How do the planets move across the sky? This lecture discusses the motions of the 5 naked-eye planets (Mercury, Venus, Mars, Jupiter, and Saturn) as seen from the Earth. We introduce the major configurations of the planets, and then discuss their apparent retrograde motions. The apparent motions of the planets are far more complex than those of the Sun, Moon, and stars, and present a great challenge to understand. The centuries long effort to understand these motions was to give birth to modern science. Recorded 2007 Oct 4 in 1000 McPherson Lab on the Columbus campus of The Ohio State University.