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New NASA Maps Show A Bad Day On Earth

Posted by timothy on from the that-is-a-bad-day dept.

Stephen Lau writes "ScienceDaily has an article talking about the new NASA maps that reveal the geography of the North American continent in amazing detail. One of the maps provides strong evidence of a 112 mile wide, 3000 foot deep impact crater which they believe was the comet/asteroid impact that killed the dinosaurs and more than 70% of Earth's living species 65 million years ago."

8 of 392 comments (clear)

  1. Dupe by Anonymous Coward · · Score: 5, Informative

    From the 7th - NASA Releases New Topographic Map of North America

  2. no nuclear winter by wwest4 · · Score: 5, Informative
    The most important finding as a result of new imaging is that the mass extiction may have been caused by sulfur fumes, and fires started by hot falling debris. Before they thought photosynthesis was halted by solar obstruction from the dust cloud.


    Which means that a similarly-sized asteroid may be slightly less apocalyptic than thought. Sort of comforting, though I wonder how we'd deal with global forest fires when we can't even handle a relatively small number now.

  3. Re:Man, every asteroid kills the poor dinosaurs by $$$$$exyGal · · Score: 5, Informative
    Quote from the article:

    ... the flat limestone plateau of Mexico's Yucatan Peninsula

    In this particular case, though, this research is verifying a long held belief that a giant asteroid/comet hit the Yucatan Peninsula. This is not news of a new asteroid.

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    Very popular slashdot journal for adul
  4. Re:Man, every asteroid kills the poor dinosaurs by DrinkDr.Pepper · · Score: 4, Informative

    They had evidence of soil from the Yucatan peninsula in the K/T layer from outcroppings around to world, indicating that the impact took place there and scattered material specific to the peninsula, around the globe. Dinosaurs are found up to the K/T layer, but not above. This has been known for quite some time. The exact location of the crater was located around 1991 I believe, but was only corroborating evidence. The evidence comes from the composition of the K/T layer. This link might help.

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    0xfeedface
  5. Re:Alternate image by mithras+the+prophet · · Score: 5, Informative

    Since this is a dupe from last week, I had already downloaded the TIFF of the North America image, and converted it to a 1600x1200 JPEG.

    You can grab it here.

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  6. partial mirrors by cetan · · Score: 4, Informative

    I managed to save some of the two catalog pages here:

    http://www.phule.net/mirrors/PIA03379.html
    and
    http://www.phule.net/mirrors/PIA03377.html

    PIA03379.html has the 1.5MB image.

    No, I'm not going to try and mirror the 600+MB TIFF file :)

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    In Soviet Russia...michael would be rotting in Siberia!
  7. Re:Man, every asteroid kills the poor dinosaurs by Graff · · Score: 4, Informative
    how do they know that this *particular* asteroid wiped out most of the species on the planet 65 million years ago?

    They can't be 100% absolutely positively certain, but they can get pretty close to certain. There are several ways to find out if a particular asteroid was the cause of a certain effect.

    We can get fairly accurate dating of both the asteroid event and the extinction event. You can find out when the impact occurred by noting how deep the the impact site and the material ejected from it is buried and comparing it to the sedimentation rates in the area. You can also perform carbon dating or other isotopic analysis on material that was killed in the region of the event at the impact layer.

    If the impact was large enough then the material that made up the asteroid should have been deposited around the world. Each asteroid has a "fingerprint" of different isotopes that is fairly unique, so the deposited layer can be identified as to which asteroid caused it. This means that there will be an identifiable layer of material in the arctic ice. Since each yearly layer has seasonal dark and light bands, just count the rings to find out how old the deposited layer is.

    Dating the dinosaurs is also done pretty easily. Carbon dating and isotopic analysis can narrow down the date pretty well, as well as buried depth, sedimentation rates, and other geological identifiers. Finally, the layer that the dinosaur fossils are found in will have some of that isotopic "fingerprint" from the asteroid that impacted the Earth.

    With this information you can narrow down both the impact date and the extinction dates to a narrow range. If those ranges overlap and the impact was large enough, you probably have the impact that caused the extinction. It turns out that there is probably the major impact in the Yucatan Peninsula and a few much more minor impacts that caused the extinction of the dinosaurs. We've known about this for years, but more evidence never hurts.
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    Sapere aude!
  8. Re:Man, every asteroid kills the poor dinosaurs by dsz · · Score: 4, Informative
    There's a well-written book called T. rex and the Crater of Doom by the man who was part of the team that figured out how, when and where the asteroid hit, Walter Alvarez.

    It's a very accessible read, and explains their thought processes quite clearly.

    As I recall, the discovery of iridium, an element only found extraterrestrially (i.e. on asteroids), in the strata of rock that corresponds to the date of the extinction of the dinosaurs tipped them off.

    -DZ