Vatican Observatory Tour

I follow the blog The Catholic Astronomer from the Vatican Observatory Foundation. I’ve heard of the Vatican Observatory for a long time but never knew much about it. It sits a above an extinct volcanic lake at Castel Gandolfo in the Papal Gardens near Rome.

© Paul A. Zalonski

Very recently, the observatory director and foundation director led a tour of the place. Joining them was Christopher Graney who is an astronomy teacher in Louisville, KY. He recorded videos for his class to see later. His videos are posted here on the blog site.

Scroll to the bottom of his post and click the left of three small images about the history and telescopes. His link will take you to the three videos.

One aspect of interest in the tour was of the women computers who worked there and their machine used to measure stars on the glass plates. It connected well with the work of the women computers in The Glass Universe by Dava Sobel. Those women laid the foundations for many of the important principles used in modern astronomy.

Venus | Inferior Conjunction | 2017

Venus is closer to the Sun and orbits faster than Earth. Earth takes just over 365 days. Venus orbits in just under 225 Earth days. During the recent few months, Venus was bright and easily visible in the evening sky as it caught up to and passed Earth. In doing so, it came closer and appeared larger when viewed with a telescope or binoculars. This animation from a desktop program illustrates their motions. Mercury is not shown in order to simplify the view. The sizes are exaggerated.

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Venus | Morning View | 24 Mar 2017

I got my first morning view of Venus this spring at 6:45. There was a layer of high clouds to the east dimming the view quite a lot. Binoculars helped locate it for a photograph. Thanks to Scott at Scott’s Sky Watch for pointing out Venus is now visible both in the evening and the morning if the sky is clear enough. He called it a double dose of Venus.

Looking slightly north of east through high clouds.

Clouds made the image a little hazy.

There was another bonus this morning. Looking to the southeast, the waning crescent Moon shined through a clear break in the clouds.

Occultation | Aldebaran Hidden Again

Once more, the Moon occulted the bright star Aldebaran in the constellation Taurus. Previous three posts are found here describing earlier occultations. I stepped out early to see if the sky was clear and got this image at 9:24 pm CST. My phone said the occultation occurred a few seconds past 9:52.

28 min prior to the 9:52 occultation

28 min prior to the 9:52 occultation

Aldebaran disappeared from view about 6 seconds into the video. I looked again at 10:33 pm and saw it had reemerged into view at the upper right of the Moon.


Earlier in the evening at 6:38 pm, I captured this slim crescent of Venus. It will quickly descend toward the Sun during the next two weeks and show a thinner crescent. On about 25 March, it will be aligned with the Sun and not in view. Early in April, it will emerge as a thin crescent before dawn.