Occultation of Venus

On the afternoon of August 13, Venus was occulted by the waning crescent moon. The disappearance, on the moon's bright limb, was visible across the entire United States. Observing the event from my home in Minnesota was difficult, however, because the sun was high in the sky and the moon, approximately 45 degrees away, was rather low in the west. I had spotted the moon without much trouble when it was high in the south earlier in the day, but had a much harder time finding it later in the afternoon. A slightly hazy background sky added to the difficulty. After finding it in binoculars, I could just barely see it with the naked eye.

I then used a 127mm Maksutov-Cassagrain telescope to watch the moon slowly overtake Venus. A magnification of approximately 60 seemed to work best. At higher magnifications, the contrast between the moon and background sky was so poor that the moon became almost invisible. Venus, on the other hand, was extremely bright, in approximately a half full phase. I took the attached picture just a few minutes before the occultation began. Note the huge difference in surface brightness between Venus and the moon. I used a Canon A710 IS camera to take the picture. Later I cropped and enlarged it. Unfortunately, as I was adjusting my equipment, I missed seeing and photographing Venus when it was actually partly occulted.