Is there life at other galaxies, what proof do we have?

Question

Are there extraterrestials living in other planets in this or other galaxies, do we have proof that they exist, have they contacted us, or have they ignored us if they do exist???

Answer 1

We don't have any proof.

From relatively near (like say Mars), you could tell there was life on Earth with a good spectal analysis. You could see all the methane from the cows and termites. You could also hear our radio signals.

You can't do spectral analysis on a planet around another star, because the light reflected from the planet gets lost in the light from the star. So you are stuck with radio waves.

The problem is that although we have been broadcasting radio for over 100 years, AM, our earliest radio, is reflected by the atmosphere. FM goes through, and we've really only been broadcasting in FM for 80 years. (That's why in the movie Contact, the message sent back is a television signal from the 1936 Olympics. Television is FM.)

Radio waves move at the speed of light, so anyone within about 70 Light Years could conceivably pick us up, assuming of course that they use radio. A non-visual species or water-going species might never make the connection to communicate with light.

But there really aren't any good places to live within 70 LY.

There's a very famous equation, called the Drake equation -- http://en.wikipedia.org/wiki/Drake_equation -- that estimates the number of intelligent species with whom we could communicate via radio based on the percentage of certain things. Like how many stars are stable and how many of those stars have planets and how many of those planets will be in the right orbit to have water cycling around 0-20C and how many of those planets will evolve life and how many of those species will be intelligent and how many of those species will develop radio, and the big one, how many of those species will not annihilate themselves with some doomsday weapon like the nuclear bomb. The maximum was estimated to be about 10,000 intelligent species currently capable of communicating with radio waves currently alive in our galaxy. The minimus is one, us.

Now to the next problem. Our galaxy is 100,000 light years across. We're about halfway in, so there may be "neighbors" within 25,000 light years. If they started communicating today, we'd hear from them in 25,000 years. If we are still around to reply, they'll hear back in 50,000 years.

What we do know is that there seem to be a goodly number of planets out there. We find more every year. We also know that life is pervasive. Life is EVERYWHERE on Earth. There is life living under the ice off the coast of Antarctica. There is life growing deep in the ocean, feeding off the light/heat of volcanic vents. We have found amino acid chains, the building blocks of DNA, forming in stellar nebulae. We can make the same in the laboratory with a few simple gasses and a spark.

If life can form in the middle of near-empty space, surely it can form on a planet with liquid water.

I firmly believe that life is out there.

I suspect, however, that we will never have a chance to meet.

Answer 2

As far as we know, there has been no actual contact, despite the many stories of alien encounters and government coverups that you will find out there.

But the answer to whether life exists elsewhere is almost certainly yes. Our "proof" isn't much if you look for physical evidence. It's more mathematical proof. We know that the chance of life arising in some places is not zero, because we're here, after all, and this seems to be a rather ordinary corner of the universe. Given that we know there are billions of other galaxies, each with billions of star systems, it's almost a given that life started up in another place. But we don't know where.

Answer 3

Life In Other Galaxies

Answer 4

The best discussion of this I've seen is by futurist Ray Kurzweil, in his book, The Singularity is Near.

His answer; No. We're it.

His reasoning;

Because of the age of the galaxy, and infinite number of planets, it's improbable that we'd simply be so far advanced compared to others that they couldn't contact us. So, if they're out there (and there would be many, according to the "vast galaxy" arguments) then they ALL would've had to reach the same "non-interference" conclusion to avoid us. (That's unlikely, as some would've developed warlike societies, or be in dire straits, needing new resources by now.)

Plus, communication technology makes it likely that somewhere along the line, they'd have put out some type of radio, light, or particle beams that we could notice. (Our own radio signature is huge, and has existed since Marconi turned on the first radio; so it's been out there for others to notice for a long, long time.)

Answer 5

Believe all the conspiracy theories you want - but as far as public knowledge is concerned, we have not yet found nor have been contacted by any intelligent species on other planets.

At this point, technologically, we would have a better chance of finding microscopic life on one of Jupiter's moons than in another solar system (or galaxy).

Presently, we are finding planets circling other stars - but our telescopes are not strong enough to view them directly. We are only able to find them when they pass over 'their' Star because we can detect the light differential 'from' that star.

I believe there is other life out there, but we'll never find out for sure in our lifetimes. All we can do is keep looking - and hope that space travel becomes affordable in the next 30 years or I'll be too old!

Answer 6

To my knowledge, we don't have any "proof" of life in other galaxies, other than simple reasoning. There are billions of stars in the universe, which means billions of planets. Even though the odds are stacked against a planet achieving the conditions necessary to produce life, it's still mathematically possible, even probable, that somewhere in all that mess of planets, there are others that are capable of sustaining life, and in fact do so.

And from a religious standpoint, it's pretty damned arrogant of people to assume that we are the only sentient life in the universe, as that would pretty much mean the rest of it was created just to give us something to look at. However you want to look at it, I'd say there's almost certainly other sentient life out there. Somewhere.

Answer 7

Carl S. said that of the billion or so stars in our galaxy alone there are approximatele 2000 stars that might have planets. And of those, the capability of having life...
Yes, we are listening for life, but we ourselves have had radio for maybe a hundred years; this but a moment in time compared to the age of the universe. Other life could have existed and blown themselves up a million years before we evolved from the sea, or we could become extinct a million years before some other planet developes radio.
The odds are yes to other life, but less so at the same time as us.

Answer 8

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RE:
Is there life at other galaxies, what proof do we have?
Are there extraterrestials living in other planets in this or other galaxies, do we have proof that they exist, have they contacted us, or have they ignored us if they do exist???

Answer 9

I've always wondered about that. I've come up with the answer that even if there are extraterrestrials out there, what are the chances of them coming from a planet like earth? If they didn't come from a planet like earth, how could they survive on earth since they would be accustomed to the atmosphere of their planet and not ours. They might not breathe oxygen! We have no hard evidence that they exist, but it's a bit hard to think that in the entire universe with who-knows-how-many galaxies, we are the only life forms in existence.

Answer 10

We have no proof yet, but serious Scientist consider it plausable, becuase of the sheer numbers and laws of probability! That is enough to convince most people that there is life out there...it's just a matter of time?

Will S