I would like to know how the...

Most of the planets were discovered in ancient times, and most cultures named them after their gods. The Romans followed this practice, and because the Roman Empire dominated so much of the Western world, their names for the known planets were accepted as the norm. By the 18th century, when Uranus was discovered, the precursor of what is now the International Astronomical Union (IAU) decreed that the names of all heavenly bodies, those already discovered and those yet to be, must be approved by the group. The members agreed that the known planets would retain their original Roman names and that any future discoveries must follow suit. The discoverers would be allowed to make recommendations, but the international committee would have the final say. William Herschel, the discoverer of Uranus, wanted to name it Georgius after Britain’s king, but he was overruled. The name Uranus, grandfather of the god Jupiter, was chosen instead. In the 19th century, the IAU approved the name Neptune, and in the 20th century, it approved Pluto. By the way, the first two letters of Pluto are the initials of Percival Lowell, the astronomer who searched for a ninth planet for many years and after whom the Lowell Observatory is named. The discoverer of Pluto, Clyde Tombaugh, worked for the observatory.