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Observational Data for Planets and Planetary Satellites

The creation of modern ephemerides involves the fitting to a wide variety of astronomical measurements (observations). This page presents the sets of observations that are currently being used in creation and improvement of modern planetary and lunar ephemerides as well as the planetary satellite ephemerides.

In addition to data maintained here at JPL, data in support of the planetary ephemerides are available at the Bureau des Longitudes, Paris.

Data for Planetary Ephemerides

These data are currently maintained by
William Folkner; JPL/Caltech (

Meridian Circle Timings (Transits)
[ Format ] [ References ]

Photographic Astrometry of Outer Planets and Satellites
[ Format ] [ References ]

Photographic Astrometry of Pluto
[ Format ] [ References ]

CCD Astrometry of the Outer Planets and Satellites
[ Format ] [ References ]

Astrolabe Observations
[ Format ] [ References ]

Radar Ranging

from Eupatoria, Crimea

from Goldstone, California

Spacecraft Encounter Estimates

Right ascension, declination and range estimates from spacecraft encounters with tracking data (Doppler, range, and VLBI) re-reduced in ICRF frame.

Spacecraft VLBI

Data from Magellan, Venus Express at Venus, Phobos, Mars Global Surveyor, Odyssey, Mars Reconnaisance Orbiter at Mars, and Galileo at Jupiter.

Mercury Spacecraft Range

Venus Spacecraft Doppler

Mars Spacecraft Ranging

Mars Spacecraft Doppler (Differenced Range)
[ Format ] [ References ]

Juno Spacecraft Range

Cassini Spacecraft Range

DSN Station Locations

Data for Lunar Ephemeris

Lunar Laser Ranging

These data are provided by the International Laser Ranging Service.

Data for Planetary Satellite Ephemerides

These data are currently maintained by
Robert Jacobson; JPL/Caltech (

Spacecraft Optical Data
[ Format ] [ Data Processing ]

FirstGov 2019-Oct-23 17:29 UT 
(server date/time)  
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