[meteorite-list] There Were Once 18 Planets...

[Ron Baalke]

http://www.spaceweather.com/

SpaceWeather.com
September 12, 2006

18 PLANETS:  Have you ever heard of the planet Hygea? It's 
listed in the 1850 Annual of Scientific Discovery along 
with 17 other planets:

[Full Text Graphic]
http://www.spaceweather.com/swpod2006/13sep06/Pollock1.jpg
Courtesy Joe Pollock, Appalachian State University. 

In those days, large asteroids such as Hygea, Ceres and 
Vesta were widely deemed planets. They appeared so in 
textbooks and scientific journals. Adding asteroids to the 
other known planets, Mercury, Venus, Earth, Mars, Jupiter, 
Saturn, Uranus and Neptune, gave a grand total of 18. Imagine 
the mnemonic: "My Very Educated [insert ten adjectives here] 
Mother Just Served Us Noodles."

The asteroids were eventually demoted. It was a long, 
drawn-out affair, marked by decades of disagreement and 
confusion. (Sound familiar?) By 1900, however, order was 
restored to the Solar System: the planet count was down to 
eight.

And then came Pluto...