In the early 1900s, an American Astronomer by the name of Percival Lowell had discovered something unusual about the movement of planet Neptune. He predicted that there were some other heavenly body/bodies that is effecting the motion of the planet. Just as the way Neptune is acting on the motion of Uranus. He named that strange object as Planet X. Unfortunately, until his time of death in 1916; he didn’t find the mystery planet.  

            Before Lowell’s demise, he managed to leave instructions to Clyde Tombaugh on how to catch the new planet. After following the instruction for just one year, in 1930, Tombaugh had discovered the heavenly object that is affecting the motion of Neptune. He quickly announced this great discovery, thus a nine planet solar system was born.  

            Suggestions on the name of this new planet came from every part of the world. Tombaugh even asked the late Lowell’s widow to quickly suggest some names for it, but her suggestion was met with dismay of the astronomer’s union. It was until then somewhere in Oxford, England, an eleven years old girl, Venetia Phair, had suggested the name Pluto, the ancient Roman name for their God of the Underworld (The Greeks call him - Hades). She was an enthusiast of Roman and Greek mythology. The name was received with great interest. The name was accepted unanimously by the International Astronomer Union and announced in March 5, 1930. 

            The name was accepted because of the unique way it was spelt. The first two letters was P-L, the initials of Percival Lowell, the person that had influenced the discovery and the place where it was observed by Tombaugh, the Lowell Observatory. Then after World War II, problem started brewing for Pluto. 

             As space observing technology grew and the birth of the Hubble satellite, it had broadened up our view of the universe. In recent years, modern astronomers discovered more and more object at the tip of our solar system. One was discovered in 1989, was designated as Xena. It was bigger than the size of Pluto but still smaller then our moon. It was once been proclaimed as the tenth planet but then IAU was slow to acknowledge it as a planet as if Xena was accepted then we are going to have a 12 planet solar system in our hands! (More is coming!) This recent discoveries had put Pluto’s position as a planet in jeopardy.

        The name was accepted because of the unique way it was spelt. The first two letters was P-L, the initials of Percival Lowell, the person that had influenced the discovery and the place where it was observed by Tombaugh, the Lowell Observatory. Then after World War II, problem started brewing for Pluto.

            Why? This is mainly contributed to the increasing number of objects discovered near and beyond Pluto. Astronomers began to question the validity of Pluto as a planet. It was then the Astronomers realized that they had never had a clear definition of a planet. So, in early 2006, they set a few simple criteria of a planet. First, the candidate must be spherical. As any space object with the approximate radius size of 1000km, its own gravity will mold them into spherical shape. Since even our moon is also spherical the next criteria is that the candidate must orbits the sun and not other planets. Lastly, the candidate must dominate its own orbit, clearing it immediate regions of any smaller object. With all the above, lets us look at Pluto. 

            Firstly, Pluto has the radius of 1,400km, which passed the first criteria. Even thought, it has a moon that as big as it self called Charon (pronounced Sharon). Secondly, Pluto was orbiting the sun. Well it passed the second criteria no doubt. Then third criteria, it must dominate its own orbit. This third criteria was the sole characteristic which disqualify Pluto as a planet. Why?  

Pluto is orbiting among the Kuiper Belt. It is like the asteroid belt between Mars and Jupiter. The difference is that the region is beyond Neptune and objects discovered in the Kuiper Belt are also known as Trans-Neptunian Object (TNO). Up to recent date, there were 800 objects observed in the region. Gerard Kuiper (who suggested the existence of the region) speculated it could be the source of short period comets. That’s why some astronomer thinks that Pluto is actually a comet and not a planet. Some thinks that Pluto was just another enormous asteroid. Pluto’s unusual orbiting path also contributes to the notions. It is slanted up to 17º and eccentrically in shape rather than a bit circular like the other planets. That odd orbit resulted in Pluto venturing into Neptune’s orbit. Thus once in every cycle; Pluto is closer to the sun than Neptune.

            Thus by August 2006, in Prague, the IAU had voted to demote Pluto from a planet to a dwarf planet. This decision has disappointed Tombaugh’s widow, Patricia, saying that she is now had been demoted from a wife of a discoverer of a planet to a discoverer of a dwarf planet. Surprisingly, she not the only one feeling dejected. When Rose Center for Earth and Space (an American Natural Museum) opened in 2000, it was exhibiting an 8 planet solar system. This has cause the center to received angry letters mainly from children, protesting the vote by IAU. Children in America had been associating Pluto to Mickey Mouse’s dog, by the same name. It has saddens them in finding out that they can’t find it among the displayed exhibits.  

            Louis Friedman, executive director of Planetary Society, doesn’t think children wouldn’t mind to know that they now have one less planet to be memorized. “It wouldn’t upset the schoolchildren” he predicts. “It’s those of us who used to be schoolchildren.“

Source :

-          Wikipedia; Pluto, Kuiper Belt.

-         Newsweek; September 4th edition: ‘Of Cosmic Proposition’.

3 Comments

by faruqy @ 03 Oct 2006 10:13 am

thanks ezdwan.. really informative piece of writing..

by Zalan Zalfrecko @ 04 Oct 2006 11:02 pm

The subject of whether Pluto is a planet has been debated for ages. I expected it would swerve out of its orbit one day. But really, sad to say goodbye to it. Pernah tgk artist impression of life-forms in Pluto. cool giler

by Datuk D @ 13 Oct 2006 04:05 pm

cool.. very cool