earth's axis and revolution

1. Space

2. The Sun, Earth, & Moon

3. Comparing the sizes of the
Sun
Earth
Moon
Click to compare
the Earth, Moon,
and Sun
Another way to think about it...
If the Sun were the
size of a basketball...
the Earth would be
about the size of a pea....
the Moon would be about
the size of a pinhead....
Watch
a clip
Click to hear song

7. Click on the
Earth to see
how it revolves
Revolution and Rotation of the Earth,Moon and Sun.
Revolution-to go around
something else
Rotation-to turn around itself
What's the difference between rotation and revolution?
Earth's
Rotation
Click to see

8. A teacher
walking
around desks
A twirling
ballerina
The hands
of a clock
A car wheel
If an object rotates, the center stays in
the same place.
Notice how the middle of the fan stays in the same
spot while the rest of the fan travels in a circle around
the middle.
Is it Revolution or Rotation?
People often get Revolution and Rotation confused! Here's a trick to
help you remember the difference:
If an object revolves, the whole object
circles a center object or area.
Click on the dog to watch a dog's revolution around the center of
the pool. Notice how the whole dog moves around the center of
the pool.
Is the object showing REVOLUTION or ROTATION?

9. So, What is the EFFECT of our Earth's Rotation?
D
A
Y
N
I
G
H
T
How long does
it take for Earth
to make one
complete rotation?
About 24
hours
(1 Day)
The part of the Earth
that is facing the
sun is having what?
The part of the Earth
that is facing away
from the sun is
having what?
night
day

10. As the Earth is rotating, it appears as if the Sun is moving across
the sky (apparent movement).
East to west- the Sun is stationary, but the Earth is turning - so
the sun appears to rise in the east and set in the west.
Earth’s rotation causes Day and Night on our planet.
The rotation of the Earth also causes shadows to change.
Shadows are longest in the early morning and at dusk
(just before sunset).
Shadows are shortest at noon 12:00pm because the Sun
is directly overhead.

11. So, What is the EFFECT of our Earth's Revolution?
Seasons
To understand how this works, we need to study about:
*Earth's Orbit *Earth's Axis
click click

12. Earth's orbit is almost
completely circular and
centered around the sun,
but some planets' orbits
are not
Earth's Orbit
An orbit is the path that something makes as it revolves around another object
click to explore
orbit shapes
The Earth follows an
ORBIT around the SUN
return
So the Earth is always about
the same distance from the
sun. Do you remember
what that distance is?
93 million miles

13. Earth's Axis
An AXIS is an imaginary line that runs through the center of an object.
The Earth's Axis is
tilted 23.5 degrees

14. So, how does Earth's AXIS and it's ORBIT around the sun
cause us to have SEASONS?
If the Earth weren't titled on its axis, the same parts
of the earth would always receive the same amount
of direct sunlight and their weather would remain
the same throughout the year
Watch the Earth's
Revolution around
the sun

15. Sun
sunlight
Earth and the Moon are always half lit.
It's a little more complicated with moonlight. Since the moon revolves around the Earth, the amount of the half lit moon that we see
changes depending on where the moon is in its month long rotation around the earth. We call these different amounts of moonlight
Moon Phases.
We've already learned that the half of the Earth that's lit is experiencing
daytime and the other half is having nighttime.
Let's learn more!
http://youtu.be/OZIB_leg75Q
Click here for an
Animation of the moon's
rotation and revolution.

16. The Phases of Our Moon
There are 8 moon phases.
Each one shows a different amount or
area of moonlight.
The moon takes about one month to go through each of the
8 phases.
see the
moon phases

17. Sun
First Quarter
Waxing
Crescent
New
Waxing
Gibbous
Full
Waning
Gibbous
Last Quarter
Waning
Crescent

18. Ice has been found
in the dark parts of
craters where no
sunlight hits the
surface.
The moon is covered
with craters caused by
the impact of
meteors.
The moon has 1/6 the
gravity of Earth.
The moon is made of
rock.
The moon does not
produce its own light.
It reflects light from
the sun.
The moon has
mountains, some of
which are over 10,000
feet tall.
The moon rotates on
its axis once about
every 27 days.
The moon revolves
around the Earth.
The moon has no
atmosphere and
no weather,
weathering or
erosion
Moon Facts -Click on the moons

19. Tides
Tides are the rising and falling of the ocean as a result of the gravitational pull of the moon.
There are two high tides at a specific location every 24.5 hours.
There is a high tide on the side of the Earth facing the moon due to the moon’s gravity and
on the side of the Earth directly opposite from the moon due to the inertia of the ocean waters.
Approximately twice a month the Earth has a spring tide and a neap tide.
Spring tide = an “extra high” high tide that occurs
when the sun, earth, and moon are aligned and the
gravitational pull of the moon and sun work together.
Neap tide = a “lower than normal” high tide that occurs
when the moon is at a right angle to the sun and the
gravitational pulls of the moon and the sun oppose
each other.
Click here for a simple simulation

20. A closer look at
Our Sun

21. The sun is
about 110
times the
diameter of
the Earth
The sun is
believed to be
about 4.6
billion years
old
The sun is
an
averaged-
sized yellow
star
Sun Facts...

22. The Sun is the
only star in our
solar system.
The sun is
about 110
times the
diameter of
the Earth
The sun is a
ball of hot
burning
gases
The sun is an
averaged- sized
yellow star
Sun Facts...
The dark cooler
spots on the
Sun are called
sunspots.
The Sun rotates
on its axis.
The Sun is one
of trillions of
stars in
space.
Explosions on
the Sun are
called Solar
Flares.

23. Parts of the Sun
Click the globe to see a video on the Sun.
http://www.youtube.com/watch?v=x6RYgQ2jxCU&feature=related

24. Let's take a closer look at
Our Solar System
In Our Solar System, there are 8 planets
Can you find the mistake?
Click here
for video
on inner
planets
Do you see the
mistake in the picture?
Can you name
the planets in the
correct order?
Remember
this!
My
Very
Energetic
Mother
Just
Served
Us
Nachos
Click here
for video
on outer
planets

25. In the 16th century, an
astronomer named
Copernicus developed a
HELIOCENTRIC model of the
universe, in which the sun
was the center of the universe
with the earth and other
planets orbiting around the
sun.
Soon after, an
astronomer
named Galileo
expanded upon
and offered proof
of Copernicus's
sun-centered
model of our
solar system.
Today, we understand that the
sun is the center - but not of the
universe, The sun is the center
of our solar system. We
continue to learn more and
more about our solar system,
galaxy, and our universe with
new scientific discoveries.
An earth-centered model of
the universe was developed
thousands of years ago
by Greek philosophers.
This earth-centered model is
called a GEOCENTRIC model.
How has our
understanding
of our solar
system
changed over
time?
Watch a clip
Two famous Greek
philosophers who
wrote about this are
Ptolemy and
Aristotle. Most
people believed this
Geocentric view of
the universe to be
true for a long,
long, time.

26. Watch
a clip of
JFK speaking
about this!
Watch
a clip of the
first moon
landing
National
Aeronautics &
Space
Association
The NASA Apollo missions
added greatly to our understanding of the moon.
Apollo Program
*Program of NASA - 1961-1975
*17 Missions
*Sparked interest in space exploration around the world.
*Accomplished many FIRSTS!
*Apollo 11 - July 20, 1969 - First human to walk on the
moon!!
Who?
*Neil Armstrong
*Buzz Aldrin
*Michael Collins
President
John F. Kennedy
strongly supported
the Apollo Program
and set the goal
of landing an
American on the
moon by 1970