The phrase "when the moon hatched" refers to a fantasy novel titled "When the Moon Hatched" by Sarah A. Parker, published in 2024. In this story, the title alludes to a mythic event within the book's lore where dragons, upon dying, sail skyward and curl into balls beyond gravity’s grip, becoming moons in the sky. These moons eventually fall, and the story weaves around the consequences of this event and the characters involved, including gods, dragons, and humans connected by magic and prophecy. The book's plot reveals that dragons become moons after they die, a unique fantasy element rather than a literal or scientific event. The protagonist Raeve is intertwined with this moon-hatching myth, with dragons solidifying in the sky as moons and then falling as part of the narrative's world-building and magic system. Thus, "when the moon hatched" is a metaphorical and fantasy concept tied to the creation and fate of moons as dead dragons in the novel's universe, not a historical or scientific event. If more detail about the story or the mythological concept from the book is desired, I can provide additional information from the story's plot and themes.