Sun, Earth, and Moon
The Universe and the Milky Way
http://primaxstudio.com/stuff/scale_of_universe/
Name _______________________________________
3. Why do we have seasons in New York? Why do you think it is hotter in June than in December?
(circle all of the correct answers)
A. Because the Sun itself gives off more heat and light energy in June and less in December.
B. Because the Earth is closer to the Sun in June, and farther away from the Sun in December.
C. Because the Earth is tilted toward the Sun giving us more daylight hours during the summer, therefore more
heating from the Sun…and hotter temperatures.
D. Because the Moon blocks some of the sunlight during the winter, making winter colder.
E. Because the Sun gets higher in the sky during the summer giving us more concentrated sunlight, more heating
from the Sun…and hotter temperatures.
F. Because in New York, there are more hours of daylight in June than in December…more heating from the
Sun…and hotter temperatures.
Sun-Earth Survey
1. What is the shape of Earth’s orbit around the Sun?
 Answer A – Earth’s orbit is very close to a circle. Drawings of the solar system in books and on
posters often make the orbits look like fairly skinny ellipses. This is because the orbits are drawn from
the side, as though viewed at an angle. Use a hula-hoop or other circular object to demonstrate how the
shape appears to change depending on the angle at which you view it. The distance from the Earth to the
Sun does not change much relative to the entire distance. But Earth is actually closest to the Sun, by
1.5%, on January 4! The Sun is very nearly at the center of Earth’s orbit.
2. Which is the best drawing to show the sizes and distances between the Earth and the Sun?
 Answer C – The Earth is about 90,000,000 miles away from Sun.
3. Why do you think it is hotter in the United States in June than in December?
 Answer C and F – More daylight hours. Because of Earth’s tilt at 23.5 the United States is facing
more toward the Sun in June and away in December, so there are more hours of daylight in June,
allowing more heating from the Sun, which makes June’s temperatures hotter than December. Because
the United States is facing more toward the Sun in June and away from the Sun in December, there are
more hours of daylight in June.
 Answer E – Angle and Concentration of Light. At the same time, during summer the Sun’s position in
the sky is higher, increasing the angle of incidence of the sunlight. This increases the concentration of
the light on the ground, so the ground gets warmer.
Answer B – Earth is closest to the Sun on January 2 and about 1% farther away on July 4!
Write down your age: ____ years old. Add one year to that number and write the new number here: ___. The
second number may not seem very important, but think about this: You didn’t exist that many years ago. You
had not been born or even conceived yet. That number may seem small, but just think about all the things you
have been able to do in your lifetime. Think about all the things you have learned, all the things you have seen,
and all the places you have been. You’ve certainly done a lot in the years you’ve been alive.
Now, think about this number: 4,500,000,000. That’s a very, very large number! Almost 5 billion, that’s how
many years the planet Earth has been “alive,” in existence. During that time it has undergone some remarkable
changes. Rocks have formed, seas have ebbed and flowed across vast continents, and dramatic weather
conditions have contributed to the geography and structure of our planet. Lots of things have happened to our
planet in all those years.
Here’s one more number to think about: 15,000,000,000. That’s 15 billion! That is how many years the universe
has been in existence. Astronomers, scientists who study the universe, have calculated that the universe began
about 15 billion years ago. One of the most popular theories about how the Universe began is known as the
“Big Bang” theory.
Scientists believe that 15 billion years ago everything was so close together that the universe was a tiny point,
known as singularity, much smaller than an atom. It is also thought that this singularity was billions and billions
of degrees hot. Suddenly there was a spectacular and incredible explosion, the “Big Bang” and the Universe
burst into being.
Hot material blasted out in all directions. The heat from this explosion was far greater than that of a nuclear
explosion or the temperature at the center of our Sun. Within seconds of this enormous explosion the Universe
had expanded in size to several million miles. Many scientists, but not all, believe that the Universe is still
expanding today and will continue to expand throughout its existence. This idea is confirmed by information
gathered by radio telescopes throughout the world.
The Universe contains everything that exists, from the tiniest particles to galactic super clusters (the largest
structures known). Nobody knows how big the Universe is, but astronomers estimate that it contains about 100
billion galaxies, each comprising an average of 100 billion stars. Did you know that stars produce their own
light?
A galaxy is defined as an enormous group of stars, gases, and dust, all held together by the force of gravity.
That means that there are about 10,000 million million million stars in the Universe!
http://www.history.com/content/universe/interactive-universe
As you might imagine, objects in space are far away from us and from one another. In fact, the distances
in space are enormous. It’s often hard for us to imagine these great distances, simply because they are unlike
anything with which we are familiar. Astronomers have developed a unique way of measuring the unbelievable
distances in space. They use a unit of measurement known as the light-year. Although the term light-year
sounds as though it must measure time, it is actually a measure of distance in space.
As you may know, light travels at a speed of about 186,300 miles per second. This means that light
could travel around the Earth seven times in one second! In one year, light travels about six trillion
(6,000,000,000,000) miles. The distances to stars and other objects in the Universe are measured in light-years
because the distances in space are so huge.
If you look at the Southern Sky on a clear night you may see the constellation Centaurus. One of the
bright stars in this constellation is called Alpha Centauri. Alpha Centauri is 4.3 light-years away from Earth. It
takes 4.3 years for the light from this star to reach Earth.
Imagine living in a city with 200,000,000,000 other people (There are about 45,000 people living in the town of
Lancaster). Imagine that if you wanted some milk and bread it would take you almost a million years to travel
to the nearest store. If you wanted to visit a friend on the other side of that city it would take more than 100
billion years to get there. That would be quite a large city. But even more amazing, you live in that “city” right
now!
The “city” is called the Milky Way. This is the galaxy in which we live, the one in which our solar system is
located. (If you’d like to see the Milky Way, you can do so best during the months of July and August. Stand
outside where there are no lights – far away from any city is best – and look up. You’ll see a “belt” of stars
arching across the sky. That “belt” is part of your galaxy, the Milky Way.)
The Milky Way is large, but it’s not the biggest galaxy in the Universe. If you could see the Milky Way from
the top it would look like an enormous pinwheel, with several “arms” spinning out from the core. The Milky
Way contains about 200 billion stars. Many people mistakenly believe that our Sun is at the center of this
galaxy, but in fact it is about 30,000 light-years away form the center of the Milky Way.
Fantastic Fact: Our Sun takes about 220 million years to complete a trip around the center of the Milky
Way. Since the “birth” of the Universe, the Sun has made about 25 circuits of the galaxy.
Space Science in Action – Universe
Big Bang Theory
light-year
Copernicus
Milky Way
Galileo Galilei
solar system
galaxy
Sun
gravity
Universe
1. __________________The vast expanse of space, which contains all of the matter and energy in existence.
2. __________________The distance that light can travel in one year, which is about 5.8 trillion miles.
3. __________________ A system containing billions of stars (they produce their own light), gas, dust and other
objects that is held together in space by gravity. Telescopes have revealed billions of these in
the Universe.
4. __________________ A group of planets, moons, asteroids and comets that orbit around ONE star.
5. __________________ The spiral galaxy to which our solar system and billions of other stars belong.
6. __________________ This star is the center of our Solar System. It is the closest star to planet Earth.
It is the only object in our Solar System that makes its own light!
7. __________________ A theory that states the universe began to expand after an extremely powerful
explosion of concentrated matter and energy 15 to 20 billion years ago.
8. __________________ A polish astronomer who discovered that the sun was the center of the solar system.(1473-1543)
9. __________________ An Italian astronomer who studied the skies with one of the first telescopes.(1564-1642)
10. _____________________ How many stars
are there in our Solar System?
11. _________________ This is the force that keeps the Moon orbiting planet Earth, and the planets in our solar
system orbiting the Sun.
Four and a half billion. It’s a number almost too large to comprehend. Scientists believe that about five billion
years ago, a massive explosion (maybe from a supernova – an exploding star) caused gas and dust to start
swirling in space. Gravity caused this dust to pack together. The next 500 million years saw the Sun form. Then
came the planets, 94 moons, and countless asteroids and comets that make up our solar system.
Our Solar System is made up of one star, the Sun, and its family of eight planets. A planet is a body that does
not give off light of its own. It reflects the light of the Sun. Planets can be solid rock, liquid, or gases; they all
rotate and revolve around the Sun. Stars produce and give off their own heat and light; our Sun is a star.
Orbiting between the planets Mars and Jupiter are chunks of rock and metal called asteroids. Also orbiting the
Sun are loose collections of rock and frozen gas called comets. Have you ever seen a shooting star? The bright
streak of light you may have seen moving through the night sky is actually called a meteor; it is a small space
rock that orbits the Sun. As a meteoroid enters Earth’s atmosphere, friction from Earth’s atmosphere heats the
rock and creates a tail of burning gas, which looks like a star, but it’s really a burning rock!
http://science.nationalgeographic.com/science/space/solar-system.html
Our Sun, just a medium sized star, is the center of our Solar System and the planets revolve around it. If it is just
a medium sized star, then why does it seem so enormous when we view it in the sky on a sunny day? The Sun is
the closest star to planet Earth; it is about 93 million miles away from us. The next closest star is Proxima
CentauriAlpha, it is about 4.3 light years away from Earth!
The Sun is a mass of hot burning gases, mostly hydrogen and helium. It provides us with necessary heat and
light for life on Earth. All life needs…energy, and sunshine is the ultimate source. Plants soak up the Sun’s light
energy to produce their own food and oxygen. This process is called photosynthesis.
Plant-eaters, herbivores, munch on plants to make their own energy. Meat-eaters, carnivores, get their energy
by eating plant-eaters. When the meat-eaters die, decomposers, such as fungi and bacteria, feed off the animals’
remains and return nutrients to the soil. This helps plants grow, and the cycle starts again.
In the grand scheme of things, the Sun is no big deal. It’s just another medium-size star in a remote corner of the
Milky Way galaxy. There are billions of others in the universe just like it. However, the Sun is the largest
member of our Solar System. The Sun’s gravity keeps all the planets orbiting around it. The Sun is much larger
than the Earth. The diameter of the Sun is 109 times that of the earth. You could fit about 1 million Earths
inside the Sun!
The word solar means “of the sun.” Wherever the Sun goes in space, the rest of the “family” or system goes
too! Did you know that the Sun is constantly in motion? It rotates about once every 25 days, and it revolves
around the center of the rotating Milky Way Galaxy in roughly 230 million years! And it has been spinning and
orbiting the Milky Way for about 5 billion years!
http://www.biology.ualberta.ca/facilities/multimedia/uploads/alberta/Photo.html
You Are My Sunshine
Age: 4.6 billion years old
Diameter: 865,000 miles or about 109 times larger than Earth
Temperature: About 10,000F on the surface, about
27,000,000F at its core!
Makeup: About 72% hydrogen, 26% helium, 2% other
Distance From Earth: 93,000,000 miles
Rotation: about 25 days
1. The Sun is a __________________________.
2. A ____________________________ is a celestial body that produces its own light.
3. The ____________________________ is the largest member of our Solar System.
4. A galaxy is made up of ________________________________ of stars, our Sun is just one of these stars.
5. The _______________________ orbits the Earth; it is Earth’s natural satellite.
6. The __________________________ is the center of our Solar System.
7. The Sun’s _______________________________ keeps all the planets orbiting around it.
8. Plants use the Sun’s energy to produce ________________________ and ___________________________
during the process of photosynthesis.
9. The Sun’s heat puts our weather in motion on planet Earth and it helps keep the water cycle going. Let’s
review the water cycle, write condensation, precipitation, or evaporation on the line.
Step 1 (The Sun’s heat changes liquid water into a gas called water vapor.)
_________________________________________________________________
Step 2 (Water vapor, water in its gaseous state, rises up in the troposphere to make clouds.)
_________________________________________________________________
Step 3 (Water droplets in clouds get too heavy, fall back to the Earth as rain, sleet, snow, or hail.)
_________________________________________________________________
10. How many stars are there in our Solar System? _______________________________________
The Sun, Solar Energy, and Photosynthesis
In the Universe, the Sun is no big deal. It’s just a medium-sized star in a remote corner of the
Milky Way Galaxy. There are billions of stars in the Milky Way just like it. The Sun and other stars are
composed of gases burning at very high temperatures. But for us here on planet Earth, the Sun is ultra
important. Without it, our world would be a frozen rock wondering in space.
It is the Sun’s gravitational pull that keeps our Solar System together; gravity is a force that pulls
objects toward each other. All objects produce a force of gravity. The more mass an object has, and
the Sun has the most mass in our Solar System, the greater it’s gravitational pull. The Sun is at the
center of the Solar System and the planets and other celestial objects revolve around it.
The Sun is our main source of light and heat energy. The heating of the Earth’s surface by the
Sun is one cause of our weather and climate. Green plants use carbon dioxide, water, and energy
from the Sun to manufacture food. Consumers are organisms that feed on plants or animals.
Herbivores, carnivores, and omnivores are consumers. They are dependent on the producers, green
plants that make their own food. And producers (plants) are dependent on the Sun’s energy to
manufacture their own food. Life on the Earth depends on the energy from the Sun.
Plants produce their food through the process of photosynthesis, photosynthesis occurs when
sunlight shines on the plant’s leaves. The leaves are food factories for the plant. Carbon dioxide from the air
enters the plant through tiny openings in the leaves called stomata. Water and minerals from the soil are
carried to the leaves through the roots and the stem. The chlorophyll in the leaves absorbs energy from the
Sun. The leaves use the Sun’s energy to change the carbon dioxide and water into food and oxygen. As a
result of photosynthesis, plants give off oxygen into the air. The oxygen is a waste product of photosynthesis.
The food is carried to all parts of the plant. The plant uses some; the rest is stored. Animals use the food
when they eat a plant or another animal that has eaten a plant.
1. Plants need these four things to manufacture food: ______________________________________________________
2. ________________________________________ from the air enters the plant through tiny openings in the leaves.
3. Plants get rid of ______________________________, a product of photosynthesis.
4. The _____________________________ is our main source of energy.
5. _________________________________ are producers (make their own food).
6. Name three consumers: _____________________________________________________________________
7. What force keeps Earth and other celestial bodies orbiting the Sun? __________________________
8. During photosynthesis, plants produce two things:
__________________________ & _________________________
Exploring the Solar System mini-book
Name ____________________________________
By Lindsay A. Caputo
1. The Earth moves around the Sun; it takes 365 ¼ days or one year for the Earth to make a
_______________________ around the Sun.
2. How much of the Earth is always illuminated, “lit up”, by the Sun? __________________
3. The Sun seems to move across the sky everyday, but this apparent motion is caused by Earth’s
____________________.
5. All the planets, dwarf planets, moons, asteroids, and comets orbit (revolve) around the Sun because of
the force of ______________________.
6. Name the planets in order from the Sun: (My Very Eager Mother Just Served Nachos)
M_______________, V_____________, E_____________, M____________,
J________________,S______________. N_______________
7. A shooting star is really a _____________________ that has been pulled toward Earth by Earth’s
gravitational pull.
8. Name the closest star to Earth: ___________________________
9. This system has only one star:
System
The Universe
The Milky Way Galaxy
The Solar
10. Planet Earth has four main layers.
Layer
Materials
Crust
______________________
Mantle
______________________
Outer core ______________________
Inner core
______________________
11. We have day and night because of the Earth’s ___________________________________.
12. The Moon’s changing shapes (Full Moon, Crescent Moon, New Moon) are called _________________
Earth, Moon, and Sun
Review #1
1. The Earth is tilted at about 23 ½  and it revolves around the Sun.
This is why we have __________________________.
2. What is the name of the only star in our solar system? __________________
3. We have day and night because of the Earth’s ___________________________
(One day is equal to one rotation)
4. The pull of an object on another object; this is the force that keeps all of the planets orbiting
(revolving) around the Sun. __________________________
5. Give 3 reasons why living things thrive on planet Earth:
1. _________________________________________________________
2. _________________________________________________________
3. _________________________________________________________
6. The continuous path of an object (the Moon) around another object (the Earth) is called a
__________________________________
7. One ___________________________ of the Earth equals one day.
8. Is the Sun the center of our Solar System? _______________
9. What is the name of the celestial object that orbits planet Earth? _____________________
10. It takes one year to complete all four seasons: winter, spring, summer, and fall.
It takes planet Earth one year to complete its _______________________________ around
the Sun.