Overview
- NASA Administrator Jared Isaacman told a Senate budget hearing he wants Pluto recognized as a planet again and said NASA is preparing papers to restart the scientific discussion.
- He also framed the push as a way to honor astronomer Clyde Tombaugh, the American who discovered Pluto in 1930.
- The International Astronomical Union, not NASA, sets planetary definitions, reports no active redefinition effort, and would have to vote on any change at its next General Assembly.
- Under the IAU’s 2006 rules a planet must orbit the Sun, be round, and clear its path in space, which Pluto does not do because it shares the Kuiper Belt with many objects.
- A bid to broaden the definition, such as the geophysical approach championed by some scientists, would likely add many more planets, while others like Mike Brown argue the current standard better organizes what we find in the Solar System.