Great White Spot
Why there were no spots recorded before 1876 is a mystery. It is like the break in sightings of the Great Red Spot in the 18th and early 19th centuries. The 1876 Great White Spot was very large, and could be seen even with small telescopes.  Was the earlier record simply poor, or was the 1876 GWS truly a first for the telescopic era?  Some believe that neither scenario is likely.