Jun 072012

Today is June 6, 2012.  The day after the last transit of Venus that everyone alive today will ever see.  Well, there may be a few people that were born on June 4 that will live to be 105 1/2, and see the transit that occurs in December of 2117, but we’re discounting those few.  By now, you’ve probably heard that transits of Venus occur in pairs separated by 8 years, but those pairs are separated by 105 or 121 years.  So the last one was in 2004 and the next will be 2117.

The scientific significance of the Transit of Venus may have diminished slightly since the last few times it happened (a very close approximation of the distance from the Sun to the Earth was first determined to be 153,000,000 kilometers in 1771 based on data from the 1761 and 1769 transits), but its historical significance cannot be diminished.  At best, one can hope to see two of these events in one’s lifetime.  In 2004, this Astropotamus had to be content to see pictures someone else took, since clouds dominated the skies the day of the event.  That means June 5, 2012 was the last chance.

The images I took were all made with a proper solar filter which blocks UV and IR and 99.99% of the Sun’s light, without affecting color and still allowing the blackness of space beyond the Sun’s limb to still look black.  Unfortunately, in a series of unfortunate coincidences, my primary astroimaging laptop was being used for another purpose 25 miles away, so I could not use it to control the camera, my mount was not cooperating for tracking purposes, and I came from work and hurriedly things set up with about a minute to spare before first contact (the point where Venus looks like it just touches the Sun’s edge).  This means:

  • I could not use the focusing capabilities that I get while using the Live View function of the camera through the laptop and so had to rely on my less than stellar vision through the camera view finder to determine if things were in focus.
  • I could not track the sun automatically so I had to continually adjust the telescope in both horizontal and vertical axis.  VERY awkward to do every minute.
  • I could not set up automatic interval-based imaging with the laptop camera control software and had to manually trip the shutter.
    • This introduces about 10 seconds of camera shake while the whole rig settles after I poke the button.
      • This meant I had to use the self-timer function of the camera, which only has a 2 second or 20 second mode.
        • This meant instead of taking pictures every 5 seconds with the laptop controlling everything, I could take one picture every 30 seconds while I waited for the self timer, adjusted the mount, changed the axis, tried to refocus, and then start over
  • My camera AC power was also faulty so I had to quickly find the spare battery, which, luckily, still had a charge.
  • All while basically staring at the Sun, which was causing sweat to pour down my face.

Okay.  Enough sob story.  My pictures got progressively worse as my focusing errors got greater and greater, but at least I got some images.  Here’s one just after first contact, as Venus is just starting to transit across the surface (from right to left as seen by the camera).

I may put up others over time.

First Contact, 2012 Venus Transit

First Contact, 2012 Venus Transit