Moonlight Fascination

Oct 2014

Moon - CarolInternational Observe the Moon Night was celebrated on 6 September 2014. All over the world people gathered to observe a brilliant Moon in gibbous phase.
What is this fascination we have with our nearest celestial neighbour? For one, our Moon is breathtakingly beautiful. Every night it takes on a new shape as the sunlit portion moves across its face to its own rhythm. From new moon to full moon and back to new moon takes an average 29 days 12 hours 44 minutes

The human brain seems to crave rhythm.
Though solar, lunar and seasonal cycles play a lesser role in modern society, the behaviour of our ancestors depended on these natural rhythms.

Scientists have been doing intensive studies on circadian rhythms. These are physical, mental and behavioural changes that follow a roughly 24-hour cycle and produced by natural factors within the body, but are also affected by signals from the environment.

Although not yet scientifically proven, some individuals believe that the Moon has a great influence on their well- being. They argue that if the Moon governs the tides, surely it would have an influence on the human body as well. There is one problem with this line of thought. The oceans are vast. An individual is but a very tiny speck on Earth.

The Ocean tides are controlled by the forces of gravity (tugging) of the Moon and Sun as well as by the rotation of Earth. Coastal areas usually experience two high and two low tides every 24 hours and 50 minutes. High tides occur 12 hours and 25 minutes apart. It takes six hours and 12.5 minutes for the water at the shore to go from high to low, or from low to high –the rhythm of ebb and flow.

The Earth’s axial rotation and the Moon’s orbital rotation result in a catch-up situation and moonrise for a specific location will be about 50 min later each day. The Moon is also visible during the day, except during new moon, when it occupies the same region in the sky as the Sun and at full moon .

Humans are by nature inquisitive. The Moon is tidally locked to our planet (its orbit of 27.5 is the same time as its axial rotation), showing just one side to us here on Earth. It was only natural that we wanted to know what the far side looked like. Once humans realised that the distance to the Moon could be overcome, missions to the Moon became commonplace and we now know that the most beautiful side is facing us!

Some say they can see a man on the Moon. During full moon I definitely see the rabbit who is still patiently mixing an elixir for Chang’e to be able to return to her beloved husband, Houyi, as in the Chinese legend.

In a world of bright lights we no longer rely on the Moon to guide our daily activities. How often do we forget that it is up there? Yet sometimes as you draw the curtains for the night it surprises you and your gaze locks in utter fascination.

It was fascination I know
And it might have ended
Right then, at the start
Just a passing glance
Just a brief romance
And next moment I kiss you
Fascination turned to love

– Nat King Cole

Lightbox for Deep Sky Sketching

lightbox-completeAs I developed a passion for sketching deep sky objects, it became inevitable that I would start thinking about more practical ways to do so than with a clipboard and red LEDs that were always too bright or too dim and shining all over the show except on the circle where the action was supposed to happen.

I tried a number of tricks but all were unsatisfactory. Eventually I started thinking of a hands-free, fully adjustable red LED lightbox.

My husband was ecstatic when I showed him the plan because it gave him an excuse to buy a new Weller soldering station. Our old soldering gun would have done the job just as well.

For the next few days I played the dutiful wife as I have not mastered the art of TIG welding and needed my husband to construct a lightweight A4 sized aluminum casing. I’m sure there are other ways of constructing the casing. The main thing is to keep it as light as possible.

The bottom looks like a baking tin. The inside has been sprayed white to help with reflection. The top is framed red perspex.

I have used two red wide-angle LEDs each attached to its own battery pack housing two AA batteries. The lights can be switched on individually. Using one LED at a time will give sufficient lighting most of the time, the second is mainly for backup.

The LEDS have been glued to the “baking tin” with hot glue. The LEDs need to be lifted off the bottom slightly otherwise they cause bright red spots. A thick blob of hot glue will do the trick but before fixing permanently experiment with prestik.

The lightbox is attached to a fully adjustable tripod by means of a quick release bracket which will make transporting easy.

Since designing my light box I have made a few very necessary adjustments:

  • With just the one sheet of red perspex, the LEDS were far too bright when I became dark adapted. I covered the LEDS with an extra red plastic lid with a strip of aluminum foil lining the inside rim. This helped to contain the light to almost the size of my sketching circle and toned down the brightness considerably
  • I have cut a circle (size of my sketching circle ) in a piece of cardboard (size of the lightbox frame) and put this in place before replacing the red perspex cover. I did not like the whole frame being lit up.
  • As most papers have fibres which become visible when using up-lighting, I sketch on firm tracing paper which is nice and smooth and diffuses the light as well.
  • An adapter to clamp an external red LED to the lightbox comes in handy for when I log my obs before sketching.
  • I have added a removable tray to the tripod for pencils, erasers, eyepieces and spectacles.

ConstructionLayoutTwo-red LEDSaluminum-rim

Red plastic lidcardboard layerQuick release bracketSet up with tray