| A New Scientific Paper Argues the Moon is a Planet—And So is Pluto
Every now and then a scientific paper makes a real splash. We had one recently, to judge from recent headlines. "Moon rises to claim its place as a planet" said The Sunday Times on February 19, while the Mail Online asked "Is this lunarcy?". The articles were among many responding to the humble paper: "A Geophysical Planet Definition," which suggested that the criteria for determining what constitutes a planet need an overhaul. It argued that the moon, Pluto and several other bodies in the solar system should be upgraded to planets. The paper, published in Planetary and Lunar Science, was written by a team including Alan Stern. Stern is famous for NASA's New Horizons mission, which made its spectacular flyby of Pluto in July 2015. The paper is a bit technical, but it basically argues that the geophysics of a body should determine whether it is a planet—not just whether it orbits the sun. Of course, Stern has an axe to grind. He remains furious that, in 2006, the International