Since its discovery in 1930, Pluto was heralded as the ninth planet in our Solar System. Pluto was the first world ever discovered beyond Neptune, and for nearly half a century, was the only world known beyond our last gas giant. Generations of schoolchildren learned mnemonic devices about their very educated mother just serving them nine pickles, with Pluto, the very last, lonely one out there, becoming the favorite of so many.
After 76 years, however, astronomers seemingly demoted Pluto to dwarf planet status, placing it alongside the large asteroid Ceres and other worlds out there in the Kuiper belt, reducing our Solar System’s planetary count to a mere eight. Last year, a team of scientists put forth a new definition of planetthat would bring Pluto back into the fold, and this definition has been endorsed by Alan Stern and David Grinspoon, authors of a new book on the New Horizons mission and “the planet” Pluto.