Pluto Wins Planet Poll
18 Oct 2004
(Source: The Planetary Society)
Is Pluto a Planet? Our Survey Says Yes!
It has been several months since we asked you to voice your opinion on the future of the solar system. Is Pluto a planet, we asked, or just one of many big rocks orbiting the Sun? And - depending on your answer - how many planets are there in the Solar System anyway?
The results are now in from the 1659 of you who took part in our survey, and we can confidently report that among our readers at least, Pluto's planetary status is secure. Nevertheless, before we get to the exact answers you gave to our questions, here is a brief reminder of what was at stake.
It all used to be so simple: since the discovery of Pluto by Clyde Tombaugh in 1930, the Solar System has had 9 planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. Then, in the past 15 years, astronomers have learned that Pluto is not the lonely planet it was thought to be. Pluto, it became clear, is merely the largest member of a whole class of objects orbiting in the outer Solar System, known collectively as Kuiper Belt Objects, or KBO's. Then, in the past two years, even that distinction of Pluto was cast into doubt; Quaoar, discovered in 2002 orbiting in the Kuiper belt is around 1250 kilometers across, compared to Pluto's 2300 kilometers. 2004DW, discovered in January 2004 might be as large as 1400 kilometers in diameter, and Sedna, the most recently discovered giant is estimated at 1800 kilometers. The day may not be far when objects fully the size of Pluto or even larger may be discovered in the outer edge of the Solar System.
Since Pluto is no longer a solitary planet but member of a substantial class of similar objects, this raises the question: Is Pluto a Planet? If it is, should Sedna, Quaoar, and 2004DW be designated planets as well? Or, perhaps, Pluto should not be considered a planet at all but a mere KBO, and the Solar System should be reduced to 8 planets?
Since Scientists themselves are at odds on this question, we decided to ask you. 1659 of you responded, and here is the final tally:
Question: What is A Planet?
Answer A: Pluto is a Planet, but Sedna is not
Answer B: Neither Sedna nor Pluto are Planets
Answer C: Pluto, Sedna, and other large Solar System objects are all planets
The 927 respondents who chose answers A or C make up 56% of the the respondents who think Pluto should emain a planet. 44% -- those who chose answer B --would prefer to see Pluto downgraded to a KBO. Only 24% of the respondents -- those who chose answer C -- consider any large Solar System object a planet. An overwhelming majority of 76% - those who chose answers A or B - think that the designation should be reserved for special cases.
Overall, a majority of our respondents want to keep Pluto a planet, but a substantial minority have their doubts. And so, if it was up to you, Pluto would be safe for the moment. But if many more similar objects such as Quaoar and Sedna would be discovered, it seems that opinions about Pluto may shift as well. We promise to keep you posted.