Course: Science Subtest I
Lesson: Astronomy
Topic: The Stars: Patterns and Movement      Page 7 of 18  

What is the Milky Way?

All of the stars we can see unaided — about 3,000 on any given night — are part of our own galaxy, the Milky Way. Telescopes and binoculars reveal millions more stars, and even other galaxies, such as the spiral galaxy Andromeda.

The “Milky Way” is also the term given to the faint band of light stretching across the night sky. This band of light is the glow of billions of stars in the disk of the Milky Way galaxy. The stars are too distant to be seen individually, but there are so many of them that they produce a ribbon of light. The ribbon of light appears to have ragged edges and dark spots due to clouds of gas and dust.

The Milky Way in the vicinity of the constellation Sagittarius. (Some of the stars in Sagittarius outline a teapot shape, which is how most people recognize it.) The dark areas in the photograph are clouds of gas and dust that obscure starlight in those directions.