Facts: - fields: astronomy - workplaces: southwest research institute - doctoral advisor: d.o. richstone - birth date: march 1 , 1959 - name: harold f. levison - nationality: united states - image: levisonh-full . jpg - birth place: philadelphia , pa - alma mater: franklin and marshall college Based on these bullet points, write a short biography describing the life of harold f. levison .
Answer:
harold f. '' hal '' levison is a planetary scientist specializing in planetary dynamics .he argued for a distinction between what are now called dwarf planets and the other eight planets based on their inability to '' clear the neighborhood around their orbits '' , although his proposal suggested the terms '' unterplanet '' and '' uberplanet '' and used the word '' dwarf '' to mean something else .among other distinctions , he is the co-author of swift , a commonly used symplectic integrator that solves planetary equations of motion for periods of billions of years .he currently works at the southwest research institute , boulder , co , and studies planetary orbits and their evolution through solar system history .