1. Do Now (In Notebooks)  Where did the Earth’s Moon come from?  What is the biggest effect the moon has on Earth?

3. Essential Question What if there was no moon? Objectives Students will be able to: Describe formation theories of the moon Describe how the moon affects tides Identify the phases of the moon Provide the mechanism for eclipses Differentiate between solar and lunar eclipses

4. Where did the moon come from?  There are three theories of the moon’s formation:  Capture Theory  Simultaneous Formation Theory  Impact Theory

5. Capture Theory  Moon caught by Earth’s gravitational pull  Problems:  What slowed the Moon?  Why are the compositions so similar?

6. Simultaneous Formation Theory  Moon and Earth formed at same general time in same general area  Problem:  Why does Earth have so much more iron?  Why doesn’t the moon have water like the Earth?

7. Impact Theory  Earth collided with a Mars-sized object  Materials from collision came together to form moon  Explosion evaporated water

8. The Moon’s Features  Highlands  Areas light in color  Mountainous  Maria  Dark smooth regions  From Eruptions  Impact craters  Regolith  Loose, ground up rock  Radius - 1737.4 km  About 1/4 th of Earth’s

9. How does the Moon affect us?

10. Tides  Periodic rise and fall of the level of the ocean  The moon’s gravity pulls on Earth  Gravity creates build up of ocean water on both near and far sides of the Earth

11.  The ocean water build up stays in line with the moon  The ocean level rises and falls every 12 hours

12. Tidal Range  Vertical distance between low and high tide  1- 2 m on East Coast of North America  Bay of Fundy – 20 meters

13. Tides  Semidiurnal Tide  2 high tides and 2 low tides in 24 hours  Diurnal Tide  one high tide and one low tide in 24 hours

14. The Sun’s Effect  Spring Tide  When the sun and moon are aligned  Tides are HIGHER than normal  Neap Tide  When the moon and sun are at right angles  Tides are LOWER than normal

15. Sun vs. Moon  Does the Sun or the Moon have a larger effect on tides? THE MOON!! *Even though the moon is smaller than the Sun, the moon is much closer to the Earth, and therefore has a larger effect on the tides.

16. Do Now – In Notebooks  What is the most likely theory of the Moon’s formation?  Draw the Sun, Earth, and Moon as they are arranged during a neap tide.

17. Phases of the Moon What if there was no moon?

18. What causes the moon’s phases?  The moon does not emit visible light  The moon is visible due to reflected sunlight  One side (1/2) of the moon is always lit  As the moon rotates around Earth, the light reflected by the moon changes, causing phases

19. Phase Names  Gibbous  Crescent  Quarter moon  Full Moon  New Moon

20. Waxing Vs. Waning  Waxing  Increase in visible, sunlit portion of the moon  “Right” side of moon is visible  Waning  Decrease in visible, sunlit portion of the moon  “Left” side of the moon is visible

21. Phase Names  Waxing Crescent  First Quarter  Waxing Gibbous  Full Moon  Waning Gibbous  Third Quarter  Waning Crescent

24. Eclipses What if there was no moon?

25. Eclipses  One object moves into the shadow of another  Named for the celestial body that is blocked

26. Lunar Eclipse  Moon passes into Earth’s shadow  Reflected light from the sun is blocked, instead moon seems red  Can only occur during full moon  Occur slightly more frequently than solar

28. Solar Eclipse  Moon passes between Earth and Sun  Only see outer layers of sun  Occurs during new moon

29. Regions of Solar Eclipse  Umbra  Area does not receive sunlight, total eclipse  Penumbra  Receives partial sunlight, partial eclipse

30. Why don’t we have monthly eclipses?  The moon’s orbit is tilted compared to Earth  Eclipses only occur when orbits line up