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 -- total July 22, 2009 -- India, China, Pacific

annular Jan 15, 2010 -- Africa, Indian Ocean, China

total July 11, 2011 – S. Pacific (Cook Islands, Easter Is.

Aug 21, 2017

April 8, 2024 *

Aug 23, 2044

Aug 12, 2045

Lunar -- Penumbral Feb 9, W. US

-- Partial Dec 31, E. Hemisphere