Moon Over Andromeda . ... Credit Copyright: Adam Block and Tim Puckett Explanation: The Great Spiral Galaxy in Andromeda (aka M31), a mere 2.5 million light-years distant , is the closest large spiral to our own Milky Way. Andromeda is visible to the unaided eye as a small, faint, fuzzy patch, but because its surface brightness is so low, casual skygazers can't appreciate the galaxy's impressive extent in planet Earth's sky . ... NASA Web Site Statements, Warnings, and Disclaimers . ...