💾 Archived View for koyu.space › mrael2_obsv › sessions › 2018 › 2018-03-20.gmi captured on 2023-09-28 at 16:17:49. Gemini links have been rewritten to link to archived content
⬅️ Previous capture (2022-06-03)
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Date: 2018-03-20
Time: 7:30 PM - 7:50 PM
Seeing: II - III
Transparency: 7
Object: Mercury
At last the elusive goal has been achieved. I saw a crescent phase on Mercury! The crescent appeared less than half lit but more than 25-30% lit. It showed as a clear crescent at 138x on the 254 mm reflector, which I allowed to cool for 90 minutes to avoid the poor seeing that existed the last time.
At 277x, the crescent was still visible, but the overall appearance was much more dim.
At 7:37 PM, seeing was at its best, but by 7:49 PM I found the planet again to be fringed in red and violet at opposite edges at 138x with windy conditions and the planet's closer proximity to the horizon contributing to poorer seeing and much less of a crescent shape.
At 8:05 PM as I write this, I see that Mercury is far less bright to the naked eye than it was just two days ago. It is becoming dimmer as it drops closer to the horizon each night. Tonight it is nearly exactly to the right of Venus, which appeared extraordinarily sharp in the properly cooled and collimated scope, but in subsequent days Mercury will dip more and more into twilight. If the weather permits, I will attempt to observe ever-increasing thinness to the crescent. A thin crescent on Mercury would be a tremendous sight to behind!