Last seen approximately 3.7 billion miles from the sun. Answers to the name Pluto.
It was discovered in 1930 by Clyde Tombaugh, after a 30+ year search, started by Percival Lowell in the late 1800s, and lost to us last week, when the International Astronomical Union Working Group For Planetary System Nomenclature passed a resolution and declined to continue calling Pluto a planet.
It's now been re-classified as a dwarf planet, leaving us with 8 standard planets, and 3 dwarf planets - Pluto, the currently unnamed 2003 UB313 ("Xena"), and Ceres (in the asteroid belt).
The resolution describes a dwarf planet as an object 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 neighbourhood" around its orbit
* Is not a satellite of a planet, or other nonstellar body.
The main argument against Pluto and planethood is that a dwarf planet does not clear its orbital neighbourhood. Under this new definitions, If Pluto wanted to be a planet, it would need to clear the millions of ice and rock objects way out there in the Kuiper Belt, and reign supreme.
Pluto was named after the Roman god of the dead, chosen in part to
commemorate Percival Lowell by its first two letters. It's astronomical symbol
is a monogram of the letters PL. In the Chinese, Japanese, and Korean languages
the name was translated as Star of the King of the Dead. In Vietnamese it is named after Yama, the Guardian of Hell in Hindu traditions.
Found - three dwarf planets
Traditionally, dwarf planets are known as minor planets. The IAU resolution has redefined two previous large solar system objects (and one prior planet!) as dwarves. Not Happy, Sleepy and Sneezy, these three dwarves would be better known as
Freezy - Pluto, at minus 233 degrees Celsius
Creepy - Xena, takes 557 years to complete one orbit around the sun; and
Teensie - Ceres, with a mass compared to earth a mere .00016.
Our system now looks like this image here on APOD:
Way back when the controversy of Pluto - Planet or PlaNot heated up, singer/songwriter Christine Lavin penned a little piece on the subject - lyrics under the cut
( Read more...Collapse )
If anyone is sufficiently interested, I can upload a copy of the mp3.
But now for the big question - what's the new mnemonic for this lineup of planets?
The traditional mnemonics are:
My Very Extravagant Mother Just Sent Us Ninety Parakeets
My Very Educated Mother Just Served Us Nine Pickles
My Very Easy Memory Jingle Seems Useful Naming Planets
My Very Excellent Memory Just Stores Up Nine Planets
Suggestions for new ones include:
My Very Exotic Mistress Just Showed Up Naked
My Very Educated Mother Just Served Us Noodles
My Very Evil Mother Just Served Us Nothing
What's your suggestion? Be creative!
for mundanes: most value easily memorised jingles, says union news.
in reverse: nicely unusual sexual jests make earthers very mortified.
for SGA: McKay values educational material, John sates urges naturally.
for HL: Methos vanquishes early memories, Joe scripts upheaval novel.
for Buffy: Most vampires eviscerate mortals, jealous Spike unable now.