(a) From a reliable source, find the radius and rotational 
period of Saturn.  For reference, Saturn's radius is many
times larger than Earth's, and its rotational period is less than
half of Earth's.  From this information, calculate the rotational
velocity of Saturn's clouds at the planet's equator, in km/sec.

(b) If we use spectroscopy to measure a single absorption line 
on Saturn, explain why one edge of that line will be Doppler shifted 
toward longer wavelengths, and the other will be Doppler shifted 
toward shorter wavelengths.  How much shift, in km/sec, will occur?
It may help to use a diagram as well as words to explain your answer.

(c) If the absorption line has a central wavelength of 5200 nm,
how broad will the absorption line become in nm, edge-to-edge, 
due to the Doppler shifting caused by planetary rotation?