Why does the Milky Way appear as a faint band of light across Earth’s night sky?

The Milky Way appears as a faint, irregular band of light across Earth’s night sky because we are viewing our own galaxy from a position located well within its equatorial plane.12

Because the Milky Way is a large spiral system, its stars and gas clouds are concentrated into a disk-like structure. When we look toward the galactic plane from our vantage point, we are looking through the vast, dense collection of stars and gas that make up this disk. The "milky" or white appearance is the result of the combined light from a very large number of distant, faint stars that are too far away to be resolved individually by the naked eye.1345

While this band is a prominent feature of the night sky, much of the galaxy's structure remains obscured from optical view by thick layers of interstellar dust that are also concentrated along the galactic plane.16