1. Eclipses

2. Lunar Eclipses
When the Moon is in the Earth's shadow, the Moon is eclipsed.

3. Total Eclipse of the Moon
When the Moon passes into the dark part of the Earth's shadow, called the umbra, it is totally eclipsed.
Penumbras: The penumbra is the lighter edge of the Earth's shadow.
Umbra
Penumbra

4. Partial Lunar Eclipse
A partial lunar eclipse occurs when only part of the Moon passes through the Earth's umbra.

5. Penumbral Eclipse
A penumbral eclipse occurs when the Moon passes through the Earth's penumbra.

6. Occurrences of Lunar Eclipses
Lunar eclipses can only occur during the phase of full Moon.
Full
Moon

7. Frequency of Lunar Eclipses
The Moon's orbit is tilted.
During most months the tilt of the Moon's orbit insures that the full Moon passes north or south of the Earth's shadow

8. Frequency of Lunar Eclipses
At roughly six month intervals the full Moon lies near or inside the Earth's shadow.
The Earth gets two or three lunar eclipses each year.

9. Total Eclipse Sequence

10. Solar Eclipses When the Moon covers the Sun, the Sun is eclipsed.
During a solar eclipse, the Moon’s shadow falls on the Earth

11. Total Eclipse of the Sun
When a place on the Earth’s surface falls in the dark part of the Moon’s shadow, called the umbra, the Sun is totally eclipsed.
Total Eclipse
Partial Eclipse
Penumbra
Umbra

12. Total Eclipse of the Sun Sequence

13. Partial Eclipse of the Sun
When a place on the Earth’s surface falls in the lighter part of the Moon’s shadow, called the penumbra, the Sun is partially eclipsed.
Partial Eclipse of the Sun

14. Occurrences of Solar Eclipses
Solar eclipses can only occur during the phase of the new moon.
New Moon

15. Frequency of Solar Eclipses
During most months, the tilt of the Moon's orbit insures that the Moon’s shadow passes north or south of the Earth. Though solar eclipses occur regularly, any one place has a total solar eclipse only about every 360 years.