Download ASTR120 Homework #9: Questions on Saturn's Rings and Moons' Orbits and Interactions - Prof and more Assignments Astronomy in PDF only on Docsity! ASTR120 Homework #9 – (Hamilton) due Thursday Nov. 29 (20 Points) Finish reading Chapter 12 and 13! These problems are from Chapter 12. 49. When Saturn is at different points in its orbit, we see different aspects of its rings because the planet has a 27◦ tilt. If the tilt angle were different, would it be possible to see the upper and lower sides of the rings at all points in Saturn’s orbit? If so, what would the tilt angle have to be? Explain your answers. 51. (a) Use Newton’s form of Kepler’s third law to calculate the orbital periods of particles at the outer edge of Saturn’s A ring and at the inner edge of the B ring. (b) Saturn’s rings orbit in the same direction as Saturn’s rotation. If you were floating along with the cloudtops at Saturn’s equator, would the outer edge of the A ring and the inner edge of the B ring appear to move in the same or opposite directions? Explain. These next six problems are from Chapter 13. 41. Using the diameter of Io (3642 km) as a scale, estimate the height to which the plume of Pele rises above the surface of Io in Figure 13-5a. (You will need to make measurements on this figure using a ruler.) Compare your answer to the value given in the figure caption. 43. Jupiter, its magnetic field, and the charged particles that are trapped in the magnetosphere all rotate together once every 10 hours. Io takes 1.77 days to complete one orbit. Using a diagram, explain why particles from Jupiter’s magnetosphere hit Io primarily from behind (that is, on the side of Io that trails as it orbits the planet). 44. Assuming material is ejected from Io into Jupiter’s magnetosphere at the rate of 1 ton per second (1000 kg/s), how long will it be before Io loses 10% of its mass? How does your answer compare with the age of the solar system? 46. How long does it take for Ganymede to entirely enter or entirely leave Jupiter’s shadow? Assume that the shadow has a sharp edge. 50. Many of the gases in the atmosphere of Titan, such as methane, ethane, and acetylene, are highly flammable. Why, then, doesn’t Titan’s atmosphere catch fire? (Hint: What gas in our atmosphere is needed to make wood, coal, or gasoline burn?) 51. Suppose the Earth’s Moon were removed and replaced in its orbit by Titan. What changes would you expect to occur in Titan’s atmosphere? Would solar eclipses be more or less common as seen from Earth? Explain your answers.
