In prehistoric times, lunar eclipses were a mysterious, unexplained portent of doom.
For example, the Babylonians considered them ‘particularly evil omens that involved their kings’ and when a lunar eclipse was predicted ‘substitute kings could be appointed who would bear the brunt of the gods' wrath.’ (NASA undated).
However, the ancient Greek philosophers started to make sense of it all, with Athens-based Anaxagoras often credited as the first to deduce that lunar eclipses were caused by the shadow of the Earth.
I could pretend that these lofty thoughts were on my mind as I watched this week’s supermoon and partial lunar eclipse, but cloud cover, timings and camera settings were higher priorities, starting with the Harvest Supermoon on 17 September.
Heading out in the early evening, the forecast of clear skies proved to be overly optimistic, so we abandoned plans to go to a city park and instead went to the coast, where it looked a little clearer. As it turned out, we were in luck as almost immediately on parking a shining sliver of light appeared in the distance. This soon developed into a spectacular orange-red semi-circle, lit by the rays of the setting sun, although all too soon it disappeared behind a layer of cloud.
The Harvest Supermoon rising; the anemometer in the foreground was on a yacht mast. An optical illusion called the Moon Illusion makes the moon seem larger when it is close to the horizon.
In ancient times, full moons were often named after natural or wildlife phenomena, and the Harvest Moon perhaps got its name as crops could continue to be harvested by moonlight when skies were clear.
The term supermoon is another colloquial expression and is used when a full moon occurs unusually close to earth, causing it to appear slightly larger and brighter than average; according to NASA, the relevant figures are 14% bigger and 30% brighter. Views on the term ‘supermoon’ are mixed amongst astronomers, with some preferring to call it a perigee full moon and others thinking that if it increases interest in astronomy, why not use the name?
A rare supermoon eclipse was predicted later in the night so – although only partial – it seemed worth getting up early for, and by 3am I was setting up tripod and camera at a local golf course, with just one slightly nervous pause as footsteps approached, before realizing that it was a late night reveller on his way home.
Camera and tripod during the partial eclipse
While waiting for the eclipse to develop, there was more time for reflection than earlier in the night, such as on the extraordinary distances and geometry involved when an eclipse occurs. In newspaper and web graphics, we’re used to seeing the sun, moon and earth close together and of a similar size, but if the sun was drawn to be 1cm in diameter, the earth when drawn to scale would appear as a small dot and more than a metre away.
Three images of the partial eclipse near the start, peak and end of the event
On first arriving, the moon was dimmed slightly by the earth’s outer shadow - the penumbra – but the partial eclipse began a few minutes later, as the umbra began to pass across its surface. Within about half an hour this shadow had reached a maximum, with a surprisingly large amount of the moon affected, given that only a small percentage was in full darkness. Then, after another half an hour or so the main part of the eclipse was over and it was time to head home to catch up on some sleep.
So, despite the cloud cover early on, this was a generally successful trip and, looking forward, we should get two total lunar eclipses next year so here’s hoping for clear skies and light winds!
Further reading
NASA (undated) Ancient eclipse forecasts, when successful, were a powerful means of divining omens for anxious Kings. Technology through Time Issue #32: Ancient Babylon
Spectacular Britain: A spotter's guide to the UK’s most amazing natural phenomena, Kevin Sene, Bloomsbury. For more insights into viewing and photographing supermoons and lunar and solar eclipses. https://www.bloomsbury.com/uk/spectacular-britain-9781844866342/
Another great post Kevin and I’m so pleased that your efforts were rewarded with fab photos… the one of your camera at the ready is very atmospheric.
The first photo is amazing! I was once lucky enough to watch a full lunar eclipse from the comfort of my own living room. An amazing experience