Homework Set 6 -- Solutions
DUE: Friday, June 28
Some of these questions entail looking up concepts and numbers in the book and in the Handout 3, "Does Titan Have Oceans?". In your book, you will have to look in Ch 5 for temperature scales. Please use a separate piece of paper for your answers.
1. How far are each of the Galilean satellites from Jupiter, in kilometers? How many times further are each of them from Jupiter, compared with the distance between the Earth and the Moon?
Io: 422,000 km 1.1 x Earth-Moon distance
Europa: 677,000 km 1.76 x Earth-Moon distance
Ganymede: 1,070,000 km 2.79 x Earth-Moon distance
Callisto:1,883,000 km 4.9 x Earth-Moon distance
2. Imagine that you are in a spacecraft above the south pole of Jupiter. Draw Jupiter, it's rings, the 4 inner most satellites, the Galilean satellites, and the 8 smaller outer satellites. Label the Galilean satellites correctly, and draw the direction around Jupiter in which each of the satellites moves. Also draw the rotation of Jupiter.
Looking from the south pole of Jupiter, the 4 inner moons and the Galilean moons rotate clockwise. Most of the 8 outer moons rotate in the retrograde direction, so that they would appear to go counterclockwise. Jupiter rotates clockwise, as seen from the south pole. In order outwards from Jupiter, they are Io, Europa, Ganymede, and Callisto.
3. Does Jupiter exhibit retrograde motion in the sky? If so, is its retrograde loop bigger, smaller, or the same size as Mars? Why?
Yes, Jupiter exhibits retrograde motion in the sky. Its retrograde loop is smaller than Mars' because it is farther away. The apparent reversal of its direction is less pronounced than with Mars.
4. Saturn's rings should naturally spread apart, some of them falling in towards Saturn, and some of them drifting out into space. Why don't they do this? Please be precise with your answer. Hint: it has something to do with moons.
Saturn's rings remain there because of shephard moons. These are moons on either side of the rings. The outer moons tug the ring particels into lower orbits and the inner moons push the ring particles into higher orbits
5. At what temperature do methane-nitrogen clouds form in Titan's atmosphere? Please give your answer in Centigrade, Fahrenheit, and Kelvins. What height above Titan's surface is this?
Methane-nitrogen clouds in Titan's atmosphere form at 80 to 85 K, or -193 to -188 C, or -315 to -306 F, at about 50 km
6. What is the height of the top of the ethane-acetylene haze layer above Titan? What is the temperature there, in Celsius, Fahrenheit, and Kelvins?
The top the ethane-acetylene haze layer above Titan is at about 175 km, where it is 100 to 160 K, or -173 to 113 C or -279 to -171 F
6/25/96