science and it would never pass peer review" and claimed that Earth, Mars, Jupiter and Neptune have not fully cleared their orbital zones and has stated in his capacity as PI of the New Horizons project that "The New Horizons project [...] will not recognize the IAU's planet definition resolution of August 24, 2006." A 2000 paper by Stern and Levison proposed a system of planet classification that included both the concepts of hydrostatic equilibrium and clearing the neighbourhood used in the new definition, with a proposed classification scheme labeling all sub-stellar objects in hydrostatic equilibrium as "planets" and subclassifying them into "überplanets" and "unterplanets" based on a mathematical analysis of the planet's ability to scatter other objects out of its orbit over a long period of time. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune were classified as neighborhood-clearing "überplanets" and Pluto was classified as an "unterplanet". One could take this classification system as planet and dwarf planet respectively, with the major difference of the IAU definition classifying the two as distinct categories of celestial bodies instead of two subsets of planets. Satellite planets and belt planets Some large satellites are of similar size or larger than the planet Mercury, e.g. Jupiter's Galilean moons and Titan. Stern has argued that location should not matter and only geophysical attributes should be taken into account in the definition of a planet, and proposes the term satellite planet for a planet-sized object orbiting another planet. Likewise planet-sized objects in the asteroid belt or Kuiper belt should also be planets according to Stern. Others have used the neologism planemo'' (planetary-mass object) for the broad concept of "planet" advocated by Stern. Selected bibliography References 1957 births Planetary scientists Pluto's planethood New Horizons Jewish American scientists Jewish engineers St. Mark's School (Texas) alumni Living people Discoverers of trans-Neptunian objects NASA people University of Texas at Austin College of Natural Sciences alumni University of Colorado Boulder alumni Cockrell School of Engineering alumni