The Invisible Earths
01- 2003 VB12: Sedna
02- AU
03- The Kuiper Belt
04- The Oort Cloud
05- Invisible Earths
06- Full System
07- Baby Worlds
08- Inti / Wild 2
09- Migration

01 - 2003 VB12: Sedna

Click here for enlarged diagram

 

Sedna, or 2003 VB12, was the first of the new Kuiper Belt objects to be discovered. Xena and others followed.

Xena, or UB 313, discovered in January 2005, was the first of these new objects to exceed Pluto's diameter, which further pushed the ongoing debate amongst astronomers as to the exact nature of a planet. The recent re-classification of the solar system, which more clearly defined a planet as 'rounded by its own gravity', thereby disqualifying large asteroids, was announced by the International Astronomer's Union, the IAU, in Summer 2006.

This re-classification demoted Pluto and promoted Ceres, which lies between Mars and Jupiter, in the asteroid belt, to the class of minor planets.

 
Alan Lambert 2013