The Milky Way is a barred spiral galaxy holding hundreds of billions of stars.

The longer version

Our galaxy holds hundreds of billions of stars arranged in a flattened disk with a central bar of older stars. Spiral arms trace regions where gas piles up and star formation proceeds most actively, which is why young, bright stars concentrate there. Dust lanes block the view toward the middle.

From inside, we see the disk edge on as a hazy band across the night sky. A supermassive black hole sits at the center, and a halo of ancient stars and globular clusters surrounds everything. The whole structure rotates, though the inner and outer parts do not keep pace with each other.

Where this entry sits

The night sky looks calm, yet almost everything up there is moving, burning, or slowly changing. These facts cover planets, stars, the Moon, gravity, black holes, comets, and the story of how people began exploring beyond Earth. The full list sits on the Space and Sky page, where every entry is listed in order.