Of all the billions of stars that we know of, what is the probability of other life-forms .......?

Question

....... on the planets around them?

Answer 1

In my opinion, given that there countless billions of stars in 'our' galaxy, there must be millions of planets with similar conditions to those on Earth. So, the odds MUST be in favour of life, of whatever description, somewhere.

I wouldn't expect that they would be humanoid, or even mammalian, fish, reptillian or vegetable as we would recognise them - (so they won't speak English) - but something completely foreign.

Therefor, I'd reckon the odds of intelligent life would be further reduced, but having said that, that reduction is down to hundreds of thousands, and reduce that again for levels of technology at least equivalent to ours. So bring that down to hundreds, maybe thousands - and some of them might well be considerably more advanced than us.

Those that are more advanced may well have visited us, decided there's no intelligent life here and pissed off!

Answer 2

I think there is a good chance other forms of life exist in the universe. Why should we be the only planet to have life? The only trouble is that the universe is so vast, the chances of finding any are very slim, and it would be almost impossible, at present, to contact any, as it would take the lifetime of our planet to travel such great distances. Maybe in a thousand years time, if Humans are still about, we will have the technology to visit other worlds and find out for sure. But, in the meantime, all we can do is speculate and keep on looking. You never know.

Answer 3

Life arose on Earth by accident (lightning strikes into pools of sludge) out of non-living materials (methane, water, nitrates, etc.) that occured naturally and the elements in living things are made up of the same 99% of the natural world - hydrogen, oxygen, carbon, nitrogen, etc.

Since the universe is made up of the same materials and similar environmental conditions have been shown to exist on other planets in _this_ solar system, it's not far-fetched to think that life occured on other planets. And if the universe is truly infinite, then the further you go the more likely life on other worlds is to be. Life on other planets is almost a certainty, thought it is unproven.

The question then becomes, what sort of life will appear? I highly doubt anything as advanced as us, and I'm not talking about "human civilization". Simpler life forms are more likely to occur because of evolution, so single-celled organisms are most likely, followed by plants, and finally multicelled independent life forms (trilobytes, worms, lizards).

The chance of living things that are self-aware (only humans are) and can grasp abstract concepts is very remote. Even if such living things do exist, why would someone assume that they were here first? Who is to say that *we* aren't first, and that *our* TV and radio transmissions won't be the first thing other living beings hear instead of us hearing them?

To sum up:
Q: Is life elsewhere in the universe possible?
A: It's not just possible, it's almost an inevitable certainty.

Q: Will we ever meet or see other life forms?
A: Only if they are on Mars. Otherwise, no, even if they exist. As far as we know or will ever know, we're alone.


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Answer 4

snogledk is the only one talking any sense.

The Drake equation is a nice intellectual exercise but absolutely pointless because so many of the numbers in it are pure guesses.

In particular, we just don't know how likely it is that, given the right conditions and enough time, a true life-form will evolve. Think about it one way and it seems almost inevitable - think about it another and it seems incredibly unlikely. It's a matter of faith rather than science where you end up.

The only thing we know for sure is that life exists HERE. If it only existed on one planet, the people on that planet would naturally be looking out at the Universe and saying "Why would this be the only place...?"

Answer 5

There's actually a pretty decent chance of life on other planets simply by taking an equation which takes into account the number of stars which are like our own, the probability that there are one or two planets capable of sustaining life orbiting a percentage of those stars, and taking into account that though life will not arise on every planet capable of sustaining it on a great number of them life will more than likely be there...there's even a further equation stating the probability of intelligent life like our own. I do believe there is life out there. Whether or not we can ever communicate with it is an entirely different matter.

Answer 6

quite high i think.

100 billion of stars in our Miky Way. 100 billion of galaxies in the universe.

we've just started looking, with pretty poor instruments, and we've already found about 200 extrasolar planets. We've found the heavier ones first (because of the instruments and the methods chosen), but as we launch new, much more sensitive instruments, we'll find many more planets, and also, smaller, rocky planets (we've already found a few).

so you'll be looking at 1E22 stars, probably most of which with planets around them.

clearly many of those stars won't have the right characteristics for one reason or other (too young / old / weird) but you'll still be left with a large number of them.

clearly not all of the proper stars will have rocky planets at the right distance, but most of them will have rocky planets and many will be at the right distance. leaves you with a large number of planets that could harbour life.

water? Hydrogen is the most abundant element in the universe. And oxygen is the 3rd most abundant, and it is very reactive. So the probability of finding H2O must be high, anywhere in the universe.

bottom-line: very high probability that there are large numbers of planets with life out there.

now, how many with intelligent life? And more importantly, how many with intelligent life so advanced, that there is a chance they could visit us (which assumes faster than light travel)?

bottom-line: we may never know for sure

Answer 7

Fairly high, actually. We have been here for quite some time observing you. Over the centuries, your planet was a curious place to visit once or twice and was not considered very interesting . Sure, your wars showed us how undeveloped you are as a species and your infantile,(in cosmic terms) dependence on god concepts does not bode well for you. We are now showing an interest in you because it is not often that we get to observe a species commit suicide. You are so close to maturing as a sentient species and it will be a shame to see you kill yourselves. There are just not enough of you becoming rational enough to force the issue. You let the least among you determine your fate, so be it.

Answer 8

I'm convinced there is life on another planet out there somewhere in the Galaxy for the simple fact there are so many and one must carry life as we know it....But I think the answer to all this is thousand of years away until we have discovered with the aid of electronics and science a way to give us absolute proof and being able to mutually contact . Its so far off in the future, even life here on earth will be nothing like we know it now

Answer 9

I think the probability of life on other planets isn't very realistic. There are so many conditions that have to be prevalent in order for life to exist never mind come into being. so many people speak of chance as having some creative ability which is used to explain how life originated. Time and chance are used to explain everything. for years scientists have been trying to recreate the conditions of early earth to demonstrate how life might have evolved. The results of their experiments have been a big disappointment. Just because life can exist does not give it the impetus to come into being.

Answer 10

There is an equation out there to try and figure that out. I don't remember the name of it, but its something like:

The number of stars - the number of stars without planets - the number of planets able to support life - the number of planets that haven't developed intelligent life = how many planets have intelligent life

Problem is, while we know how many stars there are (approximately anyway), we're only just discovering planets in other solar systems, and we have no way of knowing if any of them are capable of supporting life (even bacterial) yet. I think as our technology advanced we will be able to figuring this out more definitively, especially if we ever find bacterial life somewhere else in our our solar system (perhaps on one of Saturn's moons?).