The link is at http://skytonight.com/community/skyblog/home/4313977.html .Teresa 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!


most recent comment
Planethood for Pluto & Eris
October 9, 2006
Both Pluto and Eris are a little less than one fifth the size of Earth, small seeming perhaps - and, yet, Earth is less than a tenth the size of giant Jupiter! It's all a matter of scale.

Also, a point to appreciate is the presense of a large Moon (both Pluto and Eris have one) changes the whole story. How many scientists would define the diameter of an atom by the width of its nucleus? Pluto and Eris aren't just planets* they are planetary systems with their own substantial
satellites.

Pluto's Moon Charon at 720 miles is actually larger than the giant asteroid - now "dwarf planet" - Ceres.

Eventually I believe Pluto will be reinstated proper to planethood (though perhaps with a distinction, a planet no less) and so then will Eris (Discordia) be upscaled so hopefully this new planet* can be given the rightful name Persephone or Proserpine as suggested by discoverer Mike Brown, Dane Rudhyar and many others.

Until then we may just be stuck with Discord.

–Steven L. Nelson