Seasons, solstices & equinoxes

Earth's axis

Hemispheres

Seasons

The spinning motion of a planet on its axis

The Sun and Moon seem to move across the sky each day because Earth is rotating on its axis.

Earth's rotation causes day and night.

It takes Earth about 24 hours to rotate once on its axis.

The movement of an object around another object

It takes about one year to complete one revolution around the sun.

Earth has seasons because its axis is tilted as it revolves around the sun.

In June, the north end of Earth's axis is tilted toward the Sun and it is summer in the Northern Hemisphere and winter in the Southern Hemisphere.

In December, the north end of Earth's axis is tilted away from the Sun and it is winter in the Northern Hemisphere and summer in the Southern Hemisphere.

Happens in June and December

During the summer solstice, the hemisphere tilted toward the sun will see the longest day of the year.

During the winter solstice, the hemisphere tilted away from the sun will see the shortest day of the year.

Occurs in March and September

Halfway between the solstices

Day and night are each about 12 hours long

Neither hemisphere is tilted toward or away from the Sun