Curated OER
Reasons for Seasons
Young scholars investigate a model of the tilt of the Earth in its relationship to the Sun during the different seasons of the year. They study the solstices and equinoxes, while determining how sunlight hits the Earth with different...
Northern Arizona University
Colorado Plateau: Chaco Phenomenon
A description of the building done at Chaco Canyon. Find out how the dwellings were built, where the materials came from, the agriculture that supported the population, and the road systems that connected the populace of Chaco Canyon to...
CK-12 Foundation
Ck 12: Earth Science: Seasons
[Free Registration/Login may be required to access all resource tools.] Learn how and why seasons occur.
University of St. Andrews (UK)
University of St. Andrews: Claudius Ptolemy
This site, which is provided for by the University of St. Andrews, contains biological information as well as the works of Ptolemy.