Transcript: The disk of our galaxy is traced by the band of stars in the Milky Way and also by the open star clusters which contain mostly young stars. The concentration of stars in the Milky Way is greatest in the direction of the Sagittarius constellation in the southern sky. This represents the direction towards the center of our galaxy. In visible light we cannot see much further than about a thousand parsecs in the plane of the Milky Way due to the obscuring effects of dust. This explains the patchy variations of brightness across the Milky Way caused by clouds of gas and dust that obscure the stars beyond. However, in near infrared radiation it’s possible to see all the way to the galactic center, and also the distribution of older and cooler stars becomes visible. Far infrared emission shows the distribution of cool dust and very cool stars and makes the thinness of the galactic disk clear. At twenty-one centimeters, radio waves, the neutral hydrogen can be traced, and in addition to the thin disk it shows wisps and filaments rising far above the plane of the Milky Way that represent energy deposited by supernovae and gas that leaves the disk and then eventually falls back onto the disk.