Moon rising over the Temple of Poseidon

A glorious full Moon on the rise, looking like the Sun, as viewed from the Temple of Poseidon at Sounio, Greece.   Photographer: Chris Kotsiopoulos; Chris’ Web site

Summary Author: Chris Kotsiopoulos; Jim Foster

I was positioned approximately 1.25 mi (2,000 m) to the southwest of the Temple as this golden Moon eased above the eastern horizon. A close inspection along the top edge of the Moon reveals a tinge of green. At moonrise, and more frequently at sunset, a sharp-eyed observer can sometimes detect a ray of pure green light atop the lunar rim — magnification is usually needed. Green flashes and or rims occur as a result of vertical dispersion in the atmosphere. The amount of atmospheric refraction is wavelength dependent, so the blue image of the rising Moon is slightly higher than the green and red images. Each is just one arc minute displaced from a non-dispersed image. As the Moon rises (or Sun sets), the green image briefly comes into view before giving way to the red image. Of course, green flashes can be seen at sunrise or moonset as well. Photo taken on April 28, 2010 at 8:39 p.m.

Summary Author: Chris Kotsiopoulos; Jim Foster

source EPOD