How to Participate
 Introduction Mystery Class is an eleven-week hunt in which students search for ten secret sites hidden around the globe. The hunt takes place from January 28 - May 10, 2013. Photoperiod Clues Students follow photoperiod clues to find ten secret sites. On Mondays, they calculate photoperiod for their hometown. On Fridays, photoperiod data from Mystery Class sites are revealed in News Updates. A rich array of cultural, geographic, and other interdisciplinary clues are also revealed to help students track sunlight and find the Mystery Class locations.
 Data Sheet Photoperiod Graph Download and Print DOC or HTML Download and Print DOC or PDF Tape the two pages together to create a tall graph.

The Mystery Class Season: January 28 - May 10, 2013

Teaching Suggestions
Work as a team. Divide your class into ten groups. Assign each group one of the ten sites. Your hometown is the eleventh location. Provide one Data Sheet and one Graph to each group. Each week, calculate and graph photoperiod for each site.

Modifications
If you would like information about how to modify this project for students with varied needs, Contact Journey North when Mystery Class begins in late January.

MONDAYS: Local Sunrise/Sunset Data
Monday, January 28 through Monday, April 8, 2013

1. RECORD Local Sunrise/Sunset Times
Every Monday, look up your local sunrise/sunset times in the newspaper or on the web: Sunrise/Sunset Look-up. Record the information on the Data Sheet. This sheet has columns for Universal Time (UT) which will be used later in the season when sunrise/sunset times for the secret sites are given in both local and Universal Time.

2. CALCULATE and GRAPH Local Photoperiod
Calculate photoperiod by counting the number of hours and minutes the sun is up. Choose a color for your local photoperiod and plot it on the Mystery Class Graph. Remind students that all of the Mystery Class sites are recording their Monday sunrise/sunset times, too. Encourage students to make predictions before the Mystery Class sunrise/sunset data is revealed in Friday Updates.

3. REPORT Local Photoperiod to the Mystery Class Map
(Optional)
New this year! Mystery Class participants are invited to report daylength to the Photoperiod Map on Mondays, January 28 - April 8, 2013. This map is a tool that will help students visualize photoperiod data around the globe. The ten mystery sites are at secret locations and will not be shown on this map.

FRIDAYS: Sunrise/Sunset Data from Mystery Classes
Friday, February 1 through Friday, April 12, 2013.

1. RECORD Sunrise/Sunset Data for Mystery Classes
Every Friday, read News Updates to discover Monday sunrise/sunset data from each Mystery Class. Use separate data sheets to record information for each Mystery Class.

2. CALCULATE and GRAPH Photoperiod
for Mystery Classes
Count the number of hours and minutes between sunrise and sunset. Record photoperiod on the datasheet. On the graph, use a different colored pencil or marker to plot the photoperiod for each Mystery Class.

3. ANALYZE Photoperiod Data
Weekly updates include journal questions to help students reflect on the data. You may also use the Mystery Class map to help students compare Mystery Class daylengths to photoperiods from known locations around the globe. Remember: the ten mystery sites are at secret locations and will not be shown on this map.

Additional Clues: March 15 - April 12, 2013

On March 15, Longitude Clues will be revealed. These clues help students calculate the approximate longitude of each Mystery Class.

From March 22nd - April 12th, Interdisciplinary Clues will be revealed. These clues are about the geography and culture of each Mystery Class site.

Meet the Mystery Classes: May 2013

In the month of May, the ten Mystery Classes introduce themselves and invite you to correspond with them online.