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Occultation of Mars

Posted: 18 February 2020

Open: Tuesday, 18 February 2020, 0404 MST
Temperature: 45°F
Session: 1441
Conditions: Clear

12" f/8 LX600 w/StarLock
2" 24mm UWA eyepiece
2" 2X Powermate


The occulation of Mars by the waning crescent Moon would start while the Moon was behind the hill to the east (0430 MST). I expected that the Moon would appear in time for the reappearance of Mars (0538 MST).

0410 MST: LX600 ON, StarLock OFF, High Precision OFF.

Slewed to the star Antares and SYNCed the AutoStar.

Mounted the D850 DSLR at prime focus + 2X Powermate. Focused on Antares.

0421 MST: all was in readiness for the Moon to appear.

0430 MST: occultation began. Moon was behind the hill.

0443 MST: moon began rising over the hill.

0530 MST: Stella Wi-Fi ON.

Used SkySafari 6 Pro on the iPhone 11 Pro Max to GOTO Mars. I did this because I wanted the best possible pointing at the hidden Mars since I was using a high magnication.

0532 MST: Wi-Fi OFF.

I wanted to show Earthshine in my video so I set the exposure to 1/30sec, ISO 25600. I actually started the exposure a little early because I saw what appeared to be the planet reappearing. It was actually a star. I continued the video recording.

This segment of the video shows Mars (overexposed) reappearing from behind the Moon. (It may take a while for the video to load after clicking the image.)

Click or tap on image to view video

0547 MST: viewed Mars and Earthshine, 203X. Mars had a noticeably gibbous phase.

Then viewed the crescent Moon, Earthshine, and Mars, 102X. That was a pretty sight.

0553 MST: LX600 OFF.

Close: Tuesday, 18 February 2020, 0604 MST
Temperature: 46°F
Session Length: 2h 00m
Conditions: Clear

After I left the observatory I took these handheld photos (cropped) of the Moon and Mars with the D850 DSLR (f/6.3, 1/250sec, ISO 800, and 1/60sec, ISO 6400, respectively.


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