Tuesday, 5 July 2011

Seven Years Down & Counting

In the 2004 Old Farmer's Almanac, which I get the moment it comes out and read cover to cover, I read about the transit of Venus across Sol. This is an astronomical event that only comes around once every 105.5 to 121.5 years. It's a two-part event, however. The first return comes and then exactly two days short of eight years later, the second transit follows. And then comes the century plus wait.

The Moon transits across the sun about once a year. Mercury transits across the sun 13 times each century. Venus, the last of the planets to do this, does it only 13 times every 1,000 years. (Outer planets from our point of view cannot transit across the sun - they need to have their orbits within ours. Imagine the number of transits we'd get to see from Pluto!)

In December 1874 and 1882, Venus came to do its transit for the world and people (mostly astronomers) were treated to this rare sight. Venus missed the 20th century completely to revisit us in 20o4 and next year... and will go back to its regularly scheduled programming until December 2117 - long after I'm dust.

The Old Farmer's Almanac comes out in August of the previous year. In about a month the 2012 periodical will arrive. Fortuitously, with the exception of the unknown or newly discovered comets, they know just about every astronomical event. When I read the 2004 release in September 2003, I started planning.

For Christmas, I had one item on my gift list for my parents: a $400 Orion telescope.

For my birthday, I had one item on my gift list for my parents: a $125 solar filter that fits my Orion telescope

And for the 8th day in June 2004, I had off until 1000.

So around 0500, I walked across the street to the back lot of the Heavy Rescue squad where I had an unimpeded view of the eastern sky. I set it up and had tested the solar filter to be sure that there was not a single flaw anywhere. And then I waited.

At 0513, the sun began to hoist itself over the horizon. I had my eye to 'scope, looking at the red bulk of the rising star. I cannot tell you how gorgeous, how amazing a site that was. Sun spots, although low, were delightfully visible. The ocher colour of the early morning sun makes it easy to see every nook and cranny of the seething surface. As it rose higher in the sky and finally brought the lower quarter into view, there was Venus - about 2/3 of her six-hour journey complete. She appears as a solid black round object about the size of a nickel, and she was slowly moving across the sun's bulk on an elliptical plane. Amazing! I watched fascinated for the nearly two hours she had to finish crossing the sun. I couldn't help myself. I was standing there, slightly bent, eye stuck to the telescope and grinning like an idiot.

Venus is four times the size of the Moon but at its closest last transit, it was 26,000,000 miles away. The Moon is - at perigee - 362,570 miles away from us. Not far at all. Also, on the right plane, the transits of the Moon are solar eclipses. The twist of fate that makes the Moon 1/40 the size of the sun is that the sun is 40 times away from Earth. Otherwise even in syzygy the effect would be more like the Venus transit, with no visible corona.

I wanted to share the sight with someone, but no one was around - the 8th was a Tuesday and most people were either still in bed or just getting up when I was setting up and everyone had left or was just leaving for work when I was putting the telescope away about ten after 0700.

For the last seven years I have been mostly patient. But the clock is ticking and it is eleven months (nearly to the day) until the next transit. And I am thinking about it all the time.

It is rare that I take out the telescope in daylight, but every once in a while I do. I need to again now, since the sunspot activity is high and that should be excellent viewing. I enjoy that kind of sight.

Nighttime is the more common time to take the scope out. I've seen Venus, Mars, Jupiter and Saturn floating big and bright in the sky; Uranus and Neptune are not so easy. Pluto - yikes. It's almost impossible to see. And then there was Hale-Bopp comet that came around in the spring of 1997 at perigee. For that, the telescope was a waste - it was so visible, it was too big in the viewer.

Right now I am counting down to 6 June 2012...

In December 1874 and 1882, Venus came to do its transit for the world and people (mostly astronomers) were treated to this rare sight. Venus missed the 20th century completely to revisit us in 20o4 and next year... and will go back to its regularly scheduled programming until December 2117 and 2125. I will be there to see the next transit as it will be my last.

And so worth it...

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