Why The Debate?
- For the second type, they see:
and say
"look there are 8 planets".
- The dynamical definition of planethood is useful because it give us this.
- Indeed, the most useful classification schemes follow natural boundaries.
(Courtesy of J. Spencer)
click
Comets not plotted
The Kuiper belt contains roughly 1000 objects larger than Mimas!
- The roundness definition does not do this.
- Here is a good example by John Spencer.