Galaxies can be seen in every direction in space, each with billions of stars. Galaxies often appear to be distinct but fuzzy patches of light. Dreyer compiled the New General Catalog of nearly 8000 objects around 1900. Spiral galaxies are flat disks with a nuclear bulge, a halo of old stars, and spiral arms with young stars. Arms emerge fromt he ends of the bar.
Dust is readily visible as dark streaks .
The Milky Way galaxy is a spiral galaxy. Globular clusters encircle spiral galaxies. Old stars are dominant. There is no prominent internal structure. They are circled by a halo of globular clusters.