Consider observing the sun from two planets in our solar system, Jupiter and Mercury. They both orbit our Sun, which is a pretty good blackbody, but it also has some absorption lines.

a) With an accurate enough telescope and spectrograph, can you measure the Doppler shift of the sun's lines over the course of a year on each planet? Explain how.

b) From which planet would you observe a LARGER shift in wavelength over the course of an orbit? Explain at least two key properties of the orbit that led you to your answer.

c) Estimate the maximum doppler shift of the H line, which is a prominent absorption feature at 6563A9, from Mercury.

d) The H line is produced high in the Sun's atmosphere where a cooler layer of hydrogen absorbs photons. If we observe the sun from the ground, we also sometimes see absorption features in the Solar spectrum that are produced by absorption within the Earth's atmosphere. Which line would show a larger doppler shift, the one in Earth's atmosphere (e.g. Oxygen at 7594A9), or H?

e) Can you use any stars (not the sun) to measure the Earth's orbital velocity? If not, why not? If yes, describe the properties of the star that you'd pick, or choose an actual star and explain why you chose it).