1. Sun Earth Moon Light Warmth Energy Tidal Phase Seasonal Changes
Chapter 28, Section 28.3
We, benefit from the Earth’s relationship with the Sun and Moon in many ways, some of which we are unaware of and take for granted…
Light
Warmth
Energy
Tidal Phase
Seasonal Changes
Calendar
Time

2. MOTION – Earth’s Rotation
Sun Earth Moon
Chapter 28, Section 28.3
MOTION – Earth’s Rotation
Daily rising and setting
Sun
Moon
Stars
All rise in the east and set in the west
Not all rotate about the Earth
Our observation is from a moving Earth
Rotates on its axis once per day
15° per hour
Solar Day
How do we know this?
Foucault Pendulum
Coriolis Effect

3. ANNUAL MOTION – Effect of Earth’s Tilt
Sun Earth Moon
Chapter 28, Section 28.3
ANNUAL MOTION – Effect of Earth’s Tilt
Earth’s Tilted Axis
Weather Change
Length of Day
Temperature Change
The Earth orbits the Sun via an elliptical plane
Earth’s tilt on its axis is 23.5°
The axis remains fixed in its orientation
This changes the distance a hemisphere is from the Sun
Changes the altitude of the Sun in Earth’s sky
Completed changes are approximately every six months

4. SOLSTICES – Winter and Summer
Sun Earth Moon
Chapter 28, Section 28.3
SOLSTICES – Winter and Summer
Twice a Year
Sun reaches Northern and Southern Extremes
Over the Tropic of 23.5° N (Summer ~ June 21)
Over the Tropic of 23.5° S (Winter ~ December 21)
Sun is at its greatest distance from the equator. In the Southern Hemisphere, the winter and summer solstices are reversed.

5. EQUINOX – Vernal and Autumnal The Sun’s rays strike the equator at
Sun Earth Moon
Chapter 28, Section 28.3
EQUINOX – Vernal and Autumnal
The Sun’s rays strike the equator at
90°
Vernal – March 21 or 22
Autumnal – September 22 or 23
When the Sun is directly over the equator
The hemispheres receive equal amounts of sunlight
Day an Night are equal in duration
The term EQUINOX means
“EQUAL NIGHTS”

6. Sun Earth Moon
Chapter 28, Section 28.3

7. MOON PHASES – What We See and Why
Sun Earth Moon
Chapter 28, Section 28.3
MOON PHASES – What We See and Why
Let us examine the moons cycle this way…
New moon and Full moon
1st quarter and 3rd quarter
The phases in between

8. MOON PHASES – What We See and Why
Sun Earth Moon
Chapter 28, Section 28.3
MOON PHASES – What We See and Why
New Moon and Full Moon
The “New Moon” occurs when the Moon is positioned between the Earth and Sun illuminating the back side of the moon, the half that we cannot see.
The “Full Moon” occurs when the Moon is on the opposite side of the Earth, so the entire sunlit part of the moon is facing us.

9. MOON PHASES – What We See and Why 1st Quarter and 3rd Quarter Moon
Sun Earth Moon
Chapter 28, Section 28.3
MOON PHASES – What We See and Why
1st Quarter and 3rd Quarter Moon
The 1st and 3rd quarter, each is often called a "half moon“, occurs when the moon is at a 90° angle with respect to the earth and sun. We are half illuminated and half in shadow.

10. MOON PHASES – What We See and Why
Sun Earth Moon
Chapter 28, Section 28.3
MOON PHASES – What We See and Why
Other Phases
Crescent is a phase of less than half illumination.
Gibbous is a phase of more than half illumination.
Waxing means expanding in illumination.
Waning means decreasing in illumination.

11. MOON ORBIT – Synchronous Rotation and Tides
Sun Earth Moon
Chapter 28, Section 28.3
MOON ORBIT – Synchronous Rotation and Tides
Only one face of the Moon is visible to us
This is because of the speed at which the Moon now rotates
Millions of years ago it spun faster
Slowed by the gravitational influence of the Earth
The smaller gravitational influence of the Moon create tides
Rise and fall of water level to the shore every 12 hours
Twice the influence on tides as that of the Sun