galaxies, part 1: crash course astronomy #38 Published 9 years ago • 1.5M plays • Length 12:06 Download video MP4 Download video MP3 Similar videos 15:35 galaxies, part 2: crash course astronomy #39 1:00 galaxies part crash course astronomy 5:44 our universe has trillions of galaxies, hubble study 25:54 the incredible story of the milky way [4k] 11:10 how big is the universe?