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A giant asteroid, 15 kilometers wide,
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is moving toward Earth very fast.
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Over 65 million years ago, this asteroid
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crashed into the Earth near Chicxulub, Mexico.
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It made a very large crater.
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The asteroid caused the extinction of the dinosaurs,
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scientists think.
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It also caused almost 70 percent of all life on Earth
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to die out.
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It changed our planet forever.
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But how did this happen?
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Was it the debris from the crash?
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Or the heat from the explosion?
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Or was it something else?
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To answer this question, scientists want to recreate the crash
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from 65 million years ago.
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In the United States,
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a team of scientists puts a bomb in the ground.
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The team moves to a safe place.
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And they wait.
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Standby for count.
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Five, four, three, two, one.
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Oh, man, awesome.
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Oh, beautiful ejecta falling.
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Ooh, that's a crater.
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Good job, guys, outstanding.
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Now, scientists can study the explosion.
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They watch high speed cameras.
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And they learn a lot.
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What do scientists see?
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One of the first things is the large white circle.
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This is a shockwave,
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and it is moving very fast.
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It's a very powerful wall of air.
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And it can kill almost anything.
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Sixty-five million years ago, as the wave moved,
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it probably killed anything within 150 kilometers
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in the first 10 seconds.
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Now, scientists go and look at the crater.
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The crater is big,
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but the real crater in Mexico is much larger.
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It's 180 kilometers wide!
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In this experiment, debris from the explosion
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rains down for more than 10 seconds.
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Sixty-five million years ago, a huge amount of debris
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went into the air.
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Some of the pieces of debris were the size of buildings.
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The power of the asteroid is hard to imagine.
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But now, scientists understand it a little better.