## Board Work Questions

• Why is this statement true? “If we were to measure Doppler shifts in spectra of Saturn's nearly edge-on rings, we would expect to see blueshifted lines on one side of the planet and redshifted lines on the other side.
• Why is this statement false? “It is easier to use parallax to measure distances to stars in distant galaxies.”
• Why again is Venus's surface temperature higher than that of Mercury's?
• This homework question asks us to estimate how long it would take for us to lose sight of Jupiter (at 4 AU) if the Sun were to suddenly shut off (i.e., stop shining). The problem says we can assume the Sun-Earth-Jupiter system are all aligned, for simplicity.
• What does the professor mean by the “dark side of the Moon”? I said that part of the Moon never receives sunlight and got the question wrong.
• Why do atoms only accept photons of particular wavelengths?
• I have to compare the luminosity of two stars. One of them is twice as massive as the other and I know that L goes as the fourth power of M. There aren't enough numbers here for me to calculate the answer.
• Can you go over the homework problem: Two stars at the same distance from us are the same temperature, but one is a giant while the other is a dwarf. Which appears brighter?
• The Sun appears slightly bigger in the sky in January than it does in July. Given this information, for which month is the Earth moving faster around the Sun?
• It doesn't make sense to me that we're located farther away from the Sun during summer than we are in Winter! Can you explain that to me?
• Why is Orion considered a Winter constellation?
• Why do we need to build some telescopes in space?
• I don't understand how Olber's paradox tells us that the age of the Universe is finite.
• How is the Milky Way's rotation curve different than that of our Solar System's?
• I don't understand how if I'm standing at the equator I can see all the stars.
• [lab] How do I find a star's position in my data? Can I take the maximum pixel value?
• [lab] Why do we need darks and flats when observing?
• [lab] How do I know what wavelength each pixel in my data corresponds to? 