The Milky Way
The Milky Way is the galaxy that we are part of. Our Solar System is one of billions of similar systems that make up the bulk of the Milky Way.
Facts About The Milky Way:
- The Milky Way is a "barred spiral galaxy", referring to its overall disc shape with spiral arms and a bar-shaped bulge in the centre.
- The central buldge is made up of a higher concentration of stars than the surrounding arms of the galaxy.
- At the very centre of our galaxy, in the middle of the bulge, there is a super-massive black hole. Everything in the galaxy, including our entire Solar System, is orbitting that black hole.
- The Milky Way is somewhere between 150,000 and 200,000 light-years wide but on average is only around 1,000 light-years thick.
- Earth is orbitting the Sun at 30 km/second. The Sun is orbitting the centre of the galaxy at 250 km/sec. The Milky Way galaxy is moving through space at 600 km/sec.
- Until the 1920s, most astronomers believed that the Milky Way was the whole Universe. However, observations by astronomers including Edwin Hubble showed that our galaxy is actually just one of billions of galaxies.
Classification: Galaxy
Names: The Milky Way, Tira Whetū
Naming: The name comes from latin and Greek terms meaning "milky road" or "milky circle". As seen from Earth, the Milky Way looks like a white band of light across the sky.