Aliens?!

[Gino Arcari]

What is everyone's opinion on extra-terrestrial life? Do you believe we are alone in the universe and are unique or do you think the probability of life in other solar systems is almost 100%?

I personally believe that most solar systems with "habitable" planets contain life and we are by no means alone. For me, the fact that there could be other other life out there fuels my passion for this hobby even more...when I look through my scope, it's cool to think that the star I'm looking at could be the "sun" for another earthly planet.

[xtreemchaos]

by the odds theres got to be life out there, weather its managed to become intelligent, well we havnt managed it here yet. do thay visit? I dout it, if thay where advanced enough to travel 1000s of ly thay would have the brains to keep away from us where far too dangeros.  charl.

[Pig]

I have no doubts there is intelligent life beyond planet earth.... lets face it we somehow managed it  I hope we get some scientific evidence in my lifetime or even contact.

[ronin]

As asked elsewhere define "life". Simple celled slime or another bunch of nutters wondering if there is life out there when looking through a scope.

Few years back I was at a presentation about a "Second Earth". The presenter listed a few of the standard items for life, then broke those down into more detail. It ended up with about 20 or more seperate conditions that were "easily" identified. If you take a simple idea of a 1 in 10 chance of each them then that would be way over the number of stars in the Milky Way.

I suppose a big one is "The Moon", That is very likely to be a huge rarity owing to it's size compared to our size. There is a lot of thought that a "moon" like that could be key. A numerical count is probably too simple.

Will say that the reports of a "Second Earth" are a bit over done, one find described as a second earth was 2.5 times our mass and had a surface temperature of about 1000 degreees centigrade. Hardly "earth".

[popeye85]

In the SAN magazine a few months ago ( might have been Astronomy now come to think of it) they where talking about the drake equation and they came up with the possible figure could be as high as 75million planets with 'life with the intelligence and capabilities to contact earth' in the milky way alone!!

I tad optimists I think but even if the true figure is only 0.00001% of that then it is still a startling figure if you multiply it by the number of galaxy's in the universe

[Ben the Ignorant]

The Drake equation doesn't take extra-dimensional beings into account. I wish someone could attempt that.

[Alien 13]

Simple life could exist in six or seven places within our own Solar system and we know basic intelligence has evolved in quite a few different animal groups on Earth so I cant imagine that we are the only ones.

The real issue is what is it that starts the evolutionary race for more intelligence certainly a steady state "nice " environment wont do it, mass extinctions, ice ages, predators and Lunar tides seemed to have helped here on Earth.

The other possibility is life we cant identify, I might seem a bit odd but believe that some plants communicate with each other but on a much slower time frame intelligence is not a measure of how fast neurons connect. The last possibility is AI, we are getting close to being able to create basic intelligence using machines based on semiconductor technology the next step is autonomous reproduction via factories that we build that will allow a sudden advancement due to the short timescale between generations.

Alan

P.S. It might be inevitable that Carbon based life creates a new life form that couldn't exist without its intervention, keep a lookout for microscopic spaceships 

[cloudsweeper]

There are billions of planets out there.  I was looking at 16 Cyg B just a few days ago, and it has an exoplanet - did the light I intercepted contain traces of intelligent life??

There's got to be advanced life out there, but there is another consideration.  In terms of the age of the Universe, advanced life could have been and gone already in so many places. 

And - according to Relativity - "now" is not an absolute concept.

Doug.

 

[Ouroboros]

I sometimes think we humans are reluctant to say we don't know something. That's not a reason not to carry on speculating and looking of course.  

[popeye85]

Not just if but what would be the repercussions of finding life elsewhere ( remembering to be very careful not to start discussing the 'r' word of course!!)

[Ben the Ignorant]

1 hour ago, Ouroboros said:

I sometimes think we humans are reluctant to say we don't know something.

Not me.

[cloudsweeper]

Modesty is a good thing!

Doug.

[Pete Presland]

I would be amazed if there isn't some sort of life elsewhere, the law of averages must mean its likely. What form this life maybe who knows, but life exists here on Earth in the most inhospitable places.

[michaelmorris]

If you look at the Drake equation, our understanding of the number of stars that form planets is getting better as are our estimates about the number of planets per star. Both seem to be much higher than was once thought.  The fraction of those planets that end up forming life is still totally unknown, but my gut feeling is it will be significantly less than 10%, most probably significantly less than 1%.  That still leaves an awful lot of planets harbouring life at some point in their existence.

However, the development of intelligent life (as we currently understand this somewhat poorly-defined term) is a result of evolutionary pressures, time and chance.  The development of intelligence will almost certainly require the development of highly complex multicellular organisms. This requires time - an awfully long  time.   The Earth is a very 'lucky planet' in that we have a stable orbit around a stable star, in a quiet part of the galaxy, with a large satellite to stabilise our rotation and we appear to have (just) escaped at least five cataclysmic events that could have wiped out all life on Earth. http://www.bbc.co.uk/nature/extinction_events. I suspect that most planets capable of supporting life are not so lucky.

So, I suspect intelligent life in our universe is a very rare event.  We may conceivably be the only planet to have evolved life that ponders it's own existence and has made some serious headway in understanding the fundamental forces that define the universe.

 

 

[Pete Presland]

2 minutes ago, michaelmorris said:

So, I suspect intelligent life in our universe is a very rare event.  We may conceivably be the only planet to have evolved life that ponders it's own existence and has made some serious headway in understanding the fundamental forces that define the universe.

 

 

Absolutely Micheal, I think we might maybe in the future find life or evidence of past life somewhere. Not sure we will ever find intelligent though.

[michaelmorris]

15 minutes ago, bunnygod1 said:

I would be amazed if there isn't some sort of life elsewhere, the law of averages must mean its likely. What form this life maybe who knows, but life exists here on Earth in the most inhospitable places.

Most (but not all) of these 'extremophile' organisms are in fact organisms that originally developed in relatively benign environments and who later evolved often complex defence mechanisms to exploit more inhospitable environments.  For example, most proteins are unstable at high temperatures and extremes of pH., Yet some bacteria and cyanobacter have evolved to cope with such conditions.

Thus the concept that life can start off in many of these extreme environments because life exists there now is not necessarily a safe argument. 

[Pete Presland]

1 minute ago, michaelmorris said:

Most (but not all) of these 'extremophile' organisms are in fact organisms that originally developed in relatively benign environments and who later evolved often complex defence mechanisms to exploit more inhospitable environments.  Thus the concept that life can start off in many of these extreme environments because life exists there now is not necessarily a safe argument.

A very good point Michael, I guess survival is completely different from life beginning.

[michaelmorris]

1 minute ago, bunnygod1 said:

 I guess survival is completely different from life beginning.

A much more succinct précis of my argument!

[bejay1957]

'Intelligent life' is always a complex question/issue, when most of the term time 'developed life' would be closer to the question - intelligence and development/technology may not be inclusive?

In many ways current humankind has done well to avoid an extinction level event originating from space (natural cosmic forces, not alien invasion!)  As we come to understand exo star systems in more detail, I think a key factor will be the presence of a giant planet offering a gravity well to smaller habitable planets - as we have with Jupiter.

[Dave In Vermont]

6 hours ago, bejay1957 said:

'Intelligent life' is always a complex question/issue, when most of the term time 'developed life' would be closer to the question - intelligence and development/technology may not be inclusive?

......

If we can find 'intelligent' life, I'd dismiss it as being such. Any self-respecting intelligent-being would avoid human's like the pneumonic-plague!

Is there "life?" To write this off is the epitome of imperialism. Of course there is. Study up on the meaning of 'collective-unconscious.' Limitless within the constraints our minds impose upon us for survival.

(...waiting on parts from 'Honest Uncle Breezlzozp and The House O' Used Saucers'..... )

evaD

[Macavity]

I think it was probably a Brian Cox "Life" program that raised the
interesting observation that intelligent life on Earth is Eukayotic:

https://en.wikipedia.org/wiki/Eukaryote

Whereas basic "life" (Bacteria etc.) has been around for much of
Earth's history, the latter (our kindred) only HALF this time. Who
knows? But it seems to be an additional "Fly in the Ointment", if
a prerequisite for intelligence is fusion of more primitive forms?   

On the other hand, from a human-centric perspective, I find it 
hard to envisage vast swathes of planetary real estate DEVOID
of any life? <Contemplating patch of Black Mold  in freezer...>

[kilix]

I find the thought of us being the only intelligent being in the Universe as ignorant and archaic as the thought of the Earth being in the center of the Solar system.

We are nothing special. We live on an average rocky planet near an average star, in an average galaxy. One grain of sand on Earth is more significant (relative to the Earth) than we - humans - are relative to the Universe.
The thought, that we are the only intelligent lifeform seems ridiculous to me, when in the Universe every physically possible thing exists in billions or trillions of instances. It does not make any sense to me. We are nothing special, it's our human egocentric nature to think we are, but the truth is the opposite.

[billyharris72]

I'd be very surprised if there was no other life out there (it's quite possible there is life elsewhere in our solar system and we may have detected it on Mars back in the Viking days). Scientific consensus is definitely moving the direction of life being common, maybe even inevitable. But until we get really robust evidence the truth is we don't know. It's possible that we are a one off, just counterintuitive - but intuition counts for almost nothing.

Next question would be complex life. Current opinion, while accepting that life may be common, suggests the step from prokaryotic to eukaryotic life (development of mitochondria through ingestion followed by a symbiotic relationship in which two organisms actually merge through evolution) is spectacularly unlikely. But there are many worlds and there may be more than one way to achieve complexity.

I think if we get past that hurdle the next step (development of increasingly complex life giving rise to intelligent behaviour) may actually be the easy part. All the pieces are in place.

Billy.

[Paul M]

Life elsewhere?

Perhaps there once was. Perhaps there is yet to be. The big question is whether it exists at the same time as us, is capable of communication and is within practical communication distance. The odds of us ever crossing paths with a sentient alien species are much, much lower than the odds of there having ever, or there ever being intelligent alien life somewhere in the Universe.

Perhaps our nearest neighbours "yet to be" will be made, in part, from the heavy elements created in the supernova explosion of Betelgeuse!

I think space and time will always keep us apart from our neighbours. Having said that I have for a long time held a beautiful image in my mind of graceful dolphinesque creatures inhabiting the subsurface oceans of Ganymede 

If they do exist I hope they are left in peace. We've still got some of our own world to destroy

[billyharris72]

Don't be so pessimistic. Humans are such a creative and inventive species that it's not completely out of the question that we may one day be able to destroy other worlds too.