Tonight is the night for a 'blue moon'

Tonight might be a good time do something you only do 'once in a blue moon' because we're due for the second full moon in a calendar month - or a 'blue moon'.

Tonight, Australians will be able to see a 'blue moon'. Source: AAP, AP

Australians who look towards the sky on Friday night will be able to see an uncommon ‘blue moon’.

A blue moon is the second full moon of one month.

Those only occur once every two to three years.

But, the moon will not actually be blue. The name "blue moon" is based on a misconception published in an article decades ago, NASA explains in this video.

“Most blue moons will be pale grey and white, just like the moon you’ve seen on any other night,” the narrator of NASA’s video said.

The next blue moon expected to be January 31, 2018.