The Four Seasons of the Earth
Like tides washing regularly across a beach, seasons advance and retreat across the face of the globe and bring changes that transform the face of the Earth. Whether it is the arrival of the winter snows, the monsoon rains, or the summer heat, our environment changes constantly, and these profound changes occur over relatively short time periods. What helps make such huge, complex changes comprehensible is that they reoccur in predictable ways. Many ancient civilizations observed that the Sun's position in the sky changed throughout the year and were able to construct calendars and predict seasonal change based on their observations.
Why Are There Seasons?
To Every Season There is a Reason
The Seasons
Seasons and Solstices
Why are there Seasons?
Seasons of the Year
http://aa.usno.navy.mil/faq/docs/seasons_orbit.html
The Seasons and the Earth's Orbit - Milankovitch Cycles
Season's Reasons
Seasons of the Sun
