Wonders of the Sky are lessons inspired by M. Minnaert's "Light and Color in the Outdoors
." This well-known book describes the physics behind unusual atmospheric optical effects. The slides offer images of numerous phenomena related to earth's sky and atmosphere that are mostly visible to the unaided eye. In particular, the interaction of light from the sun, moon, and stars with earth's atmosphere is emphasized. Topics of The Darkening Sky include twilight, waxing & waning moons, earthshine, Young and Old Moons, gibbous moon, inferior planets (Mercury & Venus), crescent moon and Venus, planetary conjunctions, Venus as a "UFO", artificial satellites, and noctilucent clouds.