Become a fan of Slashdot on Facebook

 



Forgot your password?
typodupeerror
Compare cell phone plans using Wirefly's innovative plan comparison tool ×
Moon Space Science

Study Questions Scientific Dating Method Used For Lunar Impacts (wisc.edu) 49

schwit1 writes: A new study has raised questions about the methods scientists have used to date the late heavy bombardment in the early solar system. According to the University of Wisconsin-Madison: "A study of zircons from a gigantic meteorite impact in South Africa, now online in the journal Geology, casts doubt on the methods used to date lunar impacts. The critical problem, says lead author Aaron Cavosie, a visiting professor of geoscience and member of the NASA Astrobiology Institute at the University of Wisconsin-Madison, is the fact that lunar zircons are ex situ, meaning removed from the rock in which they formed, which deprives geoscientists of corroborating evidence of impact. 'While zircon is one of the best isotopic clocks for dating many geological processes,' Cavosie says, 'our results show that it is very challenging to use ex situ zircon to date a large impact of known age.'" The problem is that the removal of the zircon from lunar rocks changes the data enough to make the dating unreliable. The method might work on Earth, but the dating done on Apollo samples can be questioned. This means that much of the supposed history of the solar system, centered on what planetary scientists call the late heavy bombardment, a period 4 billion years ago when the planets were being hit by innumerable impacts as they cleared the solar system of its dusty debris disk, might not have happened as dated from lunar samples. If so, our understanding of when that bombardment ended and life began to form on Earth might be considerably incorrect.
This discussion has been archived. No new comments can be posted.

Study Questions Scientific Dating Method Used For Lunar Impacts

Comments Filter:
  • by Slashdolt ( 166321 ) on Monday October 19, 2015 @05:31PM (#50761643)

    Did anyone else think this was going to help them pick up chicks? ;-)

    • by vux984 ( 928602 )

      I got to "lunar impacts" before I realized it wasn't going to be an article about matchmaking algorithms at dating websites. And I spent at least a fraction of a second considering that "lunar impacts" is a strange name for a dating website.

    • I thought it was obvious, dinner and a movie. Did this need a study?

    • Did anyone else think this was going to help them pick up chicks? ;-)

      No. That's in the "rod logic" article.

  • by Nethemas the Great ( 909900 ) on Monday October 19, 2015 @05:45PM (#50761711)
    I guess I need to brush up on my Latin...
    • by Anonymous Coward

      AOE ex-situ, meaning that they're situated outside of the area of effect.

      Is it real or is it Unicode failure? YOU'LL NEVER KNOW.

    • by aoism ( 996912 )
      It's actually the ultra rare dialect of Pinyin Mandarin Latin, you uncultured sob!
  • >evidence of early bombardment on Earth
    >assuming that this might not have happened on the Moon

    That's a pretty big assumption, because it assumes that the Earth is somehow special in "attracting" (outside of gravity, but we're not talking about that, we're just talking about "targeting") bombardment and the moon is not, while both occupy a similar orbits around the Sun.

    I don't buy this doubt. It fails the laugh test.

    --
    BMO

    • You misunderstand (Score:4, Informative)

      by grimJester ( 890090 ) on Monday October 19, 2015 @06:14PM (#50761879)
      There's no such claim in the article or summary. The moon rocks don't have the full surroundings available to make sure it wasn't just existing zircons knocked about by an impact rather than formed in that impact. Evidence from the moon is being used to time the late heavy bombardment. So we're no longer sure the evidence we found on the moon is good enough to narrow down the timing as much as we thought.
      • Criminal nonsense! The models "prove" what happened. We have a graph shaped like a hockey stick that shows the heavy bombardment started 4 BYA. It's proven science, 97.36% of scientists agree. These cheese-heads are true deniers! If there was more money and power involved in this research I'm sure they would be publicly disgraced and banned from further grant money.

        • Criminal nonsense! The models "prove" what happened. We have a graph shaped like a hockey stick that shows the heavy bombardment started 4 BYA. It's proven science, 97.36% of scientists agree. These cheese-heads are true deniers! If there was more money and power involved in this research I'm sure they would be publicly disgraced and banned from further grant money.

          Actually, my dear anti-science, echo chamber bubble boy, your sarcasm shows that you just don't get it.

          Scientists are saying that something they thought was right, may now be wrong.

          The exact opposite of your stupid rant. It's the exact thing you claim they do not do Try to self correct..

      • existing zircons knocked about by an impact rather than formed in that impact

        Which makes obvious sense, because much of the moon used to be part of the Earth, and was squashed pretty good in the impact. That would obviously confuse the process of extracting additional impact data from the same material. These numbers should always have been suspect. This is why it is important to be aware of what assumptions are being made, and to continually reconsider if existing assumptions still apply.

    • Wait, what?

      > assuming that this might not have happened on the Moon

      I can't find this quote anywhere in the summary or the story. Where did you get it?

  • It may be wrong doesn't mean it isn't right.
  • I've met a fair number of Late Heavy Bombardments, but can't say it occurred to me to date them. Have they tried rolling it in flour and going for the wet spot?

  • Yes, yes, as we all know science is wrong, and the earth was made approximately 5000 years ago. And the earth is flat.

If you're not careful, you're going to catch something.

Working...