The Time Clues are here to help you estimate the longitude of Mystery sites. But first, get some latitude and longitude flow with this music video from
Ms. Ciolkosz's Mystery Class Club in Pennsylvania (40.7 N, 78.0 W).

Ms. Ciolkosz's Mystery Class Club in Pennsylvania Furnace, PA, choreographed and performed this video. The club meets about twice a month after school, and includes students from home, private, and public schools. Like you, they're searching for the ten secret sites too.
(Lyrics)

Photoperiod Clues from the Mystery Sites

• Clues for Friday, March 9
• Record and Graph

Compare Your Photoperiod

• Look up your data for March 9
• Record and Graph
• Report to map, select Daylight
• Explore the Map
• Guiding Questions

Time Clues: Estimating Longitude
Make one copy for locating each Mystery Class site.

Sunrise on the Equinox

View animation as you work. You can estimate the 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.