Something that only happens once in a blue moon is about to happen tonight ... a blue moon! And today, 31 August, will be your only chance to see it before 2015.

So, what exactly is this blue moon thing? It's pretty straightforward: it's the second full moon in a month. Not too complicated, but it's a great excuse to sit under the stars.

It gets better: this rare phenomenon also happens to fall on the same day as the memorial service for the late Neil Armstrong – the first man to walk on the moon.

How will you mark it? Let us know in the comments below. And if you're looking for a soundtrack, this song comes highly recommended: