1.Stars move from east to west over the course of the night 2.Change slightly from one night to the next 3.However, their relative positions remain unchanged (relative to each other)

1.An imaginary sphere surrounding the earth (infinite distance) 2.Uses earth’s system of coordinates and landmarks a.North Pole b.South Pole c.Equator

Meridians Meridians: ½-circles running from pole to pole Meridians measure longitude on earth Prime Meridian: 0 point

Parallels Parallels: full circles parallel to the equator Parallels measure latitude on earth Latitude and longitude are measured as angles Degrees  Minutes  Seconds

1.Celestial Coordinates use earth’s coordinate system “exploded” onto the celestial sphere 2.North Celestial Pole (NCP) 3.South Celestial Pole (SCP) 4.Celestial Equator

5. Parallels are measured as declination a. + or - 90° from the C.E. (0º) 6. Meridians are measured as Right Ascension a. Measured in hours, minutes, seconds

1.Annual “path” of the Sun in the sky 2.Tilted 23½° with respect to the celestial equator 3.Vernal Equinox 4.Autumnal Equinox 5.Summer Solstice 6.Winter Solstice

Constellations The sky is divided into 88 regions; the constellations Based on early Greek systems, names Constellations of the Zodiac: lie along the ecliptic; sun passes “through” them