Big news in planetary circles, Pluto is no longer considered a planet:
… the International Astronomical Union stripped Pluto of the planetary status it has held since its discovery in 1930.
Much-maligned Pluto doesn’t make the grade under the new rules for a planet: “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.”
Pluto is automatically disqualified because its oblong orbit overlaps with Neptune’s. Instead, it will be reclassified in a new category of “dwarf planets,” similar to what long have been termed “minor planets.” The definition also lays out a third class of lesser objects that orbit the sun — “small solar system bodies,” a term that will apply to numerous asteroids, comets and other natural satellites.
Now we are down to 8: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Pluto will have to start eating with a different lunch crowd, hanging out with the likes of Ceres (an asteroid that was also demoted from planet status) and 2003 UB313 (who really wants to be accepted by the cool planets).