Explanation:

All too often critical astronomical observations are spoiled by untimely clouds. That happened on April 8 in south Florida when John Biondo was trying to image the partial (40%) eclipse of the Sun. Not having a solar filter he was happy to use the clouds as a filter, capturing this evocative image. But it gives more than an emotional sense of the eclipse experience, it also challenges us to understand what we are seeing. Part of the Moon is blocking the Sun, taking the characteristic bite from it. Most of the time when we see images like this they are taken through solar filters so that only the Sun is visible - Moon and sky are black. But with this cloud filter we strongly get the impression that the entire sphere of the New Moon is visible. Its continuing shadowed curvature is strongly suggested along the top of its arc. Can the entire Moon be seen during partially cloudy eclipses? Is the apparent continuation of the Moon actually its shadow that is falling on the clouds? I am not sure I believe that, but I am impressed by the nearly circular dark patch. Does anyone have an explanation? Shadow of the Moon or a quirk of lighting and clouds augmented by our minds quest for patterns?

— Chuck Wood

Technical Details:
Nikon D70, 600mm Vemar Lens, f/8 stopped down to 22, 1/64000 Sec.

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