There might be elements that we have not discovered, there might be life-forms which have a different metabolic setup when compared to life on earth! Then how can we assume that life can exist only on planets with oxygen and water?
2007-03-01 00:31:39 · 18 answers · asked by Suvin M 1 in Science & Mathematics ➔ Astronomy & Space
The only definition of "life" that we have is based on that which we know. Of course, there ARE countless things we do not know and quite likely those include some things'we'd call "life" if we knew better.
However, the search for alien life is expensive and those who do it try to maximize their chances of success. To do that they try to look at places where they think life is most likely to occur.
This is somewhat like going fishing: There might be a fish anywhere, but one nevertheless looks for "a good spot" before throwing in their line.
On the Earth, every place there is liquid water we find life. This even includes the "Black Smokers" at the bottom of deep ocean trenches where 400F water saturated with dissolved minerals emits from the bottom at enormous pressure - with no oxygen and of course never any sunlight. So, we tend to focus our searches to places where the would be liqued phase water. Some places like Jupiter's moon Europa have liquid water oceans under a thick crust of ice. The water is heated by tidal "kneading" as the moon orbits in Juptier's giant gravitational
potential and kept liquid.
So, perhaps the best answer to your question is that we look for life where it seems most likely to be. Scientists certainly do not think that it is IMPOSSIBLE for life to also be elsewhere.
2007-03-01 02:39:22 · answer #1 · answered by Gary B 3 · 2⤊ 0⤋
Very little searching for alien life has actually been done. All of the "digging and looking for microbes" has been done on Mars by a few robot landers. Venus, Titan and the Moon are pretty hopeless, and no other planets have yet been searched. There are plans to look for life on Europa---not at all earthlike. The SETI people look for intelligent life around nearby stars, regardless of what type of planet these stars may have.
2007-03-01 01:49:37 · answer #2 · answered by cosmo 7 · 1⤊ 0⤋
The main reason is that we are more likely to recognize life if it exists in a water environment (oxygen is not required by all life, so that is not an element considered critical to life-something-like-we-know-it.
Life that evolved in a very hot or very cold environment would not be easily recognized (at least from a distance).
And searching for life that we can recognize in an environment we can understand is just the first step.
Patience, my child.
2007-03-01 13:26:34 · answer #3 · answered by Anonymous · 1⤊ 0⤋
as far as we can comprehend, water and oxygen are the basics of life. so with knowing that, we follow the trail planets leave behind (similar conditions) like ice on the moon and mars. the only thing missing is a atomosphere with conditions to craddle life. only the future will tell...
2007-03-01 02:02:46 · answer #4 · answered by texcjb 2 · 0⤊ 0⤋
We go by what we know of biology and it's sustainable conditions. Our current model says that life could only exist within certain tolerances, so that's where we look. If we discovered something to alter that viewpoint, we'd change our scope of searching.
2007-03-01 01:59:27 · answer #5 · answered by xooxcable 5 · 0⤊ 0⤋
You have to narrow down the search somehow, since space is big.
Besides, if we found life based on an unfamiliar chemistry, then we probably would not recognize it as life anyway.
You tend to stick with what you know.
2007-03-01 00:39:37 · answer #6 · answered by Randy G 7 · 0⤊ 0⤋
Carbon base life there are few exceptions of silicon base life. If you look at carbon and silicon there are able to bond with other elements. Others would fall apart.
2007-03-01 00:41:23 · answer #7 · answered by Anonymous · 0⤊ 1⤋
OK.
hey man u r clever
you know why they do this,,,, because they don't want to destroy their theory (life comes from warm water and climate....etc)...
blabla.... but life is a complex type of motion and energy then when we find another thing on other planets moving eating it will be aliving creature. and it response water, food,etc......
but the matter is what will the complexity of life create.....
2007-03-01 02:27:49 · answer #8 · answered by JwH 2 · 0⤊ 2⤋
well, earth has life forms whereas none have been found on planets unlike ours. we can't assume, just following the odds.
if you had one budget where whould you look?
2007-03-05 13:50:35 · answer #9 · answered by Anonymous · 1⤊ 0⤋
The general consensus among scientists is where there is water, there is the probability of life.
2007-03-01 01:14:30 · answer #10 · answered by Dowland 5 · 0⤊ 1⤋