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Where Would Earth-Like Planets Find Water?

Soulskill posted more than 2 years ago | from the at-the-water-store-duh dept.

Space 168

astroengine writes "The term 'Earth-like worlds' is a vastly overused and hopelessly incorrect term that is popularly bandied about to explain some recent exoplanet discoveries. Although some of the distant small worlds being discovered by the Kepler space telescope may be of Earth-like size, orbiting their sun-like star in Earth-like orbits, calling those worlds 'Earth-like' gives the impression these alien planets are filled with liquid water. It turns out that we have only a vague idea as to where Earth got its water, and it will take a long time until we have any hint of this life-giving resource on worlds orbiting stars thousands of light-years away."

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Wish they would just knock it off with "earth-like (5, Informative)

elrous0 (869638) | more than 2 years ago | (#38541404)

The whole nonsense of even using the term "earth-like" is a joke, born of the press and PR-minded astronomers. Calling a planet "earth-like" implies way more than correlation with earth's size and it's orbit around the sun. There are so many characteristics which may well make the earth a very unique planet. It's not just the presence of water, either--it's also our magnetic field, the presence and effects of our moon, the nature of our core, etc. It could very well be that true earth-like planets are VERY rare in the universe. Though the shear size of the universe suggests it's likely there are other planets out there like ours and other life out there, it's probably a LONG way to our nearest earth-like neighbor--and likely a much longer way than even that to the nearest planet with similar intelligent life living coincidental with us.

Much as I hate to say it, having grown up on space dreams and science fiction, the more I learn about space the more I've become convinced that, for all intents and purposes, we're basically alone on this little blue ball. When I used to dream otherwise, I really had no real appreciation of just how vast and empty space really is, for one thing. I think the popular perception is that the next solar system begins close to the edge of our own (I certainly thought so when I was a kid watching sci-fi movies). In reality, every solar system is a tiny isolated island in a giant lonely ocean. A space probe that takes 9 years to go from earth to Pluto would take over 100,000 years to get to even our closest neighbor, a mere 4.2 light years away. And that's in a universe that's 15 *billion* light years across. It's a big place, with an unimaginable number of other planets. But mostly it's just a giant, empty void.

So there are probably indeed other earth-like planets out there. But barring some incredible technological advances (probably thousands of years worth) and a complete overthrow of Einsteinian physics, no human is ever going to see them or even be able to communicate with them.

This is usually the part where I make a joke, but somehow I just feel lonely and sad now.

Re:Wish they would just knock it off with "earth-l (4, Funny)

garyebickford (222422) | more than 2 years ago | (#38541462)

This is usually the part where I make a joke, but somehow I just feel lonely and sad now.

Maybe this will do - one of my old sigs:
"Space - it's really big. I mean, really, really, really big. Better pack a lunch."

Re:Wish they would just knock it off with "earth-l (2, Funny)

Anonymous Coward | more than 2 years ago | (#38541864)

You'd need to pack a fully self sustainable colony. Lunch would barely get you to orbit.

Re:Wish they would just knock it off with "earth-l (1)

olsmeister (1488789) | more than 2 years ago | (#38541466)

Not to mention, we don't have thousands of years...

Re:Wish they would just knock it off with "earth-l (0)

Anonymous Coward | more than 2 years ago | (#38541480)

You sir, just made me think about things, and now I am lonely.

Re:Wish they would just knock it off with "earth-l (1)

rickb928 (945187) | more than 2 years ago | (#38541962)

Being anonymous will do that also...

Re:Wish they would just knock it off with "earth-l (0)

Anonymous Coward | more than 2 years ago | (#38541490)

And I thought that the stock market this year was depressing enough.

Re:Wish they would just knock it off with "earth-l (2)

elrous0 (869638) | more than 2 years ago | (#38541834)

Christmas and contemplating the scale of the universe always gets me down.

Re:Wish they would just knock it off with "earth-l (4, Funny)

ColdWetDog (752185) | more than 2 years ago | (#38542154)

Christmas and contemplating the scale of the universe always gets me down.

Didn't get that scale model of the Enterprise again?

Maybe next year.

Re:Wish they would just knock it off with "earth-l (-1, Offtopic)

Rolgar (556636) | more than 2 years ago | (#38542086)

You ain't seen nothing yet [minyanville.com] .

I've been tracking what a lot of the writers at Minyanville have to say about various things. Mauldin especially has done very good work on what the debt is going to do to us. Compound the collapse of the Euro due to their situation, and I think we are due for a very big fall.

Some of the other indicators are that if you look at the stock market, it's been very boom and bust since the Depression (not much data from before). It' basically goes in 17 year cycles, (Slow Growth from 1932-1949, accelerating from 1949-1966 (This 34 years was unnatural due to the recovery from the Depression and WWII and the US being the only economy not devastated by the war IMO). Then 1966-1983, flat for 17 years. 1983-2000, the debt boom compounded with the tech bubble, 17 years. Now we are in year 11 since the boom. Any ideas on when we'll be seeing better times? Not for the next 5 year by cyclical estimates. Maybe more if the effects of recent measures extends this (a reverse of the boom after the depression) compounded by the wreckage of the policies of every administration going back to Roosevelt's New Deal and Johnson's Great Society, and every kick the can down the road Congress and administration since.

Re:Wish they would just knock it off with "earth-l (4, Insightful)

drewsup (990717) | more than 2 years ago | (#38541518)

... but somehow I just feel lonely and sad now.

Welcome to /.

Steal from Star Trek. (4, Interesting)

khasim (1285) | more than 2 years ago | (#38541530)

How about a basic classification scheme for planets?
http://en.wikipedia.org/wiki/Class_M_planet [wikipedia.org]
Except do it better. World size, composition, orbit, etc.

Then, instead of reporting about another "Earth-like" planet they could report on a class blah-blah-blah-blah planet that MAY be "Earth-like".

Re:Steal from Star Trek. (0)

Anonymous Coward | more than 2 years ago | (#38541830)

Until we know more about planets (and particularly, about ones that formed under different conditions, and thus necessarily in different solar systems), how do we know what parameters are most important, and what the characteristic ranges are, how big a difference is substantial, etc.?

I think if we formulated a classification scheme now, we'd find in about 30 years we messed it up, and either have to revamp it, or worse be stuck with it, like the mixed (rather than either mass-based or dynamics-based) classification of planets and minor bodies in our own system, like the "wrong" (wrt metal conductors) sign convention for electric current, like all the other inconvenient choices that are more trouble to fix than to live with.

Re:Wish they would just knock it off with "earth-l (1)

Riceballsan (816702) | more than 2 years ago | (#38541566)

Well I don't think it is as much earth is unique, as all planets are unique. Saturn is nothing like mars, which is nothing like neptune. I do also have to point out the quanity of planets we can observe, is pretty darn negligable by comparison to how many we estimate there are. Estimated planets in the milkyway, probably billions, number of galaxies that could also have billions of planets, also billions. Number of planets/dwarf planets close enough that we could possibly land a probe on in our lifetime 9. Number of planets other then earth that we have landed a man on, 0. There could be 50 or less equally common types of planets, of which water holding life supporting are just as common as the other 49 types, and we wouldn't know because we can only really make any significant observations on .00000001% of them.

Re:Wish they would just knock it off with "earth-l (5, Interesting)

Anonymous Coward | more than 2 years ago | (#38541584)

The whole nonsense of even using the term "earth-like" is a joke, born of the press and PR-minded astronomers. Calling a planet "earth-like" implies way more than correlation with earth's size and it's orbit around the sun. There are so many characteristics which may well make the earth a very unique planet. It's not just the presence of water, either--it's also our magnetic field, the presence and effects of our moon, the nature of our core, etc. It could very well be that true earth-like planets are VERY rare in the universe.

Or it could be that we're _not_ so lucky, that these are fairly common, or turn out to be much less essential than we thought. Since we can't measure those remotely (yet), we have no way to stake a solid claim either way.

So what's wrong with "Earth-like" when referring to planets of which every parameter we _can_ remotely measure at present (thus all the ones we _know_ are scarce) match? Only illiterate fools would choose to infer similarities that we couldn't possibly know from that, and frankly they'll misunderstand no matter what terminology you use.

Re:Wish they would just knock it off with "earth-l (0)

lonelytrail (1741524) | more than 2 years ago | (#38541602)

You're right. We should all just give up and kill ourselves now.
Just because some PR guy somewhere used a word in a way that doesn't please you doesn't mean it's all for naught and we should just stop trying.
Kepler is doing great science, extending our knowledge of the universe, and if it's being presented in a way that doesn't please you GO THE FUCK AWAY!

Re:Wish they would just knock it off with "earth-l (1)

gmuslera (3436) | more than 2 years ago | (#38541606)

The sad part is that is not a joke. Is a story we think we are into each time we see at the stars: somewhat, something is out there, very interested in us, and if we advance enough, we could be like them and be interested in someone else that should be within our reach, in our time or not very far enough.

The magnitude of distances, time and cost that even thinking in getting near the closest star outside this solar system implies is simply outside our reach, and will be for long time if ever, unless our current understanding on how the universe work is fundamentally wrong and there are somewhat a shortcut we could take in practice.

But that don't means that we should forget space and try to live exclusively here. Space is there, maybe interstellar space won't have enough resources/energy to worth go into it, but the inner solar system, where you have plenty of energy and resources not so far (mainly asteroids, but also moons and planets) could worth exploring, colonization or at least put around a "Kilroy was here". We won't find in the near term anything as good for us as is Earth, but probably will worth the investment.

Re:Wish they would just knock it off with "earth-l (3, Interesting)

betterunixthanunix (980855) | more than 2 years ago | (#38541708)

Spreading ourselves around the solar system might be a good idea insofar as it will reduce the probability that we kill ourselves. However, the resources that would be required just to set up a permanent colony on the moon are enormous, and there are a lot of other pressing needs competing for those resources. Frankly, I would not be surprised if the manner in which those resources are obtained triggered the sort of species-destroying war that setting up the colony was meant to mitigate.

For the near future, this planet is it, barring substantial improvements in technology. If we need to choose between a billion dollars spent establishing a colony on a celestial body or spent on developing sustaining methods of producing food in impoverished nations, the production of food must take precedence.

Re:Wish they would just knock it off with "earth-l (5, Insightful)

lacaprup (1652025) | more than 2 years ago | (#38541818)

If we need to choose between a billion dollars spent establishing a colony on a celestial body or spent on developing sustaining methods of producing food in impoverished nations, the production of food must take precedence.

I fail to see why the food needs of impoverished nations is more significant an issue for wealthy nations than the establishment of a permanent colony on another celestial body. The long-term viability of our species is far better served by expanding than trying to feed every child in the Sudan.

Re:Wish they would just knock it off with "earth-l (2)

WSOGMM (1460481) | more than 2 years ago | (#38542608)

For the near future, this planet is it, barring substantial improvements in technology. If we need to choose between a billion dollars spent establishing a colony on a celestial body or spent on developing sustaining methods of producing food in impoverished nations, the production of food must take precedence.

The thing is, we don't get to choose between a billion dollars spent here and a billion there. IMHO before we can even argue about where money gets spent, we, as a country (I'm referring to the US, you said dollars :P), need to get our priorities straight. As a country we have access to an absolutely HUGE amount of money; we just need to take it. With the proper government in place, we could advance our quality of life AND our [space] technology without even having to choose one over the other. It would, unfortunately, require a massive cultural change to a more scientific and activism oriented society.

And of course, this is obligatory: http://en.wikipedia.org/wiki/Military_budget_of_the_United_States [wikipedia.org]

But seriously, when are we going to do something about it?

Re:Wish they would just knock it off with "earth-l (3, Funny)

Anonymous Coward | more than 2 years ago | (#38541622)

Let me cheer you up with a quote from the Hitchhikers Guide to the Galaxy...

POPULATION OF UNIVERSE : None.

It is known that there are an infinite number of worlds, simply because there is an infinite amount of space for them to be in it. However, not every one of them is inhabited. Therefore, there must be a finite number of inhabited worlds. Any finite number divided by infinity is as near to nothing as makes no odds, so the average population of all the planets in the Universe can be said to be zero. From this it follows that the population of the whole Universe is also zero, and that any people you may meet from time to time are merely the products of a deranged imagination.

Re:Wish they would just knock it off with "earth-l (1)

elrous0 (869638) | more than 2 years ago | (#38541710)

I remember the old joke about aliens visiting earth, only to send a report back to their home planet that said "No intelligent life found here."

Re:Wish they would just knock it off with "earth-l (1)

Hillgiant (916436) | more than 2 years ago | (#38541812)

They found life, just not the kind they were expecting.... http://www.terrybisson.com/page6/page6.html [terrybisson.com]

Re:Wish they would just knock it off with "earth-l (1)

nedlohs (1335013) | more than 2 years ago | (#38541854)

It is known that there are an infinite number of worlds, simply because there is an infinite amount of space for them to be in it. However, not every one of them is inhabited. Therefore, there must be a finite number of inhabited worlds.

It is known that there are an infinite number of integers, simply because there is no maximum integer. However, not every one if them is even. Therefore, there must be a finite number of even integers.

We hit a major flaw with the logic on the very first inference. Of course comic science fiction isn't supposed to be a math textbook.

Re:Wish they would just knock it off with "earth-l (1)

colinrichardday (768814) | more than 2 years ago | (#38542734)

It is known that there are an infinite number of worlds, simply because there is an infinite amount of space for them to be in it.

Is there an infinite amount of space in our spacetime?

Re:Wish they would just knock it off with "earth-l (1)

ThorGod (456163) | more than 2 years ago | (#38541658)

It could also be that life, as we know it, is not the only way that life can exist. Maybe the factors we find so key (liquid water, planetary e&m field, etc) are more like the specifics of our own existence than the specifics of all existence.

Yes, "earth-like" is a misnomer and short sighted. But, believing we know the true nature of life across the universe is a whole other category of short sighted.

Re:Wish they would just knock it off with "earth-l (4, Insightful)

elrous0 (869638) | more than 2 years ago | (#38541780)

I think the trouble with finding truly alien life wouldn't just be the distances involved, communication, etc. I think it might prove difficult for two radically different alien lifeforms to even PERCEIVE one another. Sort of a "Sir, it turns out that those things we thought were rocks were actually intelligent lifeforms that just move REALLY slow" kind of thing.

the first alien life we find won't be water-based (2)

circletimessquare (444983) | more than 2 years ago | (#38541674)

we'll find it by surprise, in some ferrous sulfate or ammonia based medium, or whatever:

http://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry [wikipedia.org]

in terms of random chance, water is the most accessible medium for complex chemistry, and therefore life to evolve in, by orders of magnitude. however, it's not the only medium that can work, so there's plenty other little nooks and crannies to look into

basically, some chemists and physicists should get together, and say: for pressure X and temperature Y, solvent in which complex chemistry can evolve Z is possible. then look for those places, not just water

Re:Wish they would just knock it off with "earth-l (0)

Anonymous Coward | more than 2 years ago | (#38541680)

So there are probably indeed other earth-like planets out there. But barring some incredible technological advances (probably thousands of years worth) and a complete overthrow of Einsteinian physics, no human is ever going to see them or even be able to communicate with them.

This is usually the part where I make a joke, but somehow I just feel lonely and sad now.

I only see 3 problems with space travel to far stars: 1) fuel, since there's no free propulsion, 2) maintenance of the craft for the duration and 3) keeping the animals inside alive.

It's obvious that it's a one way trip as long as FTL isn't feasible, since once you come back, the world will have changed quite a bit. It's a sacrifice as long as there is no proof that there's anything out there ofcourse. We have 3 billion years to the next major astronomic catastrophe, would you like to be around to watch?http://science.slashdot.org/story/11/12/30/1817234/where-would-earth-like-planets-find-water#

Mars like.. (1)

gl4ss (559668) | more than 2 years ago | (#38541700)

just doesn't sell the papers so well.

Re:Wish they would just knock it off with "earth-l (0)

Anonymous Coward | more than 2 years ago | (#38541778)

Perhaps.

But if you look at a few of our "special" traits, they may not be that special after all.

Our interesting core gives us plate tectonics and a magnetic field. It is made of iron which is likely to be extremely common in most systems for planet building. It's also not the only way of having a tectonically active world, take Io for example. My personal guess is that there may be many different ways of keeping a planets' surface both active and protected. Orbiting around a gas giant being one (absent Jupiters radiation).

Our moon. Maybe instead of having one large moon, its more common to have several smaller moons which provide a more varied and smaller effect but serve the purpose of creating changeable conditions of a daily or weekly basis. There is nothing written that life must have one big moon in order to reach our stage of evolution.

An analogy I imagine when thinking about how lucky or normal earth may be is that of millionaires. For arguments sake we take that having great wealth is a sign of success that few achieve and we see the earth as a millionaire. If you and asked a million millionaires how they came by their riches you would likely get a million different stories. There would be some common themes like inheritance or lottery winnings but you would have many varied stories also, and not one of them would be a consistent method of how make a million bucks. I think that is what we will find, for every life abundant world out there, there will be a different set of events and circumstances that create it. No doubt liquid water will be common, as will changeable but calm conditions, but to think that the circumstances that created our globe must be exactly repeated to have another life ball is myopic.

So cheer up! We don't know enough and finding out is going to be exciting!

Re:Wish they would just knock it off with "earth-l (2)

h5inz (1284916) | more than 2 years ago | (#38541820)

Usage of a term depends on it's definition. So where is it?? In your post or somewhere?

There is such a term like Earth analog which is the synonym for Earth-like planet (I found it in Wikipedia and the first poster should try using it), there are no good specifications inside that specific article, although the round talk under "Attributes and Criteria" is quite similar to the above posters.

http://en.wikipedia.org/wiki/Earth_analog#Surface-water_and_hydrological_cycle [wikipedia.org]
How about somebody define it then?

There is something a little bit more specific in:
http://en.wikipedia.org/wiki/Earth_Similarity_Index [wikipedia.org]
- At least you can say for sure that KOI 736.01 has Earth Similarity Index (ESI) of 0.98 and Standard Primary Habitability (SPH) of 0.63.

Re:Wish they would just knock it off with "earth-l (2)

jollyreaper (513215) | more than 2 years ago | (#38541852)

[quote]And that's in a universe that's 15 *billion* light years across. It's a big place, with an unimaginable number of other planets. But mostly it's just a giant, empty void.[/quote]

Yakko: Everybody lives on a street in a city
Or a village or a town for what it's worth.
And they're all inside a country which is part of a continent
That sits upon a planet known as Earth.
And the Earth is a ball full of oceans and some mountains
Which is out there spinning silently in space.
And living on that Earth are the plants and the animals
And also the entire human race.

It's a great big universe
And we're all really puny
We're just tiny little specks
About the size of Mickey Rooney.
It's big and black and inky
And we are small and dinky
It's a big universe and we're not.

And we're part of a vast interplanetary system
Stretching seven hundred billion miles long.
With nine planets and a sun; we think the Earth's the only one
That has life on it, although we could be wrong.
Across the interstellar voids are a billion asteroids
Including meteors and Halley's Comet too.
And there's over fifty moons floating out there like balloons
In a panoramic trillion-mile view.

And still it's all a speck amid a hundred billion stars
In a galaxy we call the Milky Way.
It's sixty thousand trillion miles from one end to the other
And still that's just a fraction of the way.
'Cause there's a hundred billion galaxies that stretch across the sky
Filled with constellations, planets, moons and stars.
And still the universe extends to a place that never ends
Which is maybe just inside a little jar!

YW+D : It's a great big universe
And we're all really puny
We're just tiny little specks
About the size of Mickey Rooney.
You might think that you're essential
Try inconsequential
It's a small world after all!

Re:Wish they would just knock it off with "earth-l (2)

equex (747231) | more than 2 years ago | (#38541928)

I pretty much have the same story as you. Early believer, but then I came to realize the the dimensions of space and how slow our spacecrafts are. On top of that, it seems unlikely that, due to time dilation, any travel by current and near future physics will be moot. I am saying even if you can travel at 10% light speed or a hundred thousand times that, when you come back, everyone you knew will be dead and your research could be completely worthless. Sad but true.

Pedantry (1)

colinrichardday (768814) | more than 2 years ago | (#38542828)

I am saying even if you can travel at 10% light speed or a hundred thousand times that,

A hunrded thousand times 10% is 10,000. If we could travel 10,000 times the speed of light, we could cross about 4-5% of the galaxy in one year.

Re:Pedantry (1)

colinrichardday (768814) | more than 2 years ago | (#38542878)

Diameter, not radius. The Milky Way has a diameter of 100,000-120,000 light years, so that would be 8-10%.

http://en.wikipedia.org/wiki/Milky_Way [wikipedia.org]

Re:Wish they would just knock it off with "earth-l (-1)

Anonymous Coward | more than 2 years ago | (#38541956)

You're an idiot, please castrate yourself and anyone related to you.

Re:Wish they would just knock it off with "earth-l (2)

elrous0 (869638) | more than 2 years ago | (#38541978)

And a Merry Christmas to you, Mr. Scrooge!

Re:Wish they would just knock it off with "earth-l (0)

Anonymous Coward | more than 2 years ago | (#38541984)

Get Space Engine.

Not only will make you feel the vast emptiness and desolation. It will show it to you, in all its 3D glory. I've talked to other people who also find it "scary".

It's as close to the Infinite Perspective Vortex as we're gonna get.

Re:Wish they would just knock it off with "earth-l (1)

noh8rz2 (2538714) | more than 2 years ago | (#38542166)

I agree, the term is too vague. I prefer the more clearly-defined "class M planet."

At least with neighbours that distant... (1)

Mister Liberty (769145) | more than 2 years ago | (#38542200)

you can turn up the stereo without repercussion.

bjd

Re:Wish they would just knock it off with "earth-l (2)

0xdeadbeef (28836) | more than 2 years ago | (#38542328)

Calling a planet "earth-like" implies way more than correlation with earth's size and it's orbit around the sun.

Actually, no, that's about it. The problem is people are screwing that up.

no human is ever going to see them or even be able to communicate with them

Yeah, wrong [nasa.gov] . And communication is trivial for anything close enough for imaging.

Re:Wish they would just knock it off with "earth-l (1)

elrous0 (869638) | more than 2 years ago | (#38542596)

When I said "see them" I didn't mean through a telescope, I meant "see them in person" as in "go there." Also, if you believe Einstein, and you realize that the nearest planets with coincidental intelligent life using radio waves could be hundreds of thousands of light years away (if not millions), how exactly do you propose communication? About the only message you could send would be "By the time you get this message, our species will probably be long gone."

Re:Wish they would just knock it off with "earth-l (3, Interesting)

Genda (560240) | more than 2 years ago | (#38542472)

Don't feel bad. It just means we're responsible for becoming the extraterrestrials. We need to seed the universe with humanity (and as many other intelligent species as we can can help get liberated from this little mud ball.) There are countless fascinating environments in this solar system alone. Wealth and resources to beggar the imagination. With a commitment to space faring, we could have sustainable habitats all over the solar system in this century.

With the building materials available in the Asteroid Belt, Kuiper Belt and Oort Cloud, we could scatter sentience across the stars. We might master faster than light travel. We might not. We would certainly be able to ensure that whatever cataclysms that befell earth in the near or distant future, sentient life would continue to exist, and the earth's greatest gift to the universe would persist.

Maybe, one day, millions of years from now, when we fill the Orion arm of the Milky Way galaxy, and have found ways to utilize any kind of matter we come across to sustain ourselves, we will bump into another sentient life form. However, there will be no time when we are alone, because we will have each other.

Re:Wish they would just knock it off with "earth-l (0)

Anonymous Coward | more than 2 years ago | (#38542560)

"Much as I hate to say it, having grown up on space dreams and science fiction, the more I learn about space the more I've become convinced that, for all intents and purposes, we're basically alone on this little blue ball."

No, the laws of physics and chemistry should be the same all across the universe. If they aren't, what are we observing? So assuming that this is correct, life is probably everywhere, subject to the same limitiations we have. We can't get there, and they can't get here.

"The whole nonsense of even using the term "earth-like" is a joke, born of the press and PR-minded astronomers"

Drastic over-simplification and glossing over very complex subjects is the central tenet of Space Nuttery.

"When I used to dream otherwise, I really had no real appreciation of just how vast and empty space really is,"

Congratulations, you grew up. Not many Space Nutters do.

"This is usually the part where I make a joke, but somehow I just feel lonely and sad now."

There are 7 billion people here with you. The fact that you think you are lonely just shows that most Space Nutters are either seriously mentally ill, autistic, or both. You won't even live long enough to meet all the people on Earth. How can you be lonely?

Easy (1)

Grindalf (1089511) | more than 2 years ago | (#38541448)

Set fire to hydrogen, the most abundant stellar element! Next!

Re:Easy (3, Informative)

Marxist Hacker 42 (638312) | more than 2 years ago | (#38541484)

That was my response as well. Whereever Oxygen and Hydrogen exist, the problem is NOT creating water. In fact, it's very likely that the largest source of water outside of the Earth in our Solar System is orbiting Saturn.

Re:Easy (4, Interesting)

icebike (68054) | more than 2 years ago | (#38541590)

That was my response as well. Whereever Oxygen and Hydrogen exist, the problem is NOT creating water. In fact, it's very likely that the largest source of water outside of the Earth in our Solar System is orbiting Saturn.

You may be right about the source being other moons. Comets are another potential source, Louis Frank published his theory in The Big Splash [wikipedia.org] , but it never seemed to gain a lot of traction, even though the guys has a lot of credentials. It was generally disregarded, like so many other novel theories.

In the book he postulates that thousands of small fluffy snow-ball comets with no hard central core and which which don't really show up in radar or visually, deposit tons of water on the earth's atmosphere [uiowa.edu] and the moon every year. He even had images in his book about impacts on the moon.

Re:Easy (1)

Marxist Hacker 42 (638312) | more than 2 years ago | (#38542020)

I was thinking more about the rings. More surface area than any moon, even if they are just centimeters thick.

Re:Easy (1)

ThorGod (456163) | more than 2 years ago | (#38541722)

So, the limiting process would be how much oxygen there is out there, how often it co-exists with hydrogen, and how often there's 'a spark'?

Re:Easy (2)

Marxist Hacker 42 (638312) | more than 2 years ago | (#38542040)

Wouldn't even need much of a spark. Water WANTS to be water.

Filled with water, earthlike? (2)

hedwards (940851) | more than 2 years ago | (#38541506)

If it's filled with water, then it's definitely not Earthlike, if the OP is going to be a pedantic killjoy, then at least get the facts right.

Re:Filled with water, earthlike? (0)

Anonymous Coward | more than 2 years ago | (#38541544)

You're right. I prefer cream filling.

Filled with water, like the Moon (1)

hcs_$reboot (1536101) | more than 2 years ago | (#38542130)

Papers like to make us dream about these "earth-like" planet - very distant from us.
Honestly, considering the distance, time to travel, time to communicate and get feedback... Wouldn't it be faster/more feasible/realistic to make our Moon an habitable moon?
I mean, without waiting for 10^x generations of us...

there is science, and there is journalism (1, Interesting)

circletimessquare (444983) | more than 2 years ago | (#38541508)

journalism is intended for easy digestion. criticizing journalism for not getting science accurate is actually a sign you don't understand what the purpose of journalism is

the constant harping on slashdot against journalism for not getting every technical detail accurate and in context is, frankly, stupid. on YOUR part. unless journalism is lying, or saying things completely misleading and way off base, not being entirely accurate is 100% fine. the purpose is COMMUNICATION, not RESEARCH PAPER ACCURACY

look at it this way: how would you describe this issue to a curious seven year old? would the words "earth-like" be acceptable? yes? then this is a completely ridiculous topic, drop it

Re:there is science, and there is journalism (2)

MightyMartian (840721) | more than 2 years ago | (#38541682)

No one expects journalism to give us complete technical breakdowns, but science journalism has a nasty history of not just skimming over important details, but also of out-and-out sensationalism. Take your average report on some hominid fossil discovery, which by the time it gets through the editorial department has a headline "Map Of Human Evolution Redrawn!"

Re:there is science, and there is journalism (2)

circletimessquare (444983) | more than 2 years ago | (#38541790)

right, and that's exciting, and perfect for digestion by those people who will never care or be interested in the accurate details

so there's no harm. people need a gee whiz component. give it to them. science should not be completely inaccessible

because, if we abide by your standards of communication, what is said about science by scientists will be ignored: too dry and boring. and what is said in popular media will be taken over by those with anti-science agendas, and their lies and distortions will be believed. if we abide by your standards of communication

so inaccuracy is acceptable. raise your tolerance level. communicating the excitement is the most important thing

thinking like you is arrogant, and that's what people will understand about science and scientists. and they will come to dislike it and distrust it, and they will trust the charlatans and the antiscience liars, because they will speak their language

you really need an attitude adjustment. but so do a lot of scientists, when it comes to communicating with the common man. in the service of making science acceptable, accesible, exicting, and friendly, to the common man

or next you will wonder why the peasants are standing outside your offices with torches and pitchforks. or why your daughter is dying of whooping cough because herd immunity isn't protecting her anymore because people aren't immunizing the kids anymore. the proper reaction is not anger or arrogance at the "dumb"folk, but patience, kindness, respect, and COMMUNICATION

Re:there is science, and there is journalism (1)

MightyMartian (840721) | more than 2 years ago | (#38541832)

Oh give me a break. Having a journalist deliberately distorting a report to sell newspapers or banner ads or whatever isn't defensible.

Re:there is science, and there is journalism (0)

circletimessquare (444983) | more than 2 years ago | (#38542052)

excitement sells stories. sales pays journalists

until you figure out a better solution, accept that reality does not conform to your impossible ridiculous idealism about how things should work

grow up. your standards are not high. your standards are impossible. because you don't take into account what actually needs to happen to make things work

ignorant idealism is not morality nor intelligence

"Earth-like worlds" is not an incorrect term (3, Insightful)

G3ckoG33k (647276) | more than 2 years ago | (#38541510)

"The term 'Earth-like worlds' is a vastly overused and hopelessly incorrect term"

"Earth-like worlds" is not an incorrect term. Misused perhaps, but not incorrect.

Re:"Earth-like worlds" is not an incorrect term (2)

sco08y (615665) | more than 2 years ago | (#38542122)

"The term 'Earth-like worlds' is a vastly overused and hopelessly incorrect term"

"Earth-like worlds" is not an incorrect term. Misused perhaps, but not incorrect.

I thought it was pretty correct and well used, in context. After all, a planet outside the temperate zone or that is a gas giant or too small generally can't have liquid water at all, so "earth-like" can easily mean "it doesn't have the factors that obviously rule out life as we know it." And considering the context, which is usually, "we know how big it is and its orbit because we detected incredibly faint wobbles in a far larger star," I think a typically curious layman is going to grasp that no one is claiming to see majestic fjords.

Jesus made it out of the wine the Dinosaurs left. (1)

Kenja (541830) | more than 2 years ago | (#38541540)

Duh....

Alien life would need water? (5, Insightful)

hashp (68887) | more than 2 years ago | (#38541546)

Forgive my ignorance, but why do we always seem to presume alien life has to be hydrocarbon bases like ourselves? Couldn't their metabolism be based on some other chemical process?

Re:Alien life would need water? (0)

Anonymous Coward | more than 2 years ago | (#38541618)

Yes, but the wide variety of metabolisms seen on/in/near earth all have some commonalities. Carbon works very well for complex structures, and hydrogen and oxygen have convenient traits for use in complex structures as well. So it's not that something couldn't be called alive and made differently, it's that all our understanding of chemistry suggests that carbon, oxygen, and hydrogen can support a whole lot of variance and work well at it.

Re:Alien life would need water? (1)

colinrichardday (768814) | more than 2 years ago | (#38542858)

The fact that our chemistry is suited to life doesn't mean that alternative chemistries are not.

Re:Alien life would need water? (1)

Kenja (541830) | more than 2 years ago | (#38541634)

You underestimate the importance of a gin & tonic.

Re:Alien life would need water? (4, Informative)

Zocalo (252965) | more than 2 years ago | (#38541704)

It's not so "presumed" as it is believed to be the most likely basis for complex, multi-cellular, life by a considerable margin due to carbon's versatility in forming the huge number of chemical forms with other elements that necessary for the required biological processes. That said, it's definitely not the only option [wikipedia.org] , silicon, nitrogen and phosphorous based biochemisties all being seen as theorerically viable, although silicon is most often seen as the most likely alternative. Here's a (somewhat old) link to Lou Allamandola, an NAI astrobiologist, discussing [nasa.gov] the various merits of silicon- versus carbon-based life.

Re:Alien life would need water? (1)

rts008 (812749) | more than 2 years ago | (#38541736)

To put it simply, it's due to lack of knowledge and/or imagination.
What we can imagine is defined by what we know.
For examples, you can look to older Sci-F.
Jules Verne's artillery shell moon trip, Sir Arthur Canon Doyle's 'Earth passing through vapours in it's orbit and killing people' story, Edgar Rice Burroughs' John Carter of Mars books, etc.

The more we know, the more we can imagine....

Re:Alien life would need water? (2)

bware (148533) | more than 2 years ago | (#38542852)

To put it simply, it's due to lack of knowledge and/or imagination.

I object, sir. The people planning these missions are the ones who read those books and devoted their very life's work to the scientific proof of these hypotheses.

I've sat in the room while these topics are debated, at a high aggregate hourly rate, and we have discussed looking at other sources, non-earth-like planets, non-carbon based lifeforms, telescopes on the moon, telescopes in Jupiter orbit, arrays of telescopes, life on planets around binary stars, etc.

There was no lack of imagination. But no lack of calculation either.

Thing is, when the public entrusts you with millions, perhaps billions, of their dollars, and the public can only afford one of these missions per decade (if that - shall I give you a litany of cancelled planet-finding missions from the last decade?), you have to look under the streetlight, because that's where the light is. And if you're looking for a set of keys that you don't not even know what they look like, or if they're there, with a magnifying glass that defines your field of view, and the lamp is very dim, looking under the lamp is more cost-effective than any other strategy.

We know that life arises under "earth-like" conditions, for lack of a better word, so if you only get to look once in your lifetime, that's what you look for.

The whole business of "look for non-carbon forms of life" gets put on the spreadsheet, with all the other crazy ideas, and is assigned a Reward of 5, Difficulty of 5, and Risk of 5, and by any logical method of decision making, gets discarded early.

As it should be. Resources are not infinite. But these concepts, and wackier ones, are entertained. Discussed. Debated. Proposed.

You may fault us for not wasting millions/billions of your dollars proposing missions that will not get funded, and likely not be successful, but it's not for lack of imagining it, or putting it on the board for discussion. It's just unlikely that 1) it would make it through the review process, 2) Congress would fund it (imagine the headlines at election time!), and 3) a scientist would spend half a career pursuing such a likely unprofitable path.

(I hate to give up my mod points to comment on this thread, but I resent the implication that those who do this for a living are somehow without imagination or knowledge or didn't read the canon. We did. We took it seriously).

Re:Alien life would need water? (0)

Anonymous Coward | more than 2 years ago | (#38541784)

Forgive my ignorance, but why do we always seem to presume alien life has to be hydrocarbon bases like ourselves? Couldn't their metabolism be based on some other chemical process?

The point is 'Earth Like' not Life Bearing. ( * yeah waiting for the spell checkers )
I agree with above that Those who write are wanting Readers.. not doing Research papers.
I applaud the Students out there and those who 'write ' these papers.. but Nit Picking is for Grading papers.
May be we could hear a better suggestion for Earth Sized planets than Earth Like ?
Even so.. if we did coin a better term here.. who outside of /. would read it ?
Suggestions ?
I really like the stuff the guy wrote above about the Uniqueness of our Little world.. it is staggering.
Still hears Leonard Nemoy in my head. (*)
Life aside.. I wonder if Water is as rare as it seems to be.. and if so.. why here ? Why do we have water in such
abundance and no where , seemingly , else ?

Re:Alien life would need water? (3, Informative)

v1 (525388) | more than 2 years ago | (#38541838)

Once life gets going and has managed to develop evolutionary mechanisms such as sex and dna, (neither of which are specifically required) life tends to become highly adaptable and resilient to changing conditions. The problem is getting there in the first place. That first "spark of life" collection of molecules that can reproduce has to happen from an incredibly good stroke of luck.

The odds of that incredibly rare event happening are made possible by and improved on by favorable conditions. Liquid water, atmosphere, a water cycle, abundant energy, and a magnetic field are all part of that "thumb on the wheel", improving the odds of genesis occurring here on earth.

But they're not required. The only thing that is probably actually required is a liquid cycle of some sort, to provide a circulation of materials because original life was almost certainly not capable of locomotion, and an abundant source of energy. I've read several papers on a plausible genesis based on a liquid methane cycle.

Several conditions on earth are probably not even optimal. The low temperature and pressure of our atmosphere for example - someplace more like Venus has an edge on Earth in that respect. Part of why people tend to think of water/carbon as necessary is they are assuming earth's low pressure and temperature. Molecules get a lot more flexible under those different conditions. If you have "water tunnel-vision" you may completely discount a place like venus where liquid water can't really exist in any quantity.

I think it's fair to argue that some combination of a liquid cycle where the liquid is at a reactive temperature and pressure are probably almost required for genesis. I hesitate to flat out say "required" because a sufficiently lucky turn of events can lead to genesis even in the most apparently unfavorable conditions imaginable. But we can't really get anything accomplished unless we set some constraints on things and try to look at more "reasonable" scenarios. Even though the number of exoplanets in existence is nearly infinite for our practical purposes, it is a finite number, and odds must come into play. Just because there's a ton of planets out there doesn't mean a bunch of them have life. Without any control point of reference it's hard to argue that even just earth in the universe having life was anything but a stroke of incredible luck. We're probably a lot more special than any of us can possibly imagine.

Re:Alien life would need water? (1)

sco08y (615665) | more than 2 years ago | (#38542140)

Forgive my ignorance, but why do we always seem to presume alien life has to be hydrocarbon bases like ourselves? Couldn't their metabolism be based on some other chemical process?

It's a known problem. We're like the guy looking for his car keys under the streetlight. Yeah, he could have dropped them anywhere but that's the only place he's got light.

Re:Alien life would need water? (1)

khipu (2511498) | more than 2 years ago | (#38542442)

For one, because we observe the building blocks of carbon-based life throughout the universe.

Furthermore, there are essentially no other choices. There are 81 stable elements, and most of those are metals, halogens, or noble gases--unsuitable for the kinds of complex structures that life depends on. Other than carbon, the only element that conceivably might for the basis for life is silicon, but even that's a stretch.

Obvius (1)

Yoda222 (943886) | more than 2 years ago | (#38541598)

Probably in the Earth-like planets oceans.

Finally (2)

wcrowe (94389) | more than 2 years ago | (#38541616)

Finally, some common sense on this. Not only is there the question of water, but also whether a planet has a magnetic field which protects atmospheric loss to it's sun's solar wind. Yes, the term "Earth like" is overused.

Another overused term is "God particle".

Re:Finally (3, Funny)

ceoyoyo (59147) | more than 2 years ago | (#38541758)

No. Both are very valuable terms, and should be used more.

When someone reads an article with "Earth-like" in it and assumes that means this other planet is just like Earth, and comes and tells me about it, I then know that he is an idiot. On the other hand, if someone complains (especially at length) about the use of the term, I know he's pedantic. As a bonus, constant disappointment for the first guy may help him improve his critical thinking skills and general knowledge base, possibly making him not an idiot.

"God particle" is similar, except that it also elicits outraged statements that reveal the speaker is a crazy religious nut job having a crisis of faith.

See? Both terms have a habit of revealing useful information about people who see them used, potentially provide educational incentives for those people, AND provide a useful shorthand (well, God particle not so much) for the rest of us.

Re:Finally (2)

wcrowe (94389) | more than 2 years ago | (#38542586)

So the physicists who hate the term "God particle" [yahoo.com] are crazy religious nut jobs having crises of faith? I didn't know so many pysicists were "religious nut jobs".

Re:Finally (0)

Anonymous Coward | more than 2 years ago | (#38542294)

Also the usefulness of a large singular satellite to control spin and wobble of planet leading to slow changing environment. Yes, I saw the special on TV about "What if we had no Moon".

Also, to the question of where the water came from. We all know that the whales brought it with them. I am the only one that remembers Star Trek IV????

I'm excited (1)

lazycam (1007621) | more than 2 years ago | (#38541640)

Having the math/algorithms to locate planets within a "habitable" zone gives us the ability to locate planets which could support life. Nobody could predict in 1911 the level of technological progress we see today in 2011, so it may be the case that in 2111 we may very well have the technology to embark on a mission to another planet. Thinking more conservatively, the discovery of earth-like planets may encourage policymakers to increase funding in space programs (i.e., NASA and private firms). As we have read before, there can be significant payoffs from this type of investment [slashdot.org] .

Hopefully (1)

Ukab the Great (87152) | more than 2 years ago | (#38541644)

not Earth

Tough as life (1)

squidflakes (905524) | more than 2 years ago | (#38541688)

One thing that always gets me about these announcements is the intentional hand-wave regarding the ability of life to spring up in environments that are different than ours. We aren't the only game in town, statistically speaking, and "life" is such an amazingly broad term that simple definitions of it include simple self-replicating systems.

Personally, I don't think we're the only life in the Universe. There is such a wide variety of chemicals that have come together in some very interesting ways here on Earth that it stands to reason that it has probably happened elsewhere.

Would we recognize it though? Probably not.

It started out as water. (-1)

Anonymous Coward | more than 2 years ago | (#38541720)

In the beginning God created the heaven and the earth. And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters.

Re:It started out as water. (0)

Anonymous Coward | more than 2 years ago | (#38542780)

Hey... Bomb...?

Planets get thirsty? (0)

Anonymous Coward | more than 2 years ago | (#38541792)

Planets get thirsty?

What kind of fool question is that? (1)

rts008 (812749) | more than 2 years ago | (#38541800)

Water is 'out there'....a lot of it. It may not be concentrated where we would like to see it, but it's out there.

These world probably had water at sometime (1)

punisher777 (2462418) | more than 2 years ago | (#38541822)

All I would like to say is that while we do not know if these world have water looking at our own solar system there is probably a good chance these world at least had water on their surface at on point in time. We know from erosion patterns that Mars had water on its surface because there are erosion patterns of rivers and lakes/seas on the surface. We also have evidence that Venus in the past had liquid water on its surface before it became a blistering inferno. This is three planets in our own solar system that used to have water on there surface (with Earth and occasionally Mars) having liquid water on their surface. In addition, we rarely hear about the fact that each of these worlds (including Venus) have liquid water under the surface in the soil and rock. A majority of Earths bio-mass is actually contained in the soil and rock as bacteria, insects, roots, etc. We also have a number of moons in our solar system that we know contain liquid water under their icy exterior, we don't know how deep this liquid water is but we have a good idea that it is pretty much an ocean. We also have a moon in our solar system which has ice mountains that allow rivers and lakes of liquid methan. Who knows this world might allow for lifeforms that use liquid methan instead of water. In fact, because it has an icy exterior it may as well have an interior water ocean that allows for life like on planet earth. We have an abundance of water in our solar system liquid and ice, while we do not know how it got on the surface of Earth or other planets it did. And since it has happened multiple times in our own solar system wouldn't it be a safe bet that it probably happened elsewhere in the galaxy. Yes these planets in question may not have liquid water oceans and rivers like Earth does but it is a pretty safe bet that there is or has been liquid water on the surface of these planets.

It was the magical water fairy. (1)

Zoson (300530) | more than 2 years ago | (#38541860)

Don't let anyone tell you otherwise.

Water (3, Interesting)

robably (1044462) | more than 2 years ago | (#38541886)

it will take a long time until we have any hint of this life-giving resource on worlds orbiting stars thousands of light-years away.

Doesn't matter. By the time we reach any planets in other solar systems we won't need water to survive. We'll have transferred our brains to computers and will use whatever android bodies are suitable for the terrain.

I know, sounds fanciful, but it's more realistic than to think that we'll be sending human beings to other solar systems. The amount of oxygen, water, food, and other resources required - even if we invent some kind of suspended animation - makes it laughably unlikely.

Re:Water (0)

Anonymous Coward | more than 2 years ago | (#38542168)

those resources can be recycled. plants and various microorganisms are good for that. Make a big enough habitable vessel with a good ecosystem needing only energy input, and even existing conventional technology can get it to a star in reasonable time

Re:Water (1)

robably (1044462) | more than 2 years ago | (#38542558)

A bigger vessel means either more fuel or a longer journey. For humans that's a hell of a lot of fuel or an incredibly long time. It's on the scale of thinking of the Earth as a spaceship.

With computers, theoretically you could fit thousands of distinct consciousnesses in a computer the size of a sugar cube. And computer consciousnesses could be "frozen" rather than put in to suspended animation for the journey. Add some nano-tech replicators and a spacecraft could be no larger than a football, shoot out across the galaxy, find a planet and start building android bodies, buildings, telecoms, a complete civilization. Even human bodies if you really want.

Again, fanciful, but more likely than sending people.

Where Would Earth-Like Planets Find Water? (2)

bratwiz (635601) | more than 2 years ago | (#38541892)

Where Would Earth-Like Planets Find Water?

Uh, how about in the ocean..?? Or in the creeks, streams and rivers?

Or maybe they could just-- you know-- turn on the tap and out it comes.

You did specify "Earth-like"....

The question answers itself (0)

mark-t (151149) | more than 2 years ago | (#38542080)

If the planet is earth-like at all, it has, or at least had at one point, some amount of wate on it, by any remotely sane definition of "earth like".

I disagree (1)

wisnoskij (1206448) | more than 2 years ago | (#38542092)

"It turns out that we have only a vague idea as to where Earth got its water, and it will take a long time until we have any hint of this life-giving resource on worlds orbiting stars thousands of light-years away."

I have no idea of water specifically but I thought all/most mater after hydrogen and helium was made by stars.
But regardless of where it comes from it is a very common material in space so there is little reason not to assume that a planet that has the right conditions for liquid water would not have it.

water is very common in universe (1)

rubycodez (864176) | more than 2 years ago | (#38542260)

true, we've already found large amounts of exo-solar system water in nebula, dust around young stars, spectra of cool stars. not a rare compound at all in this universe.

In the Gravity Well. (1)

wideBlueSkies (618979) | more than 2 years ago | (#38542114)

Ha Ha Ha.
Thanks, I'll be here all week.

Try the Veal, it's great.

Vague? (0)

Anonymous Coward | more than 2 years ago | (#38542212)

The OP mentions only a vague idea of where we got water. This is incorrect and miscomprehends the linked article. The article is ridiculous with how it tries to make controversy where there should be none. Earth-like is a reasonable term. It only speaks to the parameters that we can observe. The offense of artistic depictions is an act by the very publication complaining of it.

The source of water is not vague. There are many specific candidates for water sources and it is likely there was more than one source. There is water lurking in many parts of our solar system. This doesn't make water on other systems a rash assumption. It makes water on other systems plausible.

Re:Vague? (1)

rubycodez (864176) | more than 2 years ago | (#38542280)

besides, we've already found water in other star systems and nebula. loads of water in this universe, documented fact

From melting ice . . . (1)

PolygamousRanchKid (1290638) | more than 2 years ago | (#38542258)

. . . caused by global warming . . .

. . . just like where our water comes from . . .

"Like" is Relative (3, Interesting)

Bob9113 (14996) | more than 2 years ago | (#38542386)

The word "Like" is relative. Relative to the past frame of reference. The second time you see a gorilla, you think it looks like the first gorilla. I suspect I would be hard-pressed to tell a male gorilla from a female on casual observation. Jane Goodall, however, probably sees as much visual distinction between individual gorillas as you see between humans.

Same with exoplanets. The first ones we detected were supergiants in close orbits around relatively small stars. Compared to those, Mars is Earth-like. Now we've found enough that "Earth-like" is evolving to mean something more specific. Vague terms in novel and rapidly advancing fields have evolving meanings. That is the nature of language.

As others have said, exoplanet taxonomy is a fine new field to plumb, but that doesn't mean Earth-like is bad -- it's just vague and unscientific. A rough measure that only has meaning in context. Conversational shorthand, useful in casual discourse.

A quick look around finds that there are people working on formal taxonomy. [arxiv.org]

Only a vague idea? (1)

TheGoodNamesWereGone (1844118) | more than 2 years ago | (#38542564)

Only a vague idea of where Earth got its water? We got it from comets. Water's a fairly common molecule throughout the universe.
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