Fifth planet (hypothetical) Fifth planet (hypothetical) In the history of astronomy, a handful of Solar System bodies have been counted as the fifth planet from the Sun. Under the present definition of a planet, Jupiter is counted as the fifth. There are three main ideas regarding hypothetical planets between Mars and Jupiter. During the early 19th century, as asteroids were discovered, they were considered planets. Jupiter became the sixth planet with the discovery of Ceres in 1801. Soon, three more asteroids, Pallas (1802), Juno (1804), and Vesta (1807) were discovered. They were counted as separate planets, despite the fact that they shared an
The Naked Sun The Naked Sun The Naked Sun is a science fiction novel by American writer Isaac Asimov, the second in his "Robot" series. Like its predecessor, "The Caves of Steel", this is a whodunit story. The book was first published in 1957 after being serialized in "Astounding Science Fiction" between October and December 1956. The story arises from the murder of Rikaine Delmarre, a prominent "fetologist" (fetal scientist), responsible for the operation of the planetary birthing center of Solaria, a planet politically hostile to Earth, whose death Elijah Baley is called to investigate, at the request of the Solarian government. He