Date post: | 13-Dec-2015 |
Category: |
Documents |
Upload: | loraine-ball |
View: | 223 times |
Download: | 3 times |
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?