M51: The Whirlpool Galaxy . ... Then, just slide your telescope a little south and west and you might find this stunning pair of interacting galaxies, the 51st entry in Charles Messier famous catalog. Perhaps the original spiral nebula , the large galaxy with well defined spiral structure is also cataloged as NGC 5194. ... Though M51 looks faint and fuzzy to the eye, deep images like this one can reveal striking colors and the faint tidal debris around the smaller galaxy . ...