Other earths?? Astronomy question/article

[wacki]

British researchers are more confident than ever that there are "Earths" out there waiting to be discovered.

The scientists say perhaps a half of all the known planetary systems today could be harbouring habitable worlds.

http://news.bbc.co.uk/2/hi/science/nature/4411865.stm

These two sentences seem to contradict each other. Does this mean that 1/2 of all solar systems could contain, or should contain, a earthlike planet?

The article also talks about supergiant planets. I'm guessing that we would not be able to live on those due to gravity. Correct?

 

[dphantom]

habitable to us or habitable to some form of life? Who knows what "life" there may be on a place like Jupiter or one if its moons. In neither place can we live.

The article seems to say that stars with super giant planets can also harbor rocky planets like Earth so I suppose given enough time, life could arise on 1/2 or more.

It's all pure speculation right now.

 

[Calin]

The Earth orbit is ok to life. However, that orbit can be in some very very tight limits so that the planet is habitable.

 

[Jeff7]

At least 200 billion stars in this galaxy alone, and trillions upon trillions of other galaxies. I'd say it's very unlikely that there wouldn't be other planets quite similar to this one. Granted, there might not be any within 1,000 light years, but as they said in Hitchiker's Guide to the Galaxy - "that's just peanuts to space."

 

[Promethply]

Even if there are habitable planets in other star systems,

we may not be able to get there since they're most likely light years away,

and we don't have the technology to create a space vehicle that can travel at the speed of light.

 

[cquark]

Originally posted by: wacki
British researchers are more confident than ever that there are "Earths" out there waiting to be discovered.

The scientists say perhaps a half of all the known planetary systems today could be harbouring habitable worlds.

http://news.bbc.co.uk/2/hi/science/nature/4411865.stm

These two sentences seem to contradict each other. Does this mean that 1/2 of all solar systems could contain, or should contain, a earthlike planet?

They're talking about planetary systems that we can see today, so that's not all solar systems by any means. We can only see planetary systems around a tiny fraction of solar systems, though we're discovering more all the time.

The article also talks about supergiant planets. I'm guessing that we would not be able to live on those due to gravity. Correct?

Gravity's only one problem among many that would prevent humans from living on giant planets.

 

[cquark]

Note that even if we discover a planet of the correct size in the right orbital zone, there are still a variety of problems to deal with:

1. Does the planet have a habitable atmosphere? If it doesn't, you're in for a centuries long terraforming project before you can live on the planet outside of domed outposts.

If the planet has a habitable atmosphere, it has life--Earth's atmospheric mix is the product of living things. However, that brings up a problem--is the life compatible with Earth life?

1. NO: If it's not, you can't eat anything from the planet, which means you're in for a terraforming project again. It may be easier, as the planet's closer to what you need, but it could be harder, as Earth crops and so forth have to compete against native lifeforms.

2. YES: It is, and now you have to worry about the myriad of microscopic pathogens like bacteria, prokaryotes, and fungi that your immune system doesn't recognize. On the bright side, your genetic material is likely sufficiently different from theirs that you'll be immune to any local viruses.

 

[MrControversial]

There's a lot of fine tuning as far as Earth is concerned, so I doubt that there's another duplicate "accident". If I slip on a bananna peel with a few cans of paint and the paint hits the ceiling looking exactly like the Cistine Chapel's that would be one hell of an accident. But to do it twice is damn near impossible. From a creationist perspective, that's quite possible. From an evolutionary perspective, the chances are close to nil.

There may be organisms alive on other planets, but I seriously doubt that there is another earth.

 

[DrPizza]

Originally posted by: MrControversial
There's a lot of fine tuning as far as Earth is concerned, so I doubt that there's another duplicate "accident". If I slip on a bananna peel with a few cans of paint and the paint hits the ceiling looking exactly like the Cistine Chapel's that would be one hell of an accident. But to do it twice is damn near impossible. From a creationist perspective, that's quite possible. From an evolutionary perspective, the chances are close to nil.

There may be organisms alive on other planets, but I seriously doubt that there is another earth.

In terms of having continents, oceans (of water), etc.; I think it's incredibly likely. If you think by "another earth" they mean another planet with the same size and shape of continents, another Rocky Mountains, etc., then of course not.


Using your paint example, there probably aren't that many combinations of conditions (how solar systems form) that cause solar systems to arise. Thus, imagine you have 20 paint cans and you get to pick 5 of them. Then you slip. Rather than painting that chapel, it's more a matter of getting the right amounts and the right combination on the ceiling... not necessarily creating such an elaborate painting.

 

[unipidity]

Given that the Universe is thought to be infinite in three different ways (well... maybe) there are certainly other Earths out there. Ones in which Anandtech exists even.




Its almost impossible to put numbers on this kind of thing. Models of planetary nebulae/star formation etc etc are not good enough to be able to suggest what constraints are required to produce Earth like planets. Considering the number of possible constraints, id say that the odds of finding a tectonically active rocky plant inside the habitable band with a similar period of rotation with a oxygen and nitrogen atmosphere is... tiny. But then there are lots of stars.

 

[Calin]

Originally posted by: MrControversial
There's a lot of fine tuning as far as Earth is concerned, so I doubt that there's another duplicate "accident". If I slip on a bananna peel with a few cans of paint and the paint hits the ceiling looking exactly like the Cistine Chapel's that would be one hell of an accident. But to do it twice is damn near impossible. From a creationist perspective, that's quite possible. From an evolutionary perspective, the chances are close to nil.

There may be organisms alive on other planets, but I seriously doubt that there is another earth.

It's Sixtine Chapel :|

 

[DrPizza]

Originally posted by: unipidity
Given that the Universe is thought to be infinite in three different ways (well... maybe) there are certainly other Earths out there. Ones in which Anandtech exists even.




Its almost impossible to put numbers on this kind of thing. Models of planetary nebulae/star formation etc etc are not good enough to be able to suggest what constraints are required to produce Earth like planets. Considering the number of possible constraints, id say that the odds of finding a tectonically active rocky plant inside the habitable band with a similar period of rotation with a oxygen and nitrogen atmosphere is... tiny. But then there are lots of stars.

Except for the period of rotation, why tiny? Fusion reactions in stars, and supernovas don't produce an even distribution of elements... some are favored more than others. Since the elements composing the earth other than hydrogen have all come from the remnants of some long ago exploded star (or some other later generation cosmological happening (what?)), I'd think that many nebulae have/had similar compositions to our own.

 

[imported_Mitchell]

Statistically the odds are in favor of life existing in the universe in multiple locations.

Does that mean we will ever meet them, see them, find them? No. The universe is so vaste it's hard to comprehend it even if you try, because you will always picture it as a bubble, and for all we know the universe never ends.

 

[networkman]

If we're speaking of "life" in terms of all living organisms including bacteria, viruses and other single/multi-celled organisms, then I believe that such "life" already does exist in locations outside our Earth.

We need only look to the bizarre environments here on Earth that sport such life - bizarre to us - such as geo-thermal vents in the ocean, fishes and other creatures found at the bottom of the Mariannes Trench(some 7 miles down(with extreme pressures and no sunlight), as well as other places such as the Gobi desert(dry) and even the arctic(cold) for examples of what might exist on planets that are not within the current thinking of what constitutes a "habitable zone." Such zones are usually reserved for mammals and the like. There's speculation that perhaps under the miles of ice on Europa(moon of Jupiter), there may be liquid water.. combine that with volcanic activity and there may well be some critters swimming around.

Of course, the odds of having meaningful radio conversations with such things is probably pretty remote.

 

[DrPizza]

Originally posted by: networkman
If we're speaking of "life" in terms of all living organisms including bacteria, viruses and other single/multi-celled organisms, then I believe that such "life" already does exist in locations outside our Earth.

We need only look to the bizarre environments here on Earth that sport such life - bizarre to us - such as geo-thermal vents in the ocean, fishes and other creatures found at the bottom of the Mariannes Trench(some 7 miles down(with extreme pressures and no sunlight), as well as other places such as the Gobi desert(dry) and even the arctic(cold) for examples of what might exist on planets that are not within the current thinking of what constitutes a "habitable zone." Such zones are usually reserved for mammals and the like. There's speculation that perhaps under the miles of ice on Europa(moon of Jupiter), there may be liquid water.. combine that with volcanic activity and there may well be some critters swimming around.

Of course, the odds of having meaningful radio conversations with such things is probably pretty remote.

One of my biggest hopes for science for my lifetime is that they'll manage to send a probe to Europa and actually send back video of strange life-forms around thermal vents.

 

[Jeff7]

Originally posted by: MrControversial
There's a lot of fine tuning as far as Earth is concerned, so I doubt that there's another duplicate "accident". If I slip on a bananna peel with a few cans of paint and the paint hits the ceiling looking exactly like the Cistine Chapel's that would be one hell of an accident. But to do it twice is damn near impossible. From a creationist perspective, that's quite possible. From an evolutionary perspective, the chances are close to nil.

There may be organisms alive on other planets, but I seriously doubt that there is another earth.

Universe is damn big though. The odds of it happening somewhere, at some time are good. The chance that the occurrances will be close enough, both in terms of time and space, for one person to be there to observe it - THAT is not probable.

Are there other life forms out there? Very likely. Are they near us? Not as likely.

 

[silverpig]

The truth is no one can say statistically what the chances of life forming on another planet are. We have no idea how likely it is to create life so no one can say anything about it other than there are a LOT of other stars out there, and a lot of them so far seem to have planets around them, hence, there are a LOT of planets out there. Anything beyond that is really an educated guess at best. It seems like most stars have planets around them, and it seems reasonable to say that most do, but because we only know of a few (~100 now I think?) planets around a few stars, we can't really project that with much certainty. It starts to get on shaky ground when you say how many earth-like planets there are, and then it all goes to hell in a handbasket when you start talking about life.

What you can say though is that because of the sheer size of the universe, and the number of stars in it, that in order for life to not exist anywhere else, the chances of it occuring around any single star would have to be EXTREMELY small in order for this universe to not be extremely improbable itself.

 

[unipidity]

Whats the name of the theory that postulates the existence of no technologically advanced lifeforms in the galaxy? The one that says that there is a good chance of other life being curious, and a good chance of them making self replicating exploring vehicles, that there is no evidence of them, and the chances of us being the first is remote. Its quite rubbish.

Anyway; id say the chances are 'tiny' (>0.1%?) because of the numbers of degrees of freedom of the inputs. Since models of PPN etc are fairly medicore (and I dont know them), a random distribution...

 

[jagec]

Originally posted by: cquark
1. Does the planet have a habitable atmosphere? If it doesn't, you're in for a centuries long terraforming project before you can live on the planet outside of domed outposts.

"We call it a 'Shake and bake' colony"

 

[L00PY]

Originally posted by: unipidity
Whats the name of the theory that postulates the existence of no technologically advanced lifeforms in the galaxy?

You're probably thinking of the Fermi Paradox in response to the the Drake Equation.