[meteorite-list] 'Plutons' Push Planet Total Up To 12
From: Sterling K. Webb <sterling_k_webb_at_meteoritecentral.com>
Date: Wed Aug 16 00:09:15 2006 Message-ID: <008201c6c0e9$0c0adfb0$6a4fe146_at_ATARIENGINE> 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". > > > ______________________________________________ > Meteorite-list mailing list > Meteorite-list_at_meteoritecentral.com > http://six.pairlist.net/mailman/listinfo/meteorite-list > Received on Wed 16 Aug 2006 12:04:18 AM PDT |
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