The Next Blue Moon will be on Sunday, May 31st. It’ll be the sixth full moon of the year. There are two kinds of full moons. The best known and most common is when two full moons happen in the same month. (The second one is a blue moon, natch.) The other kind is when a season has a quartet of full moons. The third one is a blue moon–actually, a seasonal blue moon. This month’s blue moon will be the last full moon of Spring and will be in Sagittarius. That will add power to an already formidable situation. A blue moon is magically stronger than a normal full moon. It serves…