Planet Nine

This page is about Planet Nine. You may be looking for Nibiru, Tyche, or the Fifth Giant .

Planet Nine
An Artist Impression
Discovery
Discovered By	Nobody (Existence hasn't been confirmed)
Discovery Data	Yet to be discovered
Orbital Characteristics
Apoapsis	~560 AU
Periapsis	~340 AU
Semi-major Axis	~460 AU
Eccentricity	~0.2 – 0.5
Orbital Period (sidereal)	~9,900 Years
Inclination	16°
Satellites	???
Physical Characteristics
Dimensions	~40,000 Km
Mean Radius	~20,000 Km
Circumference (meridional)	~125,663.7 Km
Surface Area (total)	~1,256,637,061 Km2
Mass	6.3 Earth Masses
Surface Gravity (mean)	~0.6402 G
Apparent Magnitude	~21

The orbit of 2015 KG₁₆₃ (right side, in orange) and other extreme detached objects, along with the hypothetical Planet Nine's orbit on the right

Planet Nine, also known as Persephone, is a hypothetical planet hypothesized to exist in the outermost edges of the Solar System, possibly in the Oort Cloud. It is thought to be about 39,000 kilometers in diameter, probably larger than Earth but smaller than Neptune. It is composed of the same materials as the ice giants, like hydrogen, helium, methane, water, and ammonia. It is also likely to have a simple ring system similar to that of Neptune's. Because of its distance from the Sun, it is hypothesized that a year on Planet Nine would take around 20,000 years

Origins

It is still unclear how Planet Nine could have gotten into the outer Solar System. Numerous theories declare that it was ejected from the Solar System long ago.

Many theories suggest that Planet Nine could have been ejected into the Oort Cloud during the rapid migration of Neptune and the ejection of the Fifth Giant, while others suggest that Planet Nine could be a rogue exoplanet that was captured by the Sun in the past.

Evidence

Recently, scientists observed clustering of objects beyond Neptune's orbit, and that something large was affecting their stability.

This led to the theory of a ninth planet existing in the outermost edges of the Kuiper Belt, but no such planet was found.

Later, scientists theorized that Planet Nine could be a black hole, but this theory is not widely accepted.

Moons

According to Tim, Planet Nine might be host to up to 3 moons, each up to 62 miles (100 kilometers) across. If it does have those moons, they might be the key to revealing Planet Nine's presence in the Kuiper Belt, and the secret is tides.

Name

Planet Nine has no Official Name, and thus wouldn't receive one until its Existence has been proven. Via Imaging and such. if is confirmed to Exist, the IAU will certify a Name, with the Priority being given to a Name proposed by its Discoverers. it is very likely that Planet Nine would receive a Name hailing from Roman or Greek Mythology.

Originally, Batygin and Brown referred Planet Nine as "Perturber". though, this name would slowly be ruled away when they started using the Planet Nine Name. a few proposed names were made, such as "Jehoshaphat" or "George". the latter is a reference to William Herschel's Proposed name for the Seventh Planet in the Solar System, Uranus. another name, "Phattie", was also proposed, but would never be used too often.

Batygin had also suggested that the Planet should be named after David Bowie, and any of the Proposed Moons of Planet Nine would likely be named after Characters from David Bowie's Song Catalog.

Persephone was also another Proposed name for Planet Nine, as it was a popular name used in Sci-fi for Planets sitting Beyond Neptune. however, it is unlikely that Planet Nine would receive the name "Persephone", as thats already the name of 399 Persephone. a Main-belt Asteroid. another Name, "Telisto", was proposed by Lorenzo Lorio. the said Name comes from the Greek Word, "τήλιστος", or "Farthest" or "Most Remote".

Gallery

Planet Nine in Real Life (Planet Nine is too far from the Sun to reflect light)

Hypothetical Bodies in the Solar System
Hypothetical Planets	Inner Solar System	Vulcan • Counter-Earth • Nibiru • Theia • Phaeton • Enyo and Bellona • Krypton
	Outer Solar System	Fifth Giant • Unnamed ancient Super-earth • Triton’s Binary Partner • Planet 9 • Planet 10 • Tyche • Nemesis
Hypothetical Moons	Inner Solar System	Disproven Moons of Mercury • Neith • Petit's moon • Waltemath's moons • Moons of Pallas • Moon of Hebe
	Outer Solar System	Chiron • Chrysalis • Themis • Sedna I • Varuna I • Herschel's Moons
Other Hypothetical Objects	Hypothetical Regions	Vulcanoid Belt • Hills Cloud • Oort Cloud
Hypotheses for Explanation of Occurrences	Hypotheses	Giant impact hypothesis • Himalia Crash Theory