How does the phenomena of "seasons" occur. Why would it be summer in Maryland when it is winter in the southern hemisphere? Does the moon have seasons?
The Earth has seasons because it is tilted about 23.5 degrees from straight up and down. Think of the Earth as a spinning top, tipped over to one side. It remains tipped in the same direction as it travels around the Sun. This means that sometimes the northern hemisphere of the Earth is pointing towards the Sun, and sometimes it is pointing away.
When the northern half of the Earth is pointing towards the Sun, the northern hemisphere of the Earth gets more direct sunlight. We call this the "summer" season for the north. At this same time, the southern half of the Earth is pointed away from the Sun, so people in the southern hemisphere get less direct sunlight. We call this "winter" for the southern hemisphere. So, because of the tilt of the Earth's axis, the seasons in the south are the opposite of those in the north.
Suppose the Earth's axis was not tilted. Then everybody would have the same season all year round! No more summer and winter! The Moon is only tipped over about 1 degree. Since it has such a small tilt, each spot on the Moon has the same "season" all year.
Even if the Moon had seasons, they would differ from seasons on the
Earth. The Moon has no atmosphere. Hence, many of the weather
phenomena which we associate with seasons (wind, rain, and snow, for
example) cannot occur on the Moon.
Submitted by Joan (age 35+, Massachusetts, USA)
Submitted by Alex (age 11, Maryland, USA)
(October 22, 1997)
