The Voynich Ninja

The moon under her feet could be a crescent, facing any direction, or a full moon.
One favorite of mine, although it is centuries later than the Voynich, is the one painted for the Pauline chapel of the Basilica of Sta Maria Maggiore, Rome, in 1612 by Cigoli, who was a friend of Galileo's. 

Depending on the sources, it is said that Cigoli either based his moon on Galileo's sketches, or that he actually used the telescope himself and drew from observation, as Galileo had apparently placed the telescope in the dome of the chapel for several months.
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Here's a link with lots of different interpretations.

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There are further links to other examples in heraldry, painting and sculpture.

If VMs Virgo has been combined with the Virgin Mary on the moon (Madonna on the crescent), what is the reason for this subtle construction?

At the moment I can't believe everything that Galileo says.

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All this has its roots in Revelation 12:

"And there appeared a great wonder in heaven; a woman clothed with the sun, and the moon under her feet, and upon her head a crown of twelve stars" etc

Many Russian Orthodox churches and cathedrals feature crescent at the foot of their crosses. Here's one in the Kremlin:

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The  Woman of the Apocalypse (etc.)

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