Phaeton (hypothetical planet) Only in 1949 did the well-known Soviet astronomer Sergej Vladirimovich Orlov give it the name Phaeton... This name has become established." Theories regarding the formation of the asteroid belt from the destruction of a hypothetical fifth planet are today collectively referred to as the "disruption theory". This theory states that there was once a major planetary member of our solar system circulating in the present gap between Mars and Jupiter, which was variously destroyed when: Today, the Phaeton hypothesis has been superseded by the accretion model. Most astronomers today believe that the asteroids in the main belt are remnants of
Eleventh planet Eleventh planet Eleventh planet (of the Solar System) may refer to Vesta, the eleventh object to be named a planet, later to be reclassified as an asteroid; Uranus, the eleventh planet from the Sun upon Vesta's discovery, though this was quickly superseded by new discoveries; or Haumea, which would be the eleventh planet if the classification advocated by Alan Stern "et al." were adopted; or Makemake, which would be the eleventh planet in terms of distance from the Sun, as opposed to order of discovery. The eleventh planet in the early 19th century was Uranus by order of distance from