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Venus & Mercury Conjunction,
Full Moon on Observatory Dome

Posted: 2 March 2018

Thursday afternoon, 1 March 2018, I attended a meeting of the Oracle Dark Skies Committee at our local IDA "International Dark Sky Park". After the meeting one of the Committee members came to see the observatory. He left before sunset though.

Open: Thursday, 1 March 2018, 1826 MST
Temperature: 71°F
Session: 1208
Conditions: Mostly clear

Equipment Used:
12" f/8 LX600 w/StarLock
2" 24mm UWA eyepiece


1830 MST: LX600 ON, StarLock OFF, High Precision OFF.

Viewed the planets Mercury and then Venus, low in the west, 102X.

1836 MST: Venus was now visible to the naked eye. Mercury was not yet visible.

Viewed Venus and Mercury, 12x50 binoculars. Both nicely in the same field-of-view. Closest separation for this conjunction will be Saturday (1.1°).

1843 MST: Took this handheld D850 DSLR photo of Venus and Mercury in the sky from inside of the observatory (f/3.5, 1/50sec, ISO 250, FL 70mm, cropped):

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1848 MST: Mercury was now visible (with difficulty) to the naked eye.

1853 MST: I took this handheld D850 photo from outside of the observatory (f/2.8, 1/15sec, ISO 400, FL 45mm, slightly cropped):

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Mercury will be difficult to find in the photos so mouseover or tap on the images for labels.

1900 MST: the Full Moon (1 hour, 10 minutes past precisely Full) began rising over the hill to the east. I watched it rise using the 12" telescope, 102X. A very slight terminator was visible.

1918 MST: took this handheld photo of the Full Moon projected onto the observatory dome with the D850 DSLR (f/2.8, 1/2sec, ISO 6400, FL 24mm):

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The constellation of Canis Major is visible at the upper left, along with part of a cloud. The bright stars Sirius and Canopus are labeled (mouseover or tap on the image).

I returned back inside of the observatory and mounted the D850 DSLR at prime focus + focal reducer.

1930 MST: Full Moon (color saturated in post-processing), 1/800sec, ISO 100:


1938 MST: unmounted the camera and took a last look at the Full Moon, 102X.

1939 MST: LX600 OFF.

Close: Thursday, 1 March 2018, 1947 MST
Temperature: 56°F
Session Length: 1h 21m
Conditions: Mostly clear

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