I figured out the answer to the question in the title. The seasons are due to the earths north to south axis facing towards or away from the sun at different times in the year. I have a couple of other questions: 1.) What does a week signify? A day is how long it takes for the earth to make a full rotation, a month is the time it takes for the moon to orbit the earth and a year, the time it takes for the earth to orbit the sun. What is a week? 2.) Does the earth have a circular or eliptical orbit around the sun?