Thursday, August 24, 2006

Pluto is no longer a Planet

Since 1930 Pluto has been the little, last planet known at the end of the Milky Way solar system. That has changed. Pluto was stripped of it's planet status when astronomers developed new historic guidelines on what constitutes a planet. So after 76 years, Pluto got a demotion.

The new rules for a planet is as follows:

"a celestial body that is in orbit around the sun, has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a ... nearly round shape, and has cleared the neighborhood around its orbit."

Apparently Pluto is oblong and overlaps with Neptune. Who knew?

Pluto is now considered a dwarf planet and apparently there could be dozens of other dwarf planets. Third grade was a long (long!) time ago, but I don't remember dwarf planets.

Sadly, my third grade paper mache model of the solar system is outdated now. Wow--I'm old.

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