case study pluto

Is Pluto a planet?

Recently their has been some argument and discussion on whether Pluto fits the description of a planet due to it size, scientist have been saying if Pluto is a planet then many other orbital pieces of ice and rock may have to be called planets as well, in this study I will observe arguments for and against Pluto being called a planet, the true definition of a planet and come to my own conclusion on whether Pluto is a planet or not.

First of all the true definition of a planet is that the planet must orbit the sun, and have sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and has cleared the neighbourhood around its orbit. Another description of a planet is According to the new definition; a full-fledged planet is an object that orbits the sun and is large enough to have become round due to the force of its own gravity. In addition, a planet has to dominate the neighbourhood around its orbit.

There are many points of view from both sides I will acknowledge both sides before coming to a conclusion.

First of all many scientist say Pluto failed to dominate it orbit around the sun in the same way as the other planets

Professor Iwan Williams said “The need for a strict definition was deemed necessary after new telescope technologies began to reveal far-off objects that rivalled Pluto in size.

Without a new nomenclature, these discoveries raised the prospect that textbooks could soon be talking about 50 or more planets in the Solar System”

This point illustrates that if we continue to call Pluto a planet we will have to start to call many other items in orbit planets as well. Scientist is Czech also said, “Pluto was automatically disqualified because its highly elliptical orbit overlaps with that of Neptune. It will now join a new category of dwarf planets” this tells us that Pluto failed to meet the requirements of a planets description.

Another point of view from the against side of the argument

Some scientist say that Pluto was only named a plane due to the fact that there was not as many planetary labels available as there are now when Pluto was discovered and planet was the only label that fitted Pluto’s description however now that we developed our knowledge in the planetary subject we have discovered that there are many different types of planets and relabelling Pluto would give it a better description of what it is.

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Astronomers also say that Size. Size. Pluto's mass is 25 times smaller than Mercury's and only 9 times larger than that of Ceres, the largest body in the asteroid belt. Some recent large Kuiper Belt Objects (notably Sedna) are likely larger than Ceres, if smaller than Pluto (and the recently discovered Eris (previously "Xena" or 2003 UB313) may be larger than Pluto). However, any lower cut-off in size for planets is arbitrary, and putting it above or below Pluto's size and mass is a question of individual preference. Also, if, for example, the lowest diameter a planet can have is ...

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Another astronomer Mike Brown of Caltech and his colleagues have recently proposed that population of small bodies which may share the orbit with the candidate body should be taken into account when defining a planet. They propose that if a body's mass is greater than the total mass of small stuff, which orbits in the same region, it is a planet. So, Mercury might not be too big, but since very few asteroids orbit the Sun in its vicinity, it is definitely a planet. Jupiter shares its orbit with numerous so-called Trojan asteroids, but their total mass is negligible compared with that of Jupiter, so Jupiter is also a planet. Pluto, according to this criterion, is not a planet, because its mass is smaller than the estimated total mass of all other Kuiper Belt Objects.

Also last year some mebers of the astronomical union decided it was time to give Pluto a minor planet label due to the fact it is very small/ it is six times smaller then earth, and even smaller than seven of the solar system's moons (the Moon, Io, Europa, Ganymede, Callisto, Titan and Triton) and and even smaller than seven of the solar system's moons (the Moon, Io, Europa, Ganymede, Callisto, Titan and Triton). They also say since then nearly 100 objects like QB1 have been found. They are thought to be similar to Pluto in composition and, like Pluto, many orbit the sun in a 3:2 resonance with Neptune. This swarm of Pluto-like objects beyond Neptune is known as the Kuiper Belt, after Gerard Kuiper, who first proposed that such a belt existed and served as a source of short period comets. Astronomers estimate that there are at least 35,000 Kuiper Belt objects greater than 100 km in diameter, which is several hundred times the number (and mass) of similar sized objects in the main asteroid belt.

Some astronomers also say that Pluto is not a planet due to the fact it is just a ball of ice in orbit, they also say that Pluto is no planet due to eris just being discovered which is bigger then Pluto, also some astronomers that are for Pluto being a planet say that it is because it has air around it however astronomers against the Pluto being a planet say it makes no difference if it has air around because titan has air that is thicker then earths and it is only a moon of Saturn and has no planet label.

However many astronomers that support the view that Pluto is a planet have agreed that Pluto is a planet because firstly Pluto is a planet. It is the tenth largest object that goes around the Sun. Although it is smaller than Mercury, Pluto is two and a half times the diameter of Ceres, the largest asteroid. That’s large enough for Pluto to be a planet.

Secondly Pluto is big enough to be a planet. Our solar system has more than 160 moons, and Pluto is larger than all but seven of them. Furthermore, Mercury is smaller than two moons and nearly as small as a third moon—yet Mercury is a planet. So is Pluto.

Thirdly Pluto is not an ice ball. It’s twice as dense as water. It’s therefore made mostly of rock, not ice. Also that Mercury also has a very elliptical (oval-shaped) orbit around the Sun. Mercury’s orbital eccentricity—a measure of how elliptical an orbit is—is nearly as great as Pluto’s. Yet Mercury is a planet. So is Pluto.

, Also like most planets Pluto has an atmosphere. In fact, Pluto’s air is mostly nitrogen, the same gas that makes up most of Earth’s atmosphere. So Pluto is a planet.

Comments on this argument

On many petition websites I have seen that people still value and see Pluto, as a planet as oppose to the minority who have the idea that Pluto is not a planet.

There are many scientist opinion on this matter which I will know tell you about

Karl Glazebrook, professor in the Department of Physics and Astronomy: "My take is that a physical definition like the one proposed makes sense: something large enough to be spherical and which is not a satellite. But if I were in charge, I would insist on a diameter of greater than 1,000 kilometres to define a 'planet' in order to remove Ceres from the list. But that would be an arbitrary cut to preserve the order of the main nine and to save the hassle of rewriting textbooks. ? Definitions and naming really matter little physically, anyway."

William P. Blair, research professor in the Department of Physics and Astronomy and chief of observatory operations for NASA's Far Ultraviolet Spectroscopic Explorer Satellite, operated by JHU: "This is really not a burning issue for most astronomers. It really is a 'classification' problem more than an issue of science. ?From what I can tell, they have tried to come up with a consistent definition: an object roughly spherical under its own gravity, orbiting a star, and not orbiting something else. OK, so far. Then they are apparently willing to immediately bend this relatively simple definition and allow Charon to itself be called a planet, with Pluto and Charon being a 'double planet' system. This goes too far and seems inconsistent to me."

Richard Conn Henry, professor in the Department of Physics and Astronomy: "I think the notion that Pluto is a planet is absurd. When it was initially discovered, it was thought to be vastly more massive than it turned out to be. Its orbit is radically different from that of all the other planets. 'Down with Pluto' is what I say!"

Harold A. Weaver Jr., project scientist, Johns Hopkins University Applied Physics Laboratory: "Personally, I'm in favour of the resolution, mainly because it's about time we had a formal definition of the word 'planet,' and the proposed definition is relatively straightforward. However, we must not forget that any attempts by us to pigeonhole objects in the universe are bound to have shortcomings. The classification schemes that we invent help us to place diverse objects in context, but we must also recognize that nature often doesn't adhere to our attempts to categorize things. Although a 'planet,' Pluto has more in common with the horde of 'Kuiper belt objects' on the outskirts of our solar system than it does with, say, Jupiter. On the other hand, to those who complain that Pluto doesn't deserve to be in the company of planets like Jupiter, I point out that there are also huge differences between Jupiter and Earth, for example. In any case, I doubt that the IAU could come up with a resolution that would please everyone."

Andy Cheng, Johns Hopkins University Applied Physics Laboratory: "Yes, keeping Pluto as a planet is the correct decision. However, the new definition of planet does not work for me, because 'hydrostatic equilibrium' is an idealization -- it is approximately correct for planets like Earth but is not exact. There is still no criterion for deciding how far from hydrostatic equilibrium an object can be and still qualify as a planet. Much of the science of geophysics deals with the different ways, and the reasons why, planets are not quite in hydrostatic equilibrium. Also the suggested term 'pluton' is a bad idea, in my opinion."

My conclusion on this matter is that Pluto should remain labelled as a planet, because firstly it has always been known as a planet and changing its label may not be the wisest ideas as it may cause conflict in school or any study building,, secondly so what is a little lighter and smaller then its neighbour you don’t say someone who has dwarfism isn’t human do you and thirdly what so different between it and mercury all mercury is, is a hot ball of gas liquid, Pluto is a cold ball of ice, water and rock, ,so therefore my conclusion is Pluto is a planet.