Mystery Class Sunlight Challenge: Week #6
March 2, 2018 by Julie Brophy

The Vernal Equinox is coming! Notice how the line between light and dark on the equinoxes matches longitude.

Animation: Sunrise on the Equinox

Seasons Comparison
Week #6: Sunrise on the Equinox

Only on the equinoxes do locations at the same longitude experience sunrise at the same time. Next week's Time Clues will help you estimate the longitude of the Mystery sites.

Looking for a Clue?
When sunrise occurs at the Prime Meridian on the Vernal Equinox, eight Mystery sites will already have had sunrise and the other two will still be waiting.


Photoperiod Clues from the Mystery Sites

Mystery Class Photoperiod Map

Compare Your Photoperiod

Report Photoperiod

Mystery Class Photoperiod Map


Student Activity
Try this activity to help students make connections between time and longitude.

Teacher Planning Packet
Includes background information that will help you understand the science and math behind time clues.

Time and Longitude


Journal: Predicting Photoperiod

Draw your photoperiod graph the way you predict it will look at the end of March.

Journal #6
Next Update March 9, 2018