Scope on the Skies: And then there were eight

by: Bob Riddle

This past summer the International Astronomical Union (IAU) approved new definitions for objects in our solar system that orbit the Sun. The definitions now allow for only eight planets, while objects smaller than planets will be known as dwarf planets, and those even smaller will be referred to as small solar system bodies. Most notable of the changes was the redefinition of planet and the subsequent transfer of Pluto from planetary status to its new designation as a dwarf planet. The reasoning behind the new definitions and the reclassification of objects is illuminated in this month’s Scope on the Skies column.


Type Journal ArticlePub Date 1/1/2007Stock # ss07_030_05_78Volume 030Issue 05

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