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First Organic Molecules Found on Alien World
Galactic_grub writes "The detection of planet HD 189733b is in some ways just another small victory for extra-solar planetary science. It is too hot for there to be anything 'alive'. Just the same, somewhere on the planet are trace amounts of the gas methane. The fact that the element was detected at all offers hope for understanding future discoveries of Earth-like worlds, says NewScientistSpace. Researchers from Caltech and University College London used the Hubble Space Telescope to peer at the planet and examined spectral signature of starlight filtered by the planet's atmosphere, to identify different chemicals. 'The authors suggest that some ill-understood chemical process might be responsible, either concentrating the methane in cooler parts of the atmosphere, or generating extra methane directly. Alternatively, the methane might simply mean that the planet happens to be very rich in carbon.'"
One day I'm gonna bang me a green chick.
SJW: Someone who has run out of real oppression, and has to fake it.
methane... aliens can fart...?
The problem with socialism is that they always run out of other people's money. - Margaret Thatcher
Methane can be formed by inorganic processes...although how enough of it could be formed to be detectable to us way over here is an intriguing question.
Also, the planet is around 700 degrees Celsius...why are we so sure this completely precludes the possibility of life?
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Meh, I'm positive that the FSM put it there, to test our faith in his noodly appendages. Life on another planet?! Preposterous!
Please no more overlords, my back fucking hurts from the whip with those we got now...
The surprising thing here isn't that the astronomers discovered methane on a planet. Heck, Uranus is full of the stuff and other gas giants have it as well.
It's not surprising to find methane on an extrasolar planet. What is different about this is, to QTFA:
"Initially, that is surprising," says Sara Seager of MIT in Cambridge, US, who was not involved in the study. Because HD 189733b orbits very close to its parent star - just 10% of Mercury's distance from the Sun, it is very hot, with atmospheric temperatures of about 700 Celsius. "When the temperature is this high, the dominant form of carbon should be carbon monoxide, not methane," says Seager.
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"trace amounts of the gas methane" != "First Organic Molecules Found"
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Alternatively, the methane might simply mean that the planet happens to be very rich in carbon.
Most likely it's because of cows. Space cows.
Democrats or Republicans. They are both taking us to the same place and they are not afraid of us anymore.
We know tons about the enthalpy of formation of various chemicals, family of chemicals, not only from carbonated life but other type of chemicals. The problem is to have molecule which bond easily enough, quickly enough, but not strongly enough that you have to spend a lot of energy to break bonds. Furthermore there are good indication that a liquid phase of some sort is necessary. If I recall correctly from the first proposition one can deduce life would use carbonated compound, as other type of compound (Si for example) would either not bind strongly enough, or too strongly. From the second in conjunction of the first, water present all sort of advantage. It ain't that we are so earth centric that we can't imagine other form of life, it is more that the chemistry of other compound don't seem to lend to the type of reaction necessary for life. Finally if you have carbonated compound as condition sine qua non, then 700C is enough to dissociate most of them.
Now, mind you, even if we have to abandon dreams of Silicate life in extrem hot environment, it does not mean we think life could be identical to what we have on earth.
C. Sagan : A demon haunted world:
http://www.amazon.com/gp/product/0345409469/
visit randi.org
The Drake Equation is getting pretty close to 1.0 in a lot of categories.
Dude! That's funny.
R* = We have some guesses from a few years of observation, but nothing approaching mathematical certainty.
fp = We just recently learned how to find planets, and the number found is extremely low compared to the number of stars found. It would be silly to try to assert with any certainty what percentage of stars have planets.
ne = Other than Earth, none have been found. No indication that any other will be found has been found. Nearly everything found so far have been gas giants orbiting close to their suns.
fl = Other than Earth, none have been found. No indication that any other will be found has been found.
fi = Other than Earth, none have been found. No indication that any other will be found has been found.
fc = Other than Earth, none have been found. No indication that any other will be found has been found.
L = Other than Earth, none have been found. No indication that any other will be found has been found.
If anything, the Drake equation is still sitting imperceptibly close to 0.
Aah, change is good. -- Rafiki
Yeah, but it ain't easy. -- Simba
First, life as we know it is essentially a precarious delicate balance of chemical reactions that can go either way. For example, we need to break down the proteins we eat so that we can build up or own proteins. We need to create energy-rich substances (like fat) to store energy, so that later we can consume them to provide energy. We assemble DNA into chromosomes and then pack it away for safe storage, but then we need to partially disassemble it to use it. And so on.
All this has to take place in essentially an isothermal environment. We can't change the temperature of a cell by several hundred degrees to get different reactions to go in different ways, or forward and back. We can't compartmentalize the cell and have different temperatures in different parts so that different reactions are favored.
To get a set of chemical reactions that can be delicately balanced so that very small changes -- e.g. the addition or withholding of an enzyme (catalyst) -- can tip the balance this way and that, nothing is as useful as the hydrogen bond, which is a somewhat like a chemical bond in that it involves sharing a small charged particle between atoms, but in this case the particle is a proton instead of an electron. Since the proton is much larger than the electron, the bond is far weaker, typically. Helpfully, it can easily be broken and made at temperatures where water is a liquid by very small changes in the conditions. Indeed, they're made and broken in liquid water all the time.
You might easily say that life is fundamentally based around the existence of the hydrogen bond, and its ability to be formed and broken easily at certain temperatures. There really isn't anything else like it in chemistry. You couldn't imagine ordinary chemical bonds playing this role at, say, a much higher temperature, because the problem is that all chemical bonds become flexible and easy to make and break at about the same temperature (5000-10000 K). You couldn't have some bonds flexible and some others sturdy. It would be like trying to pour and shape steel with iron tools close to the melting point of iron.
Fortunately for us, because of the peculiar stability of the oxygen nucleus, there is a great deal of oxygen in the universe. Since there is also, naturally, a very large amount of hydrogen, it turns out that water (H2O) is probably the most common heteronuclear neutral molecule in the universe. There's a huge amount of it out there. And water is an ideal basic substrate on which to be building your life based on hydrogen bonds, because of course water is one of the best hydrogen-bonding substances there is. Think of it as the "silicon" in life "microelectronics," the substance that you can dope with other molecules and get all kinds of useful behavior.
It might well be the case that there is some other model for life, one not based on ordinary chemistry -- for example you could have Robert L. Forward's life based on nuclear chemistry, living on neutron stars, with a natural time-scale a billion or more times faster than ours. But no one outside of fantasy has ever proposed a plausible model for it.