Where did the term lunacy come from? What does apogee and perigee mean? Aim: How does the moon affect the earth? Topic: Unit 8 Earth in Space Main Idea: Tides and Eclipses 1) What are tides? Cyclic and predictable changing levels of the ocean water caused by gravitational pull of the moon and sun. 2) Which has a greater effect? Why? The moon has a greater effect because it is closer. Where are the biggest differences between high tide and low tide? The Bay of Fundy in Nova Scotia where it could change as much as 52.5 feet. How many high and low tides do we have daily? 3) What are spring tides? These are the really high and really low tides caused when the sun, earth and moon are lined up. 3) What are neap tides? Low high tides and high low tides when the earth, moon and sun are 90 o to each other. 4) What is a solar eclipse? The moon blocks the sunlight and casts a shadow on the earth. Because the moon is closer it can block out the sun. 4) What is a lunar eclipse? This is when the moon falls into the earths shadow. The moon appears red. Sunlight is being refracted and projected onto the moon. Why dont eclipses happen twice a month? 5) Why dont eclipses happen twice a month? The moon is tilted at a 5 degree angle to the earths orbit so at times it is too high or low.