Astronomy 161 - Introduction To Solar System Astronomy - Autumn 2007

Why do celestial objects appear to rise and set every day? How does this depend on where you are on the Earth, or the time of year? In today's lecture we we set the heavens into motion and review the two most basic celestial motions. Apparent Daily Motion reflects the daily rotation of the Earth about its axis. Apparent Annual Motion reflects the Earth's annual orbit around the Sun. We introduce the Ecliptic, the Sun's apparent annual path across the Celestial Sphere, and note four special locations along the Ecliptic: the Solstices and Equinoxes. This sets the stage for many of the topics of the rest of this section. Recorded 2007 Sep 26 in 1000 McPherson Lab on the Columbus campus of The Ohio State University.