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Speaker 1: Hey guys, Welcome to this day in History class, where

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Speaker 1: we bring you a new tidbit from history every day.

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Speaker 1: Today is February nineteen. The day was February eighth, nineteen thirty.

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Speaker 1: After about a year of searching for an unknown planet

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Speaker 1: beyond Neptune, an amateur astronomer named Clyde W. Tomball found

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Speaker 1: the object that would become known as Pluto. Tom Baugh

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Speaker 1: was working at Lowell Observatory in Flagstaff, Arizona, using a

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Speaker 1: camera equipped telescope to record images of the sky on

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Speaker 1: photographic plates at the same sidereal time on different nights.

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Speaker 1: Sider real time, it's just time measured based on the

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Speaker 1: positions of distant stars, as opposed to solar time, which

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Speaker 1: is measure based on the position of the Sun. Tom

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Speaker 1: Baugh would then identified differences between plates using a blink comparator,

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Speaker 1: which is a viewing instrument that helps astronomers compare photographs

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Speaker 1: of the night sky. When you look at the sky.

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Speaker 1: Using this method, stars and galaxies appeared to remain in

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Speaker 1: the same spot, while the position of moving objects like

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Speaker 1: planets would change each night, and on February eighth, nineteen thirty,

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Speaker 1: tom Ball found what he had been searching for when

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Speaker 1: a small spot of light blinked on the plates for

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Speaker 1: January and twenty nine, Local Observatory confirmed the movement with

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Speaker 1: more photographs, and it announced the discovery of this planet

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Speaker 1: X on March thirteenth. Tom Baugh became the first American

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Speaker 1: to discover a planet. That's pretty cool for a self

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Speaker 1: taught astronomer who was offered a job at the Low

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Speaker 1: Observatory because his ash aconomical drawings had impressed the director

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Speaker 1: of the observatory. But let's back up to why scientists

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Speaker 1: were even looking for another planet in our Solar system

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Speaker 1: past Neptune. Anyway, discrepancies and Uranus's orbit led scientists to

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Speaker 1: believe that another planet was out there influencing Uranus's motion,

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Speaker 1: and that helped astronomers discover that Neptune was a planet

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Speaker 1: in eighteen forty six. But by the late eighteen hundreds,

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Speaker 1: scientists already had an inkling that there was a planet

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Speaker 1: beyond Neptune. Percival Lowell, an American astronomer and founder of

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Speaker 1: the Local Observatory, observed strange deviations in the orbits of

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Speaker 1: Uranus and Neptune in the early twentieth century, so he

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Speaker 1: theorized that another planetary body's gravity had to be the

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Speaker 1: thing that was causing these deviations, and astronomers figured that,

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Speaker 1: like with Neptune, the undiscovered plan in its location could

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Speaker 1: be calculated using these irregularities. Well, we now know that

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Speaker 1: those deviations weren't accurate, and they couldn't have been caused

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Speaker 1: by a planet with a mass as small as Pluto's anyway,

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Speaker 1: But either way, Lowell's set to work on searching for

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Speaker 1: the mysterious planet X. In nineteen o six at the

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Speaker 1: observatory he had founded, he astronomer William Henry Pickering and

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Speaker 1: other scientists worked on finding planet X where they thought

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Speaker 1: it should be in the sky for years. Lowell died

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Speaker 1: in nineteen sixteen, and the search for the so called

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Speaker 1: trans Neptunean planet was put on hold because of a

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Speaker 1: lengthy battle over Lowell's estate, but the search was not forgotten.

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Speaker 1: In ninety seven, Percival's brother provided the money to build

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Speaker 1: a new telescope and dome for the search, and two

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Speaker 1: years later the telescope was ready for its intended use.

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Speaker 1: The very next year, planet X was found only six

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Speaker 1: degrees off of Lowell and Pickering's mistaken calculations. There were

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Speaker 1: a lot of suggestions for the name of the new planet,

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Speaker 1: but in the end it was dubbed Pluto, thanks to

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Speaker 1: an eleven year old English girl named Venetia Bernie, who

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Speaker 1: proposed the name. The name was perfect for the cold,

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Speaker 1: dark and distant planet. Not only did Pluto refer to

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Speaker 1: the Greek god of the underworld, but its first two

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Speaker 1: letters were also Perceival Lowell's initials. After Tomba found Pluto,

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Speaker 1: Tomba searched the entire ecliptic plane for other bodies in

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Speaker 1: the Outer Solar System, but he came up empty. Now

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Speaker 1: Pluto is no longer considered a planet. It was reclassified

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Speaker 1: as a dwarf planet in two thousand and six after

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Speaker 1: other bodies of similar size were discovered in the Kuiper

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Speaker 1: Belt and the term planet was redefined. Like planets, dwarf

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Speaker 1: planets are celestial bodies that are nearly round orbit the

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Speaker 1: Sun and are not moons, but they are not able

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Speaker 1: to clear their orbital path so that no similar objects

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Speaker 1: are at the same distance from the Sun. Pluto's downgrade

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Speaker 1: from a planet to a dwarf planet was a disappointment

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Speaker 1: to many who grew up thinking of Pluto as the

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Speaker 1: tiny icy ninth planet. However, the discovery of Pluto was

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Speaker 1: still an important milestone in the history of astronomy and

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Speaker 1: planetary science. I'm Eavestafcoat and hopefully you know a little

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Speaker 1: more about history today than you did yesterday. And if

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Speaker 1: you like to learn even more about Pluto, listen to

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Speaker 1: the episode of Stuff you Missed in History Class called

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Speaker 1: Pluto the Demoted dwarf Planet. You can subscribe to This

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Speaker 1: Day in History Class on Apple Podcasts, the I Heart

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Speaker 1: Radio app, or wherever you get your podcasts. Keep up

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Speaker 1: thus on Twitter, Instagram, and Facebook at t d I

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Speaker 1: h C podcast. Come back tomorrow for another tidbit from history.

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Speaker 1: M