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
Wonders of the Solar System Wonders of the Solar System Wonders of the Solar System is a 2010 television series co-produced by the BBC and Science Channel, and hosted by physicist Brian Cox. "Wonders of the Solar System" was first broadcast in the United Kingdom on BBC Two on 7 March 2010. The series comprises five episodes, each of which focuses on an aspect of the Solar System and features a 'wonder' relevant to the theme. The series was described as one of the most successful to appear on BBC Two in recent years. An accompanying book with the same name was also published. On