Faint band of light crossing the night sky, consisting of stars in the plane of our Galaxy. The name Milky Way is often used for the Galaxy itself. It is a spiral galaxy, about 100,000 light-years in diameter, containing at least 100 billion stars. The Sun is in one of its spiral arms, about 25,000 light-years from the center.
The densest parts of the Milky Way, toward the Galaxy's center, lie in the constellation Sagittarius. In places, the Milky Way is interrupted by lanes of dark dust that obscure light from the stars beyond, such as the Coalsack nebula in Crux (the Southern Cross).
1. The galaxy in which the Earth is located.
2. The view of this galaxy from the Earth.
3. The galaxy containing the solar system; consists of millions of stars that can be seen as a diffuse band of light stretching across the night sky; Also called: Milky Way Galaxy, Milky Way System.