Last blue moon until 2020 lights up Durham sky

DURHAM (WTVD) -- A rare blue moon lit up the skies Friday night and early Saturday morning.

It was the second blue moon of the year, and the last one until 2020.

READ MORE: Blue moon: What is it and is it really blue?

Ironically, blue moons aren't actually blue, the term actually refers to the second full moon in a calendar month.