On February 18, 1930, humans decided to call the rocky space orb at the edge of our solar system “Pluto” and “the ninth planet from the sun”.
Many people still remember learning this in school.
76 years later…
On August 24, 2006, the definition for “planet” had been altered enough for Pluto to no longer classify as planet and thus was demoted to “dwarf planet”.
Many people are still unhappy about this.
A small change in scientific definition.
But a big change for a space rock.
#PlutoDemotedDay
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