Who named the planets?

When you look up at the night sky, what do you see? Stars, moon, and maybe some shooting stars too, at times. Planets? If you look closely, you will be able to spot them. Ancient Romans and Greeks could see them with the naked eye and that’s how they named them. Yes, if you were wondering how the planets in our solar system have been named, the credit goes to the ancient Romans and Greeks. Let us go back to the history of their naming. 

Naming of the first five planets   
Thousands of years ago, ancient Romans could see five planets in the night sky. They would map their movements and even notice that each planet had different characteristics. To make it easier for them to continue the discourse on these planets, they were name. Interestingly, the names were inspired by Roman gods and goddesses.  

The first planets to be spotted were Jupiter, Saturn, Mars, Venus and Mercury. Mercury, the closest planet to the sun, was named after the Roman god of travel. Why was that? Because they realised it had the shortest revolution and this planet appeared to move faster than the others. Similarly, Venus was named after the Roman goddess of love and beauty, being the brightest in the sky. Mars was christened after the Roman god of War because because it’s red in colour . No wonder, it’s also called the Red Planet! Jupiter being the largest planet in the solar system was named after the king of the Roman gods, and the ringed planet Saturn was named after Jupiter’s father, the god of agriculture. 

The naming of other planets  
These names survived. And so did the practice of naming celestial objects after mythological stories. In fact, when British astronomer William Herschel discovered Uranus in 1781 using a telescope for the first time in a planet’s discovery, he wanted to name it after the English king, George III but wasn’t successful. German astronomer Johann Bode recommended the name Uranus, a Latinised version of the Greek god of the sky, Ouranos, the father of Saturn. This was accepted as it was in sync with the naming ritual.  

Decades later in 1846, German astronomer Johann Galle discovered the eighth planet, the first time using mathematical calculations and predictions made by astronomer Urbain Le Verrier, and wanted to name it after Le Verrier. Again, seeing the new planet’s blue tint, astronomers named it Neptune after the Roman god of the sea, as suggested by Le Verrier. 

Accordingly, Pluto, the dwarf planet, which was thought to be the ninth planet at that time, was named after the Roman god of the underworld, being the farthest from the sun.  

What about Earth, our own planet? Surprisingly, it was only Earth,. The name was an English/German word simply meaning ‘ground’. Pretty fitting though, right?  

Who names the celestial objects now?  
So does any of the newer discoveries in the sky still receives the same treatment? Who gets to name the planets or any other celestial bodies now? That job is now done by the International Astronomical Union (IAU) which is in existence since 1919. Because it is a general belief that all planets have already been discovered in our solar system, IAU is now primarily left with the task of naming newly found moons, comets, asteroids and surface features. However, this kind of body was badly needed which would decide on a naming system. It generally follows some set rules and guidelines for the naming.  

Mostly, IAU still takes help from mythology for naming new heavenly objects. For example, the moons of Jupiter got their names after the characters in the stories of Zeus, Jupiter’s Greek counterpart. Similarly, the moons of Pluto take their names from other characters in the mythological underworld. However, the moons of Uranus were treated differently and are a special case where they are named after literary characters (such as from works by William Shakespeare and Alexander Pope). 

However, the natural satellites of the planets, which are newly discovered, are first assigned a temporary name till their existence is thoroughly confirmed after additional and more detailed scientific research. The temporary name usually consists of the year of discovery and some number that indicates the order of discovery in that year. For example, when the spacecraft Voyager 2 found a bunch of new moons in its 1989 Neptune encounter, they were first given the temporary names S/1989 N 1, S/1989 N 2, etc.  

For comets, the earliest system involved naming them after the year in which they were observed (e.g. the Great Comet of 1680). Later, they started being named after the discoverer (e.g. Comet Hale–Bopp or Halley's Comet). When the technological improvements led to a massive increase in the number of comet discoveries during the twentieth century, a numeric designation scheme was adopted. Currently, comets are provisionally designated by the year of their discovery followed by a letter indicating the half-month of the discovery and a number indicating the order of discovery. For example, the fourth comet discovered in the second half of February 2006 was designated 2006 D4. 

Similarly, the first discovered asteroids were again named from mythology, such as Ceres, Juno, Pallas and Vesta. But now, IAU allows the discoverers to propose the name following some guidelines such as they must be inoffensive and not connected with the recent political or military activity or to any businesses or pets. It should not be too long and should be pronounceable.