Blue moon over Chobham Common

I was called out very late last night by the monitoring service for an elderly lady in the village we support. They had pressed their call button because the carer attending them in the evening had left the walking frame in the bathroom rather than by the bed. So it was a quick call, popping down, moving the frame so  they could access it and making sure there were no other issues. As it was a blue moon, several pictures of which had been shown on the evening news, I decided to drive up to Chobham Common to capture this image of the moon shining over the heathland. Apparently it is not called a blue moon because it is blue in colour but because having a full month twice in one month is such a rarity. It will be a decade before it happens again. However that still begs the question, why blue? So it seems to me that there must be occasions when such a full moon, so close to Earth, does take on a blue tinge.