OpinionAugust 24, 2026
Pluto still isn’t a planet—unless Earth’s moon is, too
On the 20th anniversary of Pluto’s infamous demotion, Mike “Pluto Killer” Brown explains why any reversal of that decision would be driven more by nostalgia than science
Stories by Mike Brown
Mike Brown is the Richard and Barbara Rosenberg Professor of Planetary Astronomy at the California Institute of Technology. He is best known for his 2005 discovery of the dwarf planet Eris, which prompted the reclassification of Pluto, and for his ongoing search for a hypothesized Planet Nine.