Earth, Moon, and Planets

, Volume 100, Issue 1–2, pp 83–116 | Cite as

New Definition of Discovery for Solar System Objects

  • Andrea Milani
  • Giovanni F. Gronchi
  • Zoran Knežević


We propose a new formal definition of discovery for a Solar System object. It is based on an objective and mathematically rigorous algorithm to assess when a set of observations is enough to constitute a discovery. When this definition is satisfied, in almost all cases the orbit is defined well enough to establish the nature of the object discovered (Main Belt vs. Near Earth Asteroid, Trans-Neptunian vs. long period comet). The frequency of occurrence of exceptions is estimated by a set of numerical experiments.

The availability of a non-subjective definition of discovery allows some rules to be adopted for the assignment of discovery credit with a minimum risk of dispute. Such rules should be fair, encourage good practice by the observers and acknowledge the contribution of the orbit computers providing the identifications and the orbits, as well as the one of all the contributing observers.


discovery orbit determination asteroids comets Trans-Neptunians 


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This research has been funded by the Italian Ministero dell’Università e della Ricerca Scientifica e Tecnologica, PRIN 2004 project “The Near Earth Objects as an opportunity to understand physical and dynamical properties of all the Solar System small bodies” and by the Ministry of Science and Environmental Protection of Serbia project 146004 “Dynamics of Celestial Bodies Systems and Populations”. We thank G.B. Valsecchi and R. Jedicke for enlightening discussions on this subject and S. Chesley for a careful review with many suggestions.


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Copyright information

© Springer Science+Business Media, Inc. 2006

Authors and Affiliations

  • Andrea Milani
    • 1
  • Giovanni F. Gronchi
    • 1
  • Zoran Knežević
    • 2
  1. 1.Department of MathematicsUniversity of PisaPisaItaly
  2. 2.Astronomical ObservatoryBelgradeSerbia

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