Wednesday, June 6, 2012

Venus Transit at Digital Diner

I know you are probably tired of hearing about it, but this should be the last post on the subject for about 105 years, so bear with me.  We had a little bit of an impromptu star party yesterday to watch Venus transit across our own star, the Sun.  It was a bit cold and windy, but otherwise pretty good for viewing.  Several friends showed up to watch the skies with us.  We observed the transit several different ways.
Viewing with solar glasses
With solar glasses, Venus was visible, but quite small.  We had two types of solar glasses on hand, one with a traditional filters and the other with more of a blue blocking effect.  Most people liked the traditional ones better, but ultimately it seemed up to individual taste and both showed the action just fine.
A direct photo of Venus taken through solar glasses
The photo above was taken by holding a foil framed, solar glasses lens over the end of the camera lens while taking the shot.  Thank goodness for the immediate feedback of digital cameras.  It made it possible to play around with the manual settings to get the exposure right.

Creating a projection using a spotting scope
The resulting projection was a couple inches in
diameter and clearly showed
Venus (lower left) as well as signs of Sunspots

We created a projection by connecting an old spotting scope (thanks Opa!) to some cardboard and pointing it toward the Sun.  We aimed the light beam emerging from the scope toward a piece of white foam core about 3 feet away.  The result was a projection about 2 inches in diameter that clearly showed the Sun and Venus and hints of some Sunspots [aside: those of you who know me probably understand that I have a hard time keeping from typing "Sun SPOT"]  Because of the magnification, this method worked well even for those who don't have the eagle eyes required to pick Venus out with the solar glasses.

Glenn and his solar filtered telescope
Later, our friend Glenn showed up with a refractor telescope and white light solar filter.  This type of filter is made of Mylar and produces a much more white and blue image.  The telescope produced plenty of magnification, and a nice zoomable eyepiece allowed us to really get an eyeful.  

This view was really breathtaking.  It allowed us to clearly see Venus and also count over 20 sunspots! The detail was incredible.  We didn't have a hydrogen-alpha filter, so we weren't able to watch the dramatic prominences dance over the Sun's surface, but the view was still spectacular.

The Sun as seen through the mylar white light filter.
Venus is in the upper right.  Other dots are sunspots.

Close-up view of Venus and some sunspots

Overall, I think we can mark this off our life list.  We definitely saw Venus transit the Sun.  It is interesting that there are only 3 bodies in our solar system (Mercury, Venus and the Moon - not counting asteroids and comets) that can appear to transit the Sun from our perspective here on Earth.  Mercury is VERY small and unimpressive against the Sun.  We were able to see the other two in the last two weeks while we sat on the front porch of our own Digital Diner.  Awesome!

There is something really cool about looking up in the sky and seeing a planet dangling in front of the Sun.  It makes me think about the great distances, dramatic sizes and the laws of physics they obey that let us predict and observe such events.  I get a confirmation that the Sun really must be huge as I see it in comparison to an entire planet.  Venus really does exist.  It's not just something in text books or on TV.  It's something we can watch from our own yard.  There is so much to learn in the world of science that we often have to just believe things that we are taught, but it is always nice when you can independently confirm some facts from your own direct observations.  Things are as they should be.

Now, to play us out, the Venus Transit March by John Philip Sousa.  Press play on the video below and imagine Venus marching its way through 105 Earth years to the next Sun, Venus, Earth party.  See you in 2117!

PS Thanks to Glenn (for the awesome telescope), Inna, Yuri, Alex, Daniel and Igor for making it a party.

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