Oh, Right. WE LIVE INSIDE A GALAXY.

Our Sun and its retinue of planets --including the one we live on--is located in the disk of the Milky Way galaxy, a preposterously huge and sprawling conglomeration of stars, gas, dust, invisible dark matter... and us. Located roughly halfway out from the center, we see this disk from the inside, so it's smeared out across the sky like a thick line. When we look to the center we see a region choked with dust, jammed with stars, and punctuated by the reddish glow of hydrogen clouds where stars a...