1. Lunar and Solar and Eclipses
This powerpoint compiled by the Education Staff at the Lunar and Planetary Institute
Image from
Image from days after its final encounter with the Earth, the Galileo spacecraft looked back and captured this remarkable view of the Earth and Moon. The image was taken from a distance of about 6.2 million km (3.9 million miles). The picture was made with images taken through the violet, red, and 1.0-micron infrared filters. The Moon is in the foreground, moving from left to right. The brightly-colored Earth contrasts strongly with the Moon, which reflects only about one-third as much sunlight as the Earth. Contrast and color have been computer-enhanced for both objects to improve visibility. Antarctica is visible through clouds (bottom). The Moon's far side is seen; the shadowy indentation in the dawn terminator is the south pole Aitken Basin, one of the largest and oldest lunar impact features.

2. Eclipses
The Sun and Moon occasionally line up so that we have an eclipse.
These eclipses happen every year
To see a solar eclipse, you need to be on a particular part of the Earth
Only after phases have been mastered should you try to teach the reason for eclipses; otherwise, students will often assume that the reason for the Moon’s phases is the Earth’s shadow.
To understand why we have eclipses, we use the golfballs and blacklights, along with an embroidery hoop to model out the changing intersection of the Moon’s orbit with the ecliptic, as the Earth goes around the Sun.

3. When the Earth’s shadow covers the Moon, we have a lunar eclipse
Additional details are at
When the Earth’s shadow covers the Moon, we have a lunar eclipse

4. Three types of Lunar Eclipses
Penumbral lunar eclipse—the Moon only passes through the penumbra of Earth’s shadow
Partial lunar eclipse—part of the Moon passes through the umbra of Earth’s shadow
Total lunar eclipse—the entire Moon passes through the umbra of Earth’s shadow
Who on Earth will be able to see a lunar eclipse?
Anyone who can see the Moon (anyone who is on the nighttime side of the Earth during the eclipse)

5. Images from Fred Espanak and may be found at
Images from Fred Espenak

6. Why is the Moon red during an eclipse?
The Earth’s atmosphere filters some sunlight and allows it to reach the Moon’s surface
The blue light is removed—scattered down to make a blue sky over those in daytime
Remaining light is red or orange
Some of this remaining light is bent or refracted so that a small fraction of it reaches the Moon
Exact appearance depends on dust and clouds in the Earth’s atmosphere

7. Solar Eclipses When the Moon’s shadow covers part of the Earth
Only happens at New Moon
Three types: Annular, Partial, and Total
Diagram from Fred Espenak, may be found along with lots of good information at

8. Total Solar Eclipse
Observers in the “umbra” shadow see a total eclipse (safe to view the Sun); can see the corona
Those in “penumbra” see a partial eclipse—not safe to look directly at Sun
Only lasts a few minutes
Path of Totality about 10,000 miles long, only 100 miles wide
Diagram by Fred Espenak and more information may be found at

9. Photo of a Total Eclipse
From

10. Annular Solar Eclipse
When the Moon is too far to completely cover the Sun—the umbra doesn’t reach the Earth
Sun appears as a donut around the Moon
Diagram from Fred Espenak, may be found along with information at

11. Photos of an Annular Eclipse
From photos taken by Fred Espenak
photos taken by Fred Espenak

12. Upcoming Solar Eclipses
Next Total Solar Eclipse in continental USA—August 21, 2017
Information at