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Meteorite nugget pushes back age of the solar system by nearly 2 million years

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Young solar systemA new analysis of a meteorite shows that an inclusion within the carbonaceous stone is older than any known material in the solar system. The finding pushes back the estimated age of the solar system to 4.568 billion years, older than previous estimates by up to 1.9 million years.

A piece of the meteorite, known as Northwest Africa 2364, was purchased in 2004 in Morocco and is now part of a collection at Northern Arizona University in Flagstaff, Ariz. About 150 miles south of Flagstaff, two researchers at the Arizona State University Center for Meteorite Studies in Tempe, Audrey Bouvier and Meenakshi Wadhwa, dated an especially primitive piece of the meteorite known as a calcium-aluminum-rich inclusion, or CAI. Their findings appeared online August 22 in Nature Geoscience.

Bouvier and Wadhwa measured the meteorite’s ratio of two lead isotopes, whose relative proportions change on geologic timescales. Each variety of lead is a decay product of uranium, but the two parent uranium isotopes have very different half-lives: uranium 238 decays to lead 206 with a half-life of about 4.5 billion years, whereas uranium 235 decays to lead 207 with a half-life of about 700 million years. So the relative abundances of lead 206 and 207 can be used—along with some calibration for initial uranium abundances—to determine the age of ancient objects.

The balance of lead isotopes in the Northwest Africa 2364 meteorite point to an age of 4,568,200,000 years, plus or minus a few hundred thousand years. Taking the measurement uncertainties into account, that is between 300,000 and 1.9 million years more ancient than the oldest CAIs found in other meteorites. The lead-derived age of Northwest Africa 2364, Bouvier and Wadhwa write, is "the oldest absolute age yet obtained for any Solar System material and is, therefore, the best estimate for the time of formation of the Solar System."

Artist’s impression of a protoplanetary disk: ESO/L. Calçada





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  1. 1. frgough 6:50 pm 08/23/2010

    "calibration of initial uranium abundances" Translation: guesswork.

    And, of course, lead 206 and 207 never existed at all in the beginning. And, of course, none ever leached in after its arrival on earth.

    If I tried to pull this crap in my chem labs, my prof would have flunked me out.

    Link to this
  2. 2. rodrigobernardo 7:44 pm 08/23/2010

    Is this the same accuracy that is used to determine that the big bang occurred 13bn (13,000,000,000) years ago? With a 99% chance of being correct (Rees)?

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  3. 3. tg18 7:53 pm 08/23/2010

    @frgough:

    The article clears denotes the calculation as an estimate.

    leached in… are you suggesting an element as heavy as lead or uranium is going to be absorbed into a meteorite like water into a sponge?

    you would not be talking about any of this in a chem class. chemistry deals with the interactions that occur between the electron shells of different elements or compounds. anything on the nuclear level would be addressed in a nuclear/particle/quantum physics class.

    if you’re going to be so self-righteously indignant, at least try to sound as though you know what you’re talking about…

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  4. 4. A6M4 8:45 pm 08/23/2010

    @frgough:

    All right guy, listen: When these meteors formed, they formed in such a way that objects called "chondrules" that are (essentially) embedded in whatever material the primitive asteroid is made of. These objects have presolar grains (the lead mentioned earlier) embedded in them. This rules out any "leaching in" (which is an oxymoron by the way).

    Now I’m sure you understand the process of nuclear decay and half lives, but if you don’t I can help. Basically the most chemically stable element is Iron, so anything higher wants to revert to Iron. Uranium is one of those. Now since nothing can get in and nothing can get out, you can look at how much Lead and Uranium is there and the ratio is used to find the age. Add in different elements and isotopes and, as in most sciences, the uncertainty becomes smaller and smaller. Now consider this, Uranium has 92 protons while lead has 82. This knowledge helps to erase most of the uncertainty from any preexisting lead. It’s all in the ratios.

    So we have a closed system, a highly analyzed and documented process, and fairly simple ratio relations all adding up to an uncertainty of .0002%, sounds pretty solid to me

    P.S. Your age of the universe is off by 750 million years and leach is means to leave the object not enter.

    P.P.S. Also, what you describe as guesswork is more accurately described as "Well, in all of our previous experiences in this situation, this happened."

    P.P.P.S. I REALLY hope you are not a chem major…

    Link to this
  5. 5. A6M4 8:45 pm 08/23/2010

    @frgough:

    All right guy, listen: When these meteors formed, they formed in such a way that objects called "chondrules" that are (essentially) embedded in whatever material the primitive asteroid is made of. These objects have presolar grains (the lead mentioned earlier) embedded in them. This rules out any "leaching in" (which is an oxymoron by the way).

    Now I’m sure you understand the process of nuclear decay and half lives, but if you don’t I can help. Basically the most chemically stable element is Iron, so anything higher wants to revert to Iron. Uranium is one of those. Now since nothing can get in and nothing can get out, you can look at how much Lead and Uranium is there and the ratio is used to find the age. Add in different elements and isotopes and, as in most sciences, the uncertainty becomes smaller and smaller. Now consider this, Uranium has 92 protons while lead has 82. This knowledge helps to erase most of the uncertainty from any preexisting lead. It’s all in the ratios.

    So we have a closed system, a highly analyzed and documented process, and fairly simple ratio relations all adding up to an uncertainty of .0002%, sounds pretty solid to me

    P.S. Your age of the universe is off by 750 million years and leach is means to leave the object not enter.

    P.P.S. Also, what you describe as guesswork is more accurately described as "Well, in all of our previous experiences in this situation, this happened."

    P.P.P.S. I REALLY hope you are not a chem major…

    Link to this
  6. 6. robert schmidt 9:38 pm 08/23/2010

    frgough is a troll plain and simple. He hates science because it contradicts his fundamentalist Christian agenda. He is completely ignorance of science, logic, reason or anything else not derived from blind faith. He pretends that he has studied science in an attempt to give himself credibility but the fact that he makes errors you wouldn’t even expect from a first year student shows that the closest he has ever come to science is a Christian science reading room. There are no facts you can give him that will change his mind because his ideas are not based on facts. Don’t waste your time on him.

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  7. 7. JamesDavis 9:51 pm 08/23/2010

    With the new technology and the understanding of how to use it more effectively, I bet you a dollar to a cow out on the farm, the Universe is a lot older than 14.3 billion, whatever, years old. It wouldn’t surprise me one bit if it isn’t closer to a trillion + to the tenth power. To our current understanding, the Universe could even be ageless beyond our understanding.

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  8. 8. jtdwyer 10:05 pm 08/23/2010

    Not to argue the point, but to ensure it is not overlooked, I understand that some astrophysicists consider it possible that some asteroids in our Solar system were ejected from neighboring stellar orbital systems. Surely it’s more likely that the age of the Solar system is slightly older than previously estimated.

    Wouldn’t the age of heavy elements found in the Solar system better indicate the occurrence of some preceding supernova rather than the actual formation of the Solar system? Couldn’t the elements composing the Solar system have simply hung out for many millions of years before the Solar system began to form, perhaps from elements produced by several supernovae?

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  9. 9. TreeFrog 11:42 pm 08/23/2010

    I would like to echo the sentiments of jtdwyer… It seems odd that the possibility that this meteorite originated from outside the solar system was not mentioned.

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  10. 10. A6M4 11:52 am 08/24/2010

    @jtdwyer

    Yes, all of the atoms in the Universe could be considered to have the same age. The method used to figure the age of the Solar System however, is not an age of the matter itself. Like I said before, what they are measuring is what is in the chondrules, a closed system. If the uranium is not sealed like that, it is impossible to measure the age to any acceptable certainty because any passing asteroid (and also entry into earth’s atmosphere) could cause the asteroid to lose part of the uranium or part of its decayed mass, thus rendering any attempt to use a ratio of undecayed to decayed mass useless.

    @TreeFrog

    That is certainly a good question. All I can say to this is that this particular meteor formed from materials of a typical stellar nebula. I also think it odd this was omitted, but I would consider it an oversight and nothing more.

    By the way, this is the proper doubt. Maybe not believing entirely but still realizing that these people are not idiots, that there are years and years of study that go into these things, then months of analysis when discoveries such as this are made and checked and rechecked and rechecked again.

    @robert schmidt

    I would hardly say he made first year errors, just that society today, especially religious society, has this thing about not believing what scientists say simply because it doesn’t agree with what you believe, it makes them uncomfortable so they simply ignore it. It’s no wonder there are so few real scientists, as that feeling is almost a constant in a scientist’s work.

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  11. 11. jtdwyer 5:40 pm 08/24/2010

    A6M4 – So the proportions of lead isotopes found in the chondrules indicates the duration of time that their parent uranium isotopes had spent in the closed system, correct?

    In that case, it is the age of the chondrule structure that is being measured, correct?

    As I understand, the chondrules formed as dense blobs of melted heavy elements cooled.

    I have to suggest that dense blobs of melted heavy elements were far more abundantly produced by a preceding supernova event than anytime during or after the accretion of the pre-Solar disk.

    I would not dismiss the intelligence, knowledge, expertise or effort of those producing this study. However, in my expert experience one should never presume that more knowledgeable experts have thought of all the right questions – their perspective is restricted by their knowledge.

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  12. 12. jtdwyer 6:41 pm 08/24/2010

    By the way, if correct, this interpretation of the data indicates that it is more precisely a preceding supernova(e) that occurred 4.568 billion years ago, not the aggregation of the Solar system, which could have occurred sometime thereafter.

    Link to this
  13. 13. Wayne Williamson 6:12 pm 08/27/2010

    well put jtdwyer….the initial state is set when they are created…not when they happen to pass thru our solar system…

    Link to this
  14. 14. Neptunerover 10:06 pm 08/29/2010

    Heck, for all they know, aliens from another part of the universe warped here and planted that thing just to screw with us.

    Besides, why is it important that we have an exact date? Just to rub it in the face of creationists?

    Link to this

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