Earth is a Sphere - round 3-d object◦ Aristotle Greek 350 B.C. curved shadow.

Earth is a satellite of the sun. Follows an ellipse – an elongated closed

curve. Sun is not at the center of the ellipse.

The axis is an imaginary vertical line that the Earth spins around

Referred to as one year

The earth is tilted on its axis by 23.5 degrees.

Not all the earth gets the same amount of light all year.

June 21 or 22

Sun rays hit the tropic of cancer most directly

December 21 or 22

Sun’s rays hit tropic of Capricorn most directly.

March 20 or 21-spring

September 22 or 23 –fall

Sun’s rays hit the equator most directly

Short periods of climatic change caused by changes in radiation an area receives.

Winter, spring, summer, fall

Caused by tilt of earth and angle of which the sun light hits earth

Does not really occur at equator

Is a satellite of the earth

Also rotates and revolves

Rotation and revolution takes 27.3 days to complete each.

We always see the same side of the moon

Appears to change shape called “phases”

Happens after a New moon or no moon.

Lighted side of the moon is on the right

Happens after a full moon

Light side of the moon is on the left