‘Tis the season for galaxy observing. Or at least for observing our galaxy, from edge to edge to core, as the world rotates. If you live in a particularly dark area, you can now go out and, once that Sun has fully set below the horizon and no more twilight is left, you’ll be able to make out that creamy band sprawling across the sky. We’re going to have finding charts up on our website Dailyspace.org to help you find this. 

One of the really cool things about this particular time of year is that, if you got out after evening twilight, you’re going to be seeing the part of the Milky Way that points straight out from the center of the galaxy. And as our world turns and allows us to see more and more of our galaxy, it’s going to rotate you around until, just before dawn, that band appears to bloat up into a much wider bulge that happens to be the bulge of our galaxy located in the Sagittarius constellation.

Now, living inside of a disk means we’re surrounded by dust and stars and gas, and we can’t actually look out at the universe beyond. We can only see a set distance into all of that stuff. This means we couldn’t actually figure out how far we are from the center of the galaxy by looking through the galaxy. We had to instead lookout in all other directions and look for the locations of globular clusters. Since we know that globular clusters pretty much form a sphere around the Milky way, we were able to use their distribution to figure out our place in space. 

More Information

How to see the Milky Way (Sky at Night)

Milky Way season has started! (EarthSky.org)