AaS! 218: How Do We Know What the Milky Way Looks Like?

Why is it so hard to get a picture of the Milky Way? How much of our galaxy have we mapped? What the heck is a "barred spiral" and what does that have to do with our core? I discuss these questions and more in today's Ask a Spaceman! Support the show: http://www.patreon.com/pmsutter All episodes: http://www.AskASpaceman.com Watch on YouTube: http://www.youtube.com/PaulMSutter Read a book: https://www.pmsutter.com/books  Keep those questions about space, science, astronomy, astrophysics, physics, and cosmology coming to #AskASpaceman for COMPLETE KNOWLEDGE OF TIME AND SPACE! Big thanks to my top Patreon supporters this month: Justin G, Chris L, Barbara K, Alberto M, Duncan M, Corey D, Naila, John S, Joshua, Scott M, Rob H, Louis M, John W, Alexis, Erin J, Gilbert M, Valerie H, Tim R, Mark R, Alan B, Craig B, Mark F, Richard K, Maureen R, Stace J, Stephen S, Stephen J, Joe R, David P, robert b, Sean M, Tracy F, Sarah K, Ryan L, Ella F, Sarah K, Richard S, Sam R, Thomas K, James C, Syamkumar M, Homer v, Mark D, Bruce A, Steven M, Bill E, Tim Z, Linda C, Aissa F, Marc H, Scott M, Avery P, Farshad A, Michael W, Kenneth D, Gary K, Paul G, David W, dhr18, Ron D, Lode S, Alyssa K, Roger, Bob C, Simon G, Red B, Stephen A, James R, Robert O, Lynn D, Allen E, Michael S, Jordan, Reinaldo A, Jessica M, Patrick M, Amy Z, Sheryl, John G, David W, Jonathan S, Sue T, Josephine K, Chris, Jules R, P. S, Michael S, Erlend A, and James D! Thanks to Cathy Rinella for editing. Hosted by Paul M. Sutter.