Reflections on the 2012 transit of Venus by Geoff of the Obs
Astronomy is a wonderful subject. Most people have a basic curiosity of the Universe around us and as long as they don’t stay in the heart of a bright city, most get to experience its beauty from time to time. This can be on a country drive, camping, an evening walk or a visit to an observatory. The media loves astronomical stories (especially if there is a potential ‘impending doom’ element!) and we often see short stories about a new telescope, planet, discovery, launch or failed launch. Perhaps it’s part of the quest to understand where we came from so we know where we are going? Anyhow, events come and go, some more spectacular than others, and some, very rare.
The Shoemaker-Levy 9 collisions with Jupiter in 1994 were stunning to say the least. Earth sized scars appearing just minutes after the explosive impacts were beautiful and alarming.
(Shoemaker levy image)
Comet McNaught in 2007 stretching across the sky made some jump for joy in the middle of a dark cow pat filled paddock near rural Mudgee.
And then the little black spot on the Sun in June 2004 and 2012. It was, after all, just a little black spot no? Yes and no. Physically it was no more than a blemish or was it a beauty spot, appearing on our star for just over 6 hours. So why all the excitement? I think it’s like that smelly flower, titan arum, at the Royal Botanic Gardens than only blooms every 5 years. It’s rare and we love things that are rare. Would diamonds be so valuable if the flow to retailers were not so tightly controlled? That feeling when we fall in love – if it were an everyday occurrence there might even be a pill to stop it…. but back to Venus. Yes it is rare: four every 243 years. And yes it is, as mentioned, just a little black spot. But wow! What an event – especially for the modern history of us Australians.
As has been stated so many times over the last few months, were it not for the 1769 transit seen by Lieutenant Cook from Tahiti, je pourrais être taper ceci en français, ou até mesmo em Português!* So, my limited and often spotty English grammar usage is all thanks to Cook and the little black spot. But wait there is more! Without the transit we would not have had a ball park size for the Solar System. With the benfefit of hindsight and using Cook’s data alone he got the right distance from the Earth to the Sun within his error range. Undeniably the transit has had an amazing impact on this country’s modern history and science in general. The number of people who lost their lives to the transit is testimony to the commitment of our scientific endeavours (pun intended).
So with all of this baggage the team at Sydney Observatory, with the support of our parent organisation the Powerhouse Museum, began planning for the 2012 transit more than two years ago – though it felt like it started after the 2004 transit. Led by Toner Stevenson and the lessons learnt from the 2004 event, a multi-layered program was arranged for the 2012 transit – to ensure that every visitor enjoyed a rewarding and enjoyable experience irrespective of the time of their visit or the weather conditions.
The trouble with a six-hour event with four key instants, or as they are called “contacts”, is that many people want to look through the telescopes at those exact points and then peek every now and then in-between as the dot drifts. Enter the VuVuVenus! Modelled on those ghastly Vuvuzelas from the Soccer World Cup, a prototype was cut up and used with rear projection film to make a viewer easily seen by more than one person at a time. The final version used a funnel found at Parklea Markets and an order of 15 certainly raised an eyebrow or two. Once cut, painted and covered they were inserted into the telescopes and made the contact viewing dilemma sublimate faster than Comet Halley at perihelion. The rest of the transit was much more leisurely and viewed one person at a time though each telescope.
We decided on three two-hour shifts to give people a good chance to see a change in position and look through multiple telescopes, enjoy a customised 3D Space Theatre program by our resident 3D Java expert, Dr Paul Payne, and attend a lecture or two. With 400 tickets plus VIPs and media we were ready for around 1500 people across the day. An awesome T-shirt to commemorate the occasion was made as well in advance and sold strongly beforehand and on the day. We do still have a few available….
Would people want to attend a two-hour block or would they prefer one of the other small observatories that offered drop in anytime access? All 1500 tickets were sold out within a week so, in retrospect, it was a no brainer! In order to allow more people to see the event we approached a media partner, in this case NineMSN, and we planned to stream the event for those unable to attend or without the stunningly scarce eclipse glasses. With the help of the Powerhouse IT and Media teams we were able to provide two different live videos for viewing onsite and to assorted media from around the world. (My sister on a holiday saw me on TV in South America.) The first was a neutral density view of the Sun showing its real colour filtered by 100,000 times. This gave a beautiful natural yellow disk and showed sunspots should they be present on the day which thankfully they were. The second was an H-alpha view which meant the filter blocked out all the light apart from one beautiful red wavelength of about 656nm plus or minus a tad. This sort of red filter shows prominences, flares and surface granulation in glorious detail.
All was ready: telescopes, solar filters, video cameras, VuVuVenuses (or is that VuVuVeni?) 3D Theatre content, special wrist bands, T-shirts, solar glasses and an interactive website to calculate the size of the Solar System just like Cook. What could go wrong, you ask? Weather of course!
A few days prior we received a call from one of our good friends at the Bureau of Meteorology to tell us that on the two days before the transit, Monday and Tuesday 4 and 5 June, a severe weather event in the form of an “East Coast Low” was expected. East Coast Lows that form in the tropics are given the more commonly known name of tropical cyclones. Oh dear! Indeed the weather on the 5th was foul. That night the winds picked up and it was looking very depressing. As dawn on the 6th broke there were a few gaps followed by short downpours and then more gaps. At least every now and then the Sun shone through. As the public arrived and were given glasses most managed a VuVu view of first and second contact. The pattern was set for the rest of the day. Cloud, gap with stunningly clear viewing, wind, cloud, rain then another gap and it would start over again. The last session had perhaps the worst luck but everyone managed at least a view through the glasses. As strange as it may seem, the weather added a bit of mystery and suspense to the day that made it all the more exciting. Had it been perfectly clear, it would have been nice – but who doesn’t love a thriller? Will I see it or won’t I? Yes I did, excellent!
The live streaming worked a treat too although there was some concern as to why our feed looked upside down compared to that from Hawaii. Simple, ours was the “correct” way up and that from Hawaii on the other side of the equator was upside down. That’s our story and we are sticking to it.
At 2:44pm the event was over, Venus was gone for another 105 years. All that was left to do was tidy up and think about what we had just seen. A little black spot that had a profound effect on this beautiful country and one that most of us will never see again, that’s all!
* ”I might be writing this in French, or Portuguese.”