The History of Pluto

In the 1840¶s, Urbain Le Verrier predicted the position of the then-undiscovered planet Neptune after 

analyzing disruptions in the orbit of Uranus. Observations of Neptune in the 19th

century caused astronomers to

speculate that Uranus¶ orbit was being disturbed by another planet besides Neptune. In 1906 Percival Lowell, a

wealthy Bostonian, started an extensive project in the lab he started, the Lowell Observatory, in search of a possible

ninth planet, which he referred to as Planet X. He did not find anything, though he continued searching until his death

in 1916. Unbeknownst to Lowell, on March 19, 1915, his observatory had captured two faint images of Pluto, but he

did not recognize them for what they were. After Lowell¶s death, search for Planet X did not resume until 1929. When

the Lab resumed work, it had Clyde Tombaugh systematically imaging the night sky in pairs of photographs taken two

weeks apart, then examining each pair to see if any objects had shifted position. On February 19, 1930, Tombaugh

discovered a possible moving object on the photographs taken on January 23 and January 29 of 1930. After he

obtained confirmatory photographs, news of the discovery was telegraphed to the Harvard College Observatory on

March 13, 1930. The Lowell Observatory had the right to name the planet, and many different suggestions were

received. There was over a 1000 suggestions ranging from Atlas to Zymal. Constance Lowell, Percival Lowell¶s

widow, proposed Zeus, then Lowell, and finally, Constance. All were disregarded. The name Pluto was suggested by

Venetia Burney, and eleven-year-old schoolgirl in Oxford, England. Venetia was interested in both classical

mythology and astronomy. She considered the name of the Roman god of the underworld was an appropriate name

for such a presumably dark and cold world. She suggested it in a conversation with her grandfather, who passed the

name to a Professor at the University of Oxford, who passed it to his colleagues in the US. Planet X was officially

named on March 24th, 1930. Each member of the Lowell Observatory was allowed to vote on a list of three possible

names. The names were: Minerva, which was already the name of an asteroid, Cronus, which had garnered a bad

reputation after being suggested by an unpopular astronomer named Thomas Jefferson Jackson See, and Pluto.

Pluto received every vote. Venetia got five pounds as a reward. The name was soon embraced by wider culture. The

Disney character Pluto, introduced in 1930, was named in the planet¶s honor. In 1941, Glenn T. Seaborg named the

newly created element plutonium after Pluto, in keeping with the tradition of naming elements after newly discovered

planets, such as uranium and neptunium.

Exploration of Pluto has been looked at ever since August of 1992 when NASA scientist Robert Staehle contacted

Tombaugh requesting permission to visit his planet. Tombaugh replied ³that he was welcome to it, though he¶s got to

go one long, cold trip.´ Despite that, NASA cancelled its Pluto Kuiper Express mission, citing cost and launch vehicle

delays. A revised mission to Pluto, named New Horizons, was granted funding from the U.S. government in 2003. It

was launched successfully on January 19, 2006. The leader of the mission confirmed that some of the ashes of 

Tombaugh were placed on board the spacecraft. The spacecraft¶s closest approach to Pluto will be on July 14, 2015.

Meanwhile, controversy was arising about whether Pluto should be a planet. Pluto is part of a belt of frozen globs of 

stuff called the Kuiper belt, which extends from 2,788,674,210 miles from the sun to 5,112,569,385 miles from the

sun. The issue was brought to a head with the discovery of Eris, a thing like Pluto in the Kuiper belt, which is believed

to be 27% more massive than Pluto. This discovery prompted the International Astronomical Union, or IAU, for short,

to define what a planet is. It said a planet was a celestial body that 1. is in orbit around the sun, 2. has sufficient mass

to assume hydrostatic equilibrium, or a nearly round shape, and, 3. has cleared the neighborhood around its orbit,

meaning that it is gravitationally dominant in its area. Pluto isn¶t, because it is part of the Kuiper Belt, which makes it

fall into the category of dwarf planet, or celestial bodies that don¶t meet the third criteria. Thus Pluto is the second

largest dwarf planet, behind Eris and ahead of Makemake, Haumea, and Ceres, part of the Asteroid Belt. Pluto has

been made fun of a lot more after its loss of planetship. For example, Failblog has made a shirt that says ³Silly Pluto,

orbiting the sun is for real planets.´

Well. I hope you enjoyed my speech on the history of Pluto and I hope you weren¶t bored to death by it.