1. Understanding Eclipses
This really is the eclipse of a generation. This is the first Total Solar Eclipse on the continental USA since 1979; and the first one to cross the continent from ocean to ocean since There was one that was visible from Hawaii and Mexico in Mexico closed the border with the US to anyone without hotel reservations because they could not handle the volume of people. It is the first total solar eclipse to be visible from ONLY the US since before And the first in Missouri since before Europeans got to Missouri.
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2. Celestial Eclipses
Result of the interaction between three celestial bodies.
Host Body – Location of Viewer
Eclipsing Body – Body obstructing view
Eclipsed Body – Body where view is being obstructed
Most familiar eclipses to us are
Lunar eclipses
Solar eclipses
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3. Lunar Eclipse Lunar Eclipse always occurs during the full moon.
Shadow of Earth is cast on the moon
Light through earth’s atmosphere makes the moon glow red (Blood Moon)

4. Solar Eclipse Solar eclipses occur during the new moon.
View of the sun from earth is obstructed by our moon.
Two moon shadows cast on earth during total eclipse
Penumbra – Partial Shadow – large area
Umbra – Full Shadow – small area

5. Under the Umbra

6. Annular Eclipse
Annular Eclipse is when moon is too far from the earth during a solar eclipse to completely block all direct light from the sun.
Appears as donut sun with a large hole in the middle.
Why don’t we have eclipses every month of the Year?
To answer this question we need to understand more about the relationship between sun, moon and earth.

7. Earth Orbit
Johannes Kepler discovered in 1609 that planets and moons orbit in elliptical paths.
Elliptical points of importance
Focal Point – Center of orbit
Periapsis – Closest orbital point to focal point
Apoapsis – Farthest orbital point from focal point
Earth’s mean orbital distance from the sun is million km (92.96 million mi) or one Astronomical Unit (1AU).
Perihelion – 91.4 million mi (0.983AU)
Aphelion – 94.5 million mi (1.02AU)
Orbital velocity – km/s (66,621 mph)
Orbital Period – days (1 year)
Force of attraction between earth and Sun F= g (Ms x Me)/

8. Lunar Details
Moon’s average orbital distance from earth is 238,900 mi.
Perigee = 225,327 mi
Apogee = 251,924 mi
Orbital velocity around Earth – km/s; 2,286 mph
Orbital period = 27.3 E days
Rotation CCW = 27.3 E days
Orbit and rotation is in sync with Earth’s rotation so same side of moon always faces the Earth.

9. Lunar Phases Phases of the moon are caused by its orbit around Earth.
Moon’s orbital plane around earth is tilted at an angle of 5.14° from earth’s orbital plane around the sun.

10. Inclined Lunar Orbit around Earth
This figure explains how we have to think in 3-D to understand when we don’t get eclipses every month

11. Few Eclipse Conditions Per Year
This figure brings together the earth's orbit around the sun with the moon’s orbit around the earth. Starting on the far left we see that the shadow of the moon is below the earth moving forward 3 months to the bottom-most earth we se that now when the moon gets to new moon it is lined up and we get an eclipse. This lining up happens again six months later when we get to the top most earth. There is an eclipse somewhere on earth every six months but they can only be seen from a small area of the earths surface and they aren’t all TOTAL eclipses.

13. This is obviously a map of Missouri – which cane from http://www
This is obviously a map of Missouri – which cane from - you cab find all sorts of graphics are free resources on this site – also here You may be asked about timing – you can determine the timing of the eclipse for specific locations:
For and given location – the position of the sun will vary slightly. For Missouri it is more or less consistent across the state – so 
Here’s a link for people who want a more accurate position of the sun
For CoMO at the time of totality the azimuth angle is deg (180 deg = south); evolution is 62deg – which is pretty high.

14. Safely Viewing Solar Eclipses
Only Solar Viewing glasses or welder masks (rating 14) allows us to view the sun directly without damaging our eyes.
Viewers must secure solar viewing glasses over their eyes before directly viewing the sun.
When ever any sliver of the sun’s disk is viewable, eye protections must be worn.
Sun glasses will not protect our eyes from the sun’s light radiation. Do not use them to view the sun.
Only during solar totality can eye protection be removed.
Solar Viewing Glasses

15. Safely Viewing Solar Eclipses
Viewing solar eclipse through small holes
First sheet is opaque with small holes made from a pencil
Second sheet displays sunlight passing through the holes in the first sheet.

16. Immediately precedes and follows
Total Eclipse Diamond Ring
Immediately precedes and follows
Solar totality
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