What is your opinion about life on other planets?

Question

I know it's speculation but I am sure there must be life elsewhere in the universe. It seems to me a mathematical probability that life will have evolved elsewhere. I don't know what kind of life or how far evolved but with a planet in the habitable zone of it's home star, a few billion years of relative stability and a few other variables would do the job, surely?

The BBC website on exoplanets states: "Astronomers at the Harvard-Smithsonian Center for Astrophysics (CfA) reported in January 2013, that "at least 17 billion" Earth-sized exoplanets are estimated to reside in the Milky Way galaxy." Just taking our galaxy alone, it would seem unlikely that we are one in 17 billion.

Just wondered if anyone else has any thoughts on this???

Thanks.

Answer 1

Life doesn't seem rare from my perspective at all. What I mean; of course it seems rare when all we can do, for now, is monitor light interruptions of passing planets to see if there even are any, around different stars. That is like searching microbes without glasses and having very poor eye sight.

So for me it is rather the opposite, since we did found planets orbiting other stars; and in habitable zones; and with atmospheric gases that would favor life; it seems perfectly logical to think that there is life elsewhere, considering the numbers of planets, stars, systems, galaxies....

Answer 2

Given the conditions of early Earth and what we know about other star systems, it is very probable that life exists elsewhere in our galaxy and nigh a certainty that it exists somewhere in the universe. We have little reason to believe life is a fluke.



Given that life on Earth was unicellular for billions of years and that cataclysms (greater than anything that has happened to Earth since the Theia collision) would reset the evolutionary clock, most life bearing worlds likely have very simple life (think pre-Cambrian).



Intelligent life seems to steadily progress technologically and rapidly compared to biological evolutionary progress, which likely leads to environmental instability. An intelligent species either causes the collapse of the environment on which it depends or doesn't and progresses into space. How often does intelligence evolve and how often does intelligence colonize space? No one can say, but the universe has been around for billions of years and we don't see any signs of a hundred million year old civilization encompassing large swathes of our part of the galaxy, so one might come to the conclusion that the chances of intelligence evolving or making it into space are slim. Since we know of one example of intelligence evolving and no examples of intelligence colonizing space, I tend to believe that the colonization of space before environmental collapse is the least probable of the two.

Answer 3

There is an estimated 200-400 billion stars in our galaxy with 1 trillion planets if you include multiple planets per star. This is just in our galaxy. There is also an estimated 100 billion or more galaxies in the universe. Even if I planet per galaxy had life that would mean that 100 billion or more planets have life.

Answer 4

We are finding exoplanets all the time and at least one with twice the mass of earth on the edge of the Goldilocks zone.

And that is within our own Galaxy.

So what are the chances now?

Answer 5

I have no opinion yet. I have much more important concerns than this one. Real Probability needs some basis, but there isn't any for this. Large size doesn't imply anything. "Seems likely" or "seems unlikely" are far cries from "certainly is" or "certainly isn't"! Some people evidently want to believe there's life on other planets. I don't see any good reasons why anyone wants to believe anything about it or anything else.

Answer 6

My opinion? Can you be any more vague?

It would be really cool if we can find bacterial cells on Mars. Chances are that the bacteria came from Earth, so it would establish that life is infectious.

It would be really really cool if we discovered life on one of the Gas Giant's moons.

We should explore those moons and establish whether or not life exists there. If it doesn't, we should design and introduce it.

Any life existing outside of our Solar System is unreachable and irrelevant to us.

-=-

I don't see a whole lot of difference between discussion of the existence of extra-solar life and the existence of God (at this time). Neither discussion has much, if any, value.

Answer 7

I'm not surprised to be honest, the only issue is the immense distance between solar systems. Speculation gets boring after a while.

Answer 8

My *opinion*?



Not sure what kind of opinion you're looking for... I suppose some extraterrestrial life is nice, others probably aren't so nice.



If you're interested in my conjectures about probabilities, that's another matter entirely. I estimate that life exists in approximately .5% of all star systems:



"Extraterrestrial Life: The Odds": https://sites.google.com/site/alexisbrookex/extraterrestrial-life-the-odds

Answer 9

There probably is life, of some kind, on other planets... While we can be *almost* positive there is... until a single microbe on another planet is found - the only planet in the universe we're *sure* has life - is Earth.

Answer 10

Personal opinion:

Not in our solar system. But probably in some other solar system.



Value of Opinion:

Worthless.



Even if there IS life someplace else, and even if it IS intelligent, it is so very very very VERY far away that it can never get here and we can never get there.



Life on other planets in other solar systems is MEANINGLESS to us, because it has NO POSSIBILITY of having any effect on our planet..

Answer 11

Watch "Into the Universe" with Stephen Hawking - it's on Netflix and it will certainly blow your mind! I absolutely believe in life outside of our Earth!

Answer 12

They're absolutely certain life exists on, or underneat the planet-wide ocean, of Europa - the 5th I believe moon of Jupiter.

They say they must be like squiddies.

Answer 13

Yeah, ..., I have to agree. At this stage of the game life seems pretty rare. Which makes this planet and the beings that live on it even more special and priceless.

Answer 14

there may not be life in this galaxy but there is a chance there could be life in toehr galaxy which we havent discovered

Answer 15

Must there be life,i do not know.

Answer 16

I don't believe that there's life on other planets, and my proof is that no one has proved me wrong yet. Oh and I definitely don't believe in evolution.