ANCHORAGE (KTUU) - The full moon set to rise on Saturday, May 18, 2019 will be a “blue” moon, but maybe not in the conventional sense. A blue moon has two definitions. The most common is the second full moon within a calendar month.
The other definition—and the one that matters in this situation—is the third full moon in a season with four full moons.
Spring began March 20, 2019. There have been two full moons since then—March 21 and April 19. May 18 will be the third full moon of the season and the blue moon. June 17 will be the fourth full moon before the summer solstice on June 21.
The May full moon is known as the flower moon so this year it will a blue flower moon. Seasonal blue moons occur on average every 2.68 years. The last one happened on May 21, 2016 and the next one will be August 8, 2021.
Copyright 2019 KTUU. All rights reserved.