American astronomer Clyde Tombaugh didn’t just roll over. He sat straight up in his grave and loudly cried out to the IAU, “Seriously? What are you people thinking?!”
August 24, 2006. This was our inaugural Pluto Demoted Day.
Tombaugh, who discovered Pluto in 1930, must have been just as shocked as the rest of the world when the International Astronomical Union (IAU) made its stunning pronouncement.
Why? What in the world had Pluto done that was so wrong?
According to the IAU, because it was not gravitationally dominant, poor little Pluto failed to clear the established neighborhood around its irregular orbit.
The day Pluto was downgraded to dwarf status was sad for everyone who loves gazing up into infinity.
The fact that it is not visible without a powerful telescope is not the point. It is special because it was the last one discovered in our tiny corner of the universe. This is a planet that held a unique place in our imaginations and on the maps of our solar system.
Granted, Pluto took its own sweet time orbiting the sun once every 250 years, but it was our ninth planet for 76 years. Walt Disney named one of our favorite characters after the former planet that was named after the Greek ruler of the underworld.
If you feel it’s wrong to downgrade a heavenly body graced with five moons, NASA has your back. In 2017, the agency sent a proposal to the IAU that could change Pluto Demoted Day into Pluto Reinstated Day.
NASA’s arguments for an upgrade revolve around better defining the classifications of planets. We certainly hope NASA prevails and Tombaugh can finally rest easy. Until then, we will continue to observe August 24 with deep respect for our solar system’s designated underdog planet.