The Milky Way galaxy is a spiral galaxy characterized by a central bulge and distinct spiral arms.

This galaxy spans approximately $100,000$ light-years in diameter and is home to billions of stars, as well as vast amounts of gas and dust. The central bulge is a dense region composed of stars, gas, and dust, resembling the shape of a football. Surrounding this bulge are four prominent spiral arms that extend outward from the center. These arms are structured in a spiral formation and are rich in young, hot stars, along with areas of active star formation.

Additionally, the Milky Way contains a halo—a spherical region filled with gas and dark matter that encircles the galaxy. This halo is significantly larger than the visible components of the galaxy and is believed to harbor a considerable amount of dark matter. Dark matter is an enigmatic substance that neither emits, absorbs, nor reflects light; it is thought to constitute a substantial part of the universe’s total mass.

The structure of the Milky Way is not static; it is continually evolving due to the motion of its stars and the gravitational interactions with nearby galaxies. Researchers actively study the Milky Way to deepen their understanding of its structure and evolutionary history.