Download Lab 16

Lab 16 Practice Quiz - Planetary Properties
1. Draw in the major axis for each of the ellipses (A – D) below.
2. Mark the center of each ellipse.
3. Determine the length of the semi-major axis (a), the Sun-center distance (c), and the
eccentricity (e = c/a) for each ellipse.
4. If each of the ellipses represents an orbit in a planetary system, determine the average
distance between the planet and the star it orbits if the scale of each diagram is
(1 cm = 2 AU).
5. Which orbit is the most eccentric? Most circular?
6. Label the point of perihelion and aphelion for each orbit.
A
B
Sun
Sun
C
D
Sun
Sun
Orbit
A
B
C
D
a (cm)
a (AU)
c (cm)
e
7. At what point do planets move at with the fastest velocity in their orbits? Slowest
velocity?
8. Why does a planet with an elliptical orbit experience acceleration?
9. What direction is a planet accelerated as it orbits the Sun?
10. Go to the following webpage and click on the photograph of Jupiter to show the movie.
Is the movie showing the rotation or revolution of Jupiter? How can you tell? How is the
axis of rotation or revolution oriented in the photograph?
(http://antwrp.gsfc.nasa.gov/apod/image/0703/jupiterspin_newhorizons.mpg)
11. Go to the following webpage and click on the photograph of the Sun to show the movie.
Is the movie showing the rotation or revolution the Sun? How can you tell? How is the
axis of rotation or revolution oriented in the photograph? As the Moon moves across the
frame, is the motion that of rotation or revolution?
(http://antwrp.gsfc.nasa.gov/apod/ap070303.html)
(Thought question: Is the plane of the Moon’s orbit parallel to the Sun’s equator?)
12. What is the equatorial diameter of the planet to the right?
13. What is the polar diameter of the planet to the right?
14. What is the oblateness of the planet?
15. What are reasons why planets become very oblate?
16. How does a planet’s surface gravity affect its ability to retain an atmosphere?