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The "Fornace di Montalbano" photo of the day NASA

The American space agency chooses the shot of a Sicilian astrophotographer to reveal the "double shadow" of the Earth


Once again NASA chooses a "Sicilian" image as the photo of the day. After the evocative passage from day to night, depicted as the petals of a flower composed of 16 shots by Dario Giannobile, it is the turn of Marcella Giulia Pace.

On July 27, 2018, the Sicilian astrophotographer immortalized the lunar eclipse on the Fornace Penna, a brick factory of 1909, an element of Sicilian industrial archeology, known above all for being one of the most evocative locations of the RAI series "Il Commissario Montalbano".

The American space agency recovered that splendid shot to challenge the observer to find the two shadows of the Earth hidden in the image.

It is the same astrophotographer, who has already seen her photos published by the space agency on other occasions, to explain to AGI the atmospheric optical phenomena ("photometeors"), contained in the image.

"That night, my goal was to tell a story of light, shadow, and color."

The first shadow of the Earth is the one projected on the atmosphere. The upper part of the atmosphere appears pink and the lower part blue. This is due to the fact that the upper part is exposed to direct sunlight, while the lower part is not. The darkest bluish band is concave and stretches over the atmosphere rising from the antisolar point just as the Sun sets behind the horizon.

The second shadow of the Earth is the one projected on the Moon: a portion of the lunar disk takes on a color similar to that created by the shadow of the Earth on the atmosphere. The color of the Moon "seems to recall the same colors as the Belt of Venus, although the red color assumed by the Moon is actually due to the scattering of light as it ascends through the dense lower band of the atmosphere."

But, in this photo with tones similar to a watercolor, there is another fascinating effect: it is the so-called 'Belt of Venus' or anti-twilight band, the thin band that separates the shadow of the Earth from its penumbra, with colors that turn from orange to pink.