Avatar (2009 film) themselves to change into a Na'vi. "Avatar: A Confidential Report on the Biological and Social History of Pandora", a 224-page book in the form of a field guide to the film's fictional setting of the planet of Pandora, was released by Harper Entertainment on , 2009. It is presented as a compilation of data collected by the humans about Pandora and the life on it, written by Maria Wilhelm and Dirk Mathison. HarperFestival also released Wilhelm's 48-page "James Cameron's Avatar: The Reusable Scrapbook" for children. "The Art of Avatar" was released on , 2009, by Abrams Books. The book features
Exploration of the Moon astronomer Giovanni Battista Riccioli, who gave the large naked-eye spots the names of seas and the telescopic spots (now called craters) the name of philosophers and astronomers. In 1753 the Croatian Jesuit and astronomer Roger Joseph Boscovich discovered the absence of atmosphere on the Moon. In 1824 Franz von Gruithuisen explained the formation of craters as a result of meteorite strikes. The possibility that the Moon contains vegetation and is inhabited by selenites was seriously considered by major astronomers even into the first decades of the 19th century. In 1834–1836, Wilhelm Beer and Johann Heinrich Mädler published their four-volume and