How likely is it that alien life exists?

Question

Has life on other planets ever been discovered?

Answer 1

I agree with most of the previous posters: alien life (life originating on other planets) almost certainly exists. Most of the conditions we think lead to life (abundant water, habitable zone around a star, proper chemical mix) should exist all over our own galaxy and others.

Also, when we look at ancient rocks from our own planet, we find life almost right away. It seems like microbes sprung up as soon as the ground wasn't molten lava. So it's a good bet that microbes and other single-celled organisms are scattered all over the universe.

Large, multicellular organisms like us are probably much rarer. Venus and Mars once had atmospheres that would have supported life, but they have long since become uninhabitable. We don't think large organisms had time to evolve there. To have large organisms, you need a stable environment for billions of years.

Also, multicellular organisms appeared very late in Earth's history, relatively speaking. Although single-celled creatures appeared right after the Earth formed, it took another 4 billion years for multicellular organisms to show up! Although that's only one data point (Earth's own history), it certainly looks like multicellular life is far less common.

There are probably other intelligent beings out there, but based on the data available so far, I'm guessing they are far, far rarer.

Answer 2

No solid evidence of life on other planets has been discovered. A few years back some scientists announced that they had found what appear to be microbial fossils on a meteor from Mars, but those conclusions have since been called into question.

As to the larger question of how likely it is that alien life exists, well, space is a really, really, REALLY big place.

Answer 3

Water has been discovered on mars and a planet of Jupiter's. Also, another Jupiter planet has organic matter and an atmosphere similar to Earth's. Where organic matter and water is present, simple or complex life is most likely there. ... Also, a weird probability equation predicts a most likely.

Answer 4

Of all the suns and planets in the universe, it is hard to imagine that this is the only one (earth), that has life on it.

Also why do us mere humans believe, that for other life forms to exist, the presence of air, warmth and water must be there. Just because we have adapted this way does not mean aliens have to adapt the same way.

Answer 5

I would like to think that there are many many planets out there that have life like ours. But as we look out and we cant find any solar systems set up like ours which Earth has the right setting for life(obviously) Im sure there is some planets with micro organisms on it, but I hope somewhere out there self aware life is living and will find us- or we will find it.

Answer 6

Alien life will exist that is 100%
But the point is if it is available to the 5 sense that can detect it
There can be alien that is standing next to us
But we cannot see.
IT may be visible in others dimensions

Answer 7

Life has not been discovered on other planets (if it had, it would be all over the news, the Internet, YouTube - it would not be a secret).

Most scientists believe that life of some kind on other planets is not only possible but very likely.

Answer 8

If your definition of alien life involves gray beings, then there is very little evidence. If it is any kind of celled organism, Mars has demonstrated life of microbes. Life will always form where the conditions exist.

Answer 9

The Mars rocks seemed to prove that microbes can develop on other planets, regardless of the atmosphere.

Answer 10

I think it is a given. Who could be so egotistical as to believe that we are alll there is??we havent contacted other life forms but our leading scientists think life must be carbon based. WHY when we dont know dont make ASSumptions.