At the moment, Planet 9 still a theory. It won’t be named until scientists can confirm its existence with pictures.
If and when that happens, it will be up to the members of the International Astronomical Union to decide what we call it.
The IAU not only names objects in orbit — like moons and exo-planets — it also names features on those objects, like craters and volcanoes.
“We like to be consistent,” said Rosaly Lopes, a senior research scientist at NASA’s Jet Propulsion Laboratory and a member of the IAU’s Working Group for Planetary System Nomenclature.
“We wouldn’t like to name a new planet Donald Duck or whatever even though that might be quite fun,” she laughed.
For a planet in our solar system, being consistent means sticking to the theme of giving them names from Greek and Roman mythology. But Lopes added that the precedent could be broken if there is a good, serious reason to do so.
She said that a planet can’t be given a name already used by an asteroid. If it is named for a historical person, that person must have been dead for at least a few years.
In the past, the IAU has accepted naming suggestions from the general public but ultimately the organization will choose an internal committee to make the final call.
Still Lopes said if a new planet is added to our solar system’s roster, it would be so unexpected that past protocol might be abandoned.
Jean-Luc Margot, an astronomer and UCLA professor, says if the new planet is real we should keep calling it Planet 9.
"I just love the name… I think it's perfect!" he said.
Who named the planets in our solar system?
Five of the planets have been observable for much of human history, according to the Cornell University-based blog "Ask an Astronomer."
That means there are many names for the planets in many languages. According to one website that's compiled some of them, Jupiter is, for instance, Mushtarie in Arabic, Mokusei in Japanese, Ka'aawela in Hawaiian, Guru in Gujarati.
But it was the Roman names that stuck for scientific purposes, and it is these names that are recognized by the IAU.
The Romans named the visible planets based on their movements and appearance. Venus, which appears the brightest, was named for the goddess of love and beauty. Blood-red Mars was named for the god of war.
Uranus and Neptune went by several names before their mythological equivalents became standard.
Here's the list of current planets and what their names mean.- Mercury: The Roman god of trading and thieving and the messenger of the other gods. The Greek equivalent would be Hermes.
- Venus: The Roman goddess of love. The Greek equivalent would be Aphrodite.
- Mars: The Roman god of war. The Greek equivalent would be Ares.
- Jupiter: The chief of Roman gods, originally a god of the sky associated with thunder and lightning. The Greek equivalent would be Zeus.
- Saturn: An ancient Roman god of agriculture. The Greek equivalent would be Cronus.
- Uranus: The Greek's most ancient god and the first ruler of the universe. Discovered in 1781 by William Herschel.
- Neptune: The Roman god of the sea. The Greek equivalent would be Poseidon. Discovered in 1846 by Johann Galle.
- Pluto: The Roman god of the underworld. The Greek equivalent would be Hades. Pluto was discovered in 1930 by Clyde Tombaugh, who was working at Lowell Observatory in Arizona. But, alas, Pluto was later reclassified as a dwarf planet.
Planet 9
So what should the name of the new ninth planet be, if (or when) it's discovered?