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Meteorites

Meteorites. Meteors?. Meteoroid in space. Meteor in atmosphere. Meteorite o n Earth. Where do they come from?. Asteroid belt : source of meteorites. How do we know?. Pribram 1959. Innisfree 1977. Asteroids can be really big. Often smash into each other. Mars. Meteorites are….

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Meteorites

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  1. Meteorites

  2. Meteors? Meteoroid in space Meteorin atmosphere Meteoriteon Earth

  3. Where do they come from? Asteroid belt:source of meteorites

  4. How do we know? Pribram 1959 Innisfree 1977

  5. Asteroids can be really big • Often smash into each other Mars

  6. Meteorites are…. • Samples of planetesimals • Samples of asteroids • Oldest evidence of our solar system • Up to 4.6 billion years old!

  7. Types of Meteorite Stony stony, iron or stony-iron… Iron Stony-iron

  8. Types of Meteorite Iron • Iron meteorites • Stony meteorites • Chondrites • Achondrites Stony Stony

  9. Early Solar System A star exploded Bits of the cloud, called a nebula, began to stick together Gravity pulled the lumps together The lumps gathered more and more rocky dust They became the planets

  10. Chondrite • From the oldest asteroids • Lumps ‘left over’ from when our Solar System formed!

  11. Crusty Chondrite • Can you see the ‘crust’ on this meteorite? • Friction melted the meteorite’s surface as it entered the Earth’s atmosphere Heated crust

  12. Carbonaceous chondrites • Rare meteorites • Most studied • Formed in the solar nebula 4.56 billion yrs ago • Contain elemental carbon and amino acids.

  13. Differentiation • Some planetesimals were large • They differentiated into an iron-rich core and a rocky mantle and crust

  14. Iron Meteorite • From the cores of asteroids • Dense iron-nickel • Same material as core of Earth

  15. Iron Meteorite • Has a ‘thumb pressed’ surface • Caused by melting due to friction in the atmorpshere This stamp commemorates the fall of this meteorite

  16. Iron Meteorite • Sliced to reveal the inside • Iron-nickel alloy • Unique pattern of crystals called ‘Widmanstätten’

  17. Differentiated Body Not differentiated Crust Achondrites

  18. Achondrites • From the crust of a planetary body • Created by meteorite impacts • Look like rocks from Earth

  19. Stony meteorite(Achondrite) • Some are from the crusts of asteroids • Others are from the Moon and Mars

  20. Stony meteorite(Achondrite) Vesta • This one is actually from the Asteroid Vesta!

  21. Pallasites • Mixtures of iron-nickel alloy and non-metallic minerals • Earth's core/mantle

  22. Stony meteorites(Achondrites) • Look like rocks from Earth • Some are the crusts of asteroids • Others are from the Moon and Mars

  23. Tektites • Earth rocks can be melted on impact • Molten droplets of splashed rock fall back to Earth

  24. Moldavites • A type of tektite found in the Czech Republic • From the Ries crater in Germany • 15 million years old Source crater Moldavites

  25. How to spot a meteorite • Magnetic • No holes or bubbles • Melted outside, silver inside • OR Dark crust, grey inside

  26. Impacts Try the Impact Calculator to see what effect a meteorite impact can have http://down2earth.eu/ Impact_calculator

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