ASTR 1101 Lecture Notes - March Equinox, Daylight Saving Time, Noon
Document Summary
Earth: only half of the earth is illuminated at one time. Since the earth is constantly moving, the sky and stars appear to move. If you are sitting at the north pole, stars do not rise or set, but just go around in a circle. If you are sitting at the equator, the stars go straight up i. ii: at the middle northern latitudes, stars rise in the east and set in the west. However, our stars have to dip south: coordinate system i. Because of this tilt, we get seasons: reasons for the seasons, concentration of light a. If the light is more concentrated, then the earth heats up faster. In summer, the exposure length is much longer. This gives us more exposure to sunlight and longer days. In winter, the exposure is less concentrated and gives us shorter days: the tilt of the earth really creates the seasons iii. It does not rise due east but rather southeast.
