[meteorite-list] 'Plutons' Push Planet Total Up To 12

[Sterling K. Webb]

Hi, Ron and List

    Just WHAT are those Scotsmen drinking?!!
    "The other plutons are Charon, currently described
as a moon of Pluto..."
    Please tell me the IAU is not going to name a
satellite as a planet!! Chaos! Confusion! Heresy!
    It's just a shame that the bottle got to The Scotsman
before the news did... I hope.

    Spoze he meant CHIRON?

Sterling
-----------------------------------------------------------
----- Original Message ----- 
From: "Ron Baalke" <baalke at zagami.jpl.nasa.gov>
To: "Meteorite Mailing List" <meteorite-list at meteoritecentral.com>
Sent: Tuesday, August 15, 2006 10:54 PM
Subject: [meteorite-list] 'Plutons' Push Planet Total Up To 12



>

> http://news.scotsman.com/scitech.cfm?id=1194292006

>

> 'Plutons' push planet total up to 12

> JOHN VON RADOWITZ

> The Scotsman

> August 15, 2006

>

> A NEW kind of planet, the "pluton", could soon be taking its place in the

> Solar System.

>

> Astronomers have agreed on a draft proposal for redefining what

> constitutes a planet.

>

> If approved at a meeting underway in the Czech capital, Prague, school

> science text books will have to be re-written.

>

> The new definition would mean there are 12, not nine planets, and more

> could be added to the list in the future.

>

> They include eight "classic" planets - Mercury, Venus, Earth, Mars,

> Jupiter, Saturn, Uranus and Neptune - Ceres, currently considered an

> asteroid, and three "plutons," one of which is Pluto.

>

> The other plutons are Charon, currently described as a moon of Pluto,

> and the newly-discovered object 2003 UB313, which has not been named

> officially, but is nicknamed Xena.

>

> Ceres is the largest object in the asteroid belt between Mars and

> Jupiter, and like a planet is spherical in shape.

>

> A resolution to accept the new planet definition will be voted on by

> members of the International Astronomical Union (IAU) next Thursday,

> 24 August. If passed, the days of simply learning the names of the

> nine planets will be over for the world's schoolchildren. In future,

> many more planets could join the Sun's family as other plutons are

> discovered.

>

> A dozen "candidate planets" are already on the IAUs "watchlist". They

> include Varuna, Quaor and Sedna, all Pluto-like objects residing

> within a region on the fringe of the Solar System known as the

> "Kuiper Belt".

>

> Plutons differ from classical planets in that they have orbits round

> the Sun that take longer than 200 years to complete, and their orbits

> are highly-tilted and non-circular.

>

> All these characteristics suggest that they have an origin different

> from that of classical planets.

>

> The IAU has taken two years working out the differences between planets

> and smaller Solar System bodies such as comets and asteroids.

>

> IAU president Professor Ron Ekers said: "Modern science provides much

> more knowledge than the simple fact that objects orbiting the Sun

> appear to move with respect to the background of fixed stars.

>

> "For example, recent new discoveries have been made of objects in the

> outer regions of our Solar System that have sizes comparable to and

> larger than Pluto.

>

> "These discoveries have rightfully called into question whether or not

> they should be considered as new 'planets'."

>

> According to the new draft definition, two conditions must be satisfied

> for an object to be called a "planet".

>

> First, the object must be in orbit around a star, while not itself

> being a star. Second, and most importantly, it must be massive enough

> for its own gravity to pull it into a nearly spherical shape.

>

> The IAU, responsible for the naming of planets and moons since 1919,

> set up a Planet Definition Committee (PDC) to consider the problem.

> Committee member Professor Richard Binzel said: "Our goal was to find a

> scientific basis for a new definition of planet, and we chose gravity

> as the determining factor.

>

> "Nature decides whether or not an object is a planet."

>

> Mnemonic needed

>

> IF ASTRONOMERS decide to change the number of planets in our solar

> system then piles of science textbooks will have to be rewritten.

>

> Generations of children have learned the names of the planets using

> mnemonics, listing the celestial bodies in their order from the Sun.

>

> "My Very Eager Mother Just Sent Us Nine Pies" is one popular aide

> memoir, helping students to remember Mercury, Venus, Earth, Mars,

> Jupiter, Saturn, Uranus, Neptune and Pluto.

>

> Other useful phrases include "Make Very Easy Mash - Just Squash Up

> New Potatoes" and "My Very Easy Method Just Showed Us Nine Planets".

>

>

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