Eclipses

Solar Eclipse Occurs when the Moon is positioned between the Sun and Earth and all are in complete alignment Occurs during a NEW Moon The Moon’s shadow falls on a portion of the Earth

The Geometry of a Solar Eclipse

Another View of Solar Eclipse Geometry

Total Solar Eclipse Occurs when the Moon's umbral shadow sweeps across Earth's surface. The track is typically 10,000 miles long but no more than 167 miles wide. It covers less than 1% of Earth's entire surface area. In order to see the Sun become completely eclipsed by the Moon, you must be somewhere inside the umbra.

Total Solar Eclipse

Partial Solar Eclipse Partial solar eclipses are visible from within the penumbra. Remember, the penumbral part of the shadow is larger than the umbral part of the shadow cone

Partial Solar Eclipse

Annular Eclipse Occurs when the Moon is too far from Earth to cover the Sun completely Outer edge of the Sun is seen as a ring

Annular Eclipse: Beginning, During and Ending

DateEclipseType May 20, 2012SolarAnnular June 4, 2012LunarPartial November 13, 2012SolarTotal November 28, 2012LunarPenumbral April 25, 2013LunarPartial May 10, 2013SolarAnnular May 25, 2013LunarPenumbral October 18, 2013LunarPenumbral November 3, 2013SolarHybrid (?) Eclipses

Lunar Eclipse: Occurs when the Earth is positioned between the Sun and the Moon and all three bodies are in complete alignment Occurs during the FULL Moon phase The Earth’s shadow falls on the Moon Lunar eclipses will be seen by everyone experiencing night

The Geometry of a Lunar Eclipse

3 Types of Lunar Eclipses (But we’re only discussing Total and Partial Eclipses)

West East

Total Lunar Eclipse Occurs when the entire Moon falls within the Earth’s umbra The Moon appears reddish

The Geometry of a Total Lunar Eclipse

Total Lunar Eclipse

Partial Lunar Eclipse Occurs when part of the Moon falls within Earth’s umbra

The Geometry of a Partial Lunar Eclipse Only a portion of the Moon falls in Earth’s umbra.

Partial Lunar Eclipse

Penumbral Lunar Eclipse

Comparing Solar and Lunar Eclipses Solar Lunar Differences Involves the Sun, Moon and Earth Involves the Sun, Earth and Moon Requires a New Moon Requires a Full Moon Similarities Both occur at 5 month, 3 week intervals Occurs during the day Occurs at night Seen over a narrow geographic area Seen by everyone experiencing night Can NEVER, EVER be looked at directly Safe to look at Can only occur when SEM or SME are directly lined up