Eclipses

1. Eclipses http://www.huffingtonpost.com/2013/11/02/sunday-solar-eclipse-rare-hybrid_n_4202543.html http://www.space.com/23419-hybrid-solar-eclipse-visibility-images-november-3-2013.html http://www.youtube.com/watch?v=sK-K3BSSTs4 http://www.youtube.com/watch?v=cQSO2gkPzPM

2. 0 Conditions for Eclipses (1) The moon’s orbit is inclined against the ecliptic by ~ 50. A lunar eclipse can only occur if the moon passes a node near full moon. A solar eclipse can only occur if the moon passes a node near new moon.

3. During a new or full moon phase, when the Moon, Sun, and Earth are aligned, the Moon may enter the shadow of the Earth, or the shadow of the Moon may reach the Earth, creating eclipses. However, these eclipses do not occur during every full or new moon because the Moon’s orbit is tilted by 5 with respect to the Earth-Sun (ecliptic) plane.

4. 0 Conditions for Eclipses (2) Eclipses occur in a cyclic pattern.

5. THE THREE TYPES OF LUNAR ECLIPSES PENUMBRAL = the Moon appears dimmed. PARTIAL = part of the Moon enters the umbra of the Earth’s shadow and is darkened. TOTAL = all of the Moon enters the Earth’s shadow and becomes a reddish color, only lit from light bending around the Earth’s atmosphere. During a total lunar eclipse, the Moon moves in and out of the umbra of the Earth’s shadow.

6. 0 Lunar Eclipses (2) Also Earth’s shadow consists of a zone of partial shadow, the Penumbra, and a zone of full shadow, the Umbra. If the moon passes through Earth’s full shadow (Umbra), we see a lunar eclipse. If the entire surface of the moon enters the Umbra, the lunar eclipse is total.

7. 0 A Total Lunar Eclipse (2) During a total eclipse, the moon has a faint, red glow, reflecting sun light scattered in Earth’s atmosphere.

8. 0 Lunar Eclipses: 2006-2012 Typically, 1 or 2 lunar eclipses per year.

9. SOLAR ECLIPSES occur when the moon’s shadow reaches the earth. Unlike lunar eclipses, solar eclipses occur at specific places on the Earth, indicated by the arrow.

10. 0 Solar Eclipses The sun appears approx. as large in the sky (same angular diameter ~ 0.50) as the moon. When the moon passes in front of the sun, the moon can cover the sun completely, causing a total solar eclipse.

11. If you are located where the umbra of the Moon’s shadow reaches, you will see a total solar eclipse, during which the entire disk of the Sun is covered by the Moon, revealing the faint solar corona surrounding the Sun. • Those just outside of this region where the penumbra of the Moon’s shadow reaches will only see a partial solar eclipse, during which only part of the disk of the Sun is covered by the Moon. • Sometimes eclipses occur when the Moon is too far away from the Earth to completely cover the Sun in our sky. When this occurs, the Moon appears in the center and a thin ring, or “annulus,” of light surrounds it. These are called annular eclipses. TOTAL ECLIPSE ANNULAR ECLIPSE

12. 0 Solar Eclipses: 2006-2016 Approximately 1 total solar eclipse per year

13. 0 Total Solar Eclipse Chromosphere and Corona Prominences

14. 0 Diamond Ring Effect

15. 0 Earth and Moon’s Orbits Are Slightly Elliptical Apogee = position furthest away from Earth Earth Perihelion = position closest to the sun Moon Perigee = position closest to Earth Sun Aphelion = position furthest away from the sun (Eccentricities greatly exaggerated!)

16. 0 Annular Solar Eclipses When Earth is near perihelion, and the moon is near apogee, we see an annular solar eclipse. The angular sizes of the moon and the sun vary, depending on their distance from Earth. Perigee Apogee Perihelion Aphelion

17. 0 Annular Solar Eclipses (2) Almost total, annular eclipse of May 30, 1984

19. Predicting Eclipses • Ancient Greeks http://www.youtube.com/watch?v=ITapEgyDy4U • Saros Cycle http://www.youtube.com/watch?v=35aJduq8PIs http://www.youtube.com/playlist?list=PL9D50FACE21694A26