Planetary Issues

This morning I found a message in the e-mail inbox from Andrew Fraknoi of Foothill College and editor of the Astronomy Education Review. The note highlights the articles in the latest issue. Among them is "Teaching What a Planet Is: A Roundtable on the Educational Implications of the New Definition of a Planet." The article is an in-depth look at seemingly every issue about the International Astronomical Union's controversial definition of a planet from the points of view of 14 astronomers and educators. Interesting stuff!

I haven't looked through it all yet, but one part that made me pause was that "dwarf" — as in "Pluto is now a dwarf planet" — is a problematic word for more reasons than I first considered. It's bad enough that a dwarf star is still a star, and a dwarf galaxy is still a galaxy, but a dwarf planet isn't a planet. In his introduction to the AER article, David Morrison explains: "Although astronomers have a long tradition of using this word (e.g., dwarf star, dwarf galaxy), this is not a common word in general usage. To many people, apparently, dwarf has a negative connotation, which was not intended by the IAU. (There may also be some problems with translating this word into other languages.)"

Check out the article, and . . . discuss!