Lesson Plan #7     http://www-spof.gsfc.nasa.gov/Stargaze/Llatlong.htm

(5) Latitude and Longitude

An introduction to coordinates on a sphere: how latitude and longitude define locations on Earth, and similarly, how declination and right ascension define locations on the celestial sphere. Also introduces systems of time-keeping, e.g. local solar time, time zones, universal time and the international date line.

Part of a high school course on astronomy, Newtonian mechanics and spaceflight
by David P. Stern, Code 695, Goddard Space Flight Center, Greenbelt, MD 20771
u5dps@lepvax.gsfc.nasa.gov or audavstern@erols.com

This lesson plan supplements: "Latitude and Longitude," section #5: on disk Slatlong.htm, on the web
          http://www-spof.gsfc.nasa.gov/stargaze/Slatlong.htm

"From Stargazers to Starships" home page and index: on disk Sintro.htm, on the web
          http://www-spof.gsfc.nasa.gov/stargaze/Sintro.htm


Goals: The student will

  • Know how any location on Earth can be defined by its latitude and longitude.

  • Learn the difference between local time and universal time, and the various adjustments made to "clock time," e.g. time zones, daylight saving time and the use of the international date line.

  • Know that any position on the celestial sphere can be defined by declination and right ascension. These are similar to latitude and longitude except that:
    • Declination is measured from the north pole, not from the equator (the way co-latitude is defined)
    • Right ascension is traditionally given not in degrees but in time units--in hours, minutes and seconds.

Terms: Latitude, longitude, Line of latitude, line of longitude (or meridian), co-latitude, equator, zero meridian ("prime meridian"), eastern and western hemispheres, (local) noon meridian, local time (LT), time zones, international date line, universal time (UT; of "Greenwich Mean Time" GMT), declination, right ascension, "First point in Aries" (or "vernal equinox") on the celestial sphere.

By this stage the student should also know and be able to write at least a few lower-case letters of the Greek alphabet--l, t , f, d, a, (lambda, theta, phi, delta, alpha, corresponding to (L,T,F,D,A)

Stories and extras: Origin of the word "meridian" and the abbreviations "a.m." and "p.m.". The Royal Observatory in Greenwich. Introduction of time zones.

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Author and curator: David P. Stern, u5dps@lepvax.gsfc.nasa.gov
Last updated 28 July 1999
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