How does the phenomena of "seasons" occur. Why would it be summer inMaryland when it is winter in the southern hemisphere?Does the moon have seasons?

The Earth has seasons because it is tipped over to one side. It stays tipped in the same direction as it travels around the Sun. This means that sometimes the "top" of the Earth (which we call "north") is pointing towards the Sun, and sometimes it is pointing away.

When the north half of the Earth is pointing towards the Sun, that half gets more sunlight and is warmed by the Sun. This is summer for people on the northern half of the Earth. At the same time, the "bottom" half of the Earth (which we call "south") is pointed away from the Sun. During the time that it's pointed away, that half doesn't get as much sunlight, so it is colder. This is winter for people on the southern half of the Earth. When the Earth completes half of its orbit around the Sun, the north end will be pointed away and the south end will be pointed toward the Sun and the seasons will switch! This is why seasons in the south are always the opposite of seasons in the north!

Suppose the Earth were straight up and down. Then everybody would have the same season all year round. No more summer and winter!

The Moon is nearly straight up and down. So each spot on the Moon has the same "season" all year. Even if the Moon had seasons, they would differ from seasons on Earth. There is no air on the Moon, so there can never be April showers, or snow for snowmen, or even wind for flying kites. All of these things happen on Earth because it has an atmosphere.


Submitted by Joan (Massachusetts, USA)
Submitted by Alex (Maryland, USA)
(October 22, 1997)



Shop Windows to the Universe Science Store!

Learn about Earth and space science, and have fun while doing it! The games section of our online store includes a climate change card game and the Traveling Nitrogen game!

Windows to the Universe Community

News

Opportunities

You might also be interested in:

What are the retrograde motions of planets in the sky?

It depends on which type of motion you are asking about. If you take a birds-eye view from the top of the solar system all the planets orbit around the Sun in a counter-clockwise (or direct) direction....more

How do Astronauts Live in Space?

Have you ever wondered how astronauts live in space? Did you know they do a lot of the same things we do here on Earth? Astronauts eat, exercise and sleep just like we do. However, their food isn't always...more

How far is the Earth from the Sun, the Moon and all the other planets? How far are all of the planets from the Sun? Do you know of a software that tracks the planets in real-time?

There is a really neat internet program called Solar System Live that shows where all of the planets and the Sun are. If you go to that page, you'll see an image similar to the one on the left. Below the...more

Is it really true that man never really walked on the Moon?

The picture of the American Flag (the one put there by the Apollo astronauts) is waving (or straight out) in the wind. How could that be possible if there is no atmosphere on the Moon? Was it some sort...more

How many planets orbit the sun?

I was wondering if there is a new planet? Are there planets (a tenth planet?) after Pluto belonging to our solar system? What are the names of the new planets discovered in the solar system? Are there...more

Did the Big Bang create any black holes? Wouldn't the universe evolve differently if some of the original energy had disappeared in black holes?

When an object has a really high energy, it can form a black hole. This is called a primordial black hole. Primordial black holes were formed near the beginning of the universe. Primordial black holes...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part by the National Science Foundation and NASA, our Founding Partners (the American Geophysical Union and American Geosciences Institute) as well as through Institutional, Contributing, and Affiliate Partners, individual memberships and generous donors. Thank you for your support! NASA AGU AGI NSF