How Does the Earth Move?

Lesson Plan - Get It!

Audio:

Seasonal changes bring temperature and precipitation changes.

The temperatures drop during the winter and rise in the summer. These changes are related to the movement of the earth around the sun.

It takes the earth about 365 days to orbit, or move around, the sun.

• What else do you know that takes 365 days?

A full calendar year is 365 days. This is one way the sun and earth's movement measures time.

During this movement around the sun, the amount of sunlight hitting various areas on the earth's surface changes. As a result of the changing amounts of sunlight, the earth experiences different seasons.

• Do you know another way the earth's movement is used as a time measurement?

Yes, the earth rotates on an imaginary axis every 24 hours, or one day.

The tilt of the earth is 23.5 degrees. That means an angle of 23.5 degrees exists between the imaginary axis and the vertical center of the earth.

The tilt is important because it changes the angle of sunlight, which impacts the length of our days.

As the earth moves around the sun, the North Pole points toward the sun for half of the year, and then the South Pole points toward the sun for six months.

When the North Pole points toward the sun, it is summer in the Northern Hemisphere and winter in the Southern Hemisphere. This means that the days in the North are longer.

As the earth moves, the South Pole tilts toward the sun, causing the seasons to change in both hemispheres.

The longest day in the Northern Hemisphere occurs on June 21^st (the first day of summer), with the longest night falling on December 21^st (the first day of winter).

• What do you think the longest day in the Southern Hemisphere is?

It's the opposite: December 21^st has the most sunlight, while June 21^st has the longest night!

Here are some interesting facts!

During summer in the United States, the country is tilted toward the sun but is the farthest away from the sun!

During winter in the United States, the country is the closest to the sun but tilted away.

So, distance to the sun does not impact seasons or temperatures. It is all about the tilt!

Check out the video below to review the reason for the seasons!

• If the United States is experiencing summer, what season is it in Brazil (located in the Southern Hemisphere)?

It's winter, with shorter days and lower temperatures. This difference is due to the earth's revolution along its orbit around the sun.

As the earth moves, the amount of sunlight changes, causing seasonal differences in temperature and precipitation.

In the Got It? section, learn more about the changes observed on the surface of the earth during seasonal changes.