Chapter 9 Glossary terms

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Chapter 9 Glossary terms
2013-01-16 19:40:26
Science Glossary Terms Ms Day Grade

The glossary terms for chapter 9 of Science ON 9
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  1. Milky Way
    The galaxy that includes the solar system; appears as a hazy white band in the night sky.
  2. Galaxy
    A huge collection of stars, planets, gas and dust that is held together by gravity.
  3. Star cluster
    A collection of stars held together by gravity
  4. Open Cluster
    A collection of 50-1000 stars; open clusters appear along the main band of the Milky Way.
  5. Globular Cluster
    A collection of 100,000 to a million stars that is arranged in a distinctive spherical shape; Globular clusters are around the centre of the Milky Way.
  6. Local group
    The small group of 36 galaxies that includes the Milky Way.
  7. Supercluster
    A gigantic cluster of 4 to 25 clusters of galaxies that is hundreds of millions of light-years in size.
  8. Spiral Galaxy
    • Spiral- A type of galaxy that looks like a pinwheel when viewed from above.
  9. Elliptical Galaxy
    A type of galaxy that ranges in shape from a perfect sphere to a stretched-out ellipse.
  10. Irregular Galaxy
    A galaxy that has an irregular shape.
  11. Cosmology
    The study of the universe.
  12. Doppler Effect
    The change in pitch of a sound due to the motion of the source relative to an observer; also, the change in frequency of a light source due to its motion relative to an observer.
  13. Redshift
    The effect in which objects moving away from an observer have their wavelengths lengthened, toward the red end of the visible spectrum.
  14. Blueshift
    The effect in which objects moving towards an observer have their wavelengths shortened, toward the blue end of the visible spectrum.
  15. Big bang
    The event that may have triggered the expansion of the universe 14 billion years ago.
  16. Cosmic Microwave Background(CMB) Radiation
    The radiation left over from the big bang, which fills the universe.
  17. Dark Matter
    The most abundant form of matter in the universe; invisible to telescopes.
  18. Dark Energy
    A form of energy that makes up nearly three quarters of the universe has the effect of increasing the expansion of the universe.