Blue moon is either the second full moon in a calendar month or the third in an astronomical season with four full moons. The phenomenon of a blue moon, despite its name, does not change the moon ...

And sometimes — once in a blue moon — the moon is full twice in a month (or four times in a season, depending on which definition you prefer). If you want to know what you can see tonight ...

The moon dims, the meteors fly, and the planets dance—these are the most exciting celestial events happening this month.