Sunday, 12 May 2013

May Meeting - Archeo-Astronomy

Our May meeting on the usual 1st Tuesday of the month commenced with a little excitement!!

For the first time in 18 months we were locked out!!

Fortunately the caretaker lives very close and so a quick phone call had him on site to open up.
It was then a little more hurried to get the operations room set up with chairs, tables and the projector for the meeting to commence -  but not before ......................... ........................................................the compulsory/obligatory  tea and biscuits - always a welcoming treat for all.

Patiently waiting outside we have (from right to left) Roy (1st man to arrive), moi-meme, Gladys, Sue, Brenda (friend of Gladys and 1st time attendee), Brian & Liz.

Apologies to the other two I can't identify from the picture!!

The "What's Up" in the May sky feature commenced with the reminder of an excellent April meeting which concluded with most of us viewing comet PanStarrs.

A number of events to watch for were mentioned commencing with planet Venus which made its first appearance for several months just this week low in the west after sunset.
Mercury too reappears mid-month but the real hi-light is around 24th-28th when Venus Mercury & Jupiter come together to form a neat equilateral triangle.
Saturn is still the planet of the month and pointers were given to viewing it and its moons as well as mention of the hurricane storms currently raging at its north pole!!

 Mention was made of many other things - lunar and deep space with particular reference to the great Hercules globular cluster M13 - since photographed by one of our members - Rob from Crundale.

The Virgo galaxy cluster and M104 the sombrero galaxy were also given mention and will hopefully attract attention in the next few months also..

With less on view as a result of the lightening skies of summer (cough!) special mention was made of noctilucent clouds - a particular feature of May to August at our latitude that we are hoping to see.

Some have voiced the thought that these clouds are becoming more prominent as a result of global warming - whatever the cause they are certainly a sight to behold as this picture shows.

Following refreshments the main lecture on archeo-astronomy was covered by Rob the PAG secretary.
Rob commenced with the thought that there is still more that we don't know than what we do on this subject.
Stone circles from Orkney to Stonehenge raised some discussion - how did bluestones from Pembrokeshire weighing in at up to 2 tons get all the way to Wiltshire - a distance of 160 miles!

Machu Picchu -often referred to as the "Lost City of the Incas" - is perhaps the most familiar icon of Inca civilisation.

Machu Picchu appears to lie at the center of a network of related sites and trails—and many landmarks both man-made and mountainous appear to align with astronomical events like the solstice sunset. 

The Inca had no written language, so they left no record of why they built the site or how they used it before it was abandoned in the early 16th century.

 Still in Peru lies another enigma the Nazca Lines Monkey.

The Monkey, like many Nazca geoglyphs, is a single-line drawing -- if you step onto the Monkey’s hand, for example, you could walk all the way to the center of its tail without stepping off the line. 

The spiral-tailed Nazca Monkey is approximately 328 feet (100 m) long and 190 feet (58 m) tall but how it was drawn is a mystery. Only from above can it be identified!

Created by people of the Nazca culture the Nazca Lines were made between AD 400 and AD 650. 

Essentially, the lines were made by moving or turning desert-varnished rocks so that their lighter underside is visible.

One possible interpretations of the lines is that they are a solar or lunar calendar.

Many things could be mentioned but let's conclude with this one that has also been televised recently - the antikythera mechanism.

It is allegedly  an ancient analogue computer designed to calculate astronomical positions.

Recovered in 1900/1901 from the Antikythers wreck - the construction has been dated to the early 1st century BCE.

The action of turning the hand crank would have caused all interlocked gears within the mechanism to rotate, resulting in the calculation of the position of the Sun and Moon and other astronomical information, such as moon phases eclipse cycles, and theoretically the locations of planets.

There was a lively discussion of a number of these features and the whole lecture proved an absorbing and eye opening subject.

This was a lecture that was originally scheduled for some months back - this month it took the place of Andrew's lecture on Astro-Imaging which will take place next month instead.
A little juggling is needed on occasion but it was certainly a good thing that this particular lecture was finally given - Our thanks to Rob for this enlightening material.