A habitable Planet...

[Aigbusted]

What do you think the odds are of a Planet being habitable, and how did you reach that conclusion?

[ydoaPs]

Habitable for what?

[frost]

I think he wants to say habitable for us humans. I would really like to know it too.

[insane_alien]

odds of a planet out there being habitable to us, extremely high.

odds of a planet out there being habitable to us AND being close enough to reach with current and near-future tech, extremely low.

[Science]

Extremely high too.

 

Think about this..

 

Most astronomers think the majority of stars have planets. so let's make a modest assumption.

 

Say a quarter of all the stars in our galaxy had just ONE planet. That's 100 billion planets. Times 300 billion galaxies.

 

That's how many planets probably exist. The odds are unbelievably high that life exists on many of them. Even a fraction of a fraction of that number is still incredibly high.

[CPL.Luke]

actually the number of galxies and stars is most likely infinite (the universe is flat) its just that we can only see the 300 billion galaxies in the hubble volume, if the universe is flat the entire way through then there is an earth out there orbiting a sun which is in every way identical to ours, and more so there will be the same stars in the sky and people on that planet doing the same exact things you are.

 

however without faster than light travel and a few billion years travel time you will never see one of these. (faster than light travel would be a must as this earth s receding away from us at a speed several thousand times that of light (statistically)

[Sisyphus]

The probability of being inhabited by life is as of yet completely unknowable, since we don't know all the ways in which life might exist. Can there be "life" inside superhot gas giants? Comets? We don't know. As for planets that WE could live on, they're probably EXTREMELY rare and unlikely to be found by us, but in the whole universe, nonetheless EXTREMELY numerous. However, when you expand that to planets that could be made habitable, that number rises enormously. Most of the objects in our own solar system could potentially be lived on with the right equipment, and Mars, at least, could potentially be terraformed to be quite Earthlike, indeed.

 

actually the number of galxies and stars is most likely infinite (the universe is flat) its just that we can only see the 300 billion galaxies in the hubble volume, if the universe is flat the entire way through then there is an earth out there orbiting a sun which is in every way identical to ours, and more so there will be the same stars in the sky and people on that planet doing the same exact things you are.

 

I'm not actually convinced that that follows. Not saying it's wrong, just that there are a number of assumptions underlying that conclusion, such as there being a finite amount of variation that can exist, which is not necessarily the case. There are an unlimited amount of integers, for example, but there is only one five.

 

Also, considering that our planet is not isolated, but is affected in some way by the entire hubble volume, the number of possible variations for a volume that size, even if it is finite, would be so ridiculously huge that even with faster-than-light and billions of years you could not possibly encounter one.

[Science]

actually the number of galxies and stars is most likely infinite (the universe is flat) its just that we can only see the 300 billion galaxies in the hubble volume, if the universe is flat the entire way through then there is an earth out there orbiting a sun which is in every way identical to ours, and more so there will be the same stars in the sky and people on that planet doing the same exact things you are.

 

however without faster than light travel and a few billion years travel time you will never see one of these. (faster than light travel would be a must as this earth s receding away from us at a speed several thousand times that of light (statistically)

 

 

I'm about 50/50 with this theory. I do agree we are quite limited with the view hubble gave us. The photo with every small smudge of light is a galaxy truely says words about how big the universe is. But that is indeed how far we are limited to seeing (any telescope). So if we looked beyond that we would of course see many more galaxies.

 

I believe there are possible parallel universes in which there are truely an infinite amount. But I don't necessarily believe in our universe there are exact copies of our planet and us humans as how we are today. I believe there could very well be exact copies of us and slight to major variations in parallel universes.

[padren]

What do you think the odds are of a Planet being habitable, and how did you reach that conclusion?

 

I think the idea that it is more than likely numerous habitable planets are out there in the universe is generally accepted based on the number of stars.

 

 

A more difficult question: will we ever look at enough planets - regardless of whether we'll ever be able to get to them - to find one that is habitable?

[swansont]

I'm about 50/50 with this theory. I do agree we are quite limited with the view hubble gave us. The photo with every small smudge of light is a galaxy truely says words about how big the universe is. But that is indeed how far we are limited to seeing (any telescope). So if we looked beyond that we would of course see many more galaxies.

 

 

I think CPL Luke was referring to the Hubble sphere, which basically translates as the currently observable universe, rather than photos from the satellite telescope.

[Science]

I think CPL Luke was referring to the Hubble sphere, which basically translates as the currently observable universe, rather than photos from the satellite telescope.

 

that's it

[SkepticLance]

We only know of one planet habitable by humans - Earth. And that was not habitable when it all began. It has taken literally billions of years by the right kind of organisms to re-form our planet into one that we can live on. Even after the first photosynthetic bacteria evolved, it took over 1000,000,000 years before there was enough oxygen in the air to support humans.

 

So when you ask about a habitable planet, you are asking about a planet on which life appeared, which evolved into the right kind of life, including oxygen emitting life, with a long enough time period for the proper atmosphere to form.

 

Odds against it for any specific planet. Astronomical!

[mooeypoo]

Extremely high too.

 

Think about this..

 

Most astronomers think the majority of stars have planets. so let's make a modest assumption.

 

Say a quarter of all the stars in our galaxy had just ONE planet. That's 100 billion planets. Times 300 billion galaxies.

 

That's how many planets probably exist. The odds are unbelievably high that life exists on many of them. Even a fraction of a fraction of that number is still incredibly high.

 

Wasn't this done before by the Drake equation?

 

The problem with calculations like these is that every step is dependent on a hypothesis... too many, and your margin of error is huge.

 

~moo

[Science]

Wasn't this done before by the Drake equation?

 

The problem with calculations like these is that every step is dependent on a hypothesis... too many, and your margin of error is huge.

 

~moo

 

I have no idea. Simply put the odds are more in favor of many planets with life than just one (ours).

[foodchain]

I have no idea. Simply put the odds are more in favor of many planets with life than just one (ours).

 

I have to guess that without knowing the limits on what physically constitutes life truly that making such an estimate takes on even more estimates. If quantum computing is made standard I would think for the whole of understanding and technology to change, this can means a variety of things more so in the context of looking at the impacts say the electron microscope has had for instance.

 

There will be just that much more and faster processing power for any application that can come to use it, this would mean modeling things like metabolic pathways. Taking into account the environment variable in biology such as adaptation synthetic biology all on its own stands to benefit greatly, I would say nanotechnolgy also. I mean if you could come to have real time image a living cell over its life cycle from a QM perspective should reveal so much it will probably be blinding really. The fun some people get to have in life...

 

On the other hand again not knowing the physical forms life can obtain, or only currently having the evolution of such on earth to follow from in terms of a guideline I think such estimates cant really be taken past being just estimates. I mean on some planet life could exist technically but only by pure extension of what life is, the thing might not even have cells, or dna or even be mostly organic. I think in reality to say otherwise can only be based on the limits of what we know, and nothing more.

 

I would also big to think that humans could also come to a point in understanding in which environments of various scale could simply be engineered and or constructed. That might be thinking big but I don’t see it as something impossible for all time.

[Obba]

More remote than you think.

Consider the sun 'G' type. Consider if the earth temp was + or - 5°C life (human) would not exist.

You need water and the ranges of temperatures for weather.

 

Stable land mass - no other large bodies causing gravitional upheavels etc (note most planets discovered for now are the giant gas type FAR FAR bigger than Jupiter).

 

Granted the odds with the size of the universe it has to be possible - but massive massive odds.

 

Yes we will be able teraform in the future - Mars is the first i guess.

 

So yes, as to the OP there will be other 'earth like' planets out there. But when we find it... Don't hold your breath.

[insane_alien]

Stable land mass - no other large bodies causing gravitional upheavels etc (note most planets discovered for now are the giant gas type FAR FAR bigger than Jupiter).

 

only because we do not have sufficiently powerful detection techniques to easily find the little ones. give it a few years.

 

Granted the odds with the size of the universe it has to be possible - but massive massive odds.

 

there are a lot of stars. a lot more star have planets than we thought.chances are extremely high that there are a few earthlike(though not necessarily life harbouring) planets in this galaxy alone. there are billionsmore galaxies.

[mooeypoo]

I have no idea. Simply put the odds are more in favor of many planets with life than just one (ours).

 

I believe that too, but my point was that I am not too sure how much we can actually prove those 'odds'.. if our way of calculating odds are built on assumptions that are uncertain (most of the assumptions in the Drake equation are educated guesses), then it creates a large margin of error, and that isn't very convincing.

 

Regardless, I also believe that our planet isn't the only one, but again - proving it? egh.. not sure if our *current* science is able to.

[Science]

I believe that too, but my point was that I am not too sure how much we can actually prove those 'odds'.. if our way of calculating odds are built on assumptions that are uncertain (most of the assumptions in the Drake equation are educated guesses), then it creates a large margin of error, and that isn't very convincing.

 

Regardless, I also believe that our planet isn't the only one, but again - proving it? egh.. not sure if our *current* science is able to.

 

I agree, at the moment we have no way to prove these odds. Our technology isn't up to par yet. This is all about assumptions and educated guesses.

 

I'm excited to see the 30 meter telescope, giant magellan telescope, and the european extremely large telescope go up. I do believe with these new tools we will be able to see more through the window into space.

 

Hopefully these tools should help us rely less on our assumptions and give us more facts.

[SkepticLance]

Planets around other stars that have so far been discovered, are overwhelmingly different to our solar system. Giant planets close to the star. Strongly elliptical orbits. Few large planets out towards Jupiter orbit.

 

These things mean there is a real possibility that our solar system represents a rare type. We need a Jupiter in its current orbit to sweep up asteroidal detritus and stop it reaching the Earth. We need circular orbits to prevent extremes in local temperature that would prevent life developing. Solar systems with a difference may never have a chance to develop life.

 

Another point. We often talk about conditions for life. Few people talk about conditions for the genesis of life. They are quite different. Life on Earth came into being at a time when there was no oxygen in the atmosphere,and both physical and chemical conditions were very different to that we now see. It may even be that the conditions needed for first genesis of life may only have existed in a very small place (like a puddle of very hot water) for a very short time on Earth.

 

For a planet to have life, it must not only have conditions for supporting life (like liquid water) but must also, at some stage, have had the right conditions for life to have come into being. We do not know what those conditions are, but it is very possible, they were very special, and rare conditions. Whatever they may be, the probability of having both the conditions for life to survive, and the conditions for life to come into being, is a lot less.

 

I predict that we will find life on Mars, even if it is only a tiny amount of bacteria. However, I predict that when we study the genomes of such bacteria, we will find they are of Earth origin. Life can exist on Mars, but is unlikely to have originated there. I say this because of the life we have found in ultra cold conditions in Antarctica. Bacteria can survive, and even reproduce, in the microscopically thin film of liquid water surrounding dark specks of dust. Bacterial spores have also been exposed to the vacuum of space in vertain experiments. Most can survive for long periods. Meteors from Mars have been found on Earth, after asteroidal collisions hitting Mars have flicked debris into space. It is seriously probable that debris from Earth has made it to Mars also. If so, that debris will have carried bacterial spores.

 

Carl Sagan and Dr. Drake used the Drake Equation to calculate the number of civilisations in the Milky Way Galaxy. Their estimate was one million. The SETI project has turned that estimate into a lie. Whatever the shortcomings of SETI, it is beyond the realms of credibility that there could be one million civilisations, and not one give out a radio signal SETI can detect.

[Michael_H]

I think the chances are extremely small because of the way in which our planet developed into a habitable planet.

First off you'd all the things discussed already. Such as liquid water, the right distance from the star, etc.

After all that you also have the probability of microscopic life developing and evolving to a point where all the life combined can change the conditions of the planet to be more friendly to higher forms of life. While at the same time avoiding catastrophic events that would bring the developmental level of lifeforms back down to the microscopic form.

 

So in order for a planet to be habitable for life (beyond the microscopic) it would need a significant amount of time to evolve to a level where it can transform the planet into a self adjusting biosphere that is required for advanced forms of life to be around.

 

The chances of there being a planet with the right conditions for microscopic life, then also the chances that that life can evolve with out being blown up back to the basic level... is extremely small

maybe even one per galaxy?

 

Then there is the matter of time. The chance of life existing at the same time that we are alive as a species is even smaller. There could be other planets developing life in our galaxy but the odds are that those planets have already developed the life and then died off, or have yet to develop.

[Psyber]

For a sense of proportion, and a basis for starting figures.

 

http://www.atlasoftheuniverse.com/

 

And for located planets.

 

http://www.extrasolar.net/

[Realitycheck]

I am not very confident in our planet-finding abilities based on stars' "wiggles". I mean, it might be easy enough to detect gas giants that are 5 Jupiter masses, but earth-sized planets are inevitably much harder to detect and surely easily hidden by these neighboring giants. Shouldn't every solar system have a reasonable amount of metals orbiting its birth to create terrestrial planets? I guess it's also reasonable for these metals to get thrown into the gas giant planets.

 

As far as life is concerned, all terrestrial planets should get a reasonably similar mix of elements to work with, enabling the Miller experiment to occur just about anywhere. Nucleic acids, proteins, lipids, saccharides - these are all made from the same small collection of elements that are bound to be found on any terrestrial planets.

 

Seeing how plants function so differently than animals and flourish alongside them, is it that far out to envision other life forms evolving that breathe nitrogen or helium? If we use the same evolution of biochemical precursors to life like in the Miller experiment, then maybe we end up with the same limitations everywhere, the same kingdoms of plantae and animalia on any and every planet where life evolves.

 

Of course, when it comes to Radio waves, that could be an area where we are very fortunate. Think of how many animals there are on this planet that simply have not developed Radio towers yet. Will the chimpanzees ever reach that stage? Would they ever have without our help? Are chimpanzees any different than us 100,000 years ago?

[Obba]

Humm,,

This thread should be changed to 'Habitable planets to what we humans can walk and breath on, as of now'.

I would think this would apply to the Earth for the last 500 million years.

So, as i said. The odds say yes! But i think they are less than we understand.

 

If you asked me if there is any other form of 'electotransmission' - communication form of life, then i would say there must be hundreds of thousands....

 

But "Not as we know it Jim..."

[spikerz66]

Logically, with the amount of galaxies that there are, and the vast number of stars in each galaxy, and the seemingly unmeasurable amount of planets surrounding these stars, it seems very likely that there are many a world that is habitable.

 

Now, I believe the more important question here is habitable for what?

 

Humans?

 

Intelligent life?

 

Microbial life?

 

I can almost hear Carl Sagan explaining the Drake equation to me as I write this.