🌌 Galaxies: Cities of Stars

Galaxies are the great cities of the universe — vast systems made of stars, gas, dust, planets, and dark matter, all held together by gravity. Just as cities contain billions of people and structures, galaxies contain billions or even trillions of stars organized into complex shapes and patterns. Studying galaxies helps astronomers understand how the universe formed and how it continues to evolve.

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⭐ What Is a Galaxy?

A galaxy is a massive gravitational system that includes:

• Stars and star systems

• Nebulae (gas and dust clouds)

• Planetary systems

• Star clusters

• Dark matter halos