M102 is a controversial member of Messier's list. Pierre Mechain claimed it was a duplicate of M101, although the latter looks quite different. The description of M102 by Mechain and location given by Messier do, however, match NGC5866 quite well. This galaxy is seem almost exactly edge on and it is not even clear if it is a spiral or lenticular galaxy. It has a prominent dark dust lane cutting across its centre giving rise to the name 'Cat Scratch Galaxy' and it is also sometimes called the 'Spindle Galaxy'.