Patterns in the Solar
System
Name:___________________Hour:_____
Although composed of many diverse objects, the solar system exhibits various degrees of order
and several regular patterns. To simplify the investigation of planetary sizes, masses, etc., the
planets can be arranged into two distinct groups, with the members each displaying similar
attributes. This exercise examines the physical properties and motions of the planets with the
goal of summarizing these characteristics in a few general, easily remembered statements. The
tables below provide some essential useful data regarding each of the planets:
Planet
Symbol
Mean Distance from Sun
AU
Period of
Revolution
Orbital
Velocity
(km/s)
88d
47.5
Mercury
.387
Millions of
kilometers
58
Venus
.723
108
224.7d
35.0
Earth
1.000
150
365.25d
29.8
Mars
1.524
228
687d
24.1
Jupiter
5.203
778
11.86yr
13.1
Saturn
9.539
1427
29.46yr
9.6
Uranus
19.180
2870
84yr
6.8
Neptune
30.060
4497
165yr
5.3
(Pluto)
39.440
5900
248yr
4.7
Planet
Period of
Rotation
Mercury
Venus
Earth
Diameter Relative Mass Average
(km)
(Earth = 1)
Density
(g/cm3)
59d
4854
.05
5.4
244d
12112
.82
5.2
23h56m04s
12751
1.00
5.5
Mars
Jupiter
Saturn
Uranus
Neptune
(Pluto)
24h37m23s
9h50m
10h14m
17h14m
16h03m
6.4d
6788
143000
121000
47000
46529
~2445
.108
317.87
95.14
14.56
17.21
.002
3.9
1.3
.7
1.2
1.7
1.8
Eccentricity # of known
satellites
.206
.007
.017
0
0
1
.093
.048
.056
.047
.008
.250
2
66
62
27
13
4
Comparing the Terrestrial and Jovian Planets
The physical characteristics such as diameter, density, and mass of the terrestrial planets
are very similar and can be summarized in a few statements. Likewise, the characteristics
exhibited by the Jovian planets as a group can also be generalized.
To gain an understanding of the similarities of the planets within each of the two groups
and the contrasts between the two groups, complete the following sections using the planetary
data presented in the tables on page 1. Because of a lack of sufficient data, Pluto will not be used
in determining group characteristics or for general comparisons between the groups.
Size of the Planets—The similarities in the diameters of the planets within each of the two
groups and the contrast between the groups are perhaps the most obvious patterns in the solar
system.
1. Which is the largest terrestrial planets and what is its diameter?
2. Which is the smallest Jovian planet and what is its diameter?
3. Write a general statement that compares the sizes of the terrestrial planets to those of the
Jovian planets.
Mass and Density of the Planets—Mass is a measure of the quantity of matter an object
contains. In the tables on page 1, the masses of the planets are given in relation to the mass of
the Earth. For example, the mass of Mercury is given as .506, which means that it consists of
only a small fraction of the quantity of matter that Earth contains. On the other hand, the Jovian
planets all contain several times more matter than Earth. Density is the mass per unit volume of
a substance. As a reference, the density of water is approximately one gram per cubic
centimeter.
4. Complete the following statements:
a. The planet _______________ is the most massive planet in the solar system. it is
___________ times more massive than Earth.
b. The least massive planet (excluding Pluto) is _______________, which contains
only _______________ as much mass as Earth.
The gravitational attraction of a planet is directly related to its mass.
5. Which planet exerts the greatest pull of gravity? Explain your answer.
6. Write a general statement comparing the masses of the terrestrial planets to the masses of
the Jovian planets.
Diameter vs. Density—To visually compare the diameters and densities of the planets, use the
data from page 1 to complete the diameter vs. density graph according to the directions
following.
Plot a point on the diameter vs. density graph for
each planet (excluding Pluto) where its diameter
intersects its density. Label each point with the
planet’s name. Use a different colored pencil for
the terrestrial and Jovian planets.
8. What general relation exists between a
planet’s size and its density?
9.
The average density of Earth is about 5.5
g/cm3. Considering that the densities of
surface rocks are much less than the
average, what does this suggest about the
density of the Earth’s interior?
10. Which of the planets has a density less
than water and therefore would “float”?
11. Write a brief statement comparing the
densities of the Jovian planets to the
density of water.
12. The Jovian planets can be best described as (rocky or ice and gas) worlds. Circle your
answer.
13. Write a general statement comparing the densities of the terrestrial planets to the Jovian
planets.
14. Why are the densities of the terrestrial and Jovian planets so different?
Number of Moons of the Planets
15. Write a brief statement comparing the number of known moons of the terrestrial planets
to the number orbiting the Jovian planets.
16. What is the general relation between the number of moons a planet has compared to its
mass?
Rotation and Revolution of the Planets—Rotation is the turning of a planet about its axis that is
responsible for day and night. When the solar system is viewed from above the Northern
Hemisphere of Earth, the planets, with the exception of Venus, rotate in a counterclockwise
direction. Venus exhibits a very slow clockwise rotation. The time that it takes for a planet to
complete one 360 degree rotation on its axis is called the period of rotation. The units used to
measure a planet’s period of rotation are Earth hours and/or days. Revolution is the motion of a
planet around the Sun. The time it takes a planet to complete one revolution about the Sun is the
length of its year, called the period of revolution.
17. If you could live on Venus or Jupiter, approximately how long would you have to wait
between sunrises?
a. On Venus, a sunrise would occur every __________ days.
b. On Jupiter, a sunrise would occur every _________ hours.
18. Write a statement comparing the periods of rotation of the terrestrial planets to those of
the Jovian planets.
19. Compare the planets’ periods of rotation to their periods of revolution and then complete
the following statement by circling the correct responses.
The terrestrial planets all have (long, short) days and (long, short) years, while
the Jovian planets all have (Iong, short) days and (short, long) years.
20. Explain the relation between a planet’s period of rotation and period of revolution that
would cause one side of a planet to face the Sun throughout its year.