Transit of Venus

I’m taking a break from work here at the Palo Alto church, and watching the transit of Venus. I’m projecting an image of the sun using a pair of 7×25 binoculars mounted to a tripod. I have a white card set up about six feet from the binoculars, resulting in an image that’s approximately five and three quarters of an inch in diameter. The optics in the binoculars are not particularly good, and there’s enough chromatic aberration that I don’t get a particularly crisp image. Nevertheless, I can clearly see the shadow Venus is casting as it crosses the sun; on this projection, it’s approximately three-sixteenths of an inch in diameter, and at this time about one and three sixteenths inches from the nearest edge of the sun. The card I’m projecting the image on is eight and a half by eleven inches oriented horizontally; the earth moves such that I have to readjust the binoculars every sixty or seventy seconds in order to keep a complete image on the card.

Venus does not appear to be moving in relation to the sun. I suppose if I sat out here long enough, I’d be able to see some relative motion; but the transit is going to take four hours, and I don’t suppose I can take that much time away from work.

And yes, the transit is a pretty amazing phenomenon to watch, even with my crude projection device.

Corrected per Erp’s comment.

4 thoughts on “Transit of Venus”

  1. Someone brought in a telescope to work and set it up in the courtyard (projecting not viewing directly); were you able to see the sunspots also? BTW it is Venus’s shadow on us not on the sun we are seeing.

    SUN emitting light –> venus intercepting –> earth

  2. Thanks for the correction re: shadow; stupid error, I was paying more attention to the transit than to what I was writing; I have corrected the post.

    And yes, I was able to see four fairly distinct sunspots.

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