The Celestial Sphere
Celestial Equator
Ecliptic
Two intersecting planes -- the 4 cardinal pts – equinoxes and solstices
The sky from 3 different position on Earth
Origin of the seasons -- tilt of the Earth’s axis
Precession
Phases of the Moon
Eclipses of the Sun and Moon
Solar – new moon
Lunar – full moon
Moon must be at one of the nodes of its orbit and the line nodes points to the Sun
An Eclipse of the Sun
3 types – total, partial, annular
Eclipse of the Moon
Next eclipses
Solar -- annular May 20, 2012 W. US
total Nov 13, 2012 – S. Pacific
Aug 21, 2017
April 8, 2024 *
Aug 23, 2044
Aug 12, 2045
Lunar -- no major ones 2012, none
visible from N America
Total – 2014 Apr 14, Oct 8
