Mary "Shelley was staying with her future husband, Percy Shelley, at the Villa Diodati in Switzerland in June of 1816. Also present were Lord Byron and friends Claire Clairmont and John Polidori. Byron challenged all of them to try their hand at writing a ghost story.
Shelley saw the "bright and shining moon" through her window that night and wrote the story while she was in what she called "a waking dream.""
But "Shelley has long been doubted for her version of events that led to the writing of one of the most beloved Gothic tales in the English language."
Now "Donald Olson, an astronomy professor at Texas State University in San Marcos, told Reuters on Monday that the night sky would argue that she was telling the truth.
On that night, however, "we determined that a bright, gibbous moon would have cleared the hillside to shine right into Shelley's bedroom window just before 2 a.m. on June 16," Olson said."