Download Size of Sun and Size of Planets

Name ________________________
period _____
Comparing the Sun and the Planets
Our Sun is the largest body in the Solar System but it is still considered an
average- sized star. It is over 93 million miles away from the earth. It’s light takes
about 8 minutes to reach the earth. Without its heat and light there would be no life
on our planet. The Sun has the most gravity in our Solar System but each planet has
its own gravity and the amount is determined by its size. The bigger the planet, the
greater the gravity it has.
Size of Sun and Size of Planets
Materials: Bulletin board display
What To Do:
 Observe the bulletin board your teacher has prepared showing the planet
sizes.
Questions:
1. Which planet is the largest? _______________________________
2. Which planet is the smallest? ______________________________
3. Which two pairs of planets are about the same size?
____________ and ___________ AND ______________ and _______________
 Your teacher will fold the earth model in half so you can see the diameter.
4. How many earths do you think would fit across the diameter of Jupiter? ________
 Your teacher will have a volunteer measure it.
5. How many earths fit across the diameter of Jupiter? __________________
6. How many earths fit across the diameter of Saturn? __________________
7. How many earths fit across the diameter of Neptune? _________________
 Your teacher will show you how much bigger the sun is than the planets
with a piece of string or some meter sticks.
8. The sun’s diameter on the same scale as these planets will be 11 meters across. The
earth’s diameter is 5 cm. How many earths can fit across the sun? Do the math
below.
How Close are the Planets?
Materials: calculator, toothpick (one per planet) modeling clay, tape, scissors, ruler
25 cm Sun
What To Do:
1. Using the diameters of the planets in kilometers, calculate the scale sizes of the
planets in centimeters using the chart below.
2. Fill in the chart below.
3. Your teacher will assign your group a planet.
4. Get enough clay to form a sphere the size of your planet.
5. On a small strip of paper, write the name of your planet and attach it to your planet
to label it.
6. Take your planet where your teacher has set up the sun and the scale for the solar
system.
7. One person in your group should stand with the planet where indicated and
everyone else should stand back and observe how the planets are arranged.
Planet
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
Pluto
(Dwarf planet)
Diameter
(km)
4,878
12,104
12,756
6,787
142,800
120,00
51,200
48,600








Scale
ratio
5568
5568
5568
5568
5568
5568
5568
5568
2,300

5568
Scale Diameter
(mm)
Questions:
1. Which planets are close together? _____________________________________
2. Which planets are far apart? _________________________________________
3. Which planets are large? ____________________________________________
4. Which planets are small? _____________________________________________
How Does Gravity on Earth Compare with other Planets?
Materials: Chart, calculator
What To Do:
1. Use the chart below to determine the weight of a person who weighs 85 pounds on
each planet in our solar system.
Planet
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
Pluto
(Dwarf planet)
Gravity
at
Surface
.38g
.91g
1.0g
.38g
2.53g
1.07g
.91g
1.16g
X
X
X
X
X
X
X
X
85
85
85
85
85
85
85
85
0.05g
X
85
Weight on
Earth
Weight on
Planet
Questions:
1. On which planet would you weigh the most? _______________________
2. Why do you think this is true? ______________________________________
3. On which planet(s) would you weigh the least? __________________________
4. Why do you think this is true? _______________________________________
Conclusion: (largest, Mercury, Jupiter, Earth, Uranus, Sun, gravity, size, Saturn, Mars)
The ______ is the largest body in our Solar System. _________ is the largest planet
in our Solar System. _________ is the smallest planet in our solar system. Venus is
about the same size as _________. Neptune is about the same size as ___________.
Earth and __________ are close together while Jupiter and _________ are far apart.
The amount of _________ a planet has is determined by its __________. Things will
weigh the most on Jupiter because it is the _________ planet.