If you stand outside on a clear night, you’ll see that the stars are more concentrated along the Milky Way (shown above).
Our galaxy looks like a fuzzy gray ribbon of light across the sky. A look through a low-power telescope shows that the Milky Way is actually made up of countless stars. They are too far away to be seen individually by the naked eye.
Astronomers have looked along the Milky Way with high-power telescopes for the last 200 years. They have found nebulae in many different colors and shapes, from circular to irregular. Spiral-shaped nebulae were later discovered to be whole distant cities of stars, called galaxies. Nebulae offer clues to the evolution of stars because they accompany the birth and death of stars.
