Mystery Class Sunlight Challenge: Week #5
February 23, 2018 by Julie Brophy

It's time to zero in on the line that divides the globe into Eastern and Western Hemispheres.

©Stamp Design Royal Mail Group Ltd (1984)

Week #5: Zero Longitude

This commemorative stamp features a line that divides the globe into two hemispheres. The photograph of the Earth was taken by the Apollo 11 mission to the moon.

Looking for a Clue?
On March 9, time clues will be revealed to help you estimate how far east or west each mystery site is from zero longitude.


Photoperiod Clues from the Mystery Sites


Mystery Class Photoperiod Map

Compare Your Photoperiod

Report Photoperiod

Mystery Class Photoperiod Map


Journal: It's Time to Ask Questions

Why are there 24 hours in a day? Why is the world divided into time zones? When you think about time, what questions come to mind? Use these time-related acronyms and sample questions to spark your thinking.

Worksheet | Comparing Latitude and Longitude: Venn Diagram
Next Update March 2, 2018