How big is the Milky Way galaxy?

The Milky Way has an enormous width of about 100,000 light years. The Milky Way is the most common type of galaxy in the universe—a spiral galaxy.

The Milky Way is made up of up stars, gas and dust. A large amount of the galaxy's gas and dust are found within the spiral arms of the Milky Way. These arms lie within the galaxy's disk, which has a size of about 1,000 light years. Only about 10 percent of the Milky Way is thought to consist of anything aside from dark matter, as of 2014. At the middle of the Milky Way is a black hole so great in size that the sun is minuscule in comparison.