Milky Way Blues — Listen to the Sound of our Galaxy Rotating

This musical expression lets you “hear“ how our Milky Way Galaxy rotates. Radio telescopes observe different spectral emission lines to probe different phases of gas (atomic, molecular, ionized) in our Galaxy. Astronomers measure the Doppler shifts of these lines to determine gas velocities along the path that the telescope is pointing. To turn one of these observations into musical notes, the measured gas velocities are mapped to a pentatonic minor blues scale. Every note you hear and circle you see repr