Since it was stripped of planetary status, Pluto’s defenders have been fighting
Twenty years after Pluto was reclassified as a dwarf planet, the debate remains highly polarized among scientists and the public. Proponents of Pluto's planetary status argue that the IAU's definition is scientifically flawed and ignores the emotional significance of the celestial body.
Why it matters
The ongoing controversy illustrates the intersection of scientific taxonomy, public sentiment, and the role of institutional authority in defining reality.
Status anxiety … an artist concept of Pluto with its moons. Photograph: Universal History Archive/Universal Images Group/Getty Images Status anxiety … an artist concept of Pluto with its moons. Photograph: Universal History Archive/Universal Images Group/Getty Images Astronomy Forbidden planet: was Pluto’s 2006 demotion a big mistake? Since it was stripped of planetary status, Pluto’s defenders have been fighting the decision – and they’re only getting more passionate
Tim Dowling Mon 31 Aug 2026 00.00 EDT Last modified on Mon 31 Aug 2026 00.02 EDT Share Prefer the Guardian on Google T wenty years ago, Pluto got demoted. After a vote by the International Astronomical Union (IAU) in August 2006, Pluto was relegated from major planet to dwarf planet status. Our solar system dropped from nine planets to eight. At the time, many scientists were unhappy with the decision. Two decades on, the debate is, if anything, even more polarised.
Get smarter about the news
Sign up free for a feed built around what you actually care about, Dive Deeper research on any story, and the full text of every article.
Create free accountAlready have an account? Sign in