A star with obvious Hydrogen lines in its spectrum is moving relative to the Earth. A Balmer Alpha line is clearly visible from its absorption spectrum and is measured to have a wavelength of 654.3 nm.
a. How fast is the star radially moving in relation to the earth? Show your work!

When you see distant streetlights through smog, they look dimmer and redder than they do normally. but when you see the same streetlights through fog or falling snow, they look dimmer but not redder. use your knowledge of the interstellar medium to discuss the relative sizes of the particles in smog, fog, and snowstorms compared to the wavelength of light.