The Seasons

The Earth

In space, the Earth's axis is tilted.

The Earth rotates on its axis.
It rotates once every 24 hours or 1 day.
The Earth's rotation creates day and night.

The Earth revolves around the Sun.
It takes 1 year for it to revolve all the way around.
One year also equals 12 months or 365 days.

The tilt of the Earth causes the seasons.
As the Earth orbits the Sun,
the tilt of the Earth's axis does not change.
The Earth always leans in the same direction.

When the North Pole is titled toward the Sun
during Summer, the North Hemisphere gets direct light.
The air in the atmosphere then becomes hot.

When the North Pole is titled away from the Sun
during Winter, the North Hemisphere gets indirect light.
The air in the atmosphere then becomes cold.

The Autumnal Equinox arrives on September 22 or 23.
On the first day of Autumn,
the sun's light is directly over the Equator.
This causes us to have an equal number
of hours of light and darkness.

The Winter Solstice arrives on December 21 or 22.
The North Pole is tilting far away from the Sun.
The first day of Winter is the shortest day of the year.
Because the Sun is lower in the sky,
the days are shorter and colder.

The Vernal Equinox arrives on March 20 or 21.
On the first day of Spring,
the Sun's light is directly over the Equator.
There are an equal number
of hours of daylight and darkness.

The Summer Solstice arrives on June 20 or 21.
The North Pole is as close to the Sun as it will get.
The first day of Summer is the longest day of the year.
Because the Sun is higher in the sky,
the days are longer and hotter.