Messier 102 is sometimes called the missing, or mystery, Messier object. In the past it has been considered a duplicate entry for galaxy Messier 101, but there is evidence that M102 is galaxy NGC 5866. Historians and observers still disagree on the exact identity of M102, but here we will assume that it is NGC 5866. NGC 5866 is commonly called the Spindle Galaxy. NGC 5866 is an edge-on galaxy with an extended dust disk that is located 50 million light-years away in the constellation of Draco. It has an apparent size of 6.5 x 3.1 arcminutes, and shines at magnitude 9.9. NGC 5866 was discovered by Pierre M矇chain in 1781.