Is there life beyond the Earth?

[Sonia]

Some scientific questions are of immediate and widespread interest, and they stir out imaginations. The subejct being is there is life beyond the Earth? The question for years and years has been pondered, but it is only in the last 50 years or so that we have made significant progress towards answering it. But yet today the question is still unanswered with still much uncertainty. A few people believe life is out there and claim to be visited by aliens. It is easy for us to laugh at the idea of us being visited by them, but in fact it is a serious question to ask whether it happened or not, with the serious answer being there is no scientific evidence for it. They lack objective facts. The important word in all of the "is there life beyond earth?" is unexplained, and that alien visitation is just a belief. There could always be tomorrow of alien visitation, but not happened yet.

We know that on Earth there is life. But for searching for life elsewhere we have to look at some key features, and the essential conditions.

All organisms are fundamental sense rather than similar. Familiar ones being large ones - from elephants, blue whales and trees, down to spiders and fleas, and consist of a large number of cells. Others could just be single. It is these substances in the cell that we discover and are essential for all life on Earth.

In search of for potential habitats for life beyond the Earth we should restrict ourselves to places where huge, complex compounds can exist. The availability of carbon is no problem, it is failry common and widespread element. But only under conditions of temperatures.

All life on Earth has some other requirements, but there is one more requirement that will be great importance in aiding our search for life elsewhere. Itis chemical compound found in cells.

With planets around other stars we should be able to establish whether liquid water existed at the surface, and therefore whether the surface conditions were suitable for carbon water life. If there was an ozone absorption feature we would fairly confident that life was present. We would be confident if other absorption featues were present, through space and time restrictions do not permit details to be given here.

Unfortunately, ozone could be below detectable limits even if life were present. This could happen under 3 conditions.

Local lifeforms do not photosynthesize.
Local lifeforms do photosynthesize but oxygen is not released.
The rate of release of oxygen is s slow that the atmosphere abundance, in the face of removal processes, remains low.

This took me ages to type, so would like your opinions..
Thanks! Sonia..

[Robert_T]

Hi Sonia, all pretty reasonable, but are we limiting our field of view in "But for searching for life elsewhere we have to look at some key features, and the essential conditions.". I guess this is fair enough for life as we know it, but the universe is a big and strange place and might have some surprises in it that might be in the blind spot of this carbon based lifeforms imagination.

cheers,

[shredder]

Hi Sonia

Thought I would give you my oppinion on the subject and points you raised. I also thought this was a good topic of conversation and worth some thought.

I do believe that there is other life out there. And if I had to put money on it I would say that there is significant life out there (both in numbers and diversity). And I would also say that I dont believe in any of the so called UFO sightings or abductions (not a single one).

My thoughts run along these lines. Life on Earth is in abundance, it addapts to seek out every possible corner, and take advantage of any change thrown at it. I dont see why this isnt so for other planets elsewhere. Some of it will be intelligent, some of it not so, but it will be there and one day will be found.

So why havent we heard from them yet (as I said before I dont believe in sightings / abductions from the US etc)? Why dont they reply to SETTI or similar. Its an interesting question, and if you look around the answers might already be there in front of us.

Take the ant for example, it builds civilisations, it has been around for millions of years, I understands its environment and clearly adapts to survive. This could be taken as intelligence of a sort. We however are far more advanced in our abilities and thinking (or so one would believe). Does the ant realise we even exist, does it try to make contact, do we know, do we respond? No, in general we look at ants as insignificant and not worth out attention in any respect. I believe that any extra terrestrial life that can visit us (has the capability) is going to be so far advanced that it will be the same situation, we will look like little more than dumb animals and of only a cursory interest. For the same reasons I dont believe in the sightings or abductions, any race capable of crossing the inter stellar distances is surely going to be advanced enough not to be seen by people, or need to abduct them, and if they did feel inclined they would be capable of doing so without or realising it.

In terms of SETTI, I feel inclined to believe it will fail to detect anything (but it is worth trying anyway). Only civilisations dawning into the computer age would be capable of generating messages that are recognisable over the ambiant noise as a signal. Today every effort is made to compress messages, make them as small as possible, which effectively means make them as random as possible. Imagine how capable we will be in doing this in say 100 years, would they be distinguishable over the ambient noise, I would say not. Would the be using the same frequency, or even same techniques, probably not. It would be like the ants listening for a signal from people, we are so disparate in our capabilities and technologies that it just wouldnt occur.

But have they visited us before? This was another of your questions, why is there no evidence of it? Again I suspect if they can get here they can also disguise themselves so we dont notice. But then again maybe there are other references if you look, in history there are multiple references in the Bible to people doing amazing things maybe someone did part the Red Sea, Walk on Water, cure the sick, calm the masses, or produce food from thin air, maybe they just werent the miracles we were lead to believe but rather some form of replication or advanced technology (such as in Star Trek), note this is not my belief I am religious, but it could be an explination....

In short I do believe that life is out there and that we have not made meaningful contact, and I dont expect to be proven wrong in my lifetime....

Cheers

Michael

[ACE]

It would be a brave person to staunchly refute the idea of life beyond Earth does not exist. Even from a statistical point of view, just the number of stars and galaxies out there alone make the odds of another life form being feasible and more to the point of being a likelihood.

The ubiquitous question is how do we find it!!!;) We will as iIeinspacers ever get remotely close to finding the answer ?

[Nightshift]

I think only the Human species could be egotistical enough to consider we are the only life in the universe, what a silly insignificant bunch we are to not only think we are the only life in the universe but to think that we come anywhere near the top of the evolutionary chain, I reckon one day we will discover we are little more than a phlebotomists stain on the fabric of the universe and then wont we be humbled, except me of course as I believe if life in the universe is compared with life on earth, man would be somewhere around equal to insects or perhaps small mammals.

P.S. Im not ignoring you Sonia I'm ignoring that other silly thread.

[ving]

these same egotistical humans think they can change the course of nature... ;)
(sorry bout that)


life on other planets? more than probable!
to quote star trek: "it's life Jim, but not as we know it!"
:)

[cjmarsh81]

Life on other planets? Probably

Will be see them in our lifetime? Probably not.

The spacecraft needed to travel the immense distances is not an easy feat to make. I would venture that if there is life out there like ours they are in the same predicament. I think the best we can hope for in our lifetime would be some sort of radio communication.

[Lester]

Okay I'll stick my foot in it; No there is not any intelligent life any where else. We are it. And without getting into another area to put my argument, I am forced to leave it at that.

ps. I have been wrong before.

[mickoking]

Lester, now you have me intrigued :D

[avandonk]

I always thought that life given the right environment would inevitably arise. The limiting factor is the presence of liquid water. The fact that it has started once means it can happen again. This is not proof just conjecture. We have no evidence.
When the tube worms and crustaceans were first seen living four miles underwater near volcanic vents subsisting on bacteria that converted what to us are poisonous chemicals to energy and food and a thriving though fragile ecosystem without the Sun as a primary source of energy I became convinced that life can arise anywhere given the existance of liquid water.
There are even bacteria living many kilometers underground in solid granite that only divide once in a hundred years. It is estimated that these bacteria have a larger biomass than what is above ground, that is, our biosphere. I could go on. We don't know all of it yet, what is under our feet and in our oceans. It may perish because of our greed (mine included).

There are basically two alternatives.
One: Life only exists on our planet
Two: Life is everywhere in the Universe given the right conditions.

Both are equally scary.

Bert

[gaa_ian]

Once upon a time the earth was flat (or so we thought) ...
Then we were sure the heavens revolved around the earth ...
Telescopes were invented, and we realize we are in a galaxy, which was considered our universe !
Now we realise it is one of billions !
Planets around others stars ? Sci-fi surely, yet to date we have discovered over 160.

I believe in my lifetime we will prove the existance of life (biomass) on other planets. IMHO

[josh]

To assume that we are the only life in the universe will achieve nothing. Only those who have had the courage and imagination to look outside the box will make a difference to humanity,they are the only ones that ever have. The rest just seem to stand there and say "impossible"
I dont think it possible that we are the only life the universe decided to create. And if we dont ask and look we will never know.
I wonder if we have been spotted yet?

[Starcrazzy]

I am a firm believer in only a few things..
1:When ever i buy some new gear, it will be cloudy for at least 2 weeks..
2:The laws of mathmatics are universal and can be applied to any and evry question asked by a human being...And thus we can break it down into a simple mathmatical equation..
Ns= number of stars per galaxy:1000,000,000
Ng= number of galaxy's visable from earth:1000,000,000
Np= number of planets per star(estimated):2

So if we estimate quite conservativly for Np and say that there are only 2 planets orbitting each star(ill get to this in a sec)..
so the equation would look like this..
NsxNgxNp=2,000,000,000,000,000,000
Now ...this is a very rough approximation for the number of possible planets in the universe..We have only recently been able to look close enough at other star systems and what do you know, there are planets there..Jupiter 1 for instance in the centuri star system..So it may be premature but i would assume that planets are a cosmic innevitability, they may simply be a bi-product of the production of stars..So useing the number 2 as our Np is probably quite concervative...
Now..If we are to take the formula further and estimate that the conditions for life are available on only 1% of all these planets..we get the number...2000,000,000,000,000,0.... Ok..so thats still quite a high number...lets reduce it further in the name of fairness..Say..0.1 % of the planets are suitable for sustaining life...we get..2000,000,000,000,00...so if our formula is roughly correct we have the possible life sapporting planets as 2x10 to the power of 13..
Ok..lets reduce it further..lets add another factor to the equation..The probability that the life forms evolve into intelligent book reading, relationship forming, telescope building life forms..lets make it another 0.1 % chance again..so we end up with 2x10 to the power of 10..
Now i think anyone would agree i have been quite concervative in my numbers and we still end up with the odds of us being the only life in the universe of 1:2000,000,000,00...Thats 1 in two hundred billion..

You be the judge
;)

[vespine]

Some people would argue that the chance of life forming IS billions to one. Scientists have done many experiments trying to reproduce a 'primordial soup' with the most favourable conditions they could conceive and no one has as yet managed to spring to life so much as a single cell of living matter. But, obviously it also isn't hard to think that if it happened once here then you'd have to be crazy to think it couldn't happen again, but wouldn't any winner of the universal lottery think the same thing?
I believe in an infinite universe because it fits the 'linear' reality I perceive, because of that I can't imagine an end to the universe and for that reason I do find it very hard to argue that we are the only life, but at the same time I really can't discount any other possibility because there simply is not enough input.

[Starcrazzy]

Exellent...i sence a charged intelligent debate brewing...but i do beg to differ about the primordial soup on two grounds..1. the time factor is simply unsynthesisable, we can't experiment with the effects of time without letting time pass( don't start on me with time dilation either) to study the effects, and the second point is The building blocks for life have been created in tanks..See proff Carl Sagans work at cornell uni where they created after only ten minutes the compounds required to make rna and dna..But as he puts it, the notes were there but the music was still missing...After only ten minutes of applying light heat and electricity to tanks holding the same gasses as our early world..So if you were to let these tnks go for say oh,,i dont know,, 1 billion years, what do you think would happen...Life??perhaps..I know that doesn't prove that life evolved but it for sure doesn't take anything away from the possability...i like that theory much better then the allternative(the hippies and the talking snake) no offence intended to any christian young earthers out there

[mick pinner]

Intelligent life is the term l have trouble with, we as a species have some very intelligent members but as a whole we are the most ignorant and destructive species to have walked or crawled the earth.
l think life does exist somewhere but in what form l could not imagine, for the conditions to be close to primitave earth and therefore produce a life form even similar to us l think is impossible given that even the slightest variable would throw evolution way of track.

[Starcrazzy]

Yes for sure..But i think you are missing the point..Its not a matter of the other lifeforms resembling us or acting like us(heaven forbid) its weather or not they exist...In my humble oppinion we would be arrogant and immature as a species to even contemplate the possability that we are alone...As if the entire univers(whateva that may be) is here for us and us alone....Is too much to digest..

[mick pinner]

there really is no specific point, what we think is only important to our own egos, in the end we don't know, all the assumptions in the world won't change that.

[Starcrazzy]

Well...why would mankind bother to learn or study or explore anything..if what we think is only important to our ego's??There is a point, and it is are we alone in the universe...Its probably one of the biggest questions that face us as a species at present..It has connetations that spread far beyond just the realms of science but goes to try and answer the biggest question of all....Why??why are we here...how did we get here??...A point i would say...and not just important to our ego's but important to all of humanity....Thats the point...

[jjjnettie]

We will find life on other planets, and in our own solar system.
As Bert said, there is life on the bottom of our oceans. Living under tremendous pressure, and surviving due to volcanic vents.
Why can't there be lifeforms living in similar conditions on our more geologically lively planets/moons.
Intelligent lifeforms might be pretty rare though. I only hope that when we finally get to meet them, that we don't shoot first ask questions later.

[cometcatcher]

Or eat it / get eaten by it!

Was having this discussion on another forum, and it was suggested what if we find life on another planet and it was delicious?

Or what if life on another planet finds us and we taste like chicken? :eyepop:

Maybe we should not find other life after all. :(

[Starkler]

Yes they might have a highly intelligent and technically advanced race of cephalopod :scared:

(you had to see the program;) )

[GrampianStars]

"there's life Jim but not as we know it" :P
thank $%$@ there's no Yanks :thumbsup:

[Muddy Diver]

Just to add my rather less intellectual pennies worth. Three movies spring to mind here which started my own thoughts reeling when I first saw them. The first, "Hitchhikers Guide to the Galaxy" had a piece which stated that one planet attacked another by sending its largest fleet ever assembled to take over the victim planet. This whole fleet was swallowed by a dog! Lesson Scale! So how do we know that some airborne viruses are not from outer space??????? They appear from nowhere don't they Bird Flu for example.

The second is similar to the first. The end of Men in Black where we are life on earth rotating about a star in our galaxy along with countless others within our universe which is suspended in the marble of some interstellar beast. This could go on...and on.. and on etc etc This kind of marries with my own thought process.

The third, "Matrix", where the human race is described as a virus consuming every raw resource on our planet. This kind of marries with Mick Pinners opinions and although I'm not an environmentalist, I really dont think that we appreciate what we have in Earth!

Sorry to sound like a movie buff. I'm not, I just remember a few salient bits. Is there life elsewhere? You bet! Intelligent? You bet! The most intelligent life forms though have probably learned to live within the scale of available or renewable resources which their environments can produce and have stopped fighting each other over small pieces of land which jut out from oceans or differing religeous beliefs. I also remember a book by Asimov (no not our own Asi) entitled "Was god an astronaut" compelling reading offering some very good explanation for the remarkable pre historic land markings which looked like airports in S. America and many other inexplicable wonders (many of a religeous nature).

I believe that intelligence is relative and that we have a long way to go. FWIW

[vespine]

I have not read that book by Asimov but I've read a bit of work by Erich Von Daniken which sounds along the same lines. Most famous of his works is probably "Chariots of the Gods" where he examines a lot of prehistoric evidence and draws not-so-loose conclusions from them, it's quite compelling, I believe there has been at least one documentary made from his work too, worth hunting down if you are interested in that kind of stuff...

As for the 'is there life' question, I don't believe you can deny it. Even if life is extremely "unlikely" requiring absolutely perfect conditions to 'happen' and exist, to think we are our Earth is the sole winners of some universal life lottery jackpot is crazy considering how many billions of stars we have just within out 'observable' surroundings. Wether we will ever be witness to other life is another question, the distances and times between them may just be insurmountable, but I can not believe that there is NO life anywhere else in the entire universe.

[ving]

copy cat! :P

[mattweather]

There should be another life somewhere, maybe in Alpha stars solar system? They are our closet stars to us and they are twins too. How about barnard's star?

Matt

[slice of heaven]

On the same track is a series of books by Zechariah Sitchin..The Earth Chronicles... I've read condensed versions of the first 5. Interesting read without a doubt, his conclusions...well, their his , but interesting none the less.
I liked the parts on the knowledge of astronomy of the Sumerians and their view of our solar system , some of which current scientists have only confirmed in recent times.

Is their other life out there? Without a doubt...we just have to find it.

[lone77star]

For anyone to claim that there wasn't life beyond Earth, they would be utilizing a logical fallacy (an argument to ignorance). A lack of evidence never disproves anything. It only begs for evidence to prove the existence.

There are plenty of stars in the galaxy and plenty of galaxies in the universe (something like 10-50 billion stars in the average galaxy, and billions of galaxies), but not all stars are alike.

Many stars are far too young. Any planets there would still be suffering from the heavy meteor showers of formation. The system needs to be something like 2-3 billion years old. But also the system needs to be chemically rich. The very oldest systems are only hydrogen and helium with the barest whisper of other elements, possibly picked up from the interstellar medium.

The link below is for a short article on ancient, rich stars, ripe for habitable planets. It includes a list of nearby stars that fit this "garden spot" category.

Ancient Rich Star Systems (http://www.ancientsuns.com/extrasolar-planets/humanity/ancientrich.php)