1) Earth spins on its axis once every 24 hours, causing day and night. The side of Earth facing the sun experiences day, while the opposite side experiences night. 2) Earth also revolves around the sun once every year. As it revolves, its tilted axis remains pointed in the same direction, causing seasons. 3) The tilt of Earth's axis and its revolution around the sun cause the four seasons - spring, summer, fall, and winter - in the northern and southern hemispheres.

1. April 2013 CH7Lesson3
What are
Earth`s
?patterns

2. How Earth moves
Earth is always moving. One way
Earth moves is that it spins
around its axis.
Earth`s axis is an imaginary line
that runs between the North
.Pole and the South Pole

4. The axis is not straight up and
.down. It is tilted

6. Earth turns in a
counterclockwise direction at
the North Pole.
This direction is opposite to the
direction in which the hands of a
clock move.
Earth also turns from west to
.east

7. Counterclockwise direction

10. Day and Night

11. Earth`s spinning causes day and
night.
Earth makes one complete spin
on its axis, or rotation, every 24
.hours

12. During this time, half of Earth
faces the sun. That half of Earth
has day. The half of Earth that is
.not facing the sun has night

13. As Earth spins, or rotates, a
different part of Earth turns to
.face the sun

16. Earth`s spinning also causes
changes in the sun`s position in
the sky. These changes follow a
. pattern

17. In the morning, the sun appears to
rise in the east. During the day, the
sun seems to move across the sky
and then set in the west.
You might think the sun moves
around Earth. But the sun only
appears to move across the sky.
Actually . Earth in moving

18. When it is still nighttime in Honolulu,
Hawaii, the sun is raising in Seattle.
In new Orleans, it is daytime and
some students are already starting
.their school day

19. Revolution
Around the Sun

20. Earth makes one revolution when
it makes one complete trip
around the sun.
One revolution takes about
one year.
As Earth revolves around the
sun, Earth's tilted axis always
points in the same direction in
.space

21. June December
sun
March
September

22. direct
solar
rays
Earth`s
northern
half is
tilted
toward
.the sun
Earth`s
northern half
is tilted away
.from the sun

23. Seasons

24. A year is divided into four seasons-spring,
summer, fall, and winter.
The seasons are caused by:
1
the tilt of Earth`s axis.
2
the planet`s revolution around
. the sun
.

25. As Earth moves around the sun,
different parts of the planet tilt
.toward the sun

26. Earth in June
The northern half of Earth is -
tilted toward the sun.
-It receives more direct rays of
sunlight than the southern half
and heats up more.
Summer in the northern half.
. winter in the southern half

27. Earth in December
The northern half of Earth is -
tilted away from the sun.
-It gets less sunlight and has
colder temperatures than the
southern half.
winter in the northern half.
. Summer in the southern half

28. Earth in March
and September
Neither end of Earth`s axis -
points toward the sun.
-Both halves of Earth get about
. the same amounts of sunlight

29. Shadows
During the Day

30. A shadow forms when an object -
blocks the light that hits it.
-The shadow has about the same
shape as the object that blocks
.the light

31. The length and direction of
shadows . change during the day
morning midday afternoon

32. The morning shadow is long. The
shadow stretches in the opposite
direction from the sun in the
.eastern sky

33. As the sun appears to move higher in
the sky, the shadow becomes
shorter. Around midday the sun is at
its highest point in the sky.
.The shadow is very short

34. As the sun continues moving across
the sky, the shadow becomes longer.
The afternoon shadow stretches in a
different direction.
As the sun moves toward the horizon
in the west, the shadow stretches
. toward the east

35. Shadow Length
During the Year

36. The length of a shadow changes
during the year.
In the northern half of Earth,
the sun is higher in the sky in
summer.
the sun in lower in the sky in
. winter

37. east
north south
west
winter

38. east
north
west
south
summer