Mystery Class
 
Mystery Class Update, March 13, 2015
By Julie Brophy

Time Clues are here! Use equinox sunrise times to estimate the longitude of Mystery sites.

Video of the Week


Music video
Longitude Rap
Clues: Week #7

Mystery Classes Photoperiod Data

Local Photoperiod Data

Resources


 Report Photoperiod

Mystery Class Photoperiod Map

 
Time Clues: Estimating Longitude
Make one copy for locating each Mystery Class site.
Sunrise on the Equinox Table Longitude Clues Worksheet Map
Time Clues
Sunrise on the Equinox
Worksheet
Step-by-step guide		 Map
Plot east/west location

World
Sunrise on the Equinox

View animation as you work. You can estimate the approximate longitude of each mystery site with the Time Clues and these key facts:

  • The Earth turns to the east as it rotates.
  • It spins 1 degree longitude every 4 minutes.
  • The time between sunrise at the Prime Meridian and sunrise at a mystery site on the equinox reveals approximate longitude.
Sample Worksheets for Practice
Longitude Clues Worksheet Longitude Clues Worksheet Longitude Clues Worksheet
Sample A
West of Greenwich		 Sample B
East of Greenwich		 Sample C
Farther east of Greenwich
Next Update March 20, 2015

© 1997 – 2019 Journey North. All rights reserved.