Comets, Asteroids, and Meteoroids

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Comets, Asteroids, and Meteoroids
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Comets

• Three Parts of the Comets
• Head (nucleus) glows by reflecting sunlight
• Coma hazy cloud that surrounds the nucleus
• Tail also glows by the reflecting sunlight
• It always points away from the solar winds
• When they come close to the earth the solar winds
  hit the coma the winds drive gas particles away
  form the coma (this is why the tail always points
  away from the sun)

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Where are these comets

• They spend most of their time beyond Pluto
• Many of them can only be seen through a telescope
• Most have long, elongated orbits
• The closest one, Enckes, returns every 3.3 years

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Enckes Comet
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Halleys comet

• Named after Edmund Halley, an 18th century
  astronomer
• The most popular comet
• Orbits every 76 years

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Halleys Comet
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Asteroids

• They are solid rocklike masses
• Most seems to have irregular shapes
• Most are less then 1 km long
• Planet like masses that are usually found beyond
  Mars (Asteroid Belt)

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Asteroids
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Meteors and Meteoroids

• Meteoroid is a rock or an icy fragment traveling
  in space
• Large as boulders
• Small as grains of sand
• Meteor is the light made by a meteoroid as it
  passes through the Earths atmosphere.
• FIREBALL -gt an unusually bright meteor

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Meteoroid
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Meteor
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Meteor showersMeteoroid swarms

• Meteor swarms - When meteors travel in billions
  of particles
• Meteor showers When Earth comes in contact with
  meteor swarms, which happen several times a year.

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Meteor showers
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Meteor swarms
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Meteorites

• Is part of a large meteoroid that survives its
  trip through the atmosphere and strikes the Earth
• 3 Types of Meteorites
• Stones
• 93 of the fall under this category
• Irons
• 85 90 percent of these Meteorites are made of
  Iron
• Stony- Irons
• Mixture of stone and iron

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Meteorites
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Stones
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Irons
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Stony - Iron
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Meteorite Craters

• Mainly found on other planets and their moons
• Earth still has some meteorite impacts that have
  happened recently25,000 years ago when an iron
  meteorite about 20 meters in diameter struck
  Earths Surface and explodedleaving a crater
  1300 meters in diameter and nearly 200 meters deep

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Meteors