So here you have two definitions of a blue moon but the one for a calendar blue moon does not describe the true meaning of a blue moon. Here's why:
Many people listen to the weather report on the radio before they head out the door in the morning so they can be prepared for the day to come.
The tiny moon--which for now has been designated S/2015 (136472) 1, and playfully nicknamed MK 2, for short--is more than 1,300 times dimmer than Makemake itself. MK 2 was first spotted when it was about 13,000 miles from its dwarf planet parent, and its diameter is estimated to be about 100 miles across. Makemake is 870 miles wide, and the dwarf planet, which was discovered over a decade ago, is named for the creation deity of the Rapa Nui people of Easter Island.