Once in a Blue Moon

I had a piece of rare spare time last evening, and luck seemed to be on my side as the skies had cleared after a fairly wet and miserable few days. From the comfort of my sofa I could see the full moon rising from behind the nearby oak trees that line the hill I live on, and whilst most astronomer will curse at the sight of it, I decided to embrace the opportunity, timing, and recent passing of the legend that is Neil Armstrong to set up my telescope to take a closer look.

The great thing about the moon is that it's easy to find, easy to see, and fairly easy to take pictures of to. After a spot of visual observing I was focussing away and taking a few frames with a view of seeing if I could tease out the colouration that I could quite clearly see with my binoculars and telescope. The image below is what I captured, carefully processed in Photoshop to being out the subtle colours on its surface without it looking too unreal.

Full Moon - 31st August 2012, Skywatcher 80ED, Canon 7D, ISO100 1/160s.  Mare Tranquillitatis (the Sea of Tranquility) can be seen with a blue tinge at the mid right of center.

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The hint of colours on this image are all very real - indeed you can see the brightest bluish tinges with just a pair of binoculars on a suitable night - and they tell us something about that distant world that until 43 years ago no human had set foot upon.

Just as emeralds are green and sapphires are blue, most minerals have their own distinctive colour. Normally these are quite dull, and it is only the skill of a jeweller that can turn them into such brilliant stones that are worthy of being embed into rings, but their colour still belies their presence and potential. In the case of the moon, the blue tinge comes from an abundance of Titanium Oxide and Iron, whilst the orange areas are lacking in these minerals.

The full moon also reveals majestic white rays the cross almost the entire globe. Normally hidden from view, the overhead sun reflects more clearly off these deposits than the darker ancient lava plains underlying them during a full moon. The most prominent being that of Tycho in the lower-left, and Copernicus in the mid-top-left of the image. The rays from Tycho can be followed in a curve right across the disc, revealing the Moon is indeed a spherical object and not just a two dimensional disk hanging in the night sky.

There is also something more special about this full moon that I did know know whilst I was out observing. It is what is popularly termed a Blue Moon - meaning it is the second full moon seen in the same month, the first in this case having been on August 1st. This event is quite rare to observe in the UK- they occur only twice every three years and the weather has to be on your side too! One can easily see how this name can be linked to the old phrase "Once in a Blue Moon" that is used to signify a rarity of occurrence.

My original goal was simply to gaze upon a world that, in my mind, has been too long neglected by Man. In capturing the colouration of the moon in my photograph and the coincidence of if being a Blue Moon, with blue colouration, and that colouration being present in Mare Tranquillitatis where Neil Armstrong and Buzz Aldrin first planted the feet of man beyond our own world was as beautiful a circle as viewing the moon itself.