1. Eclipses

2. Two Types Solar – Moon passes between Sun and Earth
Lunar – Moon passes through the Earth’s shadow.

3. Causes Earth orbits the Sun Moon orbits the Earth
Moon and Sun have same angular size.
Moon is small but close
Sun is large but far away

4. Shadow Parts Umbra is darker central portion.
Penumbra is weak outer portion and difficult to see.

5. Eclipse Geometry

6. Solar Eclipses Occur only at new moon. Very localized:
Inside umbra you see a total or annular eclipse.
Inside penumbra you see a partial eclipse.

7. Three Types of Solar Eclipses
Total inside umbra path.
Partial inside penumbra path.
Annular umbra does not reach the Earth.

8. Solar Eclipse Pictures

9. Lunar Eclipses Occur only at full moon.
Occur only at full moon.
Can be observed over nearly the entire night side of the Earth.

10. Three types of Lunar Eclipses
Total – moon pass completely into the Earth’s umbra.
Partial – moon does not pass completely through the umbra.
Penumbral – moon only pass through the penumbra.

11. Lunar Eclipse Pictures

12. Eclipse Seasons Moon’s orbit inclined 5 degrees to earth’s orbit.
Eclipses only occur when the intersection is aimed toward the Sun.
Eclipses come in sets

13. February 20th Total Lunar Eclipse
On October 27, 2004, the Moon was eclipsed during Game 4 of the World Series.
Rick Fienberg

14. February 20th Total Lunar Eclipse

15. February 20th Total Lunar Eclipse