A Few Thoughts on Pluto

...the dog.  No, just kidding.

I read this article on space.com today about Pluto's planetary status.  In particular, it discusses the continuing debate on whether Pluto deserved to lose it's status as the 9th planet in our solar system.  In 2006 there was outrage when the International Astronomical Union (IAU) declared that there are 8 planets in our solar system, and that Pluto was now called a  "dwarf planet."

There are a number of reasons for the disagreements with this decision, but the one I want to address is what I'll call the sentimental value arguement.  This is made by those who say that since they learned in school that Pluto was a planet, so it can't be demoted to something else.  To all 1.6 million in the Facebook group "When I was your age, Pluto was a planet" I say GET OVER IT.

For this is not the heart of the issue.  It's "emotion" rather than sense.  In the words of Dr. Spock, it is "not logical."  The fact is, now "America's favorite planet" is now part of an even more select group of 5 dwarf planets, including the troublesome Eris.  Eris is estimated by astronomers to be larger than Pluto and even farther from the sun.  According to Wikipedia it was touted briefly as the 10th planet.  The other 3 are not quite so large - but the IAU couldn't justify upping the planet count to 13 (and potentially more as the Kuiper Belt is explored more closely), because Pluto couldn't be demoted.

The creation of a new class of dwarf planets makes sense because Pluto, Eris, Ceres (actually in the asteroid belt, between Mars and Jupiter), Haumea, and Makemake are so relatively small, even to Mercury, that they don't have much in common with the rest.  It's estimated that many more dwarf planets may exist, astonomers just haven't found them yet.

To those who are still saddened by Pluto's reclassification, take heart that Pluto can still be enjoyed, and that soon it will be the first among many newly discovered heavenly bodies.


Kal