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Where Would Earth-Like Planets Find Water?
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."
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.
SJW: Someone who has run out of real oppression, and has to fake it.
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."
It's easier to be a result of the past, but more fun to be a cause of the future! http://www.spacefinancegroup.com/
... but somehow I just feel lonely and sad now.
/.
Welcome to
How about a basic classification scheme for planets?
http://en.wikipedia.org/wiki/Class_M_planet
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".
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 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.
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, 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 and the moon every year. He even had images in his book about impacts on the moon.
Sig Battery depleted. Reverting to safe mode.
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.
SJW: Someone who has run out of real oppression, and has to fake it.
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.
Faster! Faster! Faster would be better!
Wrong on both accounts.
There are actually twice as many even numbers than odd ones.
Proof:
Assume any even number "n", so
n * n = [even]
n * (n-1) = [even]
n * (n-2) = [even]
Now take any odd number "m":
m * m = [odd]
m * (m-1) = [even]
m * (m-2) = [odd]
So out of any two odd/even numbers you can generate twice as many even numbers compared to odd numbers.
q.e.d.
(and yes, for the non-maths out there, it is a joke)
There are fewer illiterates than people who can't read.
That assumes the priority of the wealthy nations is the long-term viability of our species. Considering the number of policies implemented that jeopardize the long term sustainability for the short term profit, I doubt that is the case.
I predict we will continue to waste that money in stupid bullshit instead of doing either.
Dilbert RSS feed
. . .contemplating the scale of the universe always gets me down.
It's interesting that people feel that way. Personally I find it comforting to realize that the universe is so much larger than I am that I couldn't possibly be an important part of it. A study of the cosmos actually helps me focus on life in the here-and-now, to respect and enjoy the progress made by those who came before me, and to value the company of the humans around me, on the grounds that these things are all I'll ever get to experience.
IMO, astronomy and cosmology are worthwhile pursuits, not because of what they tell us about the stars, but because of what they tell us about ourselves. Through these sciences we've come to understand that the Universe sees us the way we see atoms in the antennae of ants, if the Universe contemplates us at all.
It seems important for humans to get past the idea that we serve a mystical universal entity with specific plans for us as individuals. Put simply, in the post-nuclear age, humility is a survival tool. Letting go of one's sense of cosmic self-importance should be a liberating sensation, not a depressing one.