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More Monsoon Season Cloudy Nights,
Daytime Crescent Venus

Posted: 30 July 2015

Wednesday, 22 July 2015, dawned mostly clear after having mostly cloudy skies at the end of the previous session Tuesday night. But it is monsoon season here so cumulus clouds appeared mid-day on Wednesday, with some rain in the area before sunset. Overcast skies continued on Thursday, 23 July, with a few light rainshowers (0.04" rain). Cloudy skies continued on Friday and Saturday, 24-25 July. I attended "Bat Night" at Oracle State Park on Saturday, 25 July. I have posted some photos on the Oracle Dark Skies Committee web site. As expected, cloudy skies continued. Tuesday, 28 July, a nice monsoon thunderstorm came through with lots of sound effects (thunder). Dropped 0.23" rain here in 30 minutes. Wednesday afternoon and evening more monsoon storms came through with lots of thunder and wind, but only 0.08" rain here. Some places nearby got a lot more rain. I did a short Periscope Livestream of the storm clouds:

Click or tap on image for video

Thursday, 30 July, dawned mostly clear with a forecast of less monsoon storms. As the sky was only partly cloudy shortly after noon I decided to try for some daytime imaging of Venus.

Open: Thursday, 30 July 2015, 1238 MST
Temperature: 107°F
Session: 850
Conditions: Partly cloudy

1245 MST: slewed to Venus but of course clouds were now hiding it. 1250 MST: cloud cover near Venus was increasing. 1251 MST: saw a crescent Venus, 83X, for a few seconds through a thin spot in the clouds.

Began setting up to image Venus at prime focus + 2X PowerMate using the D7200 DSLR. This 10 second video shows some of the clouds that I was dealing with while trying to video record the planet:

Click or tap on image for video

This is a stack of 142 HD video frames, 1.3X crop factor, 60 fps, 1/400sec, ISO 400, that was cropped from another longer video:


(Know what the music is that is playing in the observatory during this session?)

Seeing was obviously not very good due to the clouds and instability in our atmosphere from the monsoon weather pattern and daytime heating. But at least I was able to get the crescent Venus in the daytime since the evening and nighttime skies have been cloudy for so long.

Since the clouds were increasing as they moved in from the south I ended the imaging. After removing the camera and switching to the eyepiece I had to focus on the passing clouds in order to get close to the proper focus for Venus and then wait for Venus to appear from behind the passing clouds. 1317 MST: finally briefly saw Venus and was able to refine the focus so that the telescope would be in focus for my next session, whenever that is.

Close: Thursday, 30 July 2015, 1327 MST
Temperature: 94°F
Session Length: 0h 49m
Conditions: Partly cloudy

Reminder: if you want to know when the observatory is open you can visit the Cassiopeia Observatory home page. The Open/Close status is displayed there (as well as on most site pages). You can also follow me on Twitter at @mweasner where I post open/close updates, notices of new Reports, weather related Tweets, and other Tweets I deem appropriate. If you are not on Twitter you can still view my Tweets by going to If you use a RSS Reader you can subscribe to Cassiopeia Observatory updates at Lastly, you can view the current weather at Cassiopeia Observatory by going to my webcam page (

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