Developed on a volunteer basis for the 4th grade science classes of Duncan Elementary.

1. THE SUN,
The EARTH,
THE MOON (and
other space things!)
4th Grade Science
Duncan Elementary

2. THE SOLAR SYSTEM
The Sun is at the center of our Solar System, and 8 planets revolve
around the Sun in a circular or elliptical orbit. Our Earth is the third
planet from the Sun, and the only planet in the Solar System with
plants, animals, and people!
Jupiter
Mercury Earth Saturn
Uranus Neptune
Venus
Mars

3. THE SOLAR SYSTEM AND THE MILKY WAY
Our Solar System is a very small part of a VERY LARGE collection of stars, planets,
and space, called the MILKY WAY GALAXY.
The Milky Way Galaxy is a very small part of the UNIVERSE, whose size cannot be
determined with certainty.
THE UNIVERSE
MILKY WAY
GALAXY

4. LIVING THINGS ON SOLAR SYSTEM PLANETS?
Because they are so close to the Sun, planets Mercury and Venus are too hot for
plants, animals and people to live there.
Because they are so far from the Sun, Jupiter, Saturn, Neptune and Uranus are too
cold for most living things. Mars is colder than Earth, and various studies have been
conducted to determine whether there are any living things on “the Red Planet”.
Jupiter
Mercury Earth Saturn
Uranus Neptune
Venus
Mars

5. THE STARS IN THE SKY
On a cloudless night, away from city lights (or using a telescope), you would be
able to see millions of stars in the sky. Some stars are brighter and closer than
others. These stars are so far away that the light from these stars took hundreds
or thousands of years to reach the Earth.
Some bright stars form a pattern called a CONSTELLATION that looks like a
person, animal or thing. The most common one we see in our sky is the “BIG
DIPPER” that looks like a large spoon or soup ladle.

6. OTHER INTERESTING
THINGS IN THE SKY
• At night, we can get a great view of
the MOON, in one if its many
phases (more about that later!)
• Sometimes, we can see a METEOR
flash through the sky and burn up
as it approaches the Earth.
• Earth is sometimes visited by one
of several COMETS that make their
way around the Sun.
• At times, we may see a bright
object that is a PLANET with
sunlight reflecting off its surface.
• …but you would need to look really
hard to see an astronaut cat
outside the orbiting International
Space Station!

7. FACTS ABOUT OUR SUN

8. THE SUN
The Sun is actually a large star. Because the Sun is
closer to us than any other star, it appears as a ball of
orange, yellow, or white light in the sky.
The Sun’s bright light prevents us from seeing any other
stars in the sky, and is so bright, we would hurt our
eyes if we looked at it directly.
Like most stars, the Sun is a
large mass of hydrogen and
helium gases that constantly
“burn” and re-generate, giving
off heat energy and light.
The Sun’s energy keeps us
warm. Its light helps us see
things around us, and helps
our plants to grow.

9. MORE FACTS ABOUT THE SUN
About 860,000
Miles Wide!
(about 35 times wider
than Earth)
• The Sun is 860,000 miles wide, so about 109 Earths could fit inside the Sun!
• The Sun is about 93 Million Miles away from Earth.
• The Sun does not have any air or water, and is too hot for anything to live there.
• The Sun’s light takes 8 minutes to travel to Earth, at the speed of light which is
182,200 miles per second! (fortunately, its light is sent out constantly so we
don’t notice any delay)
• The Sun’s surface is rough, with flares, spikes, waves and storms happening all
the time, and cooler areas known as sunspots appearing periodically.

10. REVIEW QUESTIONS!
Please answer these questions which are based on the information we have
covered about the SUN!
1. Other than the Sun, what are other things we can see in the night sky?
2. About how far is the Sun away from the Earth?
3. How long does it take the Earth to go around the Sun?
4. How much bigger is the Sun compared to the Earth?
5. What is the name of the closest star to Earth?
6. The Sun is part of a constellation. True or False ?
7. We would hurt our eyes if we looked directly at the Sun. True or False ?
8. The Sun’s surface is very smooth and consistent. True or False ?
9. All of our Solar System’s planets revolve around the Sun. True or False ?
10.Our Sun is the largest thing in the Universe. True or False ?
11.We could live on the Sun, but would need lots of ice to keep our ice cream
from melting. True or False ?
12.Explain why the Sun is so important to us on Earth.
13.What are the names of the other planets in our Solar System? Which
planet is closest to the Sun, and which planet is furthest?
14.Why can we have a warm day, without ever seeing the Sun shining?

11. NOW, LET’S TALK ABOUT
THE EARTH!

12. SOME FACTS ABOUT EARTH
• The Earth is shaped like a ball that is a little flat on the top and
bottom (at the North and South Poles)
• The Earth was formed millions of years ago as very hot rock,
metals and gases.
• The planet we call Earth has three parts:
o The CRUST: Rains cooled the Earth’s hot exterior, and
made it suitable for life.
o The MANTLE: A middle layer of very hot rock -- when a
volcano erupts, we see what the mantle is like
o The CORE: The extremely hot molten center of the Earth
• The Earth has an atmosphere that includes:
o Air for us to breathe (though there is less air the further
you go away from the Earth’s surface)
o Winds that move warm and cold air across the surface
o Clouds that hold moisture above the surface, and deposit
rain on the surface
o Ozone that protects us from the radiation energy given
off by the Sun.

13. MORE FACTS ABOUT EARTH
• Above the Earth’s atmosphere and out into space, there is
ZERO gravity ; that is, there is no force to hold things
down or prevent them from floating -- the Earth has
gravity that keeps people and objects on the ground.
• The Earth is about 7,900 miles in diameter , and
about 25,000 miles around (in circumference) at
the Equator .
• Millions of years ago, the Earth was covered in ice, which
eventually melted to form oceans, lakes and rivers.
• Many geologists believe that all the land we see on the
Earth today, at one time had been attached – but the land
broke apart and drifted to their current locations.
• The highest point on the Earth’s surface is Mount Everest,
and the lowest points lie deep below our oceans.

14. We live on the EARTH, in
Michigan, which is here EARTH
CLIMATE
FACTS
This is the EQUATOR, which is an
imaginary line at the middle of the
EARTH. The equator is rather
summer-like (WARM or HOT) all
The NORTH POLE is at the “topmost” year-round.
part of the EARTH, and the SOUTH POLE
is at the bottom-most part. Both these
places are winter-like (very COLD) all
year-round.

15. EARTH
CLIMATE
FACTS
Michigan is closer to the cold NORTH POLE than it is to the
warm EQUATOR, so our temperatures tend to be much
cooler than countries near the Equator.

16. EARTH
CLIMATE
FACTS
Michigan can have cool days in the Summer and warm days in
the Winter, because of the winds on the Earth’s surface that
may blow warm Equator air or cool North Pole air towards us.

17. THE EARTH’S ROTATION
The Earth spins about an
AXIS imaginary line called an AXIS
that extends from the North
Pole to the South Pole. The
Earth spins one complete
rotation (completely around)
every 24 hours – which is ONCE
EACH DAY.
The Earth spins at a rate of
about 1,000 miles per hour!
…but like flying in an airplane,
when everything moves at the
same fast speed it seems like
nothing is moving!!

18. THE EARTH’S 23o
ROTATION
Orbit Path around the Sun
NOT LIKE THIS 23o
THE EARTH’S TILT: As you may have noticed in previous slides
that the Earth is tilted relative to the path it takes around the
Sun. The line from the North Pole to the South Pole is tilted at
a small (but important) 23 degree angle.

19. DAY AND NIGHT ON EARTH
The Sun does not really move, so the
Earth’s spin about its axis is what
causes Day and Night to occur. The
Sun rises in the Eastern sky and sets
in the Western sky. Sunrise in the East
(over the Atlantic Ocean)

20. THE EARTH’S REVOLUTION AROUND THE SUN
About 93 Million
Miles
The Earth travels in an orbit around the Sun. When drawn, the orbit path
looks like an ellipse, and this is one REVOLUTION around the Sun. It takes
365 days and about 6 hours for the Earth to make one complete
revolution around the Sun.
This means that the Earth is moving around the Sun at a speed of about
66,600 miles per hour!

21. THE EARTH’S REVOLUTION AND “LEAP YEAR”
About 93 Million
Miles
Since it takes 365 days and a few extra hours for the Earth to make one
complete revolution around the Sun, we must account for these extra hours on
our calendars… This is the reason for adding an extra day to our calendar every
4 years, called a “Leap Year”. Since February is a short month, we add 1 extra
day (Feb 29th) to our calendars in February of a Leap Year (2012, 2016, etc. are
Leap Years)

22. SEASONS and AMOUNT OF DAYLIGHT
The Earth’s orbit around the Sun and the tilt of our Earth are the reasons we:
(1) experience four seasons in Michigan – Winter, Spring, Summer and
Autumn (Fall), (2) why our temperatures change during these seasons, and (3)
why we have a greater amount of daylight in the Summer than we have in
Winter. WE WILL EXPLORE THIS IN THE NEXT FEW SLIDES!!!

23. THE WINTER POSITION OF EARTH
In this position, it is WINTER in Michigan and the rest of the United States,
with the SUN’s rays coming to us at an angle and not warming us as much
as the direct sunlight that the Equator, and the countries below the equator
are getting. Note that in Australia, while we are experiencing Winter, they
are having a nice warm Summer!

24. THE WINTER POSITION OF EARTH
During Winter, we see the Sun in the southern part of the sky, because Michigan is
tilted away from the Sun at this time of year.
In this “Winter” position within our orbit around the Sun, the amount of daylight
is at a minimum -- it gets dark at around 5pm.
Note that many people say “the days are getting shorter” in Winter, but every day is still 24
hours long! – what they mean to say is that the daylight amount is getting shorter!

25. Northern Sky
Southern Sky
Duncan Elementary School
(A Blue Ribbon School!)
WINTER POSITION OF THE SUN IN OUR SKY
In the Winter position of our Earth’s orbit around the Sun, the
Earth’s tilt causes North America (including Michigan) to be tilted
away from direct sunlight, so the Sun appears in the southern sky
(closer to the southern “horizon”).

26. THE SPRING POSITION OF EARTH
In this Spring orbit position, the Earth’s tilt is starting to give
Michigan more direct sunlight, so we are starting to warm up!
Spring is in the air and the amount of daylight is increasing by a
few minutes each day!

27. THE SUMMER POSITION OF EARTH
It’s SUMMER in the United States and North America! The Sun at the center of our
solar system starts to appear directly overhead (straight up in the sky) at noon time.
The people south of the Equator, such as in Australia and the South Pole, experience
Winter at this time, when the Sun appears in their Northern sky. The Sun’s rays are
approaching those southern areas at an angle so these areas are not as warm.

28. Northern Sky Southern Sky
Duncan Elementary School
(A Blue Ribbon School!)
SUMMER POSITION OF THE SUN IN OUR SKY
In the Summer position of our Earth’s orbit around the Sun, the
Earth’s tilt causes North America (including Michigan) to be tilted
into direct sunlight, so the Sun appears directly overhead.

29. THE SUMMER POSITION OF EARTH
Here, it’s not only SUMMER for us in Michigan, but the day with the
longest period of daylight, which is usually June 21st.
South of the Equator, they experience the shortest amount of daylight!

30. THE AUTUMN POSITION OF EARTH
The Earth is still rotating at the same 23 degree axis angle, but as its REVOLUTION
around the Sun places it in this AUTUMN position, the amount of sunlight each day
is slowly shrinking, and AUTUMN is coming!

31. THE AUTUMN POSITION OF EARTH
In this position, AUTUMN is here in Michigan, and the temperature is starting
to get “chilly”.
South of the Equator, however, is experiencing springtime, as their
temperatures are starting to increase and sunlight each day is getting longer.

32. SUMMARY: THE EARTH AND THE SEASONS
In this picture, you see one full year, with a full revolution around the Sun. The
Earth keeps the same tilt throughout, therefore causing the Sun’s energy to come
to us more “directly” in Spring, more “straight-on” in the Summer, and at steeper
angles in the Autumn and Winter.

33. SUMMARY: THE EARTH AND THE SEASONS
This is an animation of the seasons occurring over one calendar year…

34. REVIEW QUESTIONS!
Please answer these questions which are based on the information we have
covered about the SUN!
1. Define “Rotation”, “Revolution”, “Axis”, and “Orbit”.
2. What is the Equator, and is it hot or cold there?
3. Where are the coldest places on Earth, (why are they so cold)?
4. How long does it take Earth to make one full rotation?
5. How long does it take Earth to make one full revolution around the Sun?
6. Explain why we have a Leap Year every 4 years?
7. What is the angle that the Earth’s axis is tilted?
8. What is the main reason why Michigan does not get as warm in the Winter
(i.e., why the Sun is in the Southern sky)
9. What season do we get the MOST sunlight in a given day, and which
season do we get the LEAST sunlight?
10.The Sun rises in the __________ and sets in the __________ .
11.The Sun moves across our sky because Earth is rotating. True or False?
12.Name several of the things in Earth’s atmosphere.
13.Why it is possible to have a warm day in Winter or a cool day in Summer?

35. THE EARTH AND ITS MOON
Many planets in our Solar System have more than one moon. The Earth has just
one Moon. Our Moon is a sphere of rock formed millions of years ago that acts
as a “satellite” orbiting the Earth as the Earth itself orbits around the Sun.
Our Moon takes about 28 days (4 weeks) to travel around the Earth, but since the
Earth makes a full rotation once each day, the Moon appears to move across our
sky slowly during each night. The Moon is about 250,000 miles away from Earth.

36. THE MOON’S PHASES
Sometimes we see the Moon as a full round object in the sky (A “Full Moon”).
However, at most times the Moon’s location relative to the Earth and Sun means
that we see a only a portion of the Moon lighted and a portion (or all) of the
Moon “not lighted” (covered in shadows). These different appearances are called
PHASES OF THE MOON, as you can see here over a month span (May-June 2005):

37. THE MOON’S ORBIT
AND ITS PHASES
The Moon’s phases have been
given names – for example, “Full
Moon” when the entire face of the
Moon is illuminated for us to see
on Earth, and “New Moon” when
the back half of the Moon is
illuminated and we can barely see
the face of the Moon at all.
Last Quarter Full Moon
First Quarter New Moon
Moon
Moon

38. A FEW MORE OF THE MOON’S PHASES
Astronomers and scientists have given names to a few other Moon phases, as
shown here (Waxing and Waning Crescent and Gibbous Moon Phases):
Waxing Crescent Waning Crescent Waxing Gibbous Waning Gibbous
(or just (or just (or just (or just
“Crescent”) “Crescent”) “Gibbous”) “Gibbous”)
Moon Moon Moon Moon

39. SUMMARY: THE MOON’S PHASES
This picture shows the positions of the Sun, Earth and Moon, and the
different Moon Phases in these positions.
SUN

40. EXPLORATION OF THE MOON
• Neil Armstrong and Edwin “Buzz” Aldrin of the
Apollo 11 mission were the 1st and 2nd persons
to walk on the Moon, on July 20, 1969.
• The Moon has no atmosphere, nor oxygen and
no plant life, so the astronauts needed special
suits with air tanks.
• The Moon’s surface has many large bowl-shaped
pits called “craters”, probably from meteor hits.
• The Moon’s has a much lower amount of gravity
so our astronauts could jump long distances, and
felt much lighter than on Earth. In fact, on the
Moon they weighed 1/6 of their weight on earth
(their Earth weight divided by 6).
Q: If you weigh 60 pounds on Earth, how
much would you weigh on the Moon?

41. SOLAR ECLIPSES
Because of the way the Moon orbits around the
Earth, the Moon sometimes moves into a
position where it entirely (or partially) covers the
Sun in the sky. This is called a “TOTAL” or
“PARTIAL” Eclipse.
Total Eclipse of the Sun (“Solar
Eclipse”) with extremely bright
light showing around the Moon
(DAMAGING TO THE HUMAN EYE!)
Note that partial solar eclipses occur
somewhere on Earth every 18
months or so. Total eclipses at any
given location on Earth are rare –
they only occur in Michigan every
410 years or so!

42. LUNAR ECLIPSES
Occasionally, the Earth casts its shadow on the Moon during the day, thus
causing the Moon to go from visible to shaded then back to visible again.

43. REVIEW QUESTIONS!
Please answer these questions which are based on the information we have
covered about the MOON!
1. The first person to walk on the Moon was Neil _______________.
2. The Moon is invisible (darkened completely) during the _________ phase.
3. _______________ are bowl shaped pits found on the Moon’s surface.
4. The Moon is Earth’s natural ______________ because it orbits the Earth.
5. A person who weighs 120 pounds on Earth will weigh only _____________
pounds on the Moon.
6. When the Moon blocks our view of the Sun, it is called an ____________.
7. The Moon shines because of reflected light from the _____________.
8. When the Moon appears as a sliver of white, we call it a ____________
Moon.
ADDITIONAL LUNAR QUESTIONS: Who was the 2nd person to walk on the
Moon? What was the name of the mission that sent the first astronauts
to walk on the Moon’s surface, and what year did this mission take place?
How many days does it take to see all the Moon’s phases? Also, draw a
few of the Moon’s phases.

44. REVIEW QUESTION ANSWERS!
1. The first person to walk on the Moon was Neil Armstrong .
2. The Moon is invisible (darkened completely) during the New Moon phase.
3. Craters are bowl shaped pits found on the Moon’s surface.
4. The Moon is Earth’s natural satellite because it orbits the Earth.
5. A person who weighs 120 pounds on Earth will weigh only 120/6 = 20
pounds on the Moon.
6. When the Moon blocks our view of the Sun, it is called an eclipse.
7. The Moon shines because of reflected light from the Sun.
8. When the Moon appears as a sliver of white, we call it a Crescent Moon.
ADDITIONAL LUNAR QUESTIONS: Who was the 2nd person to walk on the
Moon? (Buzz Aldrin) What was the name of the mission that sent the first
astronauts to walk on the Moon’s surface, and what year did this mission
take place? (Apollo 11, in 1969) How long does it take to see all the
Moon’s phases? (about 28 days)

45. MORE REVIEW QUESTIONS!
Please answer the questions presented here, which relate to the SUN, EARTH
and MOON. Circle S for Sun, E for Earth and M for Moon (all that apply)!
1. Is basically round: S E M
2. Not suitable for human life: S E M
3. Rotates fully around once each day: S E M
4. Have different shapes called phases: S E M
5. Has an atmosphere and plant life: S E M
6. Has a mantle and a core: S E M
7. Is mainly made of the elements Hydrogen and Helium: S E M
8. Is the largest item in our Solar System: S E M

46. REVIEW QUESTION ANSWERS!
1. Is basically round: S E M
2. Not suitable for human life: S E M
3. Rotates fully around once each day: S E M
4. Have different shapes called phases: S E M
5. Has an atmosphere and plant life: S E M
6. Has a mantle and a core: S E M
7. Is mainly made of the elements Hydrogen and Helium: S E M
8. Is the largest item in our Solar System: S E M

47. SUN, EARTH, MOON
CROSSWORD!

48. SUN, EARTH, MOON CROSSWORD CLUES
DOWN
ACROSS 1. Saturn has many of these around its surface
1. Mars color 2. Star pattern, the “Big ________”
4. Phase showing most of the Moon’s surface 3. Earth takes about 365 days for one or these
6. Planet between Venus and Mars 5. Planet near Neptune
8. Collection of stars that looks like a thing 7. Earth makes one full _______ each day
11. When we add a day to February 8. “Sliver” Moon phase
12. Earth’s nearest star 9. Circling around Earth or around the Sun
13. Aldrin or Toy Story’s Lightyear 10. Protective layer in the Earth’s atmosphere
17. When the Moon blocks out the Sun 14. When the Earth casts a shadow on the Moon
18. This circles Earth every 28 days 15. NASA mission to the Moon
20. Lunar holes caused by meteor strikes 16. Planet too hot for living things
24. The Moon is a natural _______ of Earth 19. A planet between the Sun and Mars
27. Planet between Earth and Saturn 21. Apollo 11 moonwalker
28. Earth spins about this imaginary line 22. Planet near Jupiter, and former car brand
extending from pole to pole 23. Lies below Earth’s crust (and above fireplace)
32. Apollo 11 moonwalker 25. Lands on this imaginary line receive more direct
33. One of earth’s poles sunlight than anywhere else
34. What keeps things from floating off – 26. Earth has 23 degrees of this
Moon has less of this than Earth! 29. The Sun rises here
36. Darkened Moon phase 30. Volcano output, evidence of Earth’s hot inner core
31. Needed to breathe, the Moon has none

49. SUN, EARTH, MOON MOON CROSSWORD SOLUTION
SUN, EARTH,
CROSSWORD!

50. Thank you
for being a GREAT
Duncan Explorer!
4th Grade Science
Duncan Elementary