PBS posted some very amusing hate mail sent from 3rd graders to the Natural History museum director about removing Pluto from the standard planetary system and labeling it instead as an icy comet.
Third graders — they can be so menacing at times. :) Read those angry letters here.
These third graders make more sense than the four percent of the IAU who voted on the ridiculous demotion. Even Tyson has come around to admitting there is no consensus among astronomers as to Pluto’s planet status. Only four percent of the IAU voted on this, and most are not planetary scientists. Their decision was immediately opposed in a formal petition by hundreds of professional astronomers led by Dr. Alan Stern, Principal Investigator of NASA’s New Horizons mission to Pluto. Stern and like-minded scientists favor a broader planet definition that includes any non-self-luminous spheroidal body in orbit around a star. The spherical part is important because objects become spherical when they attain a state known as hydrostatic equilibrium, meaning they are large enough for their own gravity to pull them into a round shape. This is a characteristic of planets and not of shapeless asteroids and Kuiper Belt Objects. Pluto meets this criterion and is therefore a planet. Under this definition, our solar system has 13 planets: Mercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto, Haumea, Makemake, and Eris.