Pluto
Published on Nov 22, 2015
To be or not to be a planet? Persuasive speech on the planetary status of Pluto.
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PRESENTATION OUTLINE
Planet x? That you?
- Discovered in 1930 by Clyde Tombaugh
- Orbital period of 248 years
- Mass 1/400th that of Earth's
- Diameter is 1430 miles.
- Three Moons: Charon, Nyx, Hydra
Began as a theoretical planet, called Planet X.
At the time of its discovery, astronomers thought it was at least the size of Earth. Afterwords, it was thought to have the same size, mass, and density of Mars.
Moons: Charon (discovered 1978 by James W. Christy), Nix, and Hydra (both discovered in 2005).
At the time of its discovery, astronomers thought it was at least the size of Earth. Afterwords, it was thought to have the same size, mass, and density of Mars.
Moons: Charon (discovered 1978 by James W. Christy), Nix, and Hydra (both discovered in 2005).
Photo by tonynetone
What makes a planet?
- Orbits a sun
- Is large enough that its gravity has molded it into a spherical shape
- Has cleared objects out of its orbital path
This last requirement is the one that Pluto failed.
Photo by osolev
Not a planet
- Can't clear its orbital neighborhood
- Too many planets otherwise
- Behaves more like an object in the Kuiper Belt
- Size
If Pluto is indeed a planet, then our solar system has thousands of potential planets.
Approximately 1,000 other obj of roughly Pluto's size have been found orbiting the sun beyond Neptune.
Behaves more like... Elongated orbit & odd orbital planet. The Kuiper Belt is similar to the Asteroid Belt in that it surrounds the sun, only it is past Neptune, extending to at least 10,000 astronomical units out. Contains some of the oldest materials in our solar system.
Approximately 1,000 other obj of roughly Pluto's size have been found orbiting the sun beyond Neptune.
Behaves more like... Elongated orbit & odd orbital planet. The Kuiper Belt is similar to the Asteroid Belt in that it surrounds the sun, only it is past Neptune, extending to at least 10,000 astronomical units out. Contains some of the oldest materials in our solar system.
Photo by David J. Thomas
objection!
- Pluto is spherical
- Has an atmosphere and seasons
- The idea that a planet has to clear its orbital neighborhood is too subjective
- The word "Planet" is not scientifically significant
The idea that....(Alan Stern, head of NASA's New Horizons probe to Pluto) This could out Neptune, Jupiter, and Earth from the ranks of planets. All three have other planets or groups of asteroids that cross their orbits.
The word....(Neil deGrasse Tyson, director of New York's Hayden Planetarium) "If we lived on Jupiter, we might say there are only the four biggest planets".
The word....(Neil deGrasse Tyson, director of New York's Hayden Planetarium) "If we lived on Jupiter, we might say there are only the four biggest planets".
Photo by NASAblueshift
Fun facts
- The cartoon character Pluto may have actually been named in honor of the planet.
- Pluto was named for the Greek god of the Underworld, Hades.
- Pluto's three moons were named similarly.
Disney technically came out with Pluto the dog in 1930, the same year as the planet's discovery, but his name was not released until the following year.
Charon: Guide to the Underworld
Nyx: The embodiment of night, mother of Charon.
Hydra: A many-headed snake, one of the creatures said to live at the entrance to the Underworld
Charon: Guide to the Underworld
Nyx: The embodiment of night, mother of Charon.
Hydra: A many-headed snake, one of the creatures said to live at the entrance to the Underworld
Photo by NASA Goddard Photo and Video
Fun facts cont.
- Clyde Tombaugh was 26 when he discovered Pluto.
- Charon, Pluto's largest moon, is approximately half the size of the planet.
Photo by NASA Goddard Photo and Video
To conclude....
- You know what makes a planet...
- You've heard the arguments against planetary status...
- And you've heard the arguments for reinstatement...
- ...So pick your side!
Photo by tonynetone
