Astronomy

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Astronomy
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• Astronomy ? the study of the universe
• Modern Calender
• Year the time required for the Earth to orbit
  once around the sun (link)
• Day the time required for the Earth to rotate
  once on its axis (link)

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• Constellation ? sections of the sky that contain
  recognizable star patterns
• In the past they were used to navigate and keep
  track of time (link)
• Helps astronomers organize the sky (map)
• Locations change in the sky due to spinning of
  the Earth

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• Three points of reference are needed to locate a
  star
• Zenith
• Altitude
• Horizon

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• Zenith ? the imaginary point in the sky directly
  above an observer on Earth, always has an
  altitude of 90
• Altitude ? the angle between an object in the
  sky and the horizon

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• Horizon ? the line where the sky and the Earth
  appear to meet

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• Earths rotation
• Causes stars to rise and set throughout the night
  like the sun
• Circumpolar Stars ? never rise or set (link)
• They can be seen all year and all night
• Found near the poles

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• Light-year ? a unit of length equal to the
  distance it takes light to travel in 1 year
• About 9.46 trillion km
• Used because the nearest stars are much farther
  than planets
• Universe 10 billion light-years across

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• Doppler Effect ?deals with object moving towards
  and away from us
• Occurs with light wavelength in space (link)
• Red shift object moves away from you
• Blue shift object moves towards you

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• Galaxies in the universe
• Found to be in the red shift
• Evidence that shows galaxies are moving away from
  us
• Therefore our universe is expanding

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Question 1

• How have constellations helped people throughout
  time?

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Answer

• They have helped people navigate and keep track
  of time and they also organize the sky like a map

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Question 2

• Why are different sky maps needed for different
  times of the year?

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Answer

• Constellations change from season to season and
  different stars are visible from the northern
  hemisphere and southern hemisphere

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Question 3

• What is the difference between red shift and blue
  shift?

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Answer

• Red shift is when an object is traveling away
  from an observer and blue shift is when an abject
  is traveling towards and observer