1. The Motions of
Earth & the Moon

2. Learning goals
We are learning the impacts of the earth’s rotation and revolution.
We are learning the connection between the sun and moon.
We are learning the impact of the sun and moon’s gravity on earth.

3. Motions of Earth

4. Earths Rotation (spin)
Earth: one complete rotation on axis once/day (west to east)
portion of Earth facing the Sun = daylight
portion of Earth facing away from Sun = darkness

5. Earths Precession (wobble)
as Earth rotates, axis slowly turns, pointing in different directions over time
precession: the changing direction of the Earth’s axis

6. Earth’s Revolution (orbit)
all planets orbit around Sun (counterclockwise)
orbits are elliptical

7. Earth’s Revolution (orbit)
because orbits are elliptical the distance of each planet from the Sun changes as it orbits
orbital radius: average distance from the Sun

8. Earth’s revolution (orbit)
orbital period: time it takes to orbit Sun
the further planet is away from Sun, the larger the orbit and orbital period
Earths orbital period = days

9. Explaining Motion Geocentric Model Heliocentric Model
the Sun and the planets revolve around the Earth
Heliocentric Model
the planets orbit the Sun (our current understanding of the Solar System)

10. Earth’s Tilt Earth’s rotational axis is tilted 23.5 from the vertical
affects average daytime temperature experienced by Earth’s hemispheres

11. The Seasons
when Earth is farthest from Sun, northern hemisphere is tilted toward Sun
N hemisphere receives more direct sunlight = summer

12. The Seasons
when Earth is closest to Sun, northern hemisphere is tilted away from Sun
N hemisphere receives less sunlight = winter

13. The Seasons
solstice: when Earth’s axis is most inclined toward or away from Sun (occurs twice a year at summer and winter)
equinoxes: days of equal daytime and nighttime hours (occurs twice a year at spring and fall)

14. The Seasons

15. Motions of the Moon Moon rotates on axis while orbiting Earth
since a complete rotation takes a full orbit, the same side of the Moon faces Earth at all times

16. Phases of the Moon the Moon is illuminated by the Sun
the illuminated side of the Moon is not always facing the Earth
we see different amounts of the illuminated surface of the Moon as it orbits the Earth

17. Phases of the Moon
Lunar Cycle: all the phases of the Moon

18. Eclipses
occur when the position of one celestial object blocks, or darkens, the view of another celestial object from Earth
eclipses are either partial or total

19. Solar Eclipse
Moon is aligned between Earth and Sun and blocks Sun from being observed from Earth

20. Solar Eclipse
Solar Eclipse Clip

21. Lunar Eclipse
Earth is positioned between Sun and Moon and casts a shadow on Moon

22. Lunar Eclipse

23. Tides are the rising and falling of the surface of the oceans
caused by the gravitational pull of the Moon (mainly) & the Sun

24. The Pull of the Moon
Moon’s gravitational force pulls Earth and its oceans towards it
bulge of water forms on the side facing the Moon and the opposite side causing high tides

25. The Pull of the Moon
The Pull of the Moon

26. The Pull of the Sun
when the Sun and the Moon are aligned the combined gravitational force causes very high tides (spring tides)

27. The Pull of the Sun
when the Sun and Moon are perpendicular Sun’s gravitational force counteracts the Moon’s causing weaker tides (neap tides)

28. Highest Tides in the World
New Brunswick: Bay of Fundy

30. Learning goals
We are learning the impacts of the earth’s rotation and revolution.
We are learning the connection between the sun and moon.
We are learning the impact of the sun and moon’s gravity on earth.

31. Please complete
8.5 #4, 8, 9, 11.