Why Isn't Pluto a Planet?

[MUSIC]

[Jackie Faherty stands talking directly to the camera on a red background. Next to her, a blue circle labeled “Pluto” appears, with “planet” written beneath it.]

JACKIE FAHERTY (Senior Scientist, Division of Physical Sciences, American Museum of Natural History): Poor Pluto was reclassified from ‘planet’ –

[The word “dwarf” is added before the word “planet”.]

FAHERTY: to ‘dwarf planet’ in 2006,

[The screen swipes left to reveal 2006, written on a yellow background. A crowd of human-like icons fills the screen, with one at the front of the group at a podium that reads “IAU.”]

FAHERTY: when the International Astronomical Union voted

[Paddles with checkmarks or x’s rise throughout the crowd.]

FAHERTY: on a new definition of the word ‘planet’

[Minimalist outlines of the nine planets in a line appears below the word “planet”. A hand reaches up and grabs the last one, Pluto, and pulls it out of the screen.]

FAHERTY: that unfortunately no longer included Pluto.

[Jackie Faherty returns to the screen.]

FAHERTY: So when that happened we went from having nine official planets to eight.

[CAMERA CLICK]

[The camera freezes on a frame of Jackie speaking. Text appears next to her with an arrow: Jackie Faherty, Astrophysicist. The logo for the American Museum of Natural History appears on top. Then Jackie appears back on screen speaking.]  

FAHERTY: The definition of the word ‘planet’ was not really well defined – and Pluto was always just a little bit of an oddball.

[The same blue circle labelled Pluto appears next to Jackie. Question marks dance around the edge.]

FAHERTY: It’s smaller than our own moon,

[A slightly larger blue circle labelled “moon” appears next to Pluto.]

FAHERTY: it’s got a very different kind of orbit than the other ‘planets’ in the solar system do.

[A simplified drawing of the solar system appears. Most of the orbits are in the same plane, but Pluto’s is tilted and off-center.]

FAHERTY: Astronomy had moved so far forward since the year 1930

[A timeline from 1930 to 2006 draws itself from left to right. Icons appear next to the timeline.]

FAHERTY: when Pluto was discovered to the current times in 2006 that astronomers decided they needed a new definition.

[The icons reveal themselves to be: Sputnik launch, moon landing, Voyager 1 Launch, Hubble Launch, and Construction begins on ISS, ending with Planet Redefined in 2006. Jackie appears back on screen.]

FAHERTY: So the definition has three components to it. The first is that

[On screen, text appears: “1. Orbits the sun.” A checkmark appears at the end of the text with a [DING].]

FAHERTY: it needs to be in orbit around the sun. Pluto is okay with that. The second is that

[On screen, text appears: “2. Is nearly round.” A checkmark appears at the end of the text with a [DING].]

FAHERTY: it has to be massive enough to be nearly round. Pluto’s okay with that. And the third component was that it needs to have cleared its orbit of objects,

[A field of circles fills the screen. In the middle of the small circles, the text “3. Clears its orbit” appears. The circles fly away from the text offscreen. An X appears next to the text along with a [BUZZER].]

FAHERTY: and this is where Pluto fails. A quote-unquote planet

In the center of the screen, a planet moves along its orbit.

FAHERTY: would be massive enough to control any other object in its orbit with its gravitational force.

[As it does so, small objects dip in and are flung away from its orbit. Speech bubbles appear from the planet, reading “Outta my way!” and “Yoink!” when it pulls another object into orbit around it. The camera zooms out so we can see the planet orbiting around the sun.]

FAHERTY: Pluto happens to be in this belt of debris,

[We zoom out even further until we can see that the sun is also surrounded by an orbit of tiny objects, like a dust cloud. A label indicates that this is the Kuiper Belt. Pluto is labeled as one of the larger objects in this area.]

FAHERTY: so Pluto isn’t the only dominating force in the area

[Inside the Kuiper belt, three other objects are labeled, which are all similar in size to Pluto: Haumea, Makemake, and Eris.]

FAHERTY: and it certainly isn’t the regulator of how everything else moves.

[The camera zooms into Pluto, where we see that its orbit is full of tiny objects. Speech bubbles appear around it, saying “ahem,” “excuse me,” “pardon me,” and “could I just…” A newspaper drops down into the center of the screen, with an illustration of Neil deGrasse Tyson in the center. The headline reads “We’ve got a dwarf planet over here!”]

FAHERTY: People were very attached to Pluto being called a planet.

[The newspaper starts moving and we see that it is held by a person who is frantically waving their arms in the air. The camera moves past this person to a person who is crying.]

FAHERTY: The public outcry really surprised astronomers

[Beyond this person, two people gasp, with exclamation points appearing over their heads. Jackie appears back on screen.]

FAHERTY: because the objects we study don’t care if you call them planets or not,

[A drawing of an asteroid and a planet shrug their arms.]

FAHERTY: it doesn’t bring anything scientifically to the table,

[A science textbook shrugs its arms.]

FAHERTY: and it means that we don’t pay as much attention to the objects in our solar system that aren’t under that umbrella of being called a planet.

[An umbrella comes down from the top of the screen. The word Planet unfurls beneath it, as names of objects that aren’t planets rain down on top of the umbrella and bounce off.]

FAHERTY: When we hear the word ‘planet’ we think exciting, life.

On screen, a circle draws and is labeled inside as a planet. Half the circle fills with trees and the other half fills with water, and two tentacles poke out of the water.

FAHERTY: When you hear the word “moon”, you may think of a dead place,

[The planet is erased and replaced by a circle that reads “moon”. This circle is empty save for a few craters.]

FAHERTY: but Enceladus is a moon around Saturn

[An image of Enceladus, an icy moon, fills the screen. It is labeled “Enceladus, moon of Saturn”.]

FAHERTY: that is probably the next best place to search for life.

[Another set of images shows Enceladus’s geysers and ice-covered ocean. Jackie appears back on screen.]

FAHERTY: So the word planet is certainly not all encompassing of the different kinds of objects that are out there. I argue that we should just get rid of using this word planet.

[Next to Jackie, the word “planet” is written out and then crossed out.]

FAHERTY: A word that I am trying to get people into

[Two human silhouette icons drop from the top of the screen. One says “Planet?” The other whacks the word planet offscreen and reveals the word “world” above them.]

FAHERTY: is ‘world’, because world is far more inclusive

[The people drop off screen and are replaced by the planet lineup, including Pluto with a star next to it.]

FAHERTY: and gives equal weight to all the kinds of exciting objects that we have in the solar system.

[The word “world” moves to the right of an equals sign. On the left of the equals sign, several objects rotate through: asteroid, dwarf planet, planet, moon, and ending on Pluto, so the last thing on screen is Pluto = World.]

[MUSIC ENDS]

[Credits roll.

Producer

Lee Stevens

Executive Producer

Eugenia Levenson

Design / Motion
Lee Stevens

Camera

AMNH / L. Stevens

Images / Archives

NASA JPL-Caltech/Space Science Institute

Noun Project / Adrien Coquet, Bakunetsu Kaito, Danil Polshin, Emma Darvick, Linseed Studio, Logan, Maxim Kulikov, Marco Hernandez, Symbolon, Tom Tom, Viktor Korobkov

Music / Sound Effects

“Narrow Escape” by Adam Saunders (PRS) & Mark Cousins (PRS) / Warner/Chappell Production Music

FreeSound / Eelke, InspectorJ, kbt3, LloydEvans09, mich3d, nebulousflynn, nofeedbak

Special Thanks

AMNH Photo Studio

©American Museum of Natural History]