When you close your eyes and picture a galaxy, what pops into your mind? For most people, it’s a beautiful, spiral shape, where a bright central region fans out with arms that wind around and around, over and over, littered with brilliant, glittering stars. And in almost all the pictures you see, there are two main arms making this up, with perhaps additional “spurs” shooting off of the primary arms.
But is this really representative of what galaxies look like? Or is it just that these are the images of galaxies that stand out most for us?
Moreover, how do the galaxies that are this way come to be this way, and will they stay this way forever?
Jillian Scudder has the (fantastic) answers for you on this edition of Astroquizzical!