Does anyone know about this phenomenon? My friend Benson Farb, under the charming misimpression that I am some sort of astronomer, sent me the following image, taken by his uncle Henry Farkas, MD.
That's the Moon on the right, somewhat overexposed. On the left is another image of the Moon -- substantially dimmer. So what is going on?
Consulting the Google, I was able to find multiple examples of similar phenomena, but no explicit explanation: see here, here, here, here, here, here. My first guess was that we were glimpsing a giant Death Star that had been hiding behind the Moon, but upon further thought I regretfully concluded that it's unlikely we would have alien invaders clever enough to build a Death Star but sloppy enough to reveal it prematurely like that.
Actually there is only one sensible explanation: some sort of lensing/reflection phenomenon that is giving rise to multiple ...
