Space is vast and has so many secrets to share with us. If we think of any planet, the first image that comes to mind is that of a round object. It can be different in color or surrounded by cloud bands, but still round. But when we think of galaxies, we imagine a thin glittering streak across the sky. Why is it so? Can galaxies be anything other than flat?

Learn more about your ad choices. Visit megaphone.fm/adchoices