1. Tides
Time and tide wait for no man

2. Tides
Daily movements of ocean water that change the level of the ocean’s surface
Tides are influenced by the sun and the moon

3. Principle of Gravitational Pull
Sir Isaac Newton 1687
Gravitational forces from both the sun and the moon pull on the earth. Although the moon is much smaller than the sun, the moon's gravity is the dominant force behind Earth’s tides

4. Tidal Variations
The combined forces of the sun, moon on the earth result in tidal ranges that vary based on the positions of all three bodies
Tidal range: difference between levels of ocean water at high and low tide.

5. High and Low Tide
How high tide gets and how often they occur depend on the position of the moon as it revolves around the Earth.

6. High and Low Tide
High tide occurs on the part of the Earth that is closest to the moon.
At the same time high tide occurs on the opposite side of the moon
Where will low tide be at this time?

7. Spring Tide
When the sun earth and moon are in alignment with each other
Maximum daily tidal range
Occur during the new and full moon every 14 days

8. Timing of the Tides
The moon revolves around the earth much more slowly then the Earth rotates. It takes 24 hours and 50 minutes for a spot on Earth that is facing the moon to rotate so that it is facing the moon again.
So.. Tides occur at different spots on the Earth because the earth rotates more quickly that the moon revolves around the earth

9. Neap Tide When the sun moon and earth form a 90 degree angle.
Tides with minimum tidal range occur during the first and third quarter of the moon

10. Spring/Neap Tide

11. Tides and Topography
Tidal Bore

12. Eclipse
An eclipse occurs when the shadow of one celestial body falls on another.

13. Lunar Eclipse
When the earth comes between the sun and the moon and the shadow of the Earth falls on the moon

14. Lunar Eclipse Why does the lunar eclipse appear red?

15. Solar eclipse
When the moon comes between the Earth and the sun, and the shadow of the moon falls on part of the earth

16. Annular Eclipse
A solar eclipse during which the outer ring of the dun can be seen around the moon

17. Why do we not have eclipses all the time!!!?
Answer: The moon’s orbit around the earth is tilted. By about 5degrees with respect to the orbit of the Earth around the sun. This tilt is enough to place the moon out of Earth’s shadow for most full moons and the Earth out of the moon’s shadow for most new moons

18. Phases of the Moon
The different phases of the moon result from the its changing position with respect to the Earth and the sun
Waxing means that the sunlit fraction we can see from Earth is getting larger.
Waning means that the sunlit fraction of the moon is getting smaller

19. Dark Side of the moon
Because the period of rotation and the period of revolution are the same for the moon we always see the same side of the moon.

21. Phases of the Moon