The Galaxy

A galaxy is a massive system composed of billions to trillions of stars, along with gas, dust, dark matter, and other celestial objects, all bound together by gravity. Our galaxy, the Milky Way, appears as a glowing, spiral-shaped band in the night sky. Galaxies come in various shapes—spiral, elliptical, and irregular—and can range from small dwarf galaxies to enormous, galaxy clusters. They are the fundamental building blocks of the universe, where star formation occurs, planets develop, and cosmic evolution unfolds over billions of years.