3/20/2003 Double-X
Navigating by Starlight

 Presented by Morgan Ames and Chinmayi Bettadapur
Double-X at Oakland Technical High School

Topics:
  • Why learn the constellations?
  • Directions from the stars
  • Latitude in the Northern hemisphere
  • Latitude and directions in the Southern hemisphere
  • Navigation by starlight historically
  • How to find longitude?
  • Links

    Why learn the constellations?

    Directions from the stars

     Reading a Star Map - finding "Ursa Major" (the official constellation) or the "Big Dipper" (the asterism)


    Finding the Big Dipper and Polaris, the north star or "pole star"
    Polaris is more accurate than a compass!
    Finding Polaris in the city




    Latitude in the Northern hemisphere

     Height of Polaris from different latitudes




    Estimating degrees in the sky
  • With hand at arm's length:
  • pinky width = 1.5 degrees
  • width of three fingers = 5 degrees
  • width of palm = 10 degrees
  • width of outstretched pinky to thumb = 20 degrees



    Latitude and directions in the Southern hemisphere

     Reading a star map for the Southern hemisphere - landmarks, differences


    The Southern Cross


    Finding where the "southern star" would be from the southern cross


    Find the celestial south pole in these images:


    Navigation by starlight historically

     Polynesians, European explorers, others by sea; almost everyone by land!
    Sextants and other tools that use the stars

    How to find longitude?

     No easy way - get to the right latitude, and travel directly east/west as needed

    Links
  • Interactive sky chart
  • How to find south in southern hemisphere
  • Free online star charts, by month
  • Estimating angles in the sky
  • Google directory: constellations
  • Google directory: sky maps and atlases
  • Stargazing at the Lawrence Hall of Science
  • UC Berkeley Astronomy Club

  • Page created by Morgan Ames