Calendar Curiosities: February 18, 1930 – Pluto Discovered
As the resident Skepchick in charge of Calendars (applications currently being accepted!!), I thought I’d bring you some short takes on dates of interest.  We’ll start today, Pluto Discovery Day!
 Very short backstory: Back in 1930, astronomer Clyde Tombaugh, at Lowell Observatory in Flagstaff, Arizona, discovered the dwarf planet we know as Pluto.  Until August 2006 it was considered the Solar System’s 9th planet, and is the largest known Kuiper Belt Object (KBO) today.
 Skepchick point of interest: A recent example of the scientific community using evidence to inform and improve. After other KBOs were first discovered in 1992 (there are now more than 1000) the 26th General Assembly of the International Astronomical Union created a formal definition for “planet;” and Pluto didn’t make the grade. Still worth studying regardless,  NASA’s New Horizons mission is on it’s way to visit Pluto. Only 2703 Earth days to go!
Not-so-Skepchick?: Astrologers carry on as ever.  Oh, except some were miffed the IAU didn’t consult them when de-planetifying Pluto, and plan to disregard the new classification. This should not be too surprising, as the 10 “planets” of astrology don’t include the earth, but do include the Sun.   Â
Oh, ordinarygirl! Perfect logical reasoning in your case. However, you have forgotten the "planet" closest to us, without being us. The "planet" you're missing is….the moon.
Yeah.
Some astrologers do include Ceres, as well as Vesta, Pallas Athene and Juno. Some even include Chiron.
Excellent post! I’ve also posted a Happy Pluto Day message, and some of the astronomy geeks here in Alaska are headed to the bar tonight to lift a glass in honor of Clyde and his ex-planet. Everyone else should do the same. (Any excuse, you know?)
As for its planet status – I’m a cynic. But not for the reasons the astrologers are. IAU simply passed a vague resolution that didn’t have meaningful, unambiguous terminology, and fought out their differences in the press before passing a resolution, which was not a good thing from a PR perspective. Other than that, can’t say anything bad about it.
10 planets of astronomy?
8 planets + 1 dwarf planet = 9
9 – earth = 8
8 + sun = 9
Ceres? I’m missing one.
Which basically guarantees that it's wrong. ;)
Great post, A. To add some useless trivia that might be totally wrong: the name “Pluto” was chosen in part to honor Percival Lowell. PLuto. I . . . read that somewhere. And have no evidence to back it up. So.
For what it is worth.
The wikipedia article on Pluto makes the same claim about Percival Lowell.