1. Eclipse
Nature is an infinite sphere whose center is everywhere and whose circumference is nowhere.    -- Blaise Pascal
A penny will hide the biggest star in the universe if you hold it close enough to your eye.   -- Samuel Grafton

2. Solar Eclipses
The Sun is vanishing! The Sun is going out! The daylight is retreating!
Bad Omens All! The Gods are MAD!

3. The answer lies hidden among the shadows.
The Modern View
The answer lies hidden among the shadows.
Moon
Earth

4. Shadow Structure
Penumbra
Umbra

5. Solar Eclipse Details North Pole Moon Sun South Pole
What is the phase of the moon?
New Moon!

8. Total Solar Eclipse

10. A Total Solar Eclipse from beginning to end

13. Interesting Features

14. Why not a solar eclipse every month then?
Moon
Earth 5o
Ecliptic
Moon’s Orbit
Sun
Moon's orbit is tilted about 5o with respect to the Earth's orbit (ecliptic), so the shadows usually miss!

15. ·  But, the Moon passes through the ecliptic twice a month.
· *IF* at new moon - SOLAR ECLIPSE probability.

16. A Lunar Eclipse Earth Sun Moon’s Path Moon
A lunar eclipse occurs when the Earth lies between the Sun and Moon, so that Earth's shadow darkens the Moon.

17. This image shows a complete transition during a lunar eclipse
This image shows a complete transition during a lunar eclipse. Notice that the phase of the moon is “full.”

19. The moon becomes a blood red color during a total lunar eclipse
The moon becomes a blood red color during a total lunar eclipse. No wonder that ancient cultures feared the appearance of the moon during a lunar eclipse.

21. The Blood Moon Moon Earth Sunlight Earth’s Atmosphere
The moon often does not totally disappear during a total lunar eclipse. Instead it can be seen as a very dark red color because of the refraction of sunlight through the Earth's atmosphere.

22. The End