NOAA
Noaa: Solar Calculators
This resource allows users to find sunset/sunrise calculations based on latitude and longitude for various locations. Provides a glossary of related terms and an explanation of their calculations.
Harvard University
Harvard Smithsonian: Everyday Classroom Tools
The focus of this series of lessons is to engage students in an exploration of the world around them. The emphasis is on inquiry as students learn about the earth, sun, light, shapes and more.