The Milky Way Galaxy is a large barred spiral galaxy that is approximately 100000 light years in diameter, and contains over 400 billion stars. The galaxy is composed of three major parts: the core, the disc, which is the ring of stars and interstellar dust that gives the galaxy its spiral shape, and the halo, which includes many older stars orbiting the core, but outside the disc, of which most are concentrated in massive globular clusters.
The Milky Way is conventionally divided into four galactic quadrants. Since the Milky Way has a diameter estimated at about 100000 light years, we can deduce that each quadrant will have a diameter of about 50000 light years.
An outline of the galaxy can be seen in the following table:
|Places of Planetes|
|Earth • Moon • Mars • El Tanika • Milky Way|