The Most Incredible Asteroid Impacts in History

 
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    November 15, 2011 at 5:45 am

    Last week an asteroid passed by Earth within the Moon’s orbit, thus making it the closest asteroid visit in decades.  This event caused a lot of buzz about possible asteroid impacts.  Earth actually has a long history of such impacts.  Most of them have been very small, often burning up in the atmosphere.  However, a handful of history’s asteroid impacts are enormous and literally Earth-shaking. That’s why we’ve compiled some of the most incredible asteroid impacts in history into this one easy-to-skim list.

    The Cretaceous-Tertiary Extinction Event

    65.5 Million BC

    asteroidMass extinctions are not uncommon on planet Earth.  In fact, there have been dozens.  The most recent and well-known would be the Cretaceous-Tertiary Extinction Event (a.k.a, the one that killed the dinosaurs, maybe.)  You probably have a rudimentary understanding of this event from seeing Jurrasic Park. Very basically, a large asteroid hit the Earth about 65.5 million years ago and did all sorts of damage.  Many scientists believe that the mass extinction resulted from a number of variables (climate change, atmospheric disturbances, sea level fluctuations, etc.) in addition to an asteroid impact.  The notion of one large impact was pretty much just a theory until the late 1970’s when oil prospectors in Mexico discovered that much of the northern Yucatan Peninsula was essentially an enormous crater dating back to (you guessed it) roughly 65 million years.  The crater measures 180 km in diameter, and is about 10km deep.  Dubbed the Chicxulub Crater, the massive indentation  made the Cretaceous-Tertiary Extinction Event practically tangible.  The impact of the asteroid (estimated to have been about 10 km accross) would have caused tsunamis, acid rain, toxic dust storms, and scores of other terrible phenomena that ensured every dinosaur on Earth was killed.  Luckily, though, our mammalian ancestors managed to  survive the global blight.  How, you ask?  Because the mammals at the time were pretty much all tiny rat type creatures that were small and durable enough seek shelter from the chaos, while the big stupid dinosaurs were running around getting brained to death by speeding space debris.  Life, as Dr. Ian Malcom once said, finds a way.

    The Giant Impact Theory

    4.5 Billion BC

    asteroidAbout 4.5 billion years ago, Earth was a cosmic baby.  It was kind of like a large warm ball of crusty Jello that was in the process of cooling and settling into its orbital groove.  Then, a tiny protoplanet about the size of Mars went all rogue and smashed into Earth.  (Protoplanet, by the way, is a term for a sizable space rock that never formed into a full planet).  This protoplanet, called Theia by scientists, probably formed from space debris between Earth and Mars, and eventually made its way into the same orbit as Earth.  Once Theia collided with Earth, the proverbial poop hit the cosmic fan.  To give you an idea of how powerful this impact was, it reached a power 100 times greater than the asteroid impact that killed the dinosaurs.  Most of Earth’s crust and mantle was flung into space, and Theia itself was entirely vaporized.  All the unfathomably hot planetary gunk that was hurled into space was quickly caught by Earth’s gravitational pull.  Within a century, the debris left over from the Theia impact began to form into our modern moon.  This explains why geological samples brought back from the moon have an identical composition to rocks on Earth.  It does not, however, explain what the Decepticons are doing on the Moon.  I’m still very confused about that.

    The Tunguska Event

    Russia, 1908

    asteroidOver a century ago in an isolated region of Siberia, an asteroid plummeted through the atmosphere and exploded in the sky just above the forest.  The otherworldly devastation completely seared 800 square miles of Siberian forest, felled 80 million trees, and killed scores of reindeer.  It is estimated that the asteroid that detonated above Tanguska weighed 200 million pounds, and was equal to 185 Hiroshima atomic explosions.  Witnesses to the event reported blinding light, towering clouds, unbearable heat, and being forcefully knocked down by the blast (It is difficult to determine, but there are no recorded human deaths associated with the event.)  Since the asteroid disintegrated in the atmosphere, there is no impact crater, which has led to many conspiracy theories about the true cause of the Tanguska event.  The theories range from extra-terrestrial weapons to tiny black holes.  One theory posits that Nikolai Tesla was to blame. Tesla was a brilliant scientist and inventor living in America who was working on designs for a “Death Ray”, which was basically a large cannon that could shoot powerful electrical bursts over large distances (like, say, from the U.S. to Siberia).  This, however, has been debunked on account of it being particularly absurd.  What is lost sight of in all of this Tanguska hoopla is the tragic deaths of hundreds of reindeer.  How will the Siberians know it’s Christmas? Come to think of it, how did Christmas continue after all those reindeer died? And since we’re talking about Christmas now, how does Santa Clause visit every house on Earth in a single night? So many questions.

    The Chi’ing Meteorite Shower

    China, 1490

    asteroidHuman deaths caused by cosmic impacts are rare.  Often times, reported deaths result from one fragment of a burnt-up space rock striking one unfortunate victim in an (almost literally) astronomical chance of bad-luck.  The Chi’ing Meteorite Shower of 1490 is so memorable solely for the fact that a reported ten thousand people died.  Well, allegedly ten thousand.  In 1490, the Shanxi province of China was directly in the cross-hairs of a large meteor shower.  This event was similar to Tanguska, in that the space-rock exploded in the sky.  However, the Chi’ing shower happened over a densely populated area.  As the meteors fragmented in the atmosphere, a veritable cosmic buck-shot rained down on the inhabitants. First-hand reports describe speeding rocks the size of goose eggs pelting villagers.  The barrage of meteorites is detailed in the official history of the Ming Dynasty, and is generally held to be accurate by modern historians (even if the fatality count is impossible to verify and almost certainly inflated.)  Some sources report ten thousand, some tens of thousands.  But again, there’s no reliable way to put a solid number on such a remote occurrence.  But historians can all agree on one thing…some crazy space rock stuff definitely went down there.

    The Interrupted Cricket Match

    United Kingdom, 2010

    asteroidI’m sure everyone reading this enjoys a ripping good cricket match, provided they are both drunk and actually know what cricket is (which we don’t, no matter how drunk we get).  But on one fateful summer afternoon in 2010, two cricket fans, Jan Marszel and Richard Haynes, were assaulted by meteorite!  It happened last summer during a county match on Sussex, England.  A five inch long space rock came tumbling down from the sky and struck Jan Marszel in the chest.  At first, the two thought that the mysterious black dot that was bearing down on them was perhaps a wayward beamer, or maybe a donkey drop, or perhaps even a nasty bosie resulting from a particularly sticky wicket (I’m assuming these are all cricket terms), but this was no ordinary delivery on the kookaburra that day, I can tell you.  The object in question was a meteorite that is estimated to be about 4.5 billion years old, which would make it a left over relic from the time of Earth’s formation.  Luckily, neither Marszel or Haynes were seriously injured.  And at least now they have a great story to tell.  This just goes to show that meteorite impacts, though rare, can happen to anyone anywhere.  So next time you find yourself at a cricket match watching your favorite batsman negotiating a tricky gazunder resulting in the ball being gouged and making the bowler flugglestuff his hoobajoob, you’d better keep watching the skies!

    Barringer Crater

    Arizona, 50,000 BC

    asteroid craterHave you ever been driving down a lonesome stretch of road, and you pass all those billboards advertising “mysterious” roadside attractions that end up being petrified opossums, or abnormally large walnuts?  Well, Barringer Crater is a mysterious western roadside attraction that is actually worth a pit-stop.  Barringer Crater is practically the poster child for impact craters on Earth.  It’s the crater-iest looking crater on record.  It’s also the best preserved in the North American Continent.  The crater was formed 50,000 years ago in northern Arizona at a time when humans had yet to migrate into the area. Today, the climate is unbearably dry, but back then the landscape was actually moist and forested, and populated with woolly mammoths and other gargantuan mammals.  The meteorite that struck the area weighed approximately 300,000 tons, and packed energy in excess of 150 Hiroshima explosions.  When the asteroid hit, it created an enormous crater nearly a mile wide and 750 feet deep.  It also left innumerable chunks of cosmic iron sprinkled around the area that was carted off by early pioneers for wagon repairs.  Due to the arid climate, Barringer Crater is remarkably preserved, and an excellent specimen for studying impact sites.  It’s perfect for folks that find themselves in Arizona and really want to see a big hole in the ground, but don’t necessarily have time for the Grand Canyon.

    With these impacts on record, one might wonder when our number will be up thanks to a huge impact. They’d better get a good band to play, that’s for sure.

     
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