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2. The Earth in the Universe
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The seasons
Apply
22.
Look at the illustration. Is it correct to say that the seasons are caused by the Earth’s revolution around the
Sun?
5.1.1.
The Earth’s seasons
Characteristics of the Earth’s revolution cause the amount and
intensity of sunlight that hits a part of the Earth to vary during
the year.
These variations cause the
seasons
.
During the summer, the sun’s rays hit the Tropic of Cancer in
the Northern Hemisphere and the Tropic of Capricorn in the
Southern Hemisphere perpendicularly.
Due to the tilt of the Earth’s axis with respect to the ecliptic
plane, the sun’s rays hit the Northern Hemisphere directly and
the Southern Hemisphere at an oblique angle. This is why when
it is summer in one hemisphere, it is winter in the other.
In spring and summer, the sun’s rays hit the Equator
perpendicularly.
The change from one season to the next is marked by the length
of day and night. The first day of summer is the longest day of
the year and the first night is the shortest.
Winter begins with the longest night. These days when the
difference between the length of night and the length of day is
the biggest, are called
solstices
.
The day and night that mark the beginning of spring and autumn
are the same length. They are called
equinoxes
.
Incidence of the sun’s rays on the Earth
Apply
21.
When it’s summer in Spain, we are further
from the Sun, so why is it hotter?
