Download Name: ____ Date: __________ Period: ________ Pluto Files (PBS

Name: ______________________
Date: _________________
Period: ________
Pluto Files
(PBS/Nova Episode)
Who is Neil deGrasse Tyson and why have some people blamed Pluto’s problems on him?
 He is an astrophysicist and the director of the Hayden Planetarium in New
York
 He decided to place Pluto near the Kuiper Belt instead of the other planets in
the Planetarium
 He is accused of being a Pluto Hater (person that agrees with Pluto no longer
being classified as a planet)
What is Pluto and how did it get its name? What do Walt Disney and Pluto have in
common? When was Pluto discovered? How did Percival Lowell and Clyde Tombaugh
participate in this discovery?
 Pluto was a planet (dwarf planet (new kind of planet)/KBO)
 The Disney character, Pluto (dog), got its name from the planet Pluto
 Walt Disney was a big fan of the planet and Space in general
 It got its name from a young English girl. She named it after the Roman God of the
underworld (Pluto). The initials would be P. L. which could stand for Percival
Lowell.
 It was discovered in 1930 by Clyde Tombaugh (he took over the work that Percival
Lowell started). Percival Lowell called it Planet X until it was named Pluto.
What does IAU stand for and what are they responsible for doing? What is their definition
of a planet? Why does Pluto not fit this description? How long was Pluto considered a
planet and what year did it all change and why?
 International Astronomical Union (IAU)---they are in charge of naming celestial
(space) objects
 Current definition:
o A planet needs to be round and orbit the Sun
o A planet must clear the neighborhood around its orbit
 Pluto is not massive enough to clear its neighbors (goes into Neptune’s orbit)
 Pluto was no longer considered a planet in 2006
 It was called a planet for 76 years (1930-2006)
In 1992, other objects around near Pluto were found. They are known as The Kuiper Belt
objects. They have wide orbits around the Sun. They are thought to be left over pieces of
the solar system from 4 billion years ago. They were pushed far out and put into a deep
freeze. Is Pluto a planet or a Kuiper Belt object? Explain your answer.
 Mike Brown wanted to find a KBO larger than Pluto
 He discovered a bigger object than Pluto
o Before it was named, it was considered possibly the 10th planet
o IAU had to decide whether it was a KBO or the 10th planet
o It is considered a Kuiper Belt object and is called Eris
 Pluto fit the description of KBO’s and the conversation started about whether Pluto
should be considered a planet or not
Alan Stern was not happy with the IAU and with Neil deGrasse Tyson’s exhibit at the
planetarium. Why? What is a dwarf planet?
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Pluto is not just a KBO. It is a dwarf planet---its icy and rocky and in miniature form
(pint size), have atmospheres, and moons; Pluto like objects
Force of gravity forced them out into the solar system and would have been larger if
there was more material available when they were formed
New Horizons (mission to Pluto and Kuiper Belt) spacecraft was sent out on 2006
and will arrive at Pluto in 2015 (July)
o Seven scientific instruments---find out the composition of Pluto’s surface,
atmosphere, temperature, interior structure, and three moons
o Takes 9 ½ years to make the journey
o Has the ashes of Clyde Tombaugh---the man who discovered Pluto
What is your stand on the controversial subject of Pluto? Should we study Kuiper Belt
objects?
 Are you a Pluto Lover or a Pluto Hater?
o Pluto Lover----person that believes that Pluto is still a planet
o Pluto Hater---person that believes Pluto is not a planet anymore
o Or are you not sure?
o Explain your position.
T.V. episode and questions adapted from http://www.pbs.org/wgbh/nova/pluto/