Earth, Sun,MoonUnderstanding how the rotational model of the Earth, Sun and Moon affects our lives

By Mr. Hartman

Appetizer Questions

• The Earth, Sun and Moon are things we see every day and capture our interests.  

• We see the Sun pass through the sky each day and see the Moon change appearance during each month

1. Does the changing appearance of the moon affect your life?

2. Do the positions of the Earth, Sun and Moon ever cause anything special to happen?

3. Does the rotation of the Earth around the Sun affect you?

Lesson OverviewThe relationship between how the Moon moves around the Earth and the Earth moves around the Sun explains the following topics that we will learn about in this lesson:

1. The Lunar Phases or Fullness of the Moon2. Eclipses of the Sun and the Moon3. The Seasons and how they differ in the Northern

and Southern Hemispheres

Rotations and OrbitsRotating on an AxisThe sun, moon and Earth all rotate on an axis like a basketball spinning

Rotations and OrbitsThey also rotate (or orbit) around other points • The moon rotates around the earth• The earth rotates around the sun• The sun rotates around the center

of the galaxy.

Moon - Lunar Phases• The moon glows because it

reflects light from the sun. Half of the moon is always facing the sun and reflecting light into space.

• As the moon circles the Earth, the shape of the moon appears to change because the part of the moon reflecting light is not always facing us directly.

• The shape varies from a full moon (when the Earth is between the sun and the moon) to a new moon (when the moon is between the sun and the Earth).

Names of the Lunar PhasesThere are eight phases of the moon that occur in the following order:1. New Moon (Moon is closest to

sun)2. Waxing Crescent3. First Quarter4. Waxing Gibbous5. Full Moon (Moon is farthest from

sun)6. Waning Gibbous7. Last Quarter (or Third Quarter)8. Waning Crescent

*Waxing means becoming more or bigger*Waning means getting less or smaller

Far Side of the Moon Did you know we can only see one side of the moon from

Earth? As the moon orbits around the Earth, the moon is also

slowing rotating so that it always shows us the same side. Is the moon hiding something on the other side?

Synchronous Rotation of the Moonhttps://www.youtube.com/watch?v=OZIB_leg75Q

Solar Eclipses A solar eclipse happens when the moon blocks our view of the

sun. This happens when the Moon is exactly between the Sun and the Earth. 

Partial Solar Eclipse - A partial solar eclipse is when the Moon only covers part of the Sun.

Total Solar Eclipse - A total solar eclipse is when the Moon appears to cover the entire Sun. This is only visible in the portion where the Umbra reaches the earth.

Totality is the short part of an eclipse when the moon entirely blocks the Sun.

Annular Eclipse - During an annular eclipse, the sun looks like an "annulus" or ring. The ring is visible when the Moon does not entirely cover the disk of the Sun during a solar eclipse.

Lunar Eclipses A lunar eclipse occurs when the Earth's shadow falls on the moon.

Lunar eclipses occur, on average, about every 6 months. Total Eclipse - When the entire moon enters the Earth's umbra (the

darkest part of its shadow), this is called a total eclipse. Partial Eclipse - When only part of the moon enters the Earth's

umbra, this is called a partial eclipse.

Why do we have Seasons?• Some people believe that

Earth is closer to the Sun in the summer and that is why it is hotter. And, likewise, they think Earth is farthest from the Sun in the winter.

• Do you agree or disagree with this reason?

• Does that explain the seasons for every place on earth?

Seasons and the Earth’s Axis The Earth's seasons are not caused by

the differences in the distance from the Sun throughout the year (these differences are extremely small). The seasons are the result of the tilt of the Earth's axis.

The Earth's axis is tilted from perpendicular to the plane of the orbit of Earth around the sun by 23.45°. This tilting is what gives us the four seasons of the year - spring, summer, autumn (fall) and winter.

Since the axis is tilted, different parts of the globe are oriented towards the Sun at different times of the year.

The seasons in the Northern Hemisphere are the opposite of those in the Southern Hemisphere because of the tilting and rotation of the earth around the sun.

Video Review of Earth’s Tilt & Seasons

Sun Earth Seasonshttps://www.youtube.com/watch?v=000-3JYM0NI