The “planet” Pluto was discovered by scientist in 1930. Even then, there was controversy over whether this little ball of ice should be considered a planet. It was decided it should, mainly because since the gravity of the eighth planet, Neptune, was found because it was tugging on the seventh planet, Uranus, and then Pluto was found when its gravity tugged on the orbit of Neptune. Pluto was just a continuation in the time-tested practice of discovering the existence of planets from the behavior of other objects in space.
However, people have proved many various reasons why this should not be enough to keep considering Pluto the ninth planet in out solar system. After researching these reasons extensively, I have decided that really, Pluto should not be considered a planet. Here are some reasons why I think what I do. Look at the composition of the first eight planets compared to Pluto. The first four planets, Mercury, Venus, Earth, and Mars, are rocky in composition, and the next four, Jupiter, Saturn, Uranus, and Neptune, are gas planets. Pluto fits in with neither of these categories, rocky or gassy.
Pluto is made up mostly of ice and rock, but not enough rock of count as a rocky planet, plus all the rocky planets are near the sun. Pluto is the farthest “planet” from the sun of the current nine known planets. In fact, less than 1/3 of Pluto is rock. It really just is this tiny little ice ball floating out in the depths of space. If there were other planets made primarily of ice too, maybe Pluto would fit in more, but as far as we know it is the only planet made of mainly ice, which just doesn’t fit in with the other planets.
So one reason not to consider Pluto a planet is; the different composition of the planet from all the other planets. Another main reason not to consider Pluto a planet is the size of the planet. Pluto is ridiculously small. It has a diameter of only 1,440 miles. That is 1/6 of the Earths, or less than half of Mercury’s diameter, and those are two of the smaller planets already. Seven moons in the solar system are even larger than this little ice ball of a planet. Many of the comets that lie in the Oort Cloud, a ring of billions of comets that lies far beyond Pluto, are larger than the planet itself.
Many scientists just think it should be classified as a large asteroid, or the largest of the Kuiper Belt objects. Another option, thought of by scientist Brian Marsden, is classifying Pluto as a “minor planet” like asteroids and comets, and giving it a number, or just lumping it with some other new class of objects. Anyway, one reason to take into account about why Pluto should not be considered a planet any more is the extreme size difference between Pluto and the other planets. If Pluto is to be called a planet, then certain actions of the past must be taken into consideration.
In 1801, a rocky body similar to Pluto was discovered between Jupiter and Mars, and was proclaimed a planet and named Ceres. However, a year later Ceres had its planethood revoked because it was evident that it really was just the largest member of what is now called the asteroid belt. Either we can do the same thing to Pluto that was done to Ceres all those years ago, or if we keep Pluto as a planet, we should really be fair and reinstate Ceres as a planet, because why should one planet get special treatment all these years later?
Honestly, stripping Pluto of its title as a planet would not be easy. Chances are there would be some sort of vote or major conference or something to have lots of people decide if it is a good idea. Also, Pluto has been considered a planet since 1930. Thousands of textbooks and scientific posters and documents have been printed saying, hey, Pluto is the ninth planet. Some of those posters and books have been sitting in schools for ages and ages.
People would have to go to a lot of trouble to reprint posters giving the new, “correct” information, or textbooks that could talk about how there USED to be nine planets, and why now there are only eight. It would be work, but life is work. If we have to get out there and redo things with newer, more correct information, than it should be done. It wouldn’t be a waste if it was being done to help people learn the correct facts about the solar system. In short, I don’t feel Pluto should be considered a planet any longer.
It is ridiculously smaller than all other planets, it is made of rock and ice while the other planets are either gas giants or all rock, and it really just fits in better as a minor planet or some type of large asteroid or comet. If you just look straight at the facts about Pluto compared to those of the main eight planets, it just doesn’t fit in. It would be a lot of work to take away Pluto’s title now, but if it means people in generations to come will be learning the correct information about the world around them, it is so worth it.