The Earth in its orbit at the solstices and equinoxes.
Click on image for full size

The Seasonal Merry-Go-Round

As the Earth travels around the Sun, it remains tipped over in the same direction, towards the star Polaris. This means that sometimes the top half of the Earth is pointing towards the Sun (summer), and sometimes it is pointing away (winter).

Did you notice that when the northern (top) half of the Earth is pointing towards the Sun, the southern (bottom) half is pointing away? This is why people in North America, Europe, Asia, and other places north of the equator have the opposite season of people in South America, Australia, and other places south of the equator.

Halfway in between the times when the Earth is pointing towards or away from the Sun, both parts of the Earth get almost equal amounts of sunlight. These times occur about halfway between summer and winter, so you might guess what we call them... spring and autumn!

Last modified October 31, 2006 by Travis Metcalfe.

You might also be interested in:

Traveling Nitrogen Classroom Activity Kit

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

North and South: Opposite Seasons

NASA now makes images of the whole Earth every month. There are no clouds in the images. They combine many pictures taken at different times. The polar ice caps look bigger than they really are. The movie...more

What is the distance from the Earth to the Sun when the Earth is at perihelion and when it is at aphelion? At what month is the Earth closest to the Sun? What is the circumference of the Earth? How fast is the Earth moving about its axis; how about around the Sun?

Scientists use fancy words to describe things sometimes. The Earth doesn't orbit the Sun in a perfect circle. So, there is a point when the Earth is closest to the Sun and farthest from the Sun. Scientists...more

What Causes the Seasons?

The Earth's orbit is in the shape of an ellipse (a stretched out circle), so that sometimes the Earth is closer to the Sun than at other times. Is this the cause of the seasons? You can imagine that if...more

Universal Time

When it is noon where you live, it is midnight on the opposite side of the world. Usually when we think of time, we mean "the time of day where I live". If we say something happened at 9 AM, we mean it...more

Native American Astronomy

People have been living in North America for a long, long time. The first people to live there were the Native Americans. They didn't have clocks or calendars so they watched tides, the Sun, the Moon,...more

Archeoastronomy

Man has always observed the sky. By watching the Sun and Moon, early man could tell what season was coming next. They had to know this to be able to farm and hunt. Archeoastronomy started in the 1960's...more

The Stones of Carnac

The stones of Carnac, France, are very famous because there are a lot of them and because they are so old! The oldest stones found in Carnac are from about 4,500 B.C. That's older than the stones at Stonehenge!...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA