Objectives  Unit Labs
 Quiz  Home
LAB 1: (20 pts)
The properties of our
solar system provide clues to how our solar system formed. Like a detective
who must recreate a crime on the basis of existing evidence, so too must
an astronomer establish hypotheses of how the solar system formed using
present day observations. What is that evidence? In this lab your will be
be exploring the properties of the Terrestrial and Jovian Planets. The four
planets closest to the Sun are called the 'terrestrial planets'. The second
four are called the 'jovian planets'. Do not include
Pluto as a either a jovian or terrestrial planet in any calculations. Pluto
has not considered either. If you include Pluto in your calculated averages
you will scew the results. 
Instructions for Doing This Lab: Print
out this lab so you can work off line. If you want, attend the chat session
on the lab after completing as much of the lab as possible. The date of the
chat session is posted in the calendar in the Communications Center.
 Read the following secdtions
in your text: Section 1.4, Section 22.4 on pages 529 and 530... up to Motion
of the Moon (do not read past the Motion of the Moon section) and Section
23.1.
 Print out this
Planetary Data Table and use it to answer some of the questions in this
lab. Post questions to the discussion board and/or attend the lab chat session
if you have any questions.
 Answer the following
questions. To save time online, I suggest that you write your answers out on
the printout of the lab.
 To what category
of planet does the Earth belong?
 What is the distance
of the Earth from the Sun? (Do not forget to include your unit.)
 Pluto is how many
times farther from the Sun than the Earth? (Hint: Remember that
"time" and "difference" represent two different mathematical
operations.)
 According to the
data table, what is the radius of the Earth? (Be sure to round your answer
to the nearest whole number and to include the unit of measurement in
your answer.)
 In terms of their
radii, how many times bigger is Jupiter than the Earth?
 In terms of their
radii, how many times bigger is the Earth than Mercury?
 The density of the
planets are measured in gm/cm^3. What two physical properties of
the planet are represented by this unit?
 What is the average
density of the terrestrial planets?
 What is the average
density of the jovian planets?
 What does the density
of the terrestrial and jovian planets suggest about their composition?
(Keep in mind that water has a density of 1 gm/cubic centimeter.)
 Which group of planets
is more massive, the terrestrials or the jovians.
 What is the average
mass of the terrestrial planets?
 What is the average
mass of the jovian planets?
 Explain how the Earth
and the other terrestrial planets can have a relatively low mass, but
a relatively high density?
 The term 'eccentricity'
refers to the shape of a planets' orbit. Eccentricity refers to
the degree to which an orbit deviates from a circle. Mathematically,
the eccentricity of a circular orbit is equal to 0. Orbits that
deviate from a circle have eccentricities which are greater than zero
and approach the value of 1. Calculate the average eccentricity
of the planets' orbits.
 Are the orbits of
the planets closer to circles or are they highly eccentric? Explain
 All of the planets
revolve around the Sun in an eastward direction. All but three of the
planets rotate in the same direction as they revolve. The three which
rotate in the opposite direction are said to have "retrograde rotation".
Which three planets have a retrograde rotation? (Retrograde rotation is
represented by a negative rotation period or clockwise rotation as viewd from the `north pole. )
 You will notice that
the orbital velocity of the planets differ. Calculate the average
orbital velocity of the terrestrial planets. (Round off to the nearest
whole number and don't forget the unit of measurement.)
 Compare the orbital
velocity of the planets with respect to their distance from the Sun. Is
the relationship between the distance of a planet from the Sun and its
orbital velocity direct or inverse? (A direct relationship exists
if an increase in a variable produces and increase in a related variable.
On the other hand, an inverse relationship exists if an increase
in a variable produces a decrease in a related variable.) Explain
how you drew your conclusion.
 The plane in which
the orbit of a planet lies is referred to its "orbital plane".
Each of the nine planets has its own orbital plane. The term
"inclination" refers to the angle at which the orbital plane
is tilted with respect to a plane that is the standard of reference. Notice
that the inclination of the Earth's orbital plane is 0. Explain
why?
 What is the average
inclination of the the planets' orbits? (Be sure to exclude the Earth
and Pluto from the average.)
 Why did I ask you
to exclude the Earth from your calculation?
 Most of the planets
are tilted on their axis. What is the Earth's tilt? (Round
your answer to the nearest tenth and don't forget to include the unit
of measurement.)
 The term "escape
velocity" refers to the speed at which an object has to move in order
to escape the gravitational pull of a planet. (Another way of thinking
about it is if we were to launch a rocket to the moon, it would have to
reach the escape velocity of the Earth in order to make it to the moon.)
What is the Earth's escape velocity in km/sec. In mi/sec?
(1km = .6mi)
 Calculate the average
escape velocity for the terrestrial planets in km/sec. (Be sure
to round to the nearest tenth and include in your answer the unit of measurement.)
 Calculate the average
escape velocity for the jovian planets in km/sec. (Be sure to round
to the nearest tenth and include in your answer the unit of measurement.
 A planet's atmosphere
consists of gases which are gravitationally bound to a planet. The
nature of the atmosphere depends on the escape velocity of a planet.
Would the terrestrial or the jovian planets be least likely to hold
on to atmospheric gases? Explain
Instructions
for submitting this lab:
After answering the questions:

Log
into the Communications Center and
go
to the Virtual Laboratory.

Select the appropriate
lab.

Answer the questions.
You will notice that each question has associated with it a SAVE ANSWER
button. Be sure to save your answer. After saving your answers, submit the
lab.

After submitting the
lab, please use the comm center email to let me know that you have submitted
the lab. Portions of the lab will be automatically graded and other portions
will be graded by me. I will notify you when the lab has been graded.

After receiving your
graded lab, you will have an opportunity to resubmit the lab with corrections
in order to improve your lab grade.
 After submitting or resumbitt
a lab, contact me via email in the communications center so that I know that
it has been submitted.
Pick
up your graded lab and submit corrections.:
 Log
into the Communications Center and
go
to the Virtual Laboratory.
 Locate the lab you want
to access and CLICK ON THE COMPLETED LAB LINK UNDER "ATTEMPTS".
 Click on the NUMBER of
the lab attempt that you want to view.
 Print out the lab and
preview my comments. Make you corrections on the printout.
 Return to this page and
complete the instructions for submitting a lab (above).
 Resubmit THE ENTIRE LAB
(both your your correct answers and the corrections you are making to your
incorrect answers).
Copyright©
1997  2003, P. Noeller
All Rights Reserved
Updated: August 12, 2003 
CCBCCatonsville
Campus
800 S. Rolling Rd.
Catonsville, Md. 21228

