Working Group on Natural Planetary Satellites
of IAU DIVISIONS 1 and 3 (commissions 4, 7, 8, 16, 20)


The Working Group on Natural Planetary Satellites was created in 1973 at the IAU General Assembly in Sydney (cf. report of Commission 20) in order to overhaul the theories of the motions of the satellites. At the present, the motions of many of the natural satellites are not well-known, especially those recently discovered by the Voyager space probes. To promote the development of high-quality ephemerides, the Working Group encourages theoretical studies, coordinates observations, and makes all data available to the user. In 1991, at the General Assembly in Buenos Aires, the Working Group proposed resolutions to make the observations more readily available.


The members of the Working Group are:
K. Aksnes, J.E. Arlot (chairman), C. Blanco, N. Emelianov, R.A. Jacobson,
G. Krasinsky, J.H. Lieske, D. Pascu, M. Rapaport, M. Soma,
P.K. Seidelmann, D.B. Taylor, R. Viera-Martins, G. V. Williams.
Click here to obtain contacts and addresses.


For each triennum, the Working Group provides a report on the activities performed on Natural Satellites. These reports are available below:

  • Report 1972-1975
  • Report 1975-1978
  • Report 1978-1981
  • Report 1981-1984
  • Report 1984-1987
  • Report 1987-1990
  • Report 1990-1993
  • Report 1993-1996
  • Report 1996-1999
  • Report 1999-2002
  • Report 2002-2005
  • Report 2005-2008

    Meetings of interest for Natural Satellites purpose:

  • Workshop "Observations of the mutual events of the Uranian satellites in 2007-2008 and further observations in network" to be held in Paris, France on November 16-18, 2006. Program here.
  • Symposium "A Giant Step for Astrometry: Hipparcos to Gaia" held in October 2007 in Shanghai, China. Program here.
  • A French-chinese spring school on Astrometry of Solar system objects will be organized in Beijing on April 7-13, 2008. Program and registration here.
  • International Astronomical Meeting Dynamics of Solar System Bodies to be held in Tomsk, Russia on July 27-31, 2008. Program available here.
  • Future ground-based solar system research to be held in Isola d'Elba, Livorno, Italy on September 8-12, 2008. Program available here.
  • European Planetary Science Congress to be held in Muenster, Germany on September 21-26, 2008. Program available here.
  • DPS of the AAS to be held at Cornell University, Ithaca, NY, USA on October 10-15, 2008. Program available here.
  • IAU Symposium 261: Relativity in Fundamental astronomy, to be held in Virginia Beach, Va, USA on 27 April-May 1, 2009. Program here.
  • General Assembly of the IAU to be held in Rio de Janeiro, Brazil on August 3-14, 2009. Program here.
  • IAU Symposium 263: Icy bodies of the solar system, to be held in Rio de Janeiro, Brazil on August 3-7, 2009, during the IAU GA. Program here.

    The Natural Satellites Data Center NSDC:

    Following the resolution of Commission 20, a Data Center providing astrometric observations of the Natural Planetary Satellites was settled. This Data Center NSDC is established on a work station at the IMCCE and provides astrometric observations under several forms.

    Constants and Data concerning the Natural Satellites:

  • Orbital elements, masses, albedoes and magnitudes
  • Parameters of the rotation (IAU WG on Cartographic Coordinates and Rotational Elements)

    Theoretical dynamical models of motion

  • MARS_SAT_V1 theory of the motion of the Satellites of Mars
  • L1 synthetic theory of the motion of the Galilean satellites
  • TASS17 theory of the motion of the First Eight Satellites of Saturn
  • GUST86 theory of the motion of the First Five Satellites of Uranus

    Natural Satellites Ephemerides Servers:

  • EPHEMERIDES Natural Satellites Server of Institut de mecanique celeste IMCCE (Paris) and Sternberg Institute (Moscow) (server MULTI-SAT)
  • EPHEMERIDES Server of the Jet Propulsion Laboratory (server HORIZONS)
  • EPHEMERIDES Server of the Minor Planet Center (Outer irregular satellites ephemerides)

    Other servers of interest for Natural Satellites purpose:

  • Campaign of observations PHEMU09 (mutual events of the Jovian and Saturnian satellites in 2009)
  • Planetary System Nomenclature of USGS
  • Giant planets Satellites System Pages of Scott Sheppard
  • Enceladus focus group
  • Mallama's Galilean Satellites Eclipses Timings
  • Campaign of observations PHE-URA07 (mutual events of the Uranian satellites)
  • Campaign of observations PHEMU03
  • Campaign of observations PHESAT95
  • JPL'server on Galileo Solid State Imaging Full Data Releases
  • Minor Planet Center
  • Mc Donald Observatory Solar System Objects Astrometry from Wide Field CCD Imaging
  • Rings Node On-line Tools (Moon Trackers)

    Servers related to the IAU (International Astronomical Union):

  • International Astronomical Union (IAU server)
  • IAU commissions
  • IAU divisions

    Last update: February 4, 2009
    nswg (at)