NASA Administrator Jared Isaacman has called for a reconsideration of Pluto’s planetary status in April 2026. Pluto was reclassified as a dwarf planet by the International Astronomical Union (IAU) in 2006 after it failed to clear its orbital neighbourhood.
Pluto and the IAU Planet Definition
The IAU adopted a formal definition of a planet in 2006. A body must orbit the Sun, have enough mass for hydrostatic equilibrium, and clear its orbital path of other debris. Pluto meets the first two criteria and does not meet the third criterion.
Pluto’s Reclassification in 2006
The IAU placed Pluto in the dwarf planet category at its 2006 General Assembly in Prague, Czech Republic. The decision also affected other trans-Neptunian objects that did not satisfy the full planet definition.
New Horizons Mission and Pluto Data
NASA’s New Horizons spacecraft flew past Pluto in July 2015. The mission returned images and measurements of Pluto’s surface, atmosphere, and moons, including Charon, Nix, Hydra, Kerberos, and Styx.
Recent Public Discussion
The renewed discussion followed a letter from Kaela Polkinghorn, a 10-year-old student from Tampa, Florida, who asked NASA to restore Pluto’s planet status. Isaacman stated that NASA is preparing papers to take the matter through the scientific community.
Earlier Views on Pluto
NASA Administrator Jim Bridenstine said in 2019 that he considered Pluto a planet. The IAU has stated that astronomical classifications depend on international consensus and evidence-based processes. Pluto remains one of the best-known dwarf planets in the Solar System. The IAU has not changed Pluto’s 2006 classification as of April 2026.
Last Modified: April 29, 2026