|January 28 - April 8
Every Monday for 11 weeks, sunrise/sunset data will be provided from all 10 sites. Use it to calculate photoperiod. Then use photoperiod to estimate the latitude of each site.
| March 11
As the spring equinox approaches, time clues will be posted on March 11 to help students estimate the longitude of each site.
|March 18 - April 8
Continent, Country, City Clues
During the final 4 weeks, clues will be provided to help you narrow your search from continent, to country, and then to city. Research to pinpoint locations.
| April 15
Locations of the 10 Mystery sites are posted.
* Please note: Due to budget limitations, our spring 2019 Mystery Class challenge will be a replay of a previous year's challenge. We will reveal the locations of the 10 Mystery sites on Monday, April 15, 2019 but will not be able to hold a year-end contest.