Figures of Cynthia

  • William Sheehan


Galileo completed his first series of lunar observations – those recorded in the ink wash drawings – on December 18. By then he had also worked out the correct explanation of the phenomenon of earthshine – the dull-red glowing of the dark side of the young Moon.1 He saw at once that earthshine was an illumination of the night-side of the Moon by sunlight reflected from the Earth. “The earth,” he wrote, “in fair and grateful exchange, pays back to the moon an illumination similar to that which it receives from her throughout nearly all the darkest gloom of night.” Having previously shown that the Moon – with its mountains and valleys – was another Earth, he could now demonstrate that the Earth was another planet, reflecting the sunlight from its continents and oceans onto the surface of the Moon.


Paradise Lost Medicean Star Ptolemaic System Lunar Observation Paul Versus 
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Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  1. 1.WillmarUSA

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