How far is the Andromeda galaxy?

The Andromeda Galaxy, also known as M31, is the nearest large spiral galaxy to our Milky Way. It is located approximately 2.5 million light-years away from Earth. This means that the light we see from Andromeda today actually left the galaxy about 2.5 million years ago. While there are smaller satellite galaxies that are closer to us—such as the Large and Small Magellanic Clouds, which are roughly 160,000 to 200,000 light-years away—the Andromeda Galaxy is the nearest major galaxy comparable in size to the Milky Way. Because of its relative proximity, Andromeda is one of the few galaxies visible to the naked eye from Earth under dark skies, appearing as a faint, blurry patch. In the grand scale of the universe, 2.5 million light-years is quite close, and astronomers study Andromeda extensively to understand the structure and evolution of galaxies, including predictions that it may eventually merge with the Milky Way in several billion years.