Fifth planet (hypothetical) orbit as defined by the Titius–Bode law. Between 1845 and 1851, eleven additional asteroids were discovered and Jupiter had become the twentieth planet. At this point, astronomers began to classify asteroids as minor planets. Following the reclassification of the asteroids in their own group, Jupiter became the fifth planet once again. With the redefinition of the term "planet" in 2006, Ceres is now considered a dwarf planet. The disruption theory suggests that a planet which was positioned between Mars and Jupiter was destroyed, resulting in the asteroid belt between these planets. Scientists in the 20th century dubbed this hypothetical planet
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