Following the discovery of the planet Neptune in 1846, there was considerable speculation that another planet might exist beyond its orbit. The search began...

fiction Neptunium Neptune, the Mystic – one of the seven movements in Gustav Holst's Planets suite Timeline of the far future Stats of planets in the Solar...

science fiction to refer to hypothetical planets beyond Neptune and Pluto (such as Planet X and even Planet Nine, theorized in 2016). Martin Nilsson (1967)...

related to this prediction." Planets beyond Neptune Hypothetical planets of the Solar System Tyche (hypothetical planet) Nemesis (hypothetical star) As...

up Planet Nine or Planet 9 in Wiktionary, the free dictionary. Ninth planet is a concept related to planets beyond Neptune. Ninth planet or Planet Nine...

and expected orbits of Uranus and Neptune suggested that there were one or more additional planets beyond Neptune. The search for these led to the discovery...

protostar orbited by a protoplanetary disk. There are eight planets within the Solar System; planets outside of the solar system are also known as exoplanets...

definition of planet Planet § History Planets beyond Neptune This disambiguation page lists articles associated with the title Twelfth planet. If an internal...

extraterrestrials from a planet beyond Neptune called Nibiru. He asserted that Sumerian mythology suggests that this hypothetical planet of Nibiru is in an...

Tenth planet is a term formerly applied to possible planets beyond Neptune, before the reclassification of Pluto. It may also refer to: 2060 Chiron, claimed...

orbits of the planets to the extent that their effects would be easily observable today. Astronomers have hypothesized many planets beyond Neptune, and though...

still be seen as an exhibit. Planets beyond Neptune Planet Nine Vulcan Hubbell, J. G.; Smith, R. W. (November 1992). "Neptune in America – Negotiating a...

incorporated Uranus, Neptune, Pluto (also referred to as "outer planets") into its methodology. The outer modern planets Uranus, Neptune and Pluto are often...

four such planets in the Solar System: Jupiter, Saturn, Uranus, and Neptune. Many extrasolar giant planets have been identified. Giant planets are sometimes...

asteroid belt, based on computer simulations. Various planets beyond Neptune: Planet Nine, a planet proposed to explain apparent alignments in the orbits...

a 2001 non-fiction book by David E. Hoffman Oligarch planet, hypothetical planets beyond Neptune Old Oligarch, author of a "Constitution of the Athenians"...

unclear causes. Orbiting bodies and rotation: Are there any non-dwarf planets beyond Neptune? Why do extreme trans-Neptunian objects have elongated orbits? The...

Saturn); and two ice giants (Uranus and Neptune). All terrestrial planets have solid surfaces. Inversely, all giant planets do not have a definite surface, as...

a popular one in fiction. Disrupted planet Hypothetical planetary object Planet § History Planets beyond Neptune Trans-Neptunian object Trans-Neptunian...

trans-Neptunian objects Extreme trans-Neptunian object Planets beyond Neptune 60 minor planets with a semi-major axis greater than 150 AU and perihelion...

Fictional planets of the Solar System have been depicted since the 1700s—often but not always corresponding to hypothetical planets that have at one point...

asteroid Fictional planets of the Solar System Hypothetical moon of Mercury Nemesis (hypothetical star) Planet Nine Planets beyond Neptune John H. Tice, weather...

Heliocentrism – Historical models of the Solar System Planets beyond Neptune List of former planets List of hypothetical Solar System objects in astronomy...

has eight planets by the most restrictive definition of the term: the terrestrial planets Mercury, Venus, Earth, and Mars, and the giant planets Jupiter...

The planet Neptune has 16 known moons, which are named for minor water deities and a water creature in Greek mythology. By far the largest of them is Triton...

Moon) or one of the modern planets. The symbols were also used in alchemy to represent the metals associated with the planets, and in calendars for their...

Kelvin–Helmholtz heating Nemesis (hypothetical star) Planet Nine Planets beyond Neptune Vulcan (hypothetical planet) A cold hydrogen-rich gas giant slightly more...

Around a Loaded Sputnik Planitia Basin, Pluto". Journal of Geophysical Research: Planets. 126. Bibcode:2021JGRE..12606964M. doi:10.1029/2021JE006964....

agree that Planet X, as Lowell defined it, does not exist, as of January 2016 there is speculation concerning Planet Nine. Planets beyond Neptune Obituary...

formed via co-accretion, similar to the process believed to have formed the planets in the Solar System. As the young gas giants formed, they were surrounded...