Transit of Venus at Sydney Observatory – a visitor’s perspective
Two avid Sydney stargazers – Daphne and Dom Gonzalvez – have kindly agreed to share their experience of the 2012 transit of Venus at Sydney Observatory…. Here is their story:
When Snoopy, Charlie Brown’s canine friend wrote, “It was a dark and stormy night…” he could have been writing about the night of 5 June. The wind was howling, the seas were roaring (waves 7 metres high were hitting the coast), and hopes of viewing anything at all on the morrow were dismal.
I was tempted to say DRAT – Dark Rainy And Tempestuous! But, so as not to jinx the 6th, we went to bed with optimism. We had booked tickets at Sydney Observatory and we were going, come hell or high water. The main actors would be on stage in the sky, and to even imagine the curtains would be drawn was not worth thinking about!
We woke up early on Wednesday 6 June 2012 – the day of the transit – and when I looked out of Bedroom Observatory, the sight that greeted me was not encouraging. But the tiny piece of brightness was enough for me! “It’s clearing up,” I said to Dom.
My optimism was rewarded. Just before we left, the sky brightened and there was an encouraging ray from the Sun. Can you see it?
And we were off. I was confident we would see the much anticipated celestial rendezvous. Our time slot at the Observatory was 10 am to 12.30 pm.
We arrived at Circular Quay and walked up Observatory Hill, well in time. The sight that greeted us confirmed that there were many Sydneysiders who were as eager as we were. Even more eager in fact for the people you see in the picture were from the earlier, stormier time slot.
The flags on the Observatory mast announced the big event. You’ll recognise the planet Venus flag, but look closely and you’ll see the yellow Transit-of-Venus flag, specially made for the occasion.
At the gate the special event sign greeted us. As we entered Sydney Observatory grounds, we received our solar glasses and yellow wrist bands to mark our time slot. As Dom put on his wrist band he joked: “Just in case I get lost and my mother comes looking for me.” Our spirits were buoyant!
My brother Neville joined us and we lined up at the first telescope. By now Venus was at 5 o’clock on the Sun. The view was reversed by the telescope so, it was up top at the 1 o’clock position.
I now had ocular proof! Venus was a clear black dot. We could see the sun spots too!
Sydney Observatory has observed all the Transits of Venus which have occurred after Captain Cook made his historic viewing. This exhibit shows the path of Venus in the three observations, 1874, 2004 and 2012.
No kidding! After all, Venus is our Earth’s sister and, as it is an inner planet, we can see it crossing the face of the Sun. Venus is a third of the distance between us and the Sun.
Its orbit is not exactly on the same plane as Earth’s orbit. It is inclined by 3.4° relative to the Earth’s, and so Venus usually appears to us to pass under (or over) the Sun. It completes an orbit every 224.65 Earth days. Astronomers calculate mathematically exactly when the next Transit will occur.
The historic 1874 telescope in the dome is seriously impressive in size and optics! And it is cared for with religious diligence. As we lined up on the stairs, a squall of rain came, and the Observatory staff closed the dome immediately. That’s why my picture is so dark.
Our next stop was for a talk in the marquee where Professor Iver H Cairns, Professor of Space Physics at Sydney University, spoke about sunspots.
12.15pm: Live screens showed us the current state of transit. Venus had half way to go.
Near the end of our time slot at the Observatory, the clouds came over and a drizzle forced Observatory staff to cover up all the telescopes and binoculars.
How lucky we were! We actually saw the Transit despite clouds, rain and wind.
Time to reward ourselves we thought, so we walked over to a nearby cafeteria and warmed ourselves with some lunch.
Post Script: We went away with a reminder from the Observatory that 2012 is the Year of the Sun. We’ve had the Annular Eclipse of the Sun (not in Australia), the Transit of Venus, and we can look forward to the Total Eclipse of the Sun in Cairns in November.
– With many thanks to Daphne and Dom Gonzalvez for this post, including all the photographs. Their complete post on the transit of Venus plus more is on their Night in focus astronomy blog.