Eclipses (23)

• Eclipses occur when the moon or sun moves into the moon’s or Earth’s shadow.

• Parts of a shadow:– Umbra: total shadow – complete eclipse.– Penumbra: partial shadow – partial eclipse

(dimmed).

Lunar Eclipse

• Can ONLY happen during a full moon.

• Moon moves into earth’s shadow.

Lunar Eclipse (cont.)

• Moon moves into the penumbra and dims.

• As it gets closer to umbra it gets darker.

• Typically lasts about 2 hrs.

Lunar Eclipses (cont.)

• Some light coming around the earth can make the moon look red/brown.

• About 2 lunar eclipses/year.

• Easy to see, needs to be night time (where you are) when the moon passes through the earth’s shadow.

• Next lunar eclipse will be June 4th (partial).

• Also one on Nov. 28th but we won’t be able to see it here.

Solar Eclipse

• May only occur during a new moon.– Sun is in moon’s shadow.

Solar Eclipse (cont.)

• Total solar eclipses are rare to see because the moon’s umbra is small.– Outside of the moon’s umbra no eclipse is seen.– Becomes so dark other stars can be seen. – Last only a few min.

Solar Eclipses (cont.)

• Last solar eclipse: July 11, 2010 – Seen only from the

Pacific Islands and South America.

• Next solar eclipse we can see: August 21, 2017.

Frequency of Eclipses

1. Earth’s and moon’s orbits are elliptical.• Distances between them vary slightly.

• Shadow sizes change.

2. Moon’s orbit is tipped slightly to earth’s and it often misses the earth’s shadow.

Eclipse Foldables (22)

• Each Foldable needs:– Term,

Explanation, & Illustration.• Umbra• Penumbra• Solar Eclipse• Lunar Eclipse

Answer the following questions at the bottom of your page:

1.Give 2 reasons why eclipses don’t happen more often.

2.Why is it more rare to see a solar eclipse than a lunar eclipse?