The sun shines down on us, giving warmth and light. But did you know that the sun also makes the seasons? As the earth makes one complete rotation around the sun every year, the seasons on the earth change -- from winter to spring to summer to fall and back to winter again. Find out how the light from the sun affects life on the earth for all living things in this look at the only star in our solar system.

Franklyn M. Branley was the originator of the Let's-Read-and-Find-Out Science series and the author of close to 150 popular books about scientific topics for young readers of all ages. He was Astronomer Emeritus and former Chairman of the American Museum of Natural History-Hayden Planetarium.