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Organic Matter Found In Canadian Meteorite
eldavojohn writes "From what sounds like the opening of an X-Files episode, Canadian scientists have reportedly found in a meteorite organic matter older than the sun at Tagish Lake in Canada. From the article: '"We mean that the material in the meteorite has been processed the least since it was formed. The material we see today is arguably the most representative of the material that first went into making up the solar system." The meteorite likely formed in the outer reaches of the asteroid belt, but the organic material it contains probably had a far more distant origin. The globules could have originated in the Kuiper Belt group of icy planetary remnants orbiting beyond Neptune. Or they could have been created even farther afield. The globules appear to be similar to the kinds of icy grains found in molecular clouds — the vast, low-density regions where stars collapse and form and new solar systems are born.' The article implies that life could potentially survive in these meteorites and maybe even travel through space — supporting the theory that life may have arrived on earth and evolved from that point on."
My life sci 101 class teached me that organic compounds also usually have hydrogen. Apparently, more than half of all known compounds are organic, according to http://en.wikipedia.org/wiki/Organic_compound .
Ninjas and pirates. How piquant.
So from what I read they structures found COULD assist organic life, but are not actual evidence of them.
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Keep in mind that organic does NOT = life, just a precursor to life. Organic molecules/matter are generally just molecules containing carbon and hydrogen making a chainlike skeleton of atoms, with oxygen and/or nitrogen depending on if it is a protein. (Source). This DOES back up the hypothesis that organic molecules can form just as well outside of early earth, as in. It'll be interesting to hear just what the molecules were, but I doubt this will spawn any new theories about the extra-solar genesis of life on earth. It doesn't take special space-dust to provide organic compounds in the early earth - just the atoms from the life cycle of stars spreading heavier elements.
Ryan Fenton
He has good novels?
LOL. True story:
Recently, I was trying to chat up a very attractive girl. I mentioned in our harried conversation (she was at work) that I enjoyed reading but hadn't been to the bookstore in ages, blah blah. She told me that she, too, loved to read, and promised to bring in some of her favourites for me. Great, I thought! This could be the start of something interesting.
A few days later I stop in to see her and she smiles and points to a small bag 'o books in the corner. How sweet, right? Well, inside the bag were 4 were Dan Brown novels. Cervantes I wasn't expecting, but Dan Brown? I tried reading one of them (maybe I was wrong about him), but the absence of any writing talent in combination with an absurd plot reminded so much of high school that all I could was groan and put the book back in the bag with the others.
Haven't been back to see her since. It's been a month, but I wonder whether that's not long enough.
First, just to whip out my creds I have a doctorate in astronomy, although not in this sub-field...
The typical way to set an age of a very old object is, as you note, by looking at its radioactive decay history. A good chronometer for meteorites is uranium, both U238 and U235. They have different decay rates, so the difference between the starting and ending abundance ratio of the two gives you the age. As you note, the trick is to determine what the starting ratio is; this is largely an educated guess, but presumably the population seen in the meteorite was created in the same supernova explosion, so a little nuclear physics tells you what that should be (Google 'neutron drip line'). A good check on the result is to also look at the isotope ratio of lead: Pb207 is the daughter of U238 decay, and Pb206 the daughter of U235. There are several other useful decays to check (Al26 comes to mind), so while it's admittedly a house of cards (but so is everything in astronomy, really) , it is at least more than one card.
And, not to be critical, but your description of determining the ages of stars is...off. To be fair, it is a difficult method to both explain and perform for individual stars.
"I guess the moral of the story is, don't paint your airship with rocket fuel." -- Addison Bain
Evolving to handle high levels of radiation doesn't seem to be a problem for number of of species of bacteria.h ile&start=0&ie=utf-8&oe=utf-8&client=firefox-a&rls =org.mozilla:en-US:official
http://www.google.com/search?q=radiation+extremop
I used to have a cool sig, back when I cared
More correctly, organic molecules are not necessarily 'organic matter'. The report does not say it is 'organic matter' - some idiot in the reporting chain just doesn't know the difference. This is one reason why Slashdot should cite the original article rather than second or third hand rubbish.
Mod parent up. Organic != life. They just tend to go together here on Earth.
"I'm a Laver, not a Phyto[plankton]"
Uh, you're a bit confused.
Carbon-13 dating does indeed need corrections for the level of solar activity,
but that's a bit of an exception. The corrections don't have *anything*
to do with how fast the Carbon-13 decays, though: they relate to how much
C-13 is in the atmosphere.
The way it works is like this:
Carbon-13 decays in about 5000 years. Why do we still have some around then?
That's because it's constantly being made as cosmic rays hit the upper atmosphere
of the earth. Now, as a tree grows, it incorporates carbon from the environment,
including C-13. When the tree dies, the incorporation pretty much stops.
So, once the tree dies, no more C-13 comes in, and whatever is there continues
to decay. Thus, some wood with a lot of C-13 is new because the C-13 hasn't
had time to decay. Wood with very little C-13 is old, because it has been
dead (i.e. disconnected from the environment) for long enough for most of the
C-13 to decay.
So, how does solar activity come into the picture? If the sun is inactive,
more cosmic rays come in from outer space and hit the Earth's atmosphere.
Thus more C-13 is made. Thus, a tree growing in a time with less solar
activity incorporates more C-13, and thus when you do C-13 dating of it,
it seems to be newer than it really is. The C-13 always decays at the same
rate, but if you start with more, you end up with more.
Vice versa, if the sun is particularly active some decade.
Now, this explanation doesn't apply to most kinds of radioactive dating.
Uranium dating, for instance, looks at U-238 that has been there since
the beginning of the solar system, and cosmic rays just don't matter.
Practically all compounds are organic. You can connect carbons in an infinite number of ways. There are an infinite number of inorganic molecules too, but it's a much smaller infinity. Large inorganic molecules tend to break apart. Most atoms either want more electrons too much or don't know what to do with the ones they have, and the resulting instabilities build up over distance. You don't see many inorganic polymers- only a few, like polyphosphazenes and asbestos needles. Carbon is good at forming large covalent molecules, and its presence stabilizes large molecules with other elements.
People think organic chemistry is hard because they see all the compounds and freak. In fact organic is actually much easier than inorganic chem. The players are C, H, O, and N, plus phosphate (PO4---) if you're talking biochemistry. Phosphate aside, these are simple, well understood atoms. Being small, they are hard atoms with limited deformation in electrical fields (like from other nearby atoms). They display a small range of behaviors and form covalent bonds in a predictable way. We still sometimes learn new stuff about carbon, for example, like we did with buckyballs and nanotubes. But neither of these involved any fundamental carbon chemistry that we didn't already understand.
Carbon atoms get 4 bonds each, nitrogens 3, oxygens 2, hydrogens 1. You can connect them up in any way that satisfies those bond number requirements. But each bond should have a carbon on one end (preferably both ends) or you get unstable stuff. (Exceptions: N-H, O-H. You can get away with O=N, O-O, N-N, and N=N sometimes, but not too much, or the results are unpleasant.) Each of C, N, and O can form double bonds. Most double bonds are between C and either O or N. Especially in biochem, where carbon-carbon double bonds are not as common. Both C and N can form triple bonds, such as in nitriles (CN) or alkynes like acetylene (HCCH). Triple bonds are even rarer. (If you're bad you can use F, Cl, Br, or I to make CFCs and similar things. Halogens generally follow the same rules as H, except the bonds are more electron-poor than with H, and more stable. CFCs almost never appear in biochemistry.) Phosphate gets 3 bonds, but they can be anionic. When covalent, the bonds are usually with hydroxyls or other phosphates across shared bridge oxygens. In biochem P never appears outside its phosphate. When it does it gets 5 bonds. Many organophosphates used in industry and agriculture incorporate direct C-P bonds. The nerve agent Sarin for example has a P-CH3 bond as well as a P-F bond with fluorine. Phosphate can appear in organic and bioorganic polymers too, like DNA. In general addition of N or especially O to organic molecules makes them electron poor, and addition of H makes them electron rich. From least to most oxidized: C-OH, C=O, COOH. Heavily oxidized molecules tend to break apart.
Being mindful of the above restrictions, you can connect C, H, O, N, phosphate, etc. up like tinkertoys to form almost anything you can think of. Mostly stuff like tar and varnish. And that's basically what you learn in organic chemistry. Then they'll have you spend most of the semester memorizing hundreds of quirky little "recipe" type reactions with various bizarre reagents, so that you can eventually synthesize any organic structure in a lab that you want. Most of these little recipes were figured out in the 19th century.
Inorganic chemistry is less systematic. Consider something like Hg. We find out new stuff about Hg all the time. We don't understand its electronic structure very well. It has lots of excited states available to it, and it displays unexplained absorption lines that appear to be influenced by what's around. Its outer 6s valence electrons fly straight through the nucleus at relativistic speeds, raising their effective mass and shrinking their orbitals below the atom's surface. As a res
In chemistry, "organic matter" refers to hydrocarbons.
Actually, it's not a silly question at all. It's a darned good one. The short answer is that it's a "best guess".
We still don't actually *know* how the solar system formed, and until then, there's no way we can actually definitely say how old the solar system is. What we think is that the system was formed in a nebula as a big cloud of dust that gradually started to clump around a center. As the protostar gathered mass, the cloud started to spin and formed into a disc, called an accretion disc. The theory is that all of the asteroids, planets and comets formed at the same time as the sun. This theory is supported, in that some of our observations have shown accretion discs in nebulae, but we really have no way to actually *prove* that this is how our solar system formed.
The thing is... if that's how our solar system formed, then we're able to measure the age of the solar system by looking at the age of some of the other objects in the solar system. Fact is that most of the objects out in the kuiper belt and oort cloud (think in the 50-100,000 AU radius) are about 4.5-5 billion years old. Given our current model for how the solar system formed, that would mean that the sun is about the same age. There are almost certainly some objects in our solar system that are older than the system itself... either as captured objects from other solar systems (100k AU is halfway to Proxima Centauri), or as objects that were part of the nursery nebula that we formed from.
As to the original article, it's really nothing special at all. "Organic" molecules just mean carbon compounds. The solar system is full of organic molecules. Something like 2/3 of the asteroids in the solar system, especially in the outer solar system, are carbonaceous. Organic != Life. It's cool that we've found a meteorite that's older than the solar system is thought to be, and it's cool that it's carbonaceous... but that's because it's extremely rare that a carbon-based meteorite survives entry into our solar system, and it's also very rare to find a meteorite that's older than the solar system. Finding the two in conjunction is a really cool thing. But it's in now ay proof of extra-terrestrial life.
If you believe everything you read, you'd better not read. - Japanese proverb
Wikipedia article on the Murchison meteorite. The entry mentions the idea that "a small amount of chiral amino acids [on meteorites] may explain the evolution of right-handedness of sugars."
Also, here is an abstract of an article on extraterrestrial chirality w.r.t. the Murchison and Murray meteorites.
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