Occultation of Venus

An unusual thing happened earlier today: The Moon passed directly between the Earth and Venus. If you were at the right place at the right time, you could see Venus disappear on behind one side of the Moon and watch it reappear from the other side about an hour later. Fortunately, San Diego is one of the right places and since all the sessions I had to attend at the meeting ended at noon, I could be outside by the 1:42pm disappearance.

An event like this called an occultation. The Moon passes near Venus about once a month. Usually, the Moon passes just to one side or the other of Venus. Occasionally, it passes right over Venus. That's what happened today.

I was outside and had my Canon Digital Rebel Xti with the 75-300mm zoom lens set up. The sky in San Diego was a bit milky white (instead of deep blue) which made the Moon harder to find and good contrast between the Moon and the sky harder to achieve. I also had trouble focusing at the disappearance (but not so much the reappearance). Still, I managed to get a reasonably good shot right before Venus vanished behind the Moon.

Venus disappeared behind the lit side of the Moon. A little over an hour later (2:49pm), Venus reappeared behind the dark side of Venus. There were some nearby clouds and I was watching them creep closer to the Moon as the time approached. However, they held off and I got a whole series of pics of the reappearance. Here is one of my favorites. 

I have a lot of pics of the reappearance. If I can get some time, I might try to animate them to watch it reappear. 

Now you might think I missed out on the event by photographing it. Not quite. I have a cable release for my camera. I was holding the cable release in one hand and shooting these pics while holding a pair of binoculars in the other hand to enjoy the spectacle for myself!

Reprinted with permission from the Half-Astrophysicist Blog.