1. Pluto: Planet or Not? Come wander with me, she said,
Into regions yet untrod;
And read what is still unread
In the manuscripts of God.
- Longfellow

2. Charon
Pluto

3. The History of Pluto
Clyde William Tombaugh discovered Pluto in Pluto was the name for Hades in Greek myths. He was god of the underworld. His name was given to the planet because it’s so far from the sun that it’s in constant darkness.

4. Which came first?
The planet, or the dog?

5. Any tie-in to Disney’s Pluto who was created in 1931?
The pup first appeared in Walt Disney's short The Chain Gang. Here the dog is named, but it is Rover, not Pluto. It was in "The Moose Hunt", released on May 8, 1931, that the dog is called Pluto the Pup, the studio's original name.
Obviously, several months had passed between the naming of what was believed to have been the ninth planet, Pluto, on March 24, 1930, and the attachment of that name to the dog character. Venetia Burney, who as an eleven-year-old schoolgirl had suggested the name Pluto for the planet, remarked in 2006: “The name had nothing to do with the Disney cartoon. Mickey Mouse's dog was named after the planet, not the other way around.”
Although it has been claimed that the Disney studio named the dog after the planet (rather than after the mythical god of the underworld), this needs further verification. Disney animator Ben Sharpsteen has said that, "We thought the name [Rover] was too common, so we had to look for something else. We changed it to Pluto the Pup, but I don't honestly remember why. I think we were stoned."

6. Overview of IAU Congress
August 24, International Astronomical Union (IAU) met to reclassify Pluto from a planet to a dwarf planet.
There are now 8 “true” planets.
3 “dwarf” planets were named.

7. What is a “true” planet? A “planet” is a celestial body that…
is in orbit around the Sun,
has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape,
has cleared the neighborhood around its orbit.
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune

8. What is a “dwarf” planet?
A “dwarf planet” is a celestial body that…
is in orbit around the Sun,
has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape,
has not cleared the neighborhood around its orbit,
is not a satellite
Currently 3 named - Pluto, Ceres, and Eris

9. Pluto, Eris, Ceres

10. True Planets vs. Dwarf Planets
Orbit around the Sun
Sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium shape
Has cleared the neighborhood around its orbit
Orbit around the Sun
Sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium shape
Has not cleared the neighborhood around its orbit
Not a satellite

11. Small Solar-System Bodies
All other objects except satellites orbiting the Sun shall be referred to collectively as “Small Solar-System Bodies”.

12. Moons of Pluto 2 new moons were named by the IAU Hydra and Nyx
Charon still is considered a moon

14. The Pluto Quadruple System
Hydra
Nix
Charon
Pluto
Combination of Four Hubble ACS Images
Taken on 2006 Feb 15.6 UT

32. New Horizons Pluto/KBO Mission

33. Mission to Pluto
“New Horizons” is a current mission designed to fly by Pluto and its moons to send data back to Earth
Launched January 19, 2006
Should encounter Pluto on July 14, 2015 (will study Pluto for ~9 months)
Mission will proceed to the Kuiper Belt (will last 5-10 years)

34. Launch 2006 January 19 14:00 EST
Launched on Atlas V Rocket
Fastest Earth departure ever
(36,000 mph)
Passed Moon’s orbit in 9 hours
Pass orbits of:
Mars on 4/7/2006
Jupiter on 2/28/2007
Saturn on 6/8/2008
Uranus on 3/18/2011
Neptune on 8/24/2014
Pluto system encounter on 7/14/2015
Total Cost ~$710M (FY08)

36. New Horizons Year–by-Year

38. New Horizons “Firsts” First mission to Pluto
First since launch Voyager in 1977 to an unexplored planet
First mission to explore a double planet
First mission to explore an ice dwarf
First mission to study Kuiper Belt Objects
Fastest space mission ever launched
First planetary mission to carry a student built instrument