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Science

New NASA Maps Show A Bad Day On Earth 392

Posted by timothy 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."
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New NASA Maps Show A Bad Day On Earth More

New NASA Maps Show A Bad Day On Earth

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  • sounds like a dupe (Score:3, Informative)

    by databoing ( 259158 ) on Tuesday March 11, 2003 @02:47PM (#5486167)
    Wasn't this in Slashdot about 2 days ago?

  • A Meteor Did *NOT* Kill the Dinosaurs (Score:4, Funny)

    by egg troll ( 515396 ) on Tuesday March 11, 2003 @02:48PM (#5486175) Homepage Journal
    Everyone knows that cigarette smoking did. At least that's what Gary Larson has hypothesized.

  • Man, every asteroid kills the poor dinosaurs (Score:5, Funny)

    by ArmorFiend ( 151674 ) on Tuesday March 11, 2003 @02:49PM (#5486193) Homepage Journal
    It seems whenever anyone finds a reasonably large crater, they declare "this is it, this is the one that killed the dinos". It grabs headlines. I'd hate to be a dinosaur, because it seems like I'd've been extinctified about 12 times over by genocidal asteroid de jour.

    • Re:Man, every asteroid kills the poor dinosaurs (Score:5, Interesting)

      by Malc ( 1751 ) on Tuesday March 11, 2003 @02:54PM (#5486260)
      They've been talking about an asteroid landing in the Gulf of Mexico since before I studied Geology in 1990. I remember being taught about the ejector blanket evidence they'd discovered in amongst the rock layers. The actual crater is rather harder to find due to it being submerged and eroded - it's not like it's obvious like the one in the desert in Arizona.

    • Re:Man, every asteroid kills the poor dinosaurs (Score:5, Funny)

      by rabiteman ( 585341 ) on Tuesday March 11, 2003 @02:59PM (#5486303) Homepage
      It seems whenever anyone finds a reasonably large crater, they declare "this is it, this is the one that killed the dinos". It grabs headlines. I'd hate to be a dinosaur, because it seems like I'd've been extinctified about 12 times over by genocidal asteroid de jour.

      Well, the first asteroid was just a warning. Then the next ten were warnings, too. This current one, on the other hand... was the final chance for the dinosaurs to get their act in gear. In a few months, satellites will discover evidence of a 13th apocalyptic asteroid in Siberia. That's the one that took out the dinosaurs.

    • Re:Man, every asteroid kills the poor dinosaurs (Score:5, Informative)

      by $$$$$exyGal ( 638164 ) on Tuesday March 11, 2003 @02:59PM (#5486307) Homepage Journal
      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.

      • Yeah, but how do they know that this *particular* asteroid wiped out most of the species on the planet 65 million years ago? As the parent poster pointed out, there have been many such asteroid impacts discovered, and there's no proof one way or the other that one or any of them caused the extinction of the dinos. It's not like anyone was around 65 million years ago to see it.

        • > how do they know that this *particular* asteroid
          > wiped out most of the species on the planet 65
          > million years ago?

          obviously they can't, with irrefutable "ah-ha this is it!" evidence. However they can narrow down the range of options for a specific candidate with things like core samples.

          when an asteroid hits, it reorders the earth around it in some fairly identifiable ways. I don't know all the specifics, but it is rather common for geologists to date asteroid impacts by analyzing not just the dirt above the old crater, but the dirt below it too.

          For example, if you take a core sample from a known undisturbed part of the planet, and identify at what age any specific depth was the surface of the earth, you can compare this sample to a sample taken from a suspected asteroid impact crater and date it that way.

          Under the impact crater, there will be undisturbed material (fossils, stones, etc). Above it will be a messy jumble of everything, from bits of glass formed in the heat of the impact, to shattered rocks, a complete reordering of dirt layers.. stuff like that.

          if you can link an event in earth's history (eg, dinosaurs going extinct) to the timeline a core sample reveals, you can get a pretty good guess for what the cause of the event was.

        • Re:Man, every asteroid kills the poor dinosaurs (Score:4, Funny)

          by Anonymous Coward on Tuesday March 11, 2003 @03:32PM (#5486617)
          Because of all the dino skeletons in this crater, twisted to look over their shoulder with forelegs raised in a defensive "oh no" posture.

        • Re:Man, every asteroid kills the poor dinosaurs (Score:5, Informative)

          by Graff ( 532189 ) on Tuesday March 11, 2003 @03:42PM (#5486689)
          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.

      • Re:Man, every asteroid kills the poor dinosaurs (Score:5, Informative)

        by DrinkDr.Pepper ( 620053 ) on Tuesday March 11, 2003 @03:26PM (#5486563)
        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. [arizona.edu]

      • Re:Man, every asteroid kills the poor dinosaurs (Score:5, Interesting)

        by fermion ( 181285 ) on Tuesday March 11, 2003 @04:01PM (#5486803) Homepage Journal
        I don't remember when the asteroid theory of dinosaur extinction was recognized as a good possibility, but it must have late 80s. At that time we didn't know if was one or many. I know that in the early 90s the the Yucatan crater was identified as the most likely culprit, as it was big enough and contemporaneous with the extinction which put the single asteroid extinction at the forefront.

        So, through most of the 90's we accepted that a single impact event wiped out the dinosaurs. Now, however, more impact craters are being found to have been formed within the crucial 65 million time frame (a search on multiple impact and dinosaur extinction). This is good news because perhaps a single big asteroid might not be fatal, and we may be more able to detect a swarm of meteors.

        Anyway, science is a self correcting system, and at this point is may be best just to say it is likely that at least one asteroid hit the earth and was a major contributor to the extinction of the dinosaur. But I know that is too long for a soundbyte.

    • Re:Man, every asteroid kills the poor dinosaurs (Score:2, Funny)

      by Anonymous Coward
      And they all fail to take the bible into account: Clearly it was GOD who smote the dinasaurs as he tired of their annoyingly repetitive and formulaic gameplay, instead installing a copy a Humans v1.0. Unfortunately he's getting a little tired of this game, too, and rumor has it that he's ready to unleash some fun WMDs to clean the slate for the next game.
      • I'm going to unleash them babies tomo...

        Oops, you aren't supposed to know that I'm Your God yet.

        Uhm...

        This is obviously another case of exploding gas mains that only sounded like me admitting to being God. Now, good netizens, if you would only look into the laser of your optical mice, we'll have the matter cleared up in a jiffy.:)
    • The Chicxulub site has been referenced and studied for quite a while now in the context of "the" meteor hit. Most of the meteor impact theory surrounds this one site, not many different sites.
      It just gets a newsworthy face lift every time someone finds yet more evidence supporting it.
    • You'd swear Apple was a dinosaur, too -- they've been declared "extinct" on a monthly basis since the early 1990's. Something weird about Asteroid Gates or something like that... I'd still love to be Apple, though.

  • Dupe (Score:5, Informative)

    by Anonymous Coward on Tuesday March 11, 2003 @02:50PM (#5486194)
    From the 7th - NASA Releases New Topographic Map of North America [slashdot.org]

  • Dino Deaths (Score:4, Funny)

    by Anonymous Coward on Tuesday March 11, 2003 @02:50PM (#5486201)
    The Dinos died coz they ran out of beer. Stop lying to us !

  • Something concrete (Score:4, Insightful)

    by BJZQ8 ( 644168 ) on Tuesday March 11, 2003 @02:50PM (#5486202) Homepage Journal
    Finally something people can "grab ahold of" out of NASA. If they made a bigger deal out of a lot of their other advances and discoveries they would be held in better public esteem. But the public usually only pays attention when something bad happens.
    • The ignorant public doesn't realize that this is just another attempt by NASA to distract us from the truth about the moon landings. They never happened! And this data is certain to all be faked as well.

      Conspiracy theorists unite and take over the airwaves!

      Oh wait, we've already done that. Unite anyway! Buy an Art Bell t-shirt and show pride in what you believe! Keep this great American country safe for truth, coverups, and UFO sightings!

  • Dinosaurs not killed by comet (Score:4, Funny)

    by guacamolefoo ( 577448 ) on Tuesday March 11, 2003 @02:52PM (#5486222) Homepage Journal
    C'mon! If the dinosaurs were killed by a comet, why weren't people killed, too? Didn't you ever watch the Flintstones? Given the interspecies symbiosis, it is highly unlikely that a sudden and catastrophic loss of the dinosaurs would not have resulted in a destruction of mankind as well. How would humans have quarried rock?

    No, I think a much more plausible explanation is that the dinosaurs were actually the victims of second-hand smoke, overpopulation, and perhaps disease. I mean, really.

    GF.

  • no nuclear winter (Score:5, Informative)

    by wwest4 ( 183559 ) on Tuesday March 11, 2003 @02:52PM (#5486224)
    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.

    • Re:no nuclear winter (Score:5, Interesting)

      by antis0c ( 133550 ) on Tuesday March 11, 2003 @03:50PM (#5486733)
      I've often wondered what I'd do if there were some kind of mass catastrophy headed our way. And I don't mean Osama setting off a Nuke on the east coast, or something, I'm talking about real apocolyptic stuff, the stuff that would destroy our entire society. Of course the first thought is to stock up on Guns, Food, Water and Toilet Paper. Build a shelter of some kind, that sort of stuff.

      Then I'm reminded that in those situations, the people that die are often the lucky ones. So I'm torn, try to survive or just give up. I'm not sure I'd want to live a life in a post apocolyptic world anyway. So I say when the big one hits, I only need 3 supplies. A Ladder, A Lawn Chair and A bottle of Southern Comfort. This way at least I have a decent view.

      • Re:no nuclear winter (Score:5, Funny)

        by Torgo's Pizza ( 547926 ) on Tuesday March 11, 2003 @04:26PM (#5486965) Homepage Journal
        Oh, don't wuss out completely. I have learned from playing Fallout 1 & 2, Wasteland and watching all the Road Warrior movies that I can finally have a pink mohawk, wear football pads and drive as fast as I want with a sawed-off shotgun in a Post-Apocolyptic world.

      • Re:no nuclear winter (Score:3, Insightful)

        by Ian Bicking ( 980 )
        Why a gun? I don't see why a post-apocolyptic world would be particularly violent, though I guess it depends on what kind of apocolypse.

        If the mass of humanity was killed, and you survived, wouldn't you seek the company and assistance of others? In the wake of tremendous destruction, what purpose would violence have? Cooperation would seem infinitely more important.

        Sure, in a riot people are violent. But a riot involves people doing things they can't normally do in their lives amidst their society. It's a temporary state, almost by definition.

        In a war people are violent, often long after the war. But that's more than just the collapse of society, that's an extension of society's self-destruction. Few apocolyptic scenarios involve mass societal collapse as a cause, unless the apocolypse is somehow based on everyone being turned crazy by Radio Waves From Space or something (very Steven King-like). In that case you wouldn't want a gun, because you'd kill someone you love or some other horror.

        It'd look real silly if the survivors of an apocolypse were toting around guns in an empty landscape.

        • Re:no nuclear winter (Score:5, Interesting)

          by maraist ( 68387 ) <michael.maraistN ... m ['AMg' in gap]> on Tuesday March 11, 2003 @06:09PM (#5488112) Homepage
          In a war people are violent, often long after the war. But that's more than just the collapse of society, that's an extension of society's self-destruction. Few apocolyptic scenarios involve mass societal collapse as a cause..

          Step 1) Shock/Fear: Mass fear (will might die, my family might die, where will I live?, what will I eat?).

          Step 2) Hysteria: People vauling their families or in worst cases, themselves over anything, including common human decency (trampling over people, driving over people, etc). At this stage, we become primally instinctive; we're in self-defense mode.. We're not able to think rationally.

          Step 3) Anarchy: Hysteria slowly calms down.. We're no longer screaming (though many are still crying). Depression will start kicking in for some.. Many will lose hope. Many will start to think about the future. They'll quickly rationalize lawless activities. Rape, looting, general acts of violence.. People will chant the "end of the world", and try and live out their fantacies.

          Step 4) Pragmatism: As the remaining loyalist military/police kills off the most violent offenders, the more remaining people are in three camps.

          a) The "victims" that will not be able to recover on their own; they will need to be followers.
          b) The "leaders", these will be people that will try and help out; working through the wake of disaster. These will be the optimisits. Being somewhat altruistic, they will fight for what they consider right, even in the face of dispair.
          c) The selfish. These are people who will quickly surmise that it will take decades (if ever) to recover, and in the mean time, we will be living in the stone age. There will not be enough resources to sustain the remaining levels of population. Fresh water will be virtually non-existant due to polluting drainage, and lack of pump-work. Rain-water is likely to be hazardous, and possibly droubting. Thus the selfish will realize that if they forcibly coerse other's, the "leaders" (including the military) will have them killed. Thus they will subtly backstab, usurping power (at least within their community).

          The problem is that only those smart enough to survive will become leaders. But as a follower, you can't be sure that your local leaders aren't secretly maliscious.

          The fact of the matter is that people will die due to shortages, and in the face of this, the majority of people will act accordingly, even in the long run.

          This will continue until either the population has dwindled to a sufficiently small group (which is unlikely given the then-newly-encouraged birthrate), or complex and corrupt power-systems will develop, which can contain the selfish class. Tyranical Dictatorships are the only systems that can contain anarchy. It is only given enough time and prosperity that benevolant systems can prevail.

          In short, we're talking hundreds if not thousands of years to rebuild society.

          If you're into apacolyptic tales, Revelation and Various profits (Nostradamus, etc) tend to talk about an apocalyptic aftermath which takes hundreds or thousands of years. So in short, I disagree that a cataclysmic event would have to be radio-enduced.

  • Alternate image (Score:2, Informative)

    by morcheeba ( 260908 )
    If the site is slashdotted, you can just download the full-resolution image [617.7 megabyte TIFF] [nasa.gov]

  • New meaning to NASA (Score:5, Funny)

    by A_Non_Moose ( 413034 ) on Tuesday March 11, 2003 @02:53PM (#5486245) Homepage Journal
    Now Another Slashdotting Attempt.

  • Not Shown... (Score:5, Funny)

    by Vampyre_Dark ( 630787 ) on Tuesday March 11, 2003 @02:54PM (#5486259)
    The crater that used to be their server before it was slashdotted.

  • Not a bad day... (Score:4, Interesting)

    by stereo_Barryo ( 530287 ) on Tuesday March 11, 2003 @02:55PM (#5486275)
    Actually it was a GOOD day for the earth as it got a major influx of material and upped its accretion rate, helping out in the race to be the biggest object orbiting the sun, though it still trails several other bodies, as of this writing. It WAS a BAD day for the life forms that inhabited the skin of the earth, but they didn't contribute a lot to the total mass. It WAS a GOOD day, though, for the minor life forms called mammals, as many of their predators and competitors were disposed of. Tough call on Good vs. Bad.
  • But I thought that was the asteroid in India.

    Or maybe it was the asteroid in the ocean.

    Everytime they find evidence of a crater its always the one that killed the dinosaurs.

  • In related news... (Score:3, Funny)

    by Anonymous Coward on Tuesday March 11, 2003 @03:02PM (#5486336)
    Scientists have been unable to found any traces of intelligent life anywhere on that side of the planet.

  • Crash? (Score:2, Insightful)

    by xanadu-xtroot.com ( 450073 )
    Scientists believe the impact, which was centered just off the coast in the Caribbean, altered the subsurface rocks such that the overlying limestone sediments, which formed later and erode very easily, would preferentially erode on the vicinity of the crater rim.

    Wait. So nothing's really changed. So they are basically still saying that the Gulf of Mexico is the "real" meteor crash site and not this dimple... Hmmm... let's see, let's keep reading:

    This formed the trough as well as numerous sinkholes (called cenotes) which are visible as small circular depressions.

    Ummm... yup. This is a sink-hole, a dimple in the earth caused by the sudden crash/explosion NEAR BY. This is not the crash site. I wish people would read the damn articles before even submitting them to the editors (and that opens another can of worms there, but I digress...).
    • This is an image of the Chicxulub impact site. The sinkholes outline the perimeter. How'f you get from This formed the trough as well as numerous sinkholes... to calling the crater "a sinkhole"?
  • Just how many asteroid impacts does it take to wipe out the dinosaurs, anyway? They find a new one every other month, it seems.
  • For the sake of tradition, shouldn't we be blaming microsoft for the death of the dinosaur? :) (And for that matter pointing out that linux helps prevent system crashes of this magnitude ;)

  • You just posted a link to a 617M image... (Score:4, Funny)

    by verch ( 12834 ) on Tuesday March 11, 2003 @03:18PM (#5486496)

    Worst slashdot effect... ever.

  • While it does not have these particular pictures (Score:3, Informative)

    by SquadBoy ( 167263 ) on Tuesday March 11, 2003 @03:29PM (#5486593) Homepage Journal
    here is yet another government server for us to destroy. It has many similar pretty thing for you to look at.

    http://photojournal.wr.usgs.gov

  • partial mirrors (Score:4, Informative)

    by cetan ( 61150 ) on Tuesday March 11, 2003 @03:31PM (#5486614) Journal
    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 :)
  • Logically thinking, since we evolved directly from the remaining 30% of life on the planet after the comet impact, wouldn't we be a likely survivor of subsequent 'extinction level' impacts?

    It's all about evolution baby:)

  • Mirror (Score:2, Informative)

    by immybaby ( 623904 )
    Here is an annotated mirror which should help: Image [cam.ac.uk]

  • Great resolution (Score:3, Funny)

    by siphoncolder ( 533004 ) on Tuesday March 11, 2003 @04:43PM (#5487172) Homepage
    *zooms in on the 600MB+ TIFF*

    Wow... I think I can see my house from here...

  • But if I wanted I really wanted I could play with the color schemes enough to make the virgin mary's face appear in the yukatan. They could have just as easily made this photo appear that Mount Doom exhisted off the coast of Mexico.

    Tell people to look for the man in the moon and they will. Or a rabbit.

    Not that I don't believe this, I'm just pointing out that all of these digitally enhanced photos, be it from this or the hubbell, or whatever are just that. Enhanced.

    Just food for thought.
  • The US really is a hole.

  • If this is where the meteor hit the earth... (Score:3, Interesting)

    by CAIMLAS ( 41445 ) on Tuesday March 11, 2003 @05:46PM (#5487842)
    If this is where the meteor hit the earth, where's the meteor? We see all these impact crators, but nobody seems to have found - or at least mention having found - the meteor. It must've been one huge SOB, so why haven't they found it?

    Could this (looking for a crater hole) be akin to something like seeing shapes and animals in the clouds? Or along the lines of finding the face of a man on mars? Topography is very diverse and complex, and there are millions of weird variations on the earth. There's a large crater in the Sea of Japan, too - has this one been discredited as causing the great evolutionary distinction of the dinosaurs?

    What if - maybe - these "caters" weren't caused by meteorites or comets, or anything like that at all? What if they're something like 'sink holes' (not the right term - what I'm thinking of are the holes that are made by fresh-water springs) that once spewed up large amounts of water to flood the earth? (another extinction theory that's equally plauseable, it's just that people disvow it because it 'supports' creationism) These 'craters' could be the result of water flowing back into the sinkhole after this flood (caused by high-presure volcanic action?), bringing large amounts of soil with them - the water had to go somewhere, right?

    If anyone has links or other information on where these craters went, I'd be glad to see them. It's pretty obvious to me that something that big doesn't just disappear.
    • The reason we don't usually get to see the original meteor is simply because it has been vapourised in the intense heat caused by impact ;) If you think about it, these things may be travelling at about 150 000km/h, and all that kinetic energy needs to go somewhere, so it gets transferred to heat energy - here's an experiment you can perform in your garage - strike a metal plate with a sledgehammer several times (wear ear protection!) not only might you see sparks fly, but feel the plate and hammer afterwards - it will be hot. Meteorites usually contain high concentrations of Platinum Group Elements (PGE's) e.g. rhodium, palladium, and platinum. They also contain relatively high concentrations of irridium relative to earth because these bodies haven't had the chance to chemically differentiate them through the forces of gravity. Moreover, they have different isotope ratio's when compared with terrestial PGE's - this is how you know if it's terrestrial or not! Now, when the impact event occurs, the atoms don't get destroyed, they get transferred to the target material. (you can vapourise the impactor, sure, but you can't destroy the atoms) So you can look for these signatures geochemically, and in some cases you can even tell what type of meteorite hit the earth (stoney, iron or carbonaceous chondrite) Reference: McDonald, I (2002): Clearwater East impact structure: A re-interpretation of the projectile type using new platinum-group element data from meteorites, Meteoritics and Planetary Science, vol.37 459-464

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