8.31.16 - 8.31.16 Celestial Map and Celestial Coordinates o...

8.31.16
 Celestial Map and Celestial Coordinates
o Analogous to latitude and longitude on the Earth – measured in degrees
o Celestial poles and Equator – extension of the Earth’s poles and Equator
o Celestial Equator is the extension of the Earth’s Equator up to the CS
 Ecliptic and the Celestial Equator
o Ecliptic is the apparent path of the sun on the Celestial Sphere
o The Ecliptic and the celestial equator intersect at vernal (spring) and autumn equinoxes
 At an angle of 23.5 degrees to each other
 Earth’s orbit and the seasons
o Earth’s orbit is circular
o In winter a bundle of light is spread over a bigger area than in summer owing to the
inclination away from the Sun
 Because Earth’s axis is tilted
 Phases of Moon: Earth-Sun Positions
o Waxing is disappearing; Waning is appearing
o Horns of a crescent moon always point away from the Sun
o What time of the day does the new moon rise and set?
 Rises in morning; sets with Sun
o What time of the day does the full moon rise and set?