Transcript The Earth in Space

The Earth and its Seasons
Taking Cornell NOtes
Let’s set up our notes …
Reasons for the Seasons Notes
Keywords/
Questions
Does the
distance
between Earth
and the Sun
change?
Rotation:
Revolution:
Tilt:
Notes
Does the distance between
Earth and the Sun change?

Earth’s orbit is elliptical, but never “super
skinny”

The distance between Earth and Sun
never changes significantly

We are actually closer to the sun in
January than any other time of the year
Earth’s Orbit Around the Sun
Rotation: the spinning of Earth on its axis

Its rotation on its axis
causes day and night


It takes 24 hours to
rotate once on its axis
Earth rotates counterclockwise
Rotation Animation
Day and Night Song
Revolution: the movement of one object
around another object

Earth travels around the
sun counter-clockwise

One complete revolution
around the sun is a year

The path is called its orbit

Earth’s revolution along
with its tilted axis cause
our seasons
Revolution Animation
Revolution
Words to Know
Orbit : a curved path followed by Earth
as it moves around the Sun
Now You Try!

Stand in place, and make one complete turn
 You

Take a trip around your chair
 You

have just rotated
have just revolved
Do you think you can rotate and revolve at
the same time?

Think about what a
spinning top, a race
car on an oval track,
and a globe have in
common.
Think – Pair - Share
1.
2.
3.
What is a spinning top doing?
What is a race car on an oval track
doing?
How does that relate to the movement of
Earth?
Turn to your neighbor and
explain…
What is the difference between
Earth’s rotation and Earth’s
revolution?
Earth in Space
Earth
rotates
On its
axis
causing
Day and
night
revolves
Around
the sun
causing
Years
Earth’s Tilted Axis

Earth is tilted toward the
North Star (Polaris) 23.5º

Earth has seasons
because its axis is tilted as
it revolves around the sun

If Earth’s axis were straight
up and down temperatures
would remain constant year
round
Direct vs. Indirect Sunlight
Direct vs. Indirect Light
Why is it warmer near the equator
than near the poles?

At the equator - sunlight
hits Earth’s surface more
directly

Closer to the poles,
sunlight hits Earth’s
surface at an angle

Near the poles, energy
from the sun is spread
out over a greater area
Predict the Season
Write “What Season?”
Write “Why?
Draw a Diagram
What Season in the Northern
Summer
Hemisphere?
Explain why
What Season in the Northern
Winter
Hemisphere?
Explain why
As the Earth moves around the
Sun, this axis always stays
pointing in the same direction.
WHY DO WE HAVE SEASONS?
So, seasons are caused by the tilt of the
Earth’s axis as it revolves around the sun.
Because of this, hemispheres receive
different amounts of direct/indirect
sunlight throughout the year, causing
seasons.
Seasons and Earth
The Seasons of Earth
Solstice and Equinox
Solstice
•
Longest and shortest day of the year
•
Winter Solstice – the Northern Hemisphere is
pointed furthest away from sun (December 21)
•
Summer Solstice – the Northern Hemisphere
is pointed furthest toward the sun (June 21)
Winter Solstice
Summer Solstice
Equinox
•
Day and night are equal length
•
Sun is directly over the equator, causing equal
hours of day and night
•
Spring Equinox (March 21)
•
Fall Equinox (September 23)
Equinox
The Earth's seasons are NOT
caused by the differences in the
distance from the Sun throughout
the year.
Section 1 Review
Question 1
Explain the process that causes day and
night.
Answer:
Earth rotates on its axis once per day. As
Earth rotates, half its surface is facing the
sun (day) and half is facing away from the
sun (night).
Question 2
What two factors cause the cycle of the
seasons?
Answer:
The cycle of the seasons is caused by
Earth’s revolution around the sun and the tilt
of Earth’s axis.
Question 3
Compare rotation and revolution.
Answer:
Rotation is turning around a point or an axis;
revolution is movement around another
object.
Question 4
What do the words solstice and equinox mean?
How are they related to the position of the earth’s
axis?
Answer:
A solstice is a day when the noon sun is overhead
at 23.5° S or 23.5° N. This occurs when one end of
Earth’s axis is tilted most directly toward the sun.
Equinox means “equal night”, and occurs when
neither pole of Earth’s axis is tilted toward the sun.
Question 5
Are changes in the distance between the Earth
and the sun important in causing the cycle of the
seasons? Explain.
Answer:
The tilt of Earth’s axis, not its distance from the
sun, is the cause of the cycle of seasons. During
the summer months in the Northern Hemisphere,
Earth is actually at its farthest point from the sun.
During winter in the Northern Hemisphere, Earth is
at its closest point to the sun.