Lesson 5: Navigation on Earth

Lesson 5: Navigation on Earth

1. Coordinate System - assigns a pair of coordinates called longitude and latitude

   • Latitude - the angular distance in degrees North or South of the equator
   • Equator - the imaginary line that circles the Earth halfway between the North Pole and the South Pole
   • Prime Meridian - the imaginary line that runs through Greenwich, England, from the North Pole to the South Pole
   • Longitude - the angular distance in degrees East or West of the prime meridian
   • Parallels - the lines that connect points of equal latitude, called parallels because they never touch
   • Meridians - the lines that connect points of equal longitude, they all meet at the poles

2. Determining Latitude

   • Latitude north = the angle of Polaris above the horizon
   • Point stars (the 2 stars at the end of the bowl of the Big Dipper) point towards Polaris
   • Astrolabe - a tool used to measure the angle above the horizon of an object in the sky

3. Determining Longitude

   • (Local Time - Greenwich Local Time) * 15 = Longitude
   • Positive Longitude = West of the Prime Meridian
   • Negative Longitude = East of the Prime Meridian