The Milky Way shines at its best on summer nights. Right now, it arcs across the east as the sky gets fully dark, and passes high overhead later on. Under dark skies, it looks like a hazy band of light.

That band outlines the disk of our home galaxy. So for the astronomers who study the Milky Way Galaxy, it’s the go-zone – there’s lots to look at. But for those who study other galaxies, it’s been the no-go zone. In fact, it’s called the Zone of Avoidance, because it’s hard to see anything through it.

The main problem is giant clouds of dust scattered throughout the galaxy. The dust absorbs visible light. Depending on which part of the disk you look through, in fact, the clouds can block more than 99 percent of the light from objects behind them.

The other problem is that the Milky Way is crowded – millions upon millions of stars everywhere you look. So when you look into the band of the Milky Way, it’s hard to know whether you’re seeing a star or gas cloud in the galaxy or something beyond it.

Fortunately, some wavelengths that are invisible to the human eye do get through: infrared light and radio waves. The infrared is best seen from space, but the radio can be turned in by giant antennas on the ground. Galaxies typically emit more of both of those forms of energy than individual stars do – important ways to avoid problems from the Zone of Avoidance.

More about the Milky Way tomorrow.

Script by Damond Benningfield