[Chaos-l] Pluto demoted; threatens to withdraw from solar system entirely

[D Gary Grady]

The IAU's new definition of "planet" leaves us with eight planets rather 
than nine or twelve, and creating a new category of "dwarf planets" that 
includes Ceres, Pluto, and "Xena":

http://skytonight.com/news/home/3728231.html

Other articles:

http://www.bloomberg.com/apps/news?pid=20601085&sid=aK.m.ZTg.GOc&refer=europe

http://www.npr.org/templates/story/story.php?storyId=5703014

http://news.com.com/Images+Its+official-Plutos+out/2300-11397_3-6106240.html

http://tennessean.com/apps/pbcs.dll/article?AID=/20060824/NEWS08/60824005

None of these, not even the first one (Sky & Telescope's) is very clear 
on exactly why Pluto and Ceres were booted out of the lineup, except 
that it has to do with orbital dynamics; Pluto and Ceres don't 
gravitationally dominate their orbital neighborhoods.

A relatively small number of astronomers actually voted, and a lot of 
people are griping about the decision, so the subject might well be 
revisited. Some even note that there's a case to be made for 
distinguishing the gas giants from the rocky planets (but then might 
Venus qualify as a dwarf gas giant?)...

Finally, here's Clyde Tombaugh's widow's reaction (in brief, Tombaugh 
would not have been distressed by Pluto's change of status):
http://today.reuters.com/news/articlenews.aspx?type=scienceNews&storyid=2006-08-24T182026Z_01_N24440274_RTRUKOT_0_TEXT0.xml&src=082406_1432_FEATURES_science

-- 
D Gary Grady
Durham NC USA
dgary at mindspring.com