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  • On, I learned that most meteors burn up in Earth's atmosphere. AHH the ATMOSPHERE!

  • AHhhhhh! ahhhhh. // But what happens to those that don't?

  • Hello Meteor. Trace here for DNews. Meteors and missiles can hit the ground with massive

  • force. The 1908 Tunguska Impact in Siberia flattened 2,000 square kilometers of Russian

  • forest with an explosion 1,000 times greater than the bomb dropped on Hiroshima. The meteor

  • left a crater, likely created local firestorms raised by superheated air, and particles from

  • the impact may have cooled Earth's climate,!

  • Tiny things hit planet Earth all the time, but they're usually not fast enough or large

  • enough to worry anyone. Observations from satellites suggest anywhere from 1 to 300

  • metric tons of dust hit the Earth, every. day. Assuming 100 tons, evenly across the

  • whole surface we'd gain around point zero two nanometers every year to the radius of

  • our planet. You can see some of these things as they fly through the atmosphere - anything

  • over 2 millimeters in size can create a streak of friction-spawned burnup. We call them shooting

  • stars, but they're just dust and bits of rock.

  • If a meteoroid is large enough to make it through our atmosphere and dent the solid

  • surface of our planet -- at least the size of a marble -- then it gets real. Most of

  • us know what happens to the stuff ON the surface, destruction, dust clouds, etc; but new research

  • from Duke University simulated high-speed impacts on sand and soil so now we know what

  • happens UNDER the surface too.

  • They based it on missiles, but it works for meteors too. When an object hits the surface

  • at high speed the soil doesn't move out of the way, but actually solidifies. Think of

  • it like a crowd of people, or a pack of snow -- the faster you try to move through the

  • mass -- the more difficult it becomes. The researchers dropped a metal rod with a rounded

  • end onto a pack of beads designed to simulate soil. They varied the strength of the beads

  • to simulate speeds from 67 to 670 miles an hour (6 to 300 m/s) and found as it sped up,

  • more of the beads took the force of the impact, more quickly, spreading the kinetic energy

  • over a wide area of soil. As the projectile speed increased, the particles of soil couldn't

  • get out of the way fast enough, When you think about it, this isn't a staggering discovery,

  • but it's useful for the production of bunker busting missiles -- it was funded by the Defense

  • Threat Reduction Agency,. AND it shows why, when a meteor hits the ground, it doesn't

  • just burrow into the planet. All that kinetic energy dissipates through the soil at such

  • a rapid rate, and creates a blast crater.

  • And in case you're wondering if ALL that energy could change the orbit of our planet, Earth

  • is real big, y'all. We're orbiting at around 67,000 miles an hour (108k kph) and we're

  • quite massive. If you were to blow a 100 mile-thick (160km) chunk of North America off the face

  • of the Earth; we'd only alter the Earth's momentum by about 50 miles an hour (80kph).

  • Meteoroid strikes like the Tunguska event do happen every 50 to 100 years or so, so

  • we'll likely see one in our lifetime! And now you know what's going on both above AND

  • below that crater.

  • We got some awesome questions last time we asked, so we're asking again, what do you

  • want to know about science? What should we talk about in a future DNews?

On, I learned that most meteors burn up in Earth's atmosphere. AHH the ATMOSPHERE!

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