When Pluto was discovered in 1930, few would be able to predict how controversial the simple word planet would become. It has been in flux for years, the definition of planethood, without a satisfactory resolution. With Pluto’s designation as a planet and successive demotion to dwarf planet in 2006, the planetary debate shifted from within the scientific community to society as a whole, as people fight for the little planet that could. Despite the recent discoveries that redefine planethood, Pluto should retain its planetary status due to its cultural and historical significance. Astronomy was the first science. Ever since the beginning of time, people have been looking up at the stars and wondering about the sky’s contents. In Greek, planet meant “wandering star”, and star meant “any astronomical body”, so they classified the sun, moon, Mercury, Venus, Mars, Jupiter, and Saturn as planets. This was accepted until the renaissance, when better tools and increased curiosity led to the Copernican heliocentric model in 1542. Kepler had realized that there was a difference between planets and moons, after Galileo’s discovery of four of Jupiter’s moons. Those moons revolved around Jupiter, not us, and thus he and Nick Copernicus created the model. This shifted the planetary list to include Earth and exclude the sun and moon, by redefining planethood to mean anything that revolved around the sun. In 1766, they began to expand their horizons and seek out other planets. Johann Titius and Johann Bode discovered a mathematical pattern in the spacing of the planets, and determined that there should be a planet between Mars and Jupiter, and one beyond Saturn. When Uranus was found, it seemed to confirm this law, so the search intensified for the one after Mars. On New Year’s Day of 1801, an Italian monk named Giuseppe Piazza discovered what looked like the answer: Ceres. The scientific community was at peace for a year. But, in 1802, another ‘planet’ was found near Ceres, dubbed Pallas. Most accepted these as planets, but others were skeptical. Herschel, who had discovered Uranus, made up a word for this astronomical body- asteroid. Many were not impressed by this, viewing it as Herschel’s attempt to make his own discovery more impressive. But in the 1850s, the only determination of planethood was size, so Ceres counted, even as a few more bodies were found. It was only after telescopes improved that scientists discovered there were thousands of bodies between Mars and Jupiter, and realized that these werent planets, but a new class of bodies. They adopted Hershel’s word, asteroid, to describe them, and this region became known as the asteroid belt. Simultaneously, scientists were noticing the Uranus’s orbit was different from how they would expect it. Alexis Bouvard guessed that there was another influence on it, perhaps even a planet. The French and the English fought it out to be the first to discover the planet. John Couch Adams worked with his English team, while Urbain Jean-Joseph Le Verrier tried to get the French to cooperate. When they refused, Le Verrier decided to contact Johann Gottfried Galle, a friend in Germany. Galle received the calculations and looked to the skies with his student Heinrich d’Arrest, finding it rather immediately. After Neptune was found, everyone was swarming to find more planets. Some had theories of a planet between Mercury and the sun (that turned out to be merely sunspots), others believed there to be multitudes of planets beyond Neptune. The search was due to Uranus’s inconsistent orbit, suggesting the presence of an astronomical body besides Neptune with enough gravitational force to pull the orbit off course. In all actuality, the orbit was fine- the inconsistencies presented were due to mathematical errors in the calculation of Neptune’s mass and position. Percival Lowell was anxious to redeem himself from the embarrassment that was his previous scientific breakthrough- canals on Mars that turned out to be nothing more than specks on his telescope lens. He thus devoted himself to finding Planet X, funding an observatory devoted exclusively to that function and setting to work calculating. Unfortunately, Lowell was never to see the fruits of his research, dying before the planet was discovered and leaving his fortune to the observatory rather than his wife. Furious, she sued, tying up the funds in a legal battle that lasted a decade. When the Lowell Observatory was finally able to function again, the planet-finding craze was largely over, but the members of the observatory were determined. They sought a new employee, one without a political agenda, and found one in farm boy Clyde W. Tombaugh. He was tasked with finding the elusive planet via a new and tedious technique. First, he was to take pictures of the night sky, the same part at different times. Then, he was to feed these into a blink comparator, which was a glorified spot-the-difference game that blinked back and forth between two images so that the differences could be observed. This process took seven thousand hours of Tombaugh’s time, but finally it paid off, and Pluto was found- ironically, in the same part of the sky that Lowell’s failed calculations had pointed so many years before. Many misconceptions were at hand when Pluto was first discovered. It was believed to be around the size of the Earth, though we now know it is actually smaller than Earth’s moon. And, of course, it was immediately dubbed a planet. This was soon to be contested. In 1999, a suggestion was made to give Pluto the designation of 10000, allowing it “dual citizenship as planet and member of the Kuiper belt”. However, many were displeased with this, and protesting, so Pluto retained its status, if for only a few more years. Perhaps they should’ve taken the compromise then. In July of 2005, Dr. Michael E. Brown, a professor at California Institute of Technology, discovered a planet near Pluto. The planet, later named Eris, was believed to be much larger than Pluto, and immediately cast doubt upon Pluto’s standing. Were there now to be ten planets? Or was this planet, even further from the sun, with an even more titled and eccentric orbit than Pluto, a dwarf planet, meaning that Pluto was a dwarf as well? This brought the planetary debate into unavoidable focus, and the International Astronomical Union (IAU) was forced to act. Act they did. The Nomenclature Committee of the IAU got together in August of 2006 to figure out a solution. The definition of a planet had been debated many times before, once for two years without resolution, yet they were now undertaking this great task. With a growing number of astronomical bodies being discovered both in the Kuiper Belt (beyond Neptune) and the asteroid belt (between Mars and Jupiter), there needed to be a clear line between planets and non-planets, whatever else they may be. They had a long list of issues to consider. Kids couldn’t be expected to remember the names of fifty planets; if scientists had known how small and eccentric it was when it was discovered, it would’ve never been called a planet; but it was, and people, especially children, and grown attached to it; therefore, was size the answer, and how would they choose the cutoff- would it be Pluto, Eris, Ceres? What else was important to be called a planet? Wasn’t it all just made-up words, anyway? The IAU decided to focus on two factors of planethood: shape/size and planetary interactions. Many resolutions failed to pass before finally, this was decided. Prague 08/24/06 “Definition of a ‘Planet’ in the Solar System” Contemporary observations are changing our understanding of planetary systems, and it is important that our nomenclature for objects reflect our current understanding. This applies, in particular, to the designation “planets.” The word “planet” originally described the “wanderers” that were known only as moving lights in the sky. Recent discoveries lead us to create a new definition, which we can make using currently available scientific information. The IAU therefore resolves that “planets” and other bodies in our solar system be defined into three distinct categories in the following way: 1. A “planet”3 is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid-body forces so that it assumes a hydrostatic equilibrium (nearly round) shape,4 and (c) has cleared the neighborhood around its orbit. 2. A “dwarf planet” is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid-body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, (c) has not cleared the neighborhood around its orbit, and (d) is not a satellite. 3. All other objects5 except satellites orbiting the Sun shall be referred to collectively as “small solar-system bodies.” (Geocenticity.com, the Reclassification of Pluto). Accordingly, Pluto was not a planet, because it does not satisfactorily clear “the neighborhood around its orbit”. Its orbit overlaps with Neptune’s, so Pluto was no longer a planet. However, this was far from final. The definition is still being debated, especially as it leaves plenty unsaid. In reality, the only thing it does is place priority on proximity to the sun. Even earth, which no one is debating shouldn’t be a planet, if in the same position, wouldn’t be able to clear its orbital neighborhood. Also, this clearing process isn’t exactly clear, as every planet has space junk cluttering their orbit- asteroids, comets, and more. Far from that disqualifying them from planethood, the clearing neighborhood idea should be rethought. The scientific community is pushing for more. Scientists had discussed going to Pluto for years to find out more about its terrain and properties. Through a tough fight against the government for funding and fuel and NASA for the right team, New Horizons finally succeeded, and the mission reached Pluto in 2015. Even once it was no longer a planet, the mission continued, proving how much Pluto means not only to the sentimental type but also to scientists seeking to learn more about the world around them, which Pluto was invariably a part. There are also missions to Ceres and more discoveries being made, and many are of the belief that scientists should hold off on trying to define planethood while they continue to learn more about their formation and properties. A new definition is now being proposed, in 2017, that a planet is “a sub-stellar mass body that has never undergone nuclear fusion and that has sufficient self-gravitation to assume a spheroidal shape adequately described by a triaxial ellipsoid regardless of its orbital parameters.” In plain language, they suggest “round objects in space that are smaller than stars.”?(Popular Science). This definition would expand the planetary list to more than a hundred, as it would cause moons and large asteroids, and, of course, dwarf planets, to now take the title of planet. This is highly debated, again bringing up the issue of magnitude of the planet list, but scientists now think that instead of merely size being a factor, other properties, such as the presence of an atmosphere, should be considered. Far from the IAU decision closing the matter, it has only incited the argument more. So what wins, history or modern science? A science, that is, that still isn’t certain about much of anything. That remains the question as scientists fight over what a word constructed of just six small letters means when translated to the grandiose scale of the universe. Pluto may not have been considered a planet if discovered in this day and age, but that doesn’t erase its significance gained- all the scientific techniques improved, knowledge expanded, and attachments made to this small, underdog planet. Pluto is so deeply ingrained into the mainstream that it has become the butt of jokes, such as the Bush administration being a dwarf presidency. Dorothy Zimmerman wrote to NASA offended, stating that she thought of Pluto as her own personal planet, because it was discovered the same year she was born. Lowell even proved, by leaving his money exclusively to the observatory, that he cared more about finding Pluto than his own wife! Pluto is clearly important not only in its cultural and personal ways, but also how it’s brought science into the modern times as they strive to answer the question that is at the very foundation of human comprehension of the surrounding world. Page Break Works Cited “Pluto Discovered.”?History.com. A&E Television Networks, 2010. Web. 04 Nov. 2017.? Bakalar, Nicholas. “March 30, 1930: Pluto Is Discovered.”?The New York Times. The New York Times, 06 July 2015. Web. 04 Nov. 2017.? Bouw, Gerardus D., Ph.D. “The Reclassification of Pluto.”?Geocentricity.com. Web. 04 Nov. 2017.? Boyle, Alan.?The Case for Pluto: How a Little Planet Made a Big Difference. Hoboken, NJ: Wiley, 2010. Print.? Chang, Kenneth. “Dwarf Planet, Cause of Strife, Gains ‘the Perfect Name’.”?The New York Times. The New York Times, 14 Sept. 2006. Web. 04 Nov. 2017.? Chang, Kenneth. “The Long, Strange Trip to Pluto, and How NASA Nearly Missed It.”?The New York Times. The New York Times, 18 July 2015. Web. 07 Nov. 2017.? Chang, Kenneth. “Pluto Terrain Yields Big Surprises in New Horizons Images.” The New York Times, The New York Times, 17 July 2015. Web. 16 Dec. 2017. Chodosh, Sara. “Pluto Might Be a Planet Again. Let’s Talk about Why This Matters.” Popular Science, N.p., 21 Feb. 2017. Web. 16 Dec. 2017. Contributor, Nola Taylor Redd?Space.com. “Eris: The Dwarf Planet That Is Pluto’s Twin.”?Space.com. Web.?07 Nov. 2017.? Millis, John P., Ph. D. “Should Pluto be a Planet?” ThoughtCo. N.p., 05 July 2017. Web. 16 Dec. 2017. Rieke, G. H. “Beyond the Planets- the Discovery of Pluto.”?Pluto.?Arizona.edu. Web. 04 Nov. 2017.? Woo, Marcus. “Earth – Ceres: The Planet That Wasn’t.”?BBC. BBC, 28 Aug. 2015. Web. 05 Nov. 2017.?