It’s Been 20 Years Since Astronomers Decided Pluto Isn’t a Planet
In August 2006, the International Astronomical Union reclassified Pluto from a planet to a dwarf planet after defining “planets” as objects that (1) orbit a star, (2) are massive enough to become nearly round, and (3) have cleared the neighborhood around their orbit of similar-size objects.
Aug 24, 2026 ·
CNET


















