Overview
- The International Astronomical Union set Pluto's current status in 2006 by defining a planet as a body that orbits the Sun, is roughly round, and has cleared its orbital neighborhood; Pluto meets the first two tests but not the third.
- New Horizons' 2015 flyby revealed active geology on Pluto, including glaciers and tectonic-like features, which many scientists cite as evidence that Pluto undergoes planetary processes similar to larger planets.
- NASA Administrator Jared Isaacman publicly said he wants Pluto returned to planet status and scientists such as Paul Byrne have argued publicly for a geophysics-based definition that would count worlds like Pluto as planets.
- Changing Pluto's classification would require a new consensus within the astronomical community because the IAU also cataloged Pluto as minor planet 134340 and no formal mechanism now exists to unilaterally override that decision.
- Beyond technical arguments, the debate touches public understanding and science communication, with proponents saying the 'demotion' narrative has distracted attention from Pluto's complex science and could shape future public support for missions.