June 6, 2011

Where Has the Earthshine Gone?

image by Peter Rosén, Stockholm, Sweden

The LPOD of May 22 about "Our daily moon" really touched me and many others as we reconized a strong and life-long "daily desire to connect to the Moon". Before setting off to work, I first have to locate the moon in the morning sky. In the evening I just have to watch the moon shining above the city or setting in the evening twighlight before going to bed. So I did yesterday shortly before midnight when I captured a beautiful crescent moon setting behind the rooftops of Stockholm. What puzzles me is that there is absolutely no visible earthshine in my pictures; even when stretching the contrast... nothing! At this phase it's usually very prominent as in my image LPOD image of March 10 2011. Other photographs taken from other places the day before show a strong earthshine even through the high clouds. I thought that the explanation for earthshine was quite straightforward but now I wonder what other factors are involved other than the relative position of the Sun, Moon and Earth with its reflective cloud layers?

Peter Rosén

Technical Details
June 4 2011 at 23h18m local time or 21h18m UT. Canon Eos5D MkII with a 70-200/2.8 zoom and a 2x extender. 1/8 sec at f/8 and 800Iso.

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