Earth’s Seasons

Brought to you by the earth’s 23.5º tilt

Rotation:Earth spinning on its axis.

Revolution:Earth’s yearly trip around the sun.

Another word for revolution is orbit.

Earth revolves around the sun in an ellipse (similar to an oval).

Why do we have seasons? Is it the distance from the sun that causes

them?

No, it’s the tilt of Earth on its axis that causes the seasons:

Axis: the imaginary line about which a rotating body, such as the earth, turns.

Summer

Winter

Solstice

• 1st day of summer (June 21 or 22) or winter (Dec 21 or 22).

• Longest day of the year (summer) or shortest day of the year (winter).

• Sun shines at its northernmost or southernmost points of the year.

Fall or Spring

Equinox

• 1st day of fall (September 22 or 23) or spring (March 20 or 21).

• Day and night are equal.

• Sun shines directly over the equator, equally on the northern and southern hemispheres.