Milky Way
Our Home Galaxy
The Milky Way is the galaxy that contains our solar system. It is a barred spiral galaxy containing an estimated 100-400 billion stars. Our solar system is located in one of the Milky Way's spiral arms, about 26,000 light-years from the galactic center.
Key Facts About the Milky Way
- Type: Barred spiral galaxy
- Diameter: 100,000-180,000 light-years
- Stars: 100-400 billion
- Age: About 13.6 billion years
- Central Black Hole: Sagittarius A* (4 million solar masses)
- Orbital Speed: 828,000 km/h around the galactic center
Structure
The Milky Way has a central bar shape with spiral arms extending from it. Our solar system is in the Orion Arm, between the Sagittarius and Perseus arms. The galaxy is surrounded by a halo of old stars and globular clusters.
Future Collision
In about 4.5 billion years, the Milky Way will collide and merge with the Andromeda Galaxy (M31). This cosmic event will result in a new, larger elliptical galaxy, but individual star collisions will be extremely rare due to the vast distances between stars.