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Comets and Asteroids

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Title: Comets and Asteroids Author: Brandy Last modified by: Brandy Created Date: 8/30/2010 12:18:43 AM Document presentation format: On-screen Show (4:3) – PowerPoint PPT presentation

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Title: Comets and Asteroids


1
Comets and Asteroids
  • What they are
  • Where the are
  • They and Us

2
Comets What they are
  • Comet A body that produces a coma of gas and
    dust a small, icy body that orbits the Sun
  • Made of ice and dust
  • Comets form tails when they pass through the
    inner solar system because solar radiation turns
    ice into gas
  • A comets tail always points away from the Sun
  • Range in size from 1 mile (think the distance
    from EWA to the Walmart) to 200 miles (think the
    distance from the bottom of NC to the top of NC)
    wide

3
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4
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5
Anatomy of a Comet
6
Comets Where they are
  • Most comets are found in the Kuiper Belt (about
    50 AU from the Sun) and the Oort Cloud (about
    50,000 AU from the Sun)
  • A few comets orbit in the inner solar system due
    to gravitational tug
  • Comets may or may not orbit the Sun in the same
    direction as the planets

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8
Anatomy of a Comet
9
The Life of a Comet
  • Scientists believe comets originated from the
    leftover debris from the creation of the solar
    system about 4.6 billion years ago
  • When comets are in the Kuiper Belt or the Oort
    Cloud, they are balls of ice
  • The comet head (coma) forms when the comet enters
    the inner solar system. The tail forms as a
    result of soar radiation turning the ice directly
    into gas and dust.
  • Comets lose ice and dust when they pass through
    the inner solar system
  • Eventually comets lose too much ice and break
    apart

10
Comets They and Us
  • Comets are usually undetectable to the naked eye,
    but may become visible when passing through the
    inner solar system
  • Meteor showers occur when Earth passes through a
    stream of particles left behind by a comet in its
    orbit
  • A notable comet Halleys comet

11
Halleys Comet
  • http//science.discovery.com/videos/100-greatest-d
    iscoveries-shorts-halleys-comet.html
  • Halleys Comet can be seen from Earth about every
    75 years
  • It is the only short period comet clearly visible
    with the naked eye

12
Asteroids What they are
  • Asteroid A small, solid, rocky body that orbits
    the Sun.
  • Asteroids are made of rocks and metals
  • They do not form tails
  • Range in size from 1000 km (the width of North
    Carolina) to less than 1 km (halfway from EWA to
    the Walmart).
  • Irregular shapes due to weak gravitational pull
  • Surfaces covered with craters, broken rock and
    dust

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15
Asteroids Where they are
  • Asteroids are found in the asteroid belt, located
    between Mars and Jupiter
  • They orbit the Sun in the same direction as the
    planets
  • There are over 4,000 asteroids in the asteroid
    belt
  • http//dsc.discovery.com/videos/fireballs-from-spa
    ce-shorts-asteroid-belt.html

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17
Asteroids They and Us
  • Asteroids are almost always undetectable to the
    naked eye
  • Asteroids produce meteors (streaks of light) upon
    entering Earths atmosphere and produce
    meteorites if they survive the trip through the
    atmosphere and hit the ground
  • Leave impact craters when they hit the Earth

18
Barringer Meteor Crater, AZ
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