Fifth planet (hypothetical) into the Sun. Unlike the Disruption Theory's fifth planet, "Planet V" is not credited with creating the asteroid belt. The concept of a fifth planet which had been destroyed to make the asteroid belt, as in the Disruption Theory, has been a popular one in fiction. 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,
Sun Dutch "zon", Old High German "sunna", modern German "Sonne", Old Norse "sunna", and Gothic "sunnō". All Germanic terms for the Sun stem from Proto-Germanic *"sunnōn". The Latin name for the Sun, "Sol", is used at times as another name for the Sun, but is not commonly used in everyday English. "Sol" is also used by planetary astronomers to refer to the duration of a solar day on another planet, such as Mars. The related word "solar" is the usual adjectival term used for the Sun, in terms such as solar day, solar eclipse, and Solar System. A mean Earth solar