Understanding Moon Phases and Tides: Earth's Celestial Dance

1. Phases of the Moon and Tides

2. The same side of the moon always faces Earth because the moon revolves at the same speed that it rotates! The moon rotates on its axis as it revolves around the earth.

3. Discuss at your table…Does the moon make its own light?

4. Phases of the Moon • We are always looking at the moon from a different angle as it orbits Earth. • We are able to see different part of the moon’s sunlit side. • The shape of the lit portion of the moon is called it’s phase. The moon goes through 8 phases each month. • When we see more of the moon each night until it becomes full, the moon is “waxing”. When we see less of the moon each night until it is New, the moon is “waning”.

6. Moon Phase Animation Link: http://www.sumanasinc.com/webcontent/animations/content/moonphase.html

7. Tides • Tides are Giant waves caused by the pull of the moon’s gravity on the waters of Earth. • Parts of Earth closest to the moon are pulled the hardest, resulting in high tides in some areas and low tides on the opposite side.   • Sun’s gravity also affects tides. •  When sun, moon and Earth line up, the pull is greater. This creates Spring Tides, which are higher and lower than normal called Spring Tides •  When Earth, sun and moon are at right angles, neap tides happen, making high tides lower and low tides higher than normal, called Neap Tides

8. Tides Animation Link: http://www.sfgate.com/getoutside/1996/jun/tides.html

9. Discuss: Captain's of large ships that carry cargo all over the world must be familiar with the moon’s cycle in order to determine when to enter a country's port. Why?