Overview
- Testifying at a Senate hearing Tuesday, NASA Administrator Jared Isaacman said he supports making Pluto a planet again and disclosed that NASA is preparing papers to revive the discussion in the scientific community.
- The International Astronomical Union set Pluto’s 2006 downgrade and still controls any change, using a three-part test that requires a body to orbit the Sun, be round, and clear its orbital neighborhood.
- Planetary scientists remain split, with critics calling the label fight a distraction and some objecting to the timing after Isaacman backed proposals to cut NASA’s science budget roughly in half.
- Supporters point to NASA’s New Horizons flyby in 2015, which revealed mountains, glaciers, and other signs of active geology on Pluto, and argue for a geophysical definition that does not hinge on orbital clearing.
- NASA has not detailed the papers Isaacman referenced, and any formal shift would need international review that could widen the roster of planets to include many Pluto-like worlds in the Kuiper Belt.