The idea of the Sunrise Project is that the students use simple self-built cardboard pinhole cameras to make very long-exposure (several days) photographs of the sunrise or sunset around vernal equinox (15 March – 25 March)  at different latitudes.

During the long exposure, the bright Sun will leave a trail on the light-sensitive material, and we can see the path of the rising Sun.

Pinhole image of the Sunrise.If the camera is level and the paper and the pinhole are aligned, you can find the horizon in the image. Credit: Sakari Ekko
Pinhole image of the Sunrise.If the camera is level and the paper and the pinhole are aligned, you can find the horizon in the image. Credit: Sakari Ekko

By measuring the rising angle and comparing it with the photographs taken in other locations students can find the connection between latitude and the rising angle.

This leads to discussions on the geometry of Earth-Sun system, climate and seasons.

In higher grades, a more mathematical treatment is possible too.