Sun, Earth, Time, and Man

angle Antarctic Circle apparent declination approximate astronomical blade calendar celestial equator Chicago circle of illumination clock computed continuous daylight darkness Date Line daylight period December 22 degrees of longitude due east due west duration of daylight Earth east-to-west equinox Greenwich high latitudes horizon at midnight horizon at noon horizon band hours of daylight intersection interval January July June 21 latitude circle latitude line light longitude Longyearbyen March 21 mean solar minutes months night noon altitude North Pole north-to-south line Northern Hemisphere northern horizon number of days number of degrees number of hours observer orbit path place of sunrise position Prime Meridian Rectify the globe rotation seasons September 23 south of due South Pole southern standard stars Sun at noon Sun is vertical Sun rises sunrise and sunset temperature tion Tropic of Cancer Tropic of Capricorn tude twilight United zenith at noon zenith distance zone ΙΟ