
I choose to think **Q.E.D.** ws sending a _very subtle_ hint to **Matchka** about when & where to goof off…I’ve been wrong before tho. 🙂 ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [January 20, 2004, 5:06am UTC](https://boards.straightdope.com/t/does-life-really-require-water/225173/11 "2004-01-20T05:06:42Z")
> [@Cheauvan](#): > > I choose to think **Q.E.D.** ws sending a _very subtle_ hint to **Matchka** about when & where to goof off…I’ve been wrong before tho. 🙂 Hey, errrr…yeah, that’s it exactly.