Ch. 16 Vocabulary

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Ch. 16 Vocabulary Our Solar System

• (p. 509, 15 terms 9)

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1. Nebula

• A large cloud of gas and dust in interstellar
  space a region in space where stars are born.

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2. Solar Nebula

• A rotating cloud of gas and dust from which the
  sun and planets formed.

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3. Astronomical Unit

• The average distance between the Earth and the
  sun approximately 150 million kilometers
  (symbol, AU).

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4. Terrestrial Planet

• One of the highly dense planets nearest to the
  sun Mercury, Venus, Mars, and Earth.

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5. Prograde Rotation

• The counterclockwise spin of a planet or moon as
  seen from above the planets North Pole rotation
  in the same direction as the suns rotation.

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6. Retrograde Rotation

• The clockwise spin of a planet or moon as seen
  from above the planets North Pole.

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7. Gas Giant

• A planet that has a deep, massive atmosphere,
  such as Jupiter, Saturn, Uranus, or Neptune.

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8. Satellite

• A natural or artificial body that revolves around
  a planet.

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9. Phase

• The change in the sunlit area of one celestial
  body as seen from another celestial body.

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10. Eclipse

• An event in which the shadow of one celestial
  body falls on another.

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11. Comet

• A small body of ice, rock, and cosmic dust that
  follows an elliptical orbit around the sun and
  that gives off gas and dust in the form of a tail
  as it passes close to the sun.

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12. Asteroid

• A small, rocky, object that orbits the sun most
  asteroids are located in a band between the
  orbits of Mars and Jupiter.

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13. Meteoroid

• A relatively small, rocky body that travels
  through space.

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14. Meteor

• A bright streak of light that results when a
  meteoroid burns up in Earths atmosphere.

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15. Meteorite

• A meteoroid that reaches Earths surface without
  burning up completely.

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16. Nuclear Fusion

• When hydrogen combines to form helium and energy
  is released.

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17. Proton

• A subatomic particle that has a positive charge
  and that is located in the nucleus of an atom
  the number of protons in the nucleus is the
  atomic number, which determines the identity of
  an element.

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18. Inner Solar System

• Contains the four planets that are located
  closest to the sun.

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19. Outer Solar System

• Contains the five planets that are located
  farthest from the sun.

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20. Period of Rotation

• The amount of time that an object takes to rotate
  once.

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21. Revolution

• The motion of a body orbiting another body in
  space.

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22. Period of Revolution

• The time that an object takes to revolve around
  the sun once.

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23. Solar Eclipse

• When the moon comes between Earth and the sun and
  the shadow of the moon falls on part of Earth.

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24. Lunar Eclipse

• When Earth comes between the sun and the moon and
  the shadow of Earth falls on the moon.

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Grading Scale

• (1 point per term)
• A 24 - 20
• B 19 - 18
• C 17 - 16
• D 15 - 14
• F 13 or less
• 2 E.C. pt.s possible