Half the planets in this solar system have planetary rings.

org, but must remain in firm negation of his resolution, as it is mathematically and scientifically incorrect. Though there are 4 standard planets and 4 giant planets recognized by the International Astronomical Union, as well as 5 dwarf planets: Pluto, Ceres, Haumea, MakeMake, & Eris. Essentially, the IAU has chosen to define these planets as having their own elliptical orbit around the sun. However, these bodies are significantly smaller than the other 8 recognized planets. Pluto, which is only the second largest dwarf planet in our solar system (being 27% smaller than Eris), is approximately half the diameter of Mercury, the first standard planet. . http://www.nineplanets.org... . http://www.nineplanets.org... In this case, leading astronomers (including a large group of senior space scientists from NASA) will tell you that size, in fact, does not matter. The orbit makes the difference, and leading scientists object to the IAU's new categorizations as there is no scientific basis for differentiating smaller planets as non-planets. As Dr. David Morrison puts it: "Astronomers use adjectives such as giant and dwarf to describe different subclasses of objects like planets, stars and galaxies, so why could Pluto not remain as a dwarf planet just as Jupiter is a giant planet…Also, around 90 per cent of the planets we know now are outside our solar system, but under the International Astronomical Union's definition, they cannot be classed as planets. " . http://www.telegraph.co.uk... The IAU's unilateral and illogical decision to discriminate on planets via a size-ist paradigm is scientifically unnecessary. Though it is true that Pluto, like the other 4 classified dwarf planets, have not managed to entirely clear their orbital neighborhoods, even the IAU cannot bring itself to declassify Pluto entirely—it is still called a planet. For some inexplicable reason, though, it cannot be a planet in our solar system. Hence, since the IAU has named these planets dwarf planets, it only makes logical sense that they be classified as planets of the solar system. With these inclusions, the number of planets in the solar system would be increased to 13. Hence, 4/13 of our planets have visible rings, which is closer to 1/3 than ï¿½. And, if the above is not sufficient reason to negate, consider that all planets of our solar system, including the terrestrial planets, have ring systems. Visibility and stability are preserved by the giant planet's gravitational forces, but the foundational forces necessary to collect particles around a planet are shared by all. Also, thinner gas and solid object rings are still present, but not thick enough to be readily visible. My opponent never specifies visibility or stability to be a necessity, however. Hence, another appropriate mathematical answer to his resolution is that 13/13 planets have rings, which is clearly not ï¿½. Even if you don't think that the dwarf planets have the gravitational pull to possess the potential to form rings or to have invisible rings (though the IAU's definition of a dwarf planet would contradict you), that's still 8/13. . http://curious.astro.cornell.edu... The resolution is negated.