This dark spots look like they are areas where there are no stars emitting light. However, Dr. Troland told us that these dark spots in the band are silhouettes formed by cold molecular gas clouds. These clouds of molecular gas block out emitted light, and appear to be dark spots.
Recently astronomers have observed that these dark spots emit radio waves, and can be observed with radio telescopes. These gas clouds are important to study, because they are composed of the same elements that scientist have theorized stars forming out of. Studying these cold gas clouds is important, because we may gain clues about how stars form, and the origins of the universe.
The Andromeda Galaxy, a galaxy that is quite similar to the Milky Way, is approximately 2.5 million lights years away. If you were to look at Andromeda with a telescope, the visible light observed would give an image that is larger than the image of the moon with the same telescope. This means that the Andromeda Galaxy is