In this outstanding and educational talk, [Michael Büker] walks us through the history of our understanding of the planets. The question “What is a planet?” is probably more about the astronomers doing the looking than the celestial bodies that they’re looking for. They got kicked out soon, but then when we started being able to see asteroids, Ceres, Vesta, and Juno made the list. But by counting all the asteroids, the number got up above 1,200, and it got all too crazy. Which we call “planets” and which we don’t is really about our perception of them and trying to fit this multiplicity into simple classification schemas.

Source: CBC News December 31, 2023 14:44 UTC