To those of us who live on earth, the most important astronomical object by far is the sun. This article explains how the motion of the sun through our sky cause day and night, the passage of the seasons, and earth's varied climates.

Wind is air in motion. It is produced by the uneven heating of the earth's surface by the sun. Since the earth's surface is made of various land and water formations, it absorbs the sun's radiation unevenly. When the sun is shining...