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Australia Earth Space

World's Largest Asteroid Impacts Found In Central Australia 74

Posted by samzenpus from the call-bruce-willis dept.
schwit1 writes Scientists doing geothermal research in Australia have discovered evidence of what they think is the largest known impact zone from an meteorite on Earth. The zone is thought to be about 250 miles across, and suggests the bolide split in two pieces each about 6 miles across before impact. The uncertainty is that the evidence for this impact is quite tentative: "The exact date of the impacts remains unclear. The surrounding rocks are 300 to 600 million years old, but evidence of the type left by other meteorite strikes is lacking. For example, a large meteorite strike 66 million years ago sent up a plume of ash which is found as a layer of sediment in rocks around the world. The plume is thought to have led to the extinction of a large proportion of the life on the planet, including many dinosaur species. However, a similar layer has not been found in sediments around 300 million years old, Dr Glikson said. 'It's a mystery – we can't find an extinction event that matches these collisions. I have a suspicion the impact could be older than 300 million years,' he said."
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World's Largest Asteroid Impacts Found In Central Australia More

World's Largest Asteroid Impacts Found In Central Australia

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  • Not Surprising (Score:5, Funny)

    by organgtool ( 966989 ) on Monday March 23, 2015 @03:06PM (#49322977)
    It wouldn't be surprising if this is true - Australia is already the home of the deadliest form of everything else on this planet.

    • Re: (Score:1)

      by Anonymous Coward

      It wouldn't be fair if Australia didn't have some down sides.

      • The animals really aren't downsides, they keep the tourist population in check.... well them and the insane prices for everything here.

    • God, having realised what he wrought, tried to destroy it. Unfortunately Australia had grown too powerful by then.

  • There was a theory that the Gulf of Mexico is a meteor crater. About 1000 miles across.

    • Re:Gulf of Mexico ? (Score:4, Informative)

      by dreamchaser ( 49529 ) on Monday March 23, 2015 @04:36PM (#49323549) Homepage Journal

      I'm not sure where you got that one. The only credible theory related to it is the Chicxulub crater, which is on the Southern edge of the Gulf, near the Yucatan Peninsula. That's what's left by the impact that many believe killed most of the dinosaurs, as well as many other species. It's not even close to the size of the whole Gulf. What theories are you talking about?

      • Tinfoil-hat type.

      • I'm not sure where you got that one [that the Gulf of Mexico is an impact crater]. The only credible theory related to it is the Chicxulub crater, which is on the Southern edge of the Gulf ........... What theories are you talking about?

        I had heard of it, not sure how. This is Wikipedia (under Gulf of Mexico):-

        In 2002 geologist Michael Stanton published a speculative essay suggesting an impact origin for the Gulf of Mexico at the close of the Permian, ...... However, Gulf Coast geologists do not regard this hypothesis as having any credibility. Instead they overwhelmingly accept plate tectonics...... This hypothesis is not to be confused with the Chicxulub Crater

        I did not say I supported the theory, only that it was suggested. I am not a geologist. Clearly it is now out of favour.

  • The moon (Score:1)

    by Anonymous Coward

    Looking at how pockmarked the moon is with well preserved craters, I wouldn't be surprised if large impacts weren't far more frequent than we estimate (on geological timescales). As for the missing sediment from this impact, maybe the dating is wrong?

    • Re:The moon (Score:4, Informative)

      by Dunbal ( 464142 ) * on Monday March 23, 2015 @04:05PM (#49323349)
      Except, the moon has no atmosphere to burn up all the smaller meteors. Here on Earth anything that reaches the surface had to start out big. Since there are more small asteroids than big ones it's much less likely we will get a surface impact compared to the moon.

      • Re: (Score:2)

        by dryeo ( 100693 )

        Consider the number of craters over a mile across on the Moon.

        • Re: (Score:3)

          by Dunbal ( 464142 ) *
          Consider that the moon has 1/6th of Earth's gravity so stuff is going to fly much further (6x) for the same energy.

          • Re: (Score:2)

            by dryeo ( 100693 )

            Congratulations, you figured out why I mentioned 1 mile crater rather then 800 ft crater.
            While it is true that certain types of meteorites burn up or disintegrate, many are chondrites, stony or iron. Lots of small iron meteorites have been found, along with slightly bigger stony and chondrites. The biggest difference between the Earth and Moon is that the smaller meteorites hit at terminal velocity and don't create much more then a pit.
            The Earth, while obviously not getting many micro-meteor hits, does get

    • Most of the Moon's craters formed during the Late Heavy Bombardment period (3.8-4.0 billion years ago). The Earth was likely similarly impacted during this time, however on the Earth, geologic processes have erased almost all evidence of these. Oceanic crust is recycled every 200 odd million years, and there wasn't much continental crust during that period. Any crust that remains has been weathered, eroded, uplifted, folded, compressed, a dozen times. The Moon being geologically dead, and lacking any weathe

  • Metric (Score:3, Informative)

    by labnet ( 457441 ) on Monday March 23, 2015 @03:24PM (#49323085)

    Would you please stop freaking using imperial units. The rest of the world has moved on, and /. Should of all places be setting an example.

    • Re:Metric (Score:5, Funny)

      by Anonymous Coward on Monday March 23, 2015 @03:33PM (#49323129)

      The biggest and most powerful military force in the world says imperial units are just fine.

      • Re:Metric (Score:5, Funny)

        by CrimsonAvenger ( 580665 ) on Monday March 23, 2015 @03:41PM (#49323199)

        The biggest and most powerful military force in the world says imperial units are just fine.

        Which, presumably, is why we use 5.56mm rounds in our rifles, 9mm rounds in our pistols, 7.62mm in our machineguns, 60mm, 81mm & 107mm mortar rounds, 105mm, 155mm & 203mm artillery, 120mm tank guns, 25mm IFV guns, and an assortment of artillery rockets in various SI calibers, right?

        That said, if a mile was good enough for Big Julie, it's good enough for me. And multiplying by 1.6 isn't really all that stressful to those of us bright enough to handle decimal points....

        • Convert that 5.56mm or 7.62 mm to inches and you will find two very common caliber rounds.

          • Convert that 5.56mm or 7.62 mm to inches and you will find two very common caliber rounds.

            Yep. It's not all that hard to label a round with SI AND Imperial units both.

            Do note that 5.56mm is NOT equal to .223, nor is 7.62mm equal to .308. It's all about supply chains - you're less likely to get a million rounds that don't fit your guns if you give each of the many (for instance) .30 caliber rounds a different label (.30-06, .30-40, .308, to give a few examples).

            It should also be noted that the 5.56/7.62

            • Thank you for the additional info. I was not aware that the calibers were originally metric.

              Also, I love your sig. I wish several people on this board felt that way on various topics.

        • Re: (Score:2)

          by MrKaos ( 858439 )

          we use 5.56mm rounds in our rifles, 9mm rounds in our pistols, 7.62mm in our machineguns, 60mm, 81mm & 107mm mortar rounds, 105mm, 155mm & 203mm artillery, 120mm tank guns, 25mm IFV guns,

          That's a metric fuckton of metric...

        • And multiplying by 1.6 isn't really all that stressful to those of us bright enough to handle decimal points....

          It would have been much neater if they could have just made the mile a nice, round 1.5km ... ;)

        • You mean the metric names of the .223 Remington in our rifles and .308 Winchester machine gun rounds. The 81mm mortar originally was Stoke's 3 in. mortar (barrel diameter 3.2") The 107mm originally was 4.2 inch M2 mortar, the improved M30 version went to the metric units. 120mm was 4.7" 155mm was 6.1", 203mm is the renamed 8 inch howitzer.

        • And multiplying by 1.6 isn't really all that stressful to those of us bright enough to handle decimal points....

          But it's not just 1.6. Sometimes it's 2.54, or it could be 4.18, or 2.2, or 0.746. Why even bother?

      • Re:Metric (Score:5, Informative)

        by JaredOfEuropa ( 526365 ) on Monday March 23, 2015 @04:01PM (#49323323) Journal
        I thought the US military uses "klicks" (which is a kilometer) rather than miles.

      • US military is mostly metric.

      • French army with metric units: Gets their asses kicked by the Germans.

        US Army with imperial units: Kicks the Germans' asses.

        Coincidence? I think not!

        • No, just retarded logic.

        • Re: (Score:2)

          by dryeo ( 100693 )

          When did the US army start using Imperial units? Imperial gallon = 160 fl ozs = 4.54 litres, one of many English gallons= 128 fl ozs = 3.78 litres. IIRC you used a weird sized inch as well which after switching to the Canadian inch of 25.4 mm back in the '50's, lives on as the surveyors inch.
          Besides everyone knows it was the Russian army that kicked the Germans arse.

      • Re:Metric (Score:4, Informative)

        by onkelonkel ( 560274 ) on Monday March 23, 2015 @05:51PM (#49323911)

        Wrong. The biggest and most powerful military force in the world uses metric units (with a few exceptions). It's the civilians that cling to imperial units.

      • No, I'm fairly certain the Chinese Army uses metric units, not imperial.

      • Who is that?
        The biggest military is the China, and they use metric.
        The most powerful is debatable. If recent history is anything to go by, then it could be any number of goat herder tribes that continually embarrass much larger foe.

      • Re: (Score:2)

        by Trogre ( 513942 )

        China uses imperial units?

  • If they haven't named the craers yet, I suggest we call them Mel Gibson's career.

  • Permian–Triassic (P–Tr) extinction eve (Score:3, Insightful)

    by Anonymous Coward on Monday March 23, 2015 @03:44PM (#49323223)

    This would certainly explain this, the world's most devastating extinction event.

    • Not if the asteroid hit between 300 and 600 million years old, and the Permian-Triassic boundary is at 252. The other issue is that people have already looked for signals of impact at the P-Tr boundary- iridium, shocked quartz, spherules like you get with the Chicxulub impact that wiped out the dinosaurs- and found nothing. The leading hypothesis right now is that massive volcanic eruption drove the P-Tr extinction.

  • What about the moon (Score:1)

    by Anonymous Coward
    What about the moon? I thought we had all agreed that its formation was the biggest collision Earth had encountered? It was pretty much the largest that Earth could survive and still be mostly recognizable.

  • Snowball - now the cause has been found (Score:4, Interesting)

    by Thorfinn.au ( 1140205 ) on Monday March 23, 2015 @06:48PM (#49324171)
    https://en.wikipedia.org/wiki/... [wikipedia.org] about 650My ago Earth looked like the planet Hoth (StarWars 5) with the southern ice cap and the northern ice cap almost meeting, a large asteroid hit would produce much dust and give impetus to such and event.

  • 250 miles or 400 km is smaller than the Golf of Mexico crater, the Hudson'bay crater.

  • Long time ago I have read about. The crater was known about for many years now. But for it to be registered officially as an impact crater [wikipedia.org], they had to find the impact center and let other scientists review the work. When I read about it, they found the suspected impact center and were preparing for drilling. From the TFA, it seems that they have finally dug up the evidence, but I see no mention of it being officially confirmed.

    Crater wasn't found. They have just dug up and analyzed the first samples. No

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