X2 – Cross-Division A-F Commission Solar System Ephemerides


Solar System Ephemerides are developed for the Sun, Moon, planets, planetary satellites, asteroids and comets to support a broad range of scientific purposes. Since most observations of other bodies are made from Earth, precise knowledge of the orbit of the Earth is used for the reduction of many, if not most, astronomical observations. Accurate ephemerides of the Moon, planets, and planetary satellites are used in the planning and operation of interplanetary spacecraft missions. Ephemerides of the asteroid are used for evaluation of the origin of the solar system, for assessment of possible Earth impact events, and for many other purposes. Rotational elements for these bodies are closely associated with their ephemerides and are often used in data reduction.

The main objectives of the present commission are to promote the acquisition and dissemination of observations of solar system bodies and estimates of their ephemerides and rotational elements. New activities for the current triennium are hints of larger bodies on the Kuiper belt that may exist and correlate the orbits of the main belt and very distant objects. A symposium to discuss recent developments will be proposed.

Commission Web Page

Commission Members (106)

Under Division

Division A Fundamental Astronomy
Division F Planetary Systems and Astrobiology

William M. Folkner

JPL m/s 301-121
4800 Oak Grove Dr.
Pasadena 91109
California (CA)
United States

Phone: +1 818-354-0443
Email: williamfolknerjplnasagov

NCA adherence: United States

Last updated:
April 30, 2019

Giovanni B. Valsecchi

Via Fosso del Cavaliere 100
Tor Vergata
00133 Roma

Phone: +39 06 4993 4446
Email: giovanniiapsinafit
Organization website: http://www.iaps.inaf.it./

NCA adherence: Italy

Last updated:
April 30, 2019

Agnès Fienga

Observatoire de la Cote d'Azur
250 avenue A. Einstein
06250 Valbonne

Phone: +33 4 83618529
Email 1: agnesfiengaocaeu
Email 2: agnesfiengageoazurunicefr
Organization website: http://www.oca.eu

NCA adherence: France

Last updated:
April 30, 2019

Organizing Committee

Search Scientific Bodies


IAU Strategic Plan 2020–2030

Strategic Plan

IAU Code of Conduct

Code of Conduct

Symposia and Meetings


IAU General Assembly 2021



How to Become a Member

IAU Catalyst

Latest Catalyst

IAU e-Newsletter
Volume 2020 n° 8

Latest e-Newsletter

Subscribe to the e-Newsletter


IAU Office of Astronomy for Development

Office for Astronomy Development

IAU Office for Young Astronomers

Office for Young Astronomers

IAU Office for Astronomy Outreach

Office for Astronomy Outreach

IAU Office of Astronomy for Education

Office of Astronomy for Education

International School for Young Astronomers

International School for Young Astronomers