A most enigmatic phenomenon known as 'black drop effect' is known from the planet Venus transitions in front of the Sun. It is seen when a dark patch appears to connect Venus with the dark sky past the edge of the Sun, sometimes giving Venus a teardrop shape. The leading theory suggests that under exceptional seeing conditions combined with very good optics the effect may not be visible at all. But how all these relate to this image? Look closely to the front of the plane. A distinct black drop effect is visible where the nose of the aircraft approaches the edge of the Moon. In this case, it is more obvious than the typical Sun - Venus black drop effect. Apparently, the effect can be observed and recorded with any transiting object in front of the Sun or the Moon. But why this one is so distinct? Perhaps the speed of the passing object is also a factor. Role the mouse over the picture to see a close up. Alternatively, click here.
Canon EOS DIGITAL REBEL XTi, Skywatcher ED 80, 7/6/2009 1:28, Shutter Speed 1/160, Aperture Value 7.5, ISO 100