Water Found in Exoplanet's Atmosphere 185
anthemaniac writes "Astronomers have long suspected that water should exist in the atmospheres of extrasolar planets. Now they have evidence. Water has been discovered in a planet called HD209458b, which was previously found to have oxygen. From the article: 'The discovery ... means one of the most crucial elements for life as we know it can exist around planets orbiting other stars.' But don't go looking for little green men. You might remember HD209458b as a 'hot Jupiter' that boils under the glow of its very nearby star."
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How many people now think that ETs of some form do exist?
Re:Straw poll: (Score:3, Interesting)
It's a big universe. Chances are very good that other life of some sort exists. However, we have found no evidence of life yet, despite the presence of oxygen which would usually be considered a strong indicator of the presence of life.
"Despite the oxygen, the faraway planet is not one that would support life. [space.com]" -- www.space.com
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I can't help but wonder how long it'll take till we have the same leap for detecting life once we know exactly what we're looking for. I'm hoping it'll be sooner rather than later.
Read this book: Rare Earth (Score:5, Interesting)
It is a very well-researched book that goes into great detail on all the different terms of the drake equation (and a few extra terms) and shows what the best scientific evidence suggests are the actual values for those terms. The bottom line of the book is that single-celled life is probably incredibly common, it's probably everywhere. Life that's big enough for you to actually see is probably pretty rare. Intelligent life is very rare, and technological civilizations are practically a miracle.
Life can easily exist (Score:4, Interesting)
They just need to evolve in that environment.
Re:Straw poll: (Score:2, Interesting)
incomplete summary (Score:3, Interesting)
But don't go looking for little green men. You might remember HD209458b as a 'hot Jupiter' that boils under the glow of its very nearby star."
but neglects to answer the very important question this raises :
Given what we remember about HD209458b, what colour little men should we look for?
My initial guess was red, but there's no guarantee HD209458b-ians can even get sunburned.
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Re:Read this book: Rare Earth (Score:3, Interesting)
So by that definition, even if there are billions of civilizations, if the ratio is 1/10000000000000 then I don't think you can call it common.
Anyway, the grandparent post asked, "who believes in ET" and I think that a scientific answer: ET is out there, but maybe not even in our galaxy. So we are very very unlikely to ever find any life that we can talk to. The question that people want to know the answer to is, is our universe like the one on Star Trek, with aliens everywhere. I think that the answer is no.
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Your Hitler comparison is flawed. Hitler was only one person, and most vegetarians are nothing like Hitler. However, a majority of Christians (at least in the USA; my apologies if you live somewhere else where Christians are not fundamentalist) do believe the earth is 6000 years old, that evolution is false, that Creationism should be taught in public schools, etc. So if you're one of the rare minority that doesn't believe this way, and doesn't try to push these beliefs on everyone else, then that's great. But you have to acknowledge that most of your co-believers are like this this.
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I agree with you that there could well be life that is vastly different than what we are used to.
But this doesn't make sense to me. When you say far-left and far-right, I assume you mean the periodic table. That means you are talking about Cl, Br, Na, K, etc. That doesn't make sense (they tend to only make 1 bond), so I figure you are talking about the p-block.
That means you are talking about B, F, C, Si, Cl and Br. What is special about carbon is that it forms 4 bonds. So, this means you are just talking about carbon and silicon. Let's throw out anything heavier (Ge, Sn) because they aren't that abundant.
Sure, there could be something based on silicon but... Look at CO2 (a gas) and SiO2 (silica, a solid). Carbon just seems like the best candidate for life to be based on. Nitrogen (or P) and boron (or Al) seem to be the best other candidates.
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That's a misconception; the sort of silicon-based life that we're talking about are not precisely the same as carbon chains. In carbon chains, you typically have C-C-C-C-C... etc. In the equivalent silicon (actually silicone) molecule, you have Si-O-Si-O-Si-O-Si.... etc. Si-Si-Si... etc doesn't chain well, but Si-O-Si-O.. chains indefinitely. Compare a hydrocarbon-based lubricant with a silicone-based one, hydrocarbon solids (plastics) with silicone ones, etc. There's been a lot more research on the former so far; the latter can likewise be functionalized.
A few differences in the chemistry:
1) C-C-C-C-C... chains can freely rotate, while Si-O-Si-O... chains need a specific "joint" to do so.
2) Carbon more readily double and triple bonds, although removing Os from the Si-O chain can create similar (but not equivalent) effects.
There are all sorts of biologically interesting silicon compounds. The silicon equivalent of methane is silane. It's even more flammable than methane; it's hypergolic with our atmosphere (burns on contact). Its giving up of its hydrogen could be seen as equivalent to ATP and its phosphorus. Longer "silanes" scale like longer hydrocarbons -- their vapor pressure decreases the longer they get (silanes with 2-3 silicons make for good wood sealants). Zeolites are silicates (your typical silicon solids that you were picturing) but with various metal ions interspersed with them; they're excellent, highly selective catalysts. Probably the most biologically interesting (to me, at least) are silanols [ic.ac.uk], which exist naturally in Earth's oceans (and probably predated life), and can form all sorts of catalytic groups, membranes, etc.
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Which tells us nothing except that it is possible for life to exist. The fact that life exists here tells us absolutely nothing about the likelihood of life arising apart from its being greater than zero because for obvious reasons we are sampling from a biased distribution, being alive ourselves. :-)
> Do you have any idea how many billions of stars are in our galaxy, and how many billions of galaxies are in the observable universe?
As it happens, yes. But I also know that combinatorial explosions [wikipedia.org] can generate numbers vastly larger than the number of things in the physical universe and the number of ways of arranging matter is described by a combinatorial explosion. Who knows how many of those combinations involve life, but it has the potential to be incredibly small. Small in a way that the size of the universe doesn't touch in bigness.
> If you are saying, "no one knows for sure. Don't say you're sure the chances are good if you can't prove they are," then that is certainly valid.
Looks like we're actually in total agreement.
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Hydrogen, helium, oxygen, carbon, neon, iron, nitrogen, silicon, magnesium, sulfur. There's your top ten, in that order. It's interesting that carbon, versatile as it is, is so very common. Considering that hydrogen and oxygen, hence water, rank even higher, I think that life as we know it has statistically higher odds of appearing, especially in conditions where water is liquid. The physics of these compounds is the same everywhere, assuming similar environmental conditions.
Now, life on earth has been through several mass extinctions and major evolutionary possibilities got cut off short. However, we have a lot of convergent evolution - for example, the similarities of fish, ichthysaurs, and dolphins being dictated by the properties of liquid water.
It might be interesting to consider the possibility that life out there will have some strong similarities, if superficial, to what we've seen.
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