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Monsoon Storms, Jupiter and Venus 37 arcminutes apart

Posted: 30 June 2015

I and another member of the Oracle Dark Skies Committee attended the Peralta Regional Park open house Tuesday evening, 23 June. This proposed park in northern Pinal County, Arizona, "will offer exceptional open space and outdoor recreation opportunity that could include hiking, equestrian riding, mountain biking, rock climbing, dark sky watching, picnicking and camping." The ODSC attended the open house to support the "dark sky watching" aspect and learn more about the proposed park. There was broad community support for the proposed park but it will still be several years before it opens.

The observatory was not opened Tuesday night after my late return from the open house. Monsoon weather pattern clouds appeared Wednesday morning, 24 June. Had a brief monsoon thunderstorm late Thursday night, 25 June, with lots of lightning but only 0.01" rain. Cloudy skies continued on Friday.

Saturday afternoon, 27 June, had a nice monsoon thunderstorm to the west of the observatory:


I did a Twitter Periscope livestream of the storm beginning a few minutes after the above photo was taken. Here is a 9 second segment from the video. The audio is just the strong wind that was blowing and masking my voice.

Click or tap on image to view video

The storm didn't drop any rain at my place.

That evening I supported the "Guided Night Walk and Lunar Viewing with Binoculars" at Oracle State Park. Unfortunately, a monsoon rainshower came through just before the start of the event, so it was cancelled. Had only 0.02" rain at Cassiopeia Observatory.

Sunday evening near sunset another monsoon thunderstorm come through. As it approached from the east there was a faint partial double rainbow visible:


A few minutes later the second bow faded but the primary bow was longer:


When the storm arrived there was a lot of lightning and brief periods of moderate rain. But only received 0.12" of rain from the storm.

The monsoon storm pattern continued on Monday, 29 June. Here is an impressive storm that appeared mid-afternoon to the northwest (ominous black-and-white version):

Mouseover or tap on image
Mouseover or tap on image to see color version

The storm above died out but reformed a little later to the west-southwest:


Another storm later that day dropped 0.02" rain.

About an hour before sunset, a dust storm was visible near Casa Grande, about 35 miles away:

Click or tap on image for larger version

All these cloudy nights prevented my monitoring Jupiter and Venus as they approach their close conjunction (20 arcminutes) on Tuesday, 30 June. The clouds briefly thinned out somewhat Monday night, 29 June, and at 2048 MST I took this D7200 DSLR photo with a 300mm lens showing the planets just 37 arcminutes apart and a few stars:

Click or tap on image for larger version

The four Galilean Moons are visible surrounding Jupiter. From left to right: Ganymede, Io, Europa, and Callisto.

2015 is the 10th anniversary year of my initial visits to "Oracle Observatory". On 11 June 2005 I was at Oracle Observatory with my ETX-90RA telescope to do some astrophotography. The report from 10 years ago details that visit.

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