The Blue Side Of The Moon

The Blue Side Of The Moon

by Robert Veitch

Common perception believes a blue moon to be an event of rarity, but Robert Veitch had his perception expanded as he went in search of ‘the truth’

“Well that only happens once in a blue moon” remarked the Sussex Living Editor as the Christmas edition of the magazine went to the printers ahead of schedule. But where does that phrase come from and what defines a Blue Moon?

Scientifically speaking, a Blue Moon is an additional full moon in a seasonal cycle where normally one fewer is scheduled. The waxing and waning of the moon takes place on a 29½ day cycle. There are 12.37 full moons each year, so every third year, a thirteenth full moon appears and resets the cycle.

The etymology is from the Catholic Church who viewed the arrival of an early full moon as a betrayer or ‘belewe’ moon. Over time the patois evolved and belewe became blue.

January will see a full moon on the 2nd and the 31st of the month. February will see no full moon at all before March has full moons on the 2nd and 31st. This rare phenomenon is more like gold dust, as scarce as Hen’s teeth, like discovering the mythical Steyning Treacle Mines or the East Grinstead Elbow Grease Factory. The Romans might have called it ‘blueus maximus significantus.’

The literal blue moon with a blueish tint can be seen when dust particles in the atmosphere scatter red light in the spectrum. Particles need to be a smidgen bigger than 0.7 of a micrometer to make it happen. However it’s more common that particles are whisker smaller than 0.7 micrometers and tend  to scatter blue light instead, which makes the ‘red sky at night, lunar observers delight’ a more common occurrence.

The moon’s distance from the earth varies from around 230,000 miles at its perigee to 250,000 miles at its apogee. When the moon appears larger in the night sky, it’s simply because it’s just a bit nearer the earth.

The sun is 400 times larger than the moon and 400 times further away. They might look the same size in the sky, but that’s pure chance. This geological magic makes a solar eclipse possible although the moon is gradually easing it’s way away from the earth…

No nation claims to ‘own’ the moon thanks to the 1967 Outer Space Treaty – yes, such a treaty does exist. The treaty regards the moon as a ‘province of all mankind’ with only peaceful activities permitted there. Maybe this will change when someone discovers oil.

Ancient philosophers believed the tidal pull of the moon affected the water in the brains of susceptible individuals and that a full moon deprived these ‘lunatics’ of sleep, leading to bizarre behaviours. The local lunatic would invariably be locked up in the nearest asylum and the rest of society could apparently sleep safely. Things began to change in the 20th century thanks to the Mental Treatment Act (1930) and the Mental Health Act (1959), which improved life considerably for many of these unfortunate and often innocent souls who had been locked away for periods of their life.

Commonly perceived wisdom is incorrect, believing a blue moon to be a second full moon in a calendar month, although this fictional definition has gained popularity over recent times. Modern parlance claims the phrase once in a blue moon as an event of rarity. General Elections, World Cups, James Bond films, Commonwealth Games, Leap Years and tours by the Rolling Stones all have a similar frequency to blue moons. The blueus maximus significantus’ occurring this year is less frequent, more along the lines of Referenda, Royal Weddings and Pink Floyd reconciliations.

If you like your Pink Floyd, then you know they preferred the far side of the moon. According to the Floyd, “There is no dark side of the Moon, really. Matter of fact, it’s all dark.” In reality the moon may appear dark but about 90% of the light that hits it is reflected. On that basis, just imagine how bright the Earth is when viewed from space.

Some lunar events are even less frequent; think moon landings for example. Only 24 men sat at the top of a Saturn V rocket intending to leave the earth’s gravity and venture to the moon. Only 12 of those men walked on the moon. Astronauts John Young, Gene Cernan and Jim Lovell are the only humans to have travelled there twice and two of those three landed. Jim Lovell who was ‘first around the moon’ on Apollo 8 in 1968 found even greater fame as Commander of Apollo (“Okay, Houston, we’ve had a problem here”) 13.

NASA sent Jim to the moon twice, but he never landed, the only human to do so. Not one in a million, or one in 24, one in 12, or one in 3, but one in all recorded history. Whatever shade of blue that might be, Jim always remained sanguine, honoured at the chances he had, not those he missed out on. He once said, “I could put my thumb up to the (spacecraft) window and completely hide the earth. I thought everything I’ve ever known is behind my thumb.” Jim Lovell has a crater named after him on the dark side of the moon, which squares the circle with Pink Floyd.

However you define your blue moon, under clear skies it’s almost always a beguiling sight that commands attention. So, let’s enjoy the sky at night this season, hope it’s not too cloudy, and hope it has something blue about it.