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Clouds, Moon, International Space Station

Posted: 21 May 2018

As I approached the observatory there were some interesting clouds in the sky near the Moon:


Open: Sunday, 20 May 2018, 1902 MST
Temperature: 76°F
Session: 1236
Conditions: Partly cloudy

Equipment Used:
12" f/8 LX600 w/StarLock
2" 24mm UWA eyepiece
2" 30mm eyepiece

iPhone 8 Plus

I probably would not have opened the observatory this session due to clouds, but there would be a good pass of the International Space Station (ISS) that I wanted to photograph. The previous session I had photographed the ISS but the images were underexposed. I would use a slightly slower shutter speed for this attempt.

1912 MST: a jet contrail made an interesting cut through some clouds:


1922 MST: sunset.


1924 MST: LX600 ON, StarLock OFF, High Precision OFF.

Viewed the Moon, 102X and 81X.

Mounted the iPhone 8 Plus on the 2" 30mm eyepiece using the Levenhuk adapter. Took this afocal 81X image of the Moon using the iOS app NightCap Camera (ISO 22, 1/1000sec):


I then began preparing for the ISS pass. Updated the ISS TLE in the AutoStar. Mounted the D850 DSLR at prime focus of the 12" telescope. Focused using the Moon. Checked the finderscope alignment and orientation. 1941 MST: all was in readiness for the ISS pass (start 2010 MST). I was concerned that the clouds would be a problem, but they were not.

I did a 6m44s video recording (2160p, 30 fps) at 1/1600sec, ISO 3200, while tracking the ISS. AutoStar tracking with manual corrections worked out pretty well. This was a brighter pass than on the previous session. The ISS was visible on the D850 DSLR Live View screen when at its brightest. As it turned out, the images this night were overexposed! Here are two images cropped from the video frames taken near mid-pass:


I hope to try again on the next good pass (22 May).

2022 MST: removed the camera. Viewed Jupiter, 102X. Four moons visible. Then began closing up due to the clouds.

2023 MST: LX600 OFF.

Close: Sunday, 20 May 2018, 2031 MST
Temperature: 72°F
Session Length: 1h 29m
Conditions: Partly cloudy

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