IAU demoted Pluto to a dwarf planet spring . only 4 percent of the critical letters the IAU received afterward came from Mars . In spring , Illinois lawmakers restored `` full planetary status '' to Pluto . Some scientists say the International Astronomical Union 's definition of a planet does n't make sense .
International Astronomical Union demoted Pluto to a dwarf planet three years ago . 90 percent of the critical letters the IAU received afterward came from North America . In spring , Illinois lawmakers restored `` full planetary status '' to Pluto . Some scientists say the IAU 's definition of a planet does n't make sense .