Blue Moon Have you ever heard the expression "once in a blue moon"? There is an actual blue moon, but the moon isn't blue in color. "Blue moon" refers to the third of four full moons in a season or the second full moon in a calendar month. In a year with a blue moon, there are 13 full moons as opposed to the normal 12 full moons in a year. A blue moon only occurs every two or three years. If a moon appears to have a bluish hue it is due to environmental factors like volcanic ash in the atmosphere. The expression "once in a blue moon" means something that rarely occurs—just like the actual blue moon.
What is the best summary of the paragraph?
A.
Have you ever heard the expression "once in a blue moon"? There is an actual blue moon, but the moon isn't blue in color. "Blue moon" refers to the third of four full moons in a season or the second full moon in a calendar month.
B.
The expression "once in a blue moon" means something that rarely occurs. A "blue moon" is actually the third of four full moons in a season or the second full moon in a calendar month. A blue moon only occurs every two or three years.
C.
A moon that appears to have a bluish hue is known as a "blue moon." It is due to environmental factors like volcanic ash in the atmosphere. The expression "once in a blue moon" means something that rarely occurs—just like the actual blue moon.
D.
A "blue moon" is the third of four full moons in a season or the second full moon in a calendar month. In a year with a blue moon, there are 13 full moons as opposed to the normal 12 full moons. A blue moon only occurs every two or three years.