Pluto: Then & Now; speech
1: intro and basic description
I did my project on Pluto and how our theories and ideas have changed over the years astronomers have been researching it. Pluto is a "dwarf planet" in the Kuiper Belt, beyond Neptune. For years it was thought of as the ninth planet, but in 2006 is was classified as dwarf. A dwarf planet is a celestial body that orbits the Sun that has a big enough mass to assume a perfect sphere or close to one. They can have moons and they travel in zones of objects similar to it. Many people make the mistake of saying "dwarf planet" but that term is actually wrong. That name would suggest that the body being talked about actually is a planet, and its not. The right way to refer to it is plutoid, planetoid or trans-Neptunial body
3: pluto's not a planet anymore
On August 24, 2006 the IAU, or the International Astronomical Union, redefined the standards for a planet that excluded Pluto. This was a major topic of controversy when the news first broke out. Which raised up a flux of articles and news stories on the subject.
2: other dwarf planets
Scientists expect that there are hundreds of dwarf planets yet to discover; but the five confirmed ones are : Pluto, Ceres, Eris, Haumea and Makemake. Pluto, in fact, has 3 moons or satellites: Charon, Nix and Hydra. Charon was found in 1978 by Jim Christy, its nearly the size of Pluto and they are sometimes called a double dwarf planet. In early pictures of Pluto, Pluto looks very big because the image blurred Charon and Pluto together. Nix and Hydra, the other two moons discovered in 2005, are extremely small at only 50-60 km in diameter each.
6: Its Name
Pluto was named by Venetia Burney who was an 11 year old from Oxford, England. The Roman god of the underworld who transported the dead across the River Acheron into the underworld, is Pluto, the name was based on this and that Pluto's discoverer, Percival Lowell's, initials are PL and those are the first two letters in Pluto obviously. Her grandfather thought it was a good name so he told people at Lowell Observatory. Pluto's biggest moon, Charon, was named after it's discoverer's wife : Charlene.
5: physical characteristics
it is about 1/5 the size of Earth, in diameter. a.k.a 2/3 the size of our moon. Pluto's core is rocky and its mantle is made of water ice with a surface layer of methane ice and nitrogen frost. As it gets closer to the sun, the ice around it transforms into a thin atmosphere. It gets strong winds when this happens. But when it gets farter away from the sun, the atmospher freezes and it becomes very cold, like around -375 F or -225 C. Because its gravity is 1/20th of Earth's, it's atmosphere extends farther. It is possible that it had carbon monoxide frost that is what the reddish grayish spots on pictures of it may be. Pluto has been getting more red over time meaning that there may be more carbon monoxide over time.
4: orbital characteristics
orbits 39.5 AU's from the sun. an AU is the average distance from the sun, we are 1 AU from the sun so Pluto is 39.5 times as far away from the sun as us. Its orbit is not consistently in a ring, it gets closer to the sun than Neptune for every 10/124ths of an Earth year. Pluto's and Neptune's orbits do cross but it will never be at the same time (thats what we think) so they should not ever collide.
