1. What causes Earth to experience seasons?
2. Why is the length of daylight longer in the summer and shorter in the winter?
CLICK HERE to see an animation courtesy of the Santa Barbara City College Dept. of Physics and Engineering. I project the animation onto a big screen and use it to explain the solstice (and its relationship to the length of daylight). CLICK HERE for more information about the solstice. CLICK HERE to see another animation (courtesy of Prentice Hall). CLICK HERE to get sunrise and sunset times for your city.
CAUTION: Animations and diagrams often depict the shape of Earth's orbit as being more elliptical than it really is. If you were to draw our orbit on the board, it would look like a circle. Here is another resource that may help. Once the page open, the diagram titled "Eccentricity" is a good one. This Hours Explorer is pretty slick too! (Thanks, Rick)