The Milky Way Is More Than 100,000 Light-Years Across

Our home galaxy is so large that its size is measured in the distance light travels in a year. NASA states that the Milky Way is a spiral galaxy with a disk of stars spanning more than 100,000 light-years. We live inside that disk. Earth is located along one of the galaxy’s spiral arms, about halfway from the center. From that vantage point, NASA explains, the Milky Way looks like a faint, milky band of light arcing across the entire sky, which is how it got its name. It is one galaxy among many. The Milky Way sits in a neighborhood of over 50 other galaxies called the Local Group, whose members range from dwarf galaxies with up to a few billion stars to Andromeda, our nearest large neighbor. The largest galaxies of all, NASA says, contain trillions of stars.