Pluto demotion debate intensifies twenty years after IAU decision

Two decades after the International Astronomical Union (IAU) voted in August 2006 to reclassify Pluto from a major planet to a dwarf planet, the debate over the decision remains highly polarized. The reclassification reduced the number of recognized planets in the solar system from nine to eight.

Critics of the decision, including scientists like Philip Metzger of the University of Central Florida, argue that the IAU's new definition of a planet is scientifically non-useful. Advocates for Pluto's reinstatement include historians from the Lowell Observatory and various amateur astronomers who participate in campaigns such as the ‘Pluto Resistance’.

While the movement to reinstate Pluto's status is largely centered in the United States, the debate has recently gained political attention. NASA administrator Jared Isaacman has expressed support for rethinking the classification during congressional testimony.