The photo above shows what appears to be an impossibly large third quarter Moon sidling up to the approximately 2,500-year-old Temple of Poseidon in Sounion, Greece. Photographer: Chris Kotsiopoulos; Chris’ Web site
It was taken on March 15, 2012 at about 2:00 a.m. Like the Earth, one-half of the Moon is always illuminated by the Sun. At the first quarter and third quarter phases, we’re seeing about one half of the portion that’s sunlit and one half that’s in shadow. The huge apparent size of this particular Moon, or any phase of the Moon when it’s near the horizon, is due to the Moon illusion effect. However, it should be noted that the primary reason for the Moon’s extra large apparent size in this photo is the 600 mm focal length of the lens that was used.