On May 1, students will predict where the ten Mystery Classes are hiding! The primary clue: As spring sweeps across the Northern Hemisphere, daylength changes everywhere on earth.

Materials, Links, & Deadlines

• Weekly Mystery Class Updates (February 6 to May 15, 2009)
• Mystery Class Calendar with deadlines
• The Mystery Class Data & Clues page
• Local sunrise and sunset times (Look-up on Web or in local newspaper)
• Colored pencils or markers. Each student will need eleven (11) different colors.
• Mystery Class Data Sheet below (one per student).
• Mystery Class Graph below (one per student)
• Optional: Student Journal Pages
• Optional: Make your own graph and/or classroom wall graph (instructions)

Mystery Class Data Sheet	Mystery Class Graph
Download and print (doc or html )	Download, print, and assemble* (doc or pdf ) *Why two pages? The graph needs height to prevent the data and lines from becoming overcrowded.

1. Register for Journey North
Registration is free. Registration is required so our staff can contact participating teachers, if needed. If you are already registered, you do not have to register again for Mystery Class.

• Register for Journey North.

2. Prepare
Mystery Class doesn't begin until late January, but to help get ready, you can brush up on the basics this fall. After all, every great journey takes a little prep time — especially when you are traveling around the world in just eleven weeks!

• Brush Up on the Basics
  Build understanding and practice skills related to these topics:
  — the earth's daily and seasonal cycles (and the reasons for seasons)
  — latitude and longitude
  — calculating & graphing photoperiod
  

3. Organize Your Class

• See the Advice other Mystery Class teachers have shared over the years.
• In general, we recommend dividing the class into ten groups and making each group responsible for one of the ten Mystery sites. (Teachers: for younger students, or for students you feel need a greater challenge, consider assigning secret locations of lesser or greater difficulty, respectively. (Contact Journey North for more information when Mystery Class begins in February.)
• Your local site will be the eleventh location. Use your local photoperiod as an example each week. This will help the ten student-groups work independently.
• Give each student (or student group) one Datasheet and one Graph. Each week, the group records the data and calculates the photoperiod for their site. Then the group shares its calculations with the rest of the class.

1. RECORD Your Local Sunrise/Sunset Times

• Dates: Monday, February 2 through Monday, April 13, 2009
• Every Monday, look up your LOCAL sunrise and sunset times.
• Your local newspaper should provide sunrise/sunset information or you can look-up your sunrise/sunset on the web: Sunrise/Sunset Look-up.
• Record the data on your Mystery Class Data Sheet (you do not send this data to Journey North).

2. CALCULATE Your Local Photoperiod

• Photoperiod is the amount of daylight between sunrise and sunset each day.
• To measure photoperiod, count the number of hours and minutes the sun is up. For example, if the sun rises at 6:50 and sets at 17:30, the photoperiod for that day is 10 hours and 40 minutes.
• Also see related Advice from Mystery Class Teachers

3. GRAPH Your Local Photoperiod

• Choose a color to represent the photoperiod of your hometown and plot it on the Mystery Class Graph.
• Do NOT send your local sunrise & sunset data to Journey North!

1. RECORD the Sunrise/Sunset Times from the ten Mystery Sites

• Dates: Friday, February 6 through Friday, April 17, 2009
• Every Friday, you will find the latest sunrise/sunset data in two places: a) in the week's Mystery Class Update and b) archived on the Mystery Class Sunrise/sunset Data & Clues page.
• Record the data from each Mystery Class site on its own individual data sheet.
• Remember: The data you receive on FRIDAYS will have been collected on MONDAYS, the same day your own readings were collected.

2. CALCULATE the Photoperiod at the ten Mystery Sites (one site per group)

• To calculate photoperiod, count the number of hours and minutes between sunrise and sunset.
• Record the photoperiod on the datasheet.

3. GRAPH the Photoperiod at the ten Mystery Sites

• Use a different colored pencil or marker to plot the photoperiod for each Mystery Class.

4. ASK QUESTIONS about the Mystery Class Graph

• Each week's update will include some questions. You can also use these prompts to help students home in on Mystery Class locations: Mystery Class Graphs: Questions to Ask.

Longitude and Interdisciplinary Clues: March 20 - April 17, 2009

• Longitude clues: Prior to March 20th, the weekly sunrise/sunset data have revealed clues about the LATITUDE of the Mystery Classes, but not about their LONGITUDE. On March 20th, the "longitude clues" will be provided. These clues help students estimate the longitude of the sites based on the time of sunrise at each Mystery Class on the vernal equinox. (Teachers Guide: A Clue About Longitude Clues)
  
  
• Interdisciplinary clues: In addition to sunrise/sunset information, starting on March 27th we'll add clues about the geography and culture of each site. You will find them in two places: a) in the week's Mystery Class Update and b) archived on the Mystery Class Data & Clues page.

Contest Deadline: May 1, 2009

• Contest Deadline: On May 1st students will race to predict the location of each Mystery Class. A "Mystery Class Answer Form" with detailed instructions will be posted. (See sample.)
• May is "Meet the Mystery Class Month." Each Mystery Class will introduce themselves on-line and you'll have a chance to correspond with them . . . whoever and wherever they are!

Assessment

As spring sweeps across the Northern Hemisphere, day length changes everywhere on earth. This central observation of seasonal change is at the heart of Journey North.

Rich assessment opportunities help teachers document student understanding of key concepts about the seasons.