KPL/PCK Planetary Constants (PCK) SPICE kernel file for the Galilean Satellites =============================================================================== Orientation and rotation model of the Galilean satellites (Io, Europa, Ganymede, and Callisto) developed by Yseboodt and Baland (2026) [1] Based on the NOE orbital motion. For an non-zero obliquity, assuming a solid and rigid satellite. This model does not have any diurnal libration yet. The kernel includes frames intended to serve as mission- or user-specific frames, allowing for the introduction of fixed rotational offsets and time-varying body rotation without modifying the IAU ones defined in pck00011.tpc Version and Date ------------------------------------------------------------------------------- Version 0.0 -- 2026 January 11 -- Marie Yseboodt (m.yseboodt@oma.be), Royal Observatory of Belgium Rafael Andres Blasco, ESAC/ESA Initial version. References and Sources ------------------------------------------------------------------------------- 1. Yseboodt, M., Baland, R.M., Transformation of orientation and rotation angles of synchronous satellites: Application to the Galilean moons, in review, Icarus, 2026. 2. Archinal, B.A., Acton, C.H., et al., "Report of the IAU Working Group on Cartographic Coordinates and Rotational Elements: 2015," Celestial Mechanics and Dynamical Astronomy 130, 22 (2018). DOI: https://doi.org/10.1007/s10569-017-9805-5 Explanatory Notes ------------------------------------------------------------------------------- This SPICE kernel includes the orientation and rotation model for the 4 Galilean satellites, developped in Yseboodt and Baland (2026) [1]. The orientation models express the direction of the pole and location of the prime meridian of the Galilean satellites as a function of time. Due to a reorganization of the frequency list to include additional terms in the models, the amplitude tables for Jupiter’s orientation and for its inner moons (Amalthea and Thebe) have been moved accordingly and are provided here as well. The orientation angles are expressed in Earth equatorial coordinates relative to the ICRF (labeled as "J2000"), namely: Right ascension (alpha) Declination (delta) Prime meridian location (W) These models account for a non-zero obliquity, based on a theoretical dynamical model for a rigid and solid satellite. They are an improved alternative to the orientation model adopted by the IAU Working Group on Cartographic Coordinates and Rotational Elements (WGCCRE) in [2] and included in the pck00011.tpc kernel, which relied on the Lieske (1979) rotation model and assumed zero obliquity. Two kernels are available: One based on the JUP387 ephemerides (R. Jacobson) One based on the NOE-5L ephemerides (V. Lainey) This one This kernel includes 14 fundamental frequencies shared among the four Galilean satellites, compared to 6 frequencies in [2]. In our solution, each frequency is assigned a sign (positive or negative) according to its original value in the forcing series, distinguishing prograde and retrograde motions. This convention is crucial for comparing with the free retrograde mode and assessing potential resonance amplifications. For each Galilean satellite, the expressions for the north pole's right ascension and declination, as well as prime meridian location, are sums of a linear polynomials and trigonometric polynomials, where the independent variable is time (in years, starting from J2000). The arguments of the trigonometric terms are linear polynomials. In this file, we call the arguments of these trigonometric terms "nutation precession angles". The orientation models for the inner Jovian moons have not yet been recomputed. However, since a reorganisation of the frequency order was needed, the amplitude coefficients of Jupiter and its inner moons (Amalthea and Thebe) were shifted to preserve consistency with [2] solution. No change for Metis and Adrastea because they have no periodic terms. For details about model accuracy, transformation errors, and validation, please refer to Yseboodt & Baland (2026) [1]. Orientation data provided in this file are used by the SPICE Toolkit to evaluate the orientation of body-fixed, body-centered reference frames with respect to the ICRF frame ("J2000" in SPICE documentation). These body-fixed frames have names of the form ROB_ Orientation models SPICE software expects the models for satellite orientation to follow the form of the model shown here: the polynomial portions of the RA, DEC, and W expressions are expected to be quadratic, the trigonometric terms for RA and W (satellite prime meridian) are expected to be linear combinations of sines of nutation precession angles, the trigonometric terms for DEC are expected to be linear combinations of cosines of nutation precession angles, and the polynomials for the nutation precession angles themselves are expected to be linear or quadratic. T represents centuries past J2000, d represents days past J2000. Body Numbers and Names ------------------------------------------------------------------------------- The following NAIF body ID codes and body names appear in this file. 501999 Io 502999 Europa 503999 Ganymede 504999 Callisto Orientation Constants for Jupiter + Frequencies of the Jovian system ------------------------------------------------------------------------------- Jupiter Old values: Values were from the IAU2015 report [2]. BODY5_NUT_PREC_ANGLES = ( 73.32 91472.9 24.62 45137.2 283.90 4850.7 355.80 1191.3 119.90 262.1 229.80 64.3 352.25 2382.6 113.35 6070.0 146.64 182945.8 49.24 90274.4 99.360714 4850.4046 175.895369 1191.9605 300.323162 262.5475 114.012305 6070.2476 49.511251 64.3000 ) Current values: For the nutation precession angles for Jupiter and its satellites, the frequency numbering has been reorganized compared to [2]. The model now includes 23 nutation–precession angles, expressed in degrees and degrees per century. First, the frequencies 1 to 5 correspond to angles Ja-Je in [2], useful for Jupiter orientation/rotation model. Ja = 99.360714 + 4850.4046 T Jb = 175.895369 + 1191.9605 T Jc = 300.323162 + 262.5475 T Jd = 114.012305 + 6070.2476 T Je = 49.511251 + 64.3000 T Second, the frequencies 6 to 9 correspond to the inner moons (Amathea and Thebe). The numerical values come from [2]. J1 = 73.32 + 91472.9 T 2*J1 = 146.64 + 182945.8 T J2 = 24.62 + 45137.2 T 2*J2 = 49.24 + 90274.4 T Third, the frequencies 10 to 23 correspond to the motion of the Galilean Satellites. The values for the precession/nutation arguments come from Yseboodt & Baland (2026) [1] and the NOE orbital theory. J3 = 259.686 - 4850.7 T J4 = 184.097 - 1191.8 T J5 = 59.999 - 261.79 T J6 = 59.519 - 261.73 T J7 = 308.856 - 64.286 T J8 = 309.328 - 64.229 T J9 = 273.900 - 52829.0 T J10 = 113.496 + 6069.9 T J11 = 8.194 - 2384.1 T J12 = 298.928 - 3034.7 T J13 = 244.217 - 1453.6 T J14 = 119.999 - 523.51 T J15 = 8.375 - 326.01 T J16 = 257.712 - 128.57 T BODY599_NUT_PREC_RA = (0.000117 0.000938 0.001432 0.000030 0.002150 ) BODY599_NUT_PREC_DEC = (0.000050 0.000404 0.000617 -0.000013 0.000926 ) BODY599_NUT_PREC_PM = (0.0 0.0 0.0 0.0 0.0 ) BODY5_NUT_PREC_ANGLES = ( 99.360714 4850.4046 175.895369 1191.9605 300.323162 262.5475 114.012305 6070.2476 49.511251 64.3000 73.32 91472.9 146.64 182945.8 24.62 45137.2 49.24 90274.4 259.686 -4850.7 184.097 -1191.8 59.999 -261.79 59.519 -261.73 308.856 -64.286 309.328 -64.229 273.900 -52829.0 113.496 6069.9 8.194 -2384.1 298.928 -3034.7 244.217 -1453.6 119.999 -523.51 8.375 -326.01 257.712 -128.57 ) Orientation constants for the Galilean satellites ------------------------------------------------------------------------------- Io Old values: Values were from the IAU2015 report [2]. Current values: The values come from Yseboodt & Baland (2026) [1] and the NOE orbital theory. Right ascension --------------- alpha = 268.0590 - 0.017 T + 0.0886 sin(J3) + 0.0233 sin(J4) + 0.0029 sin(J5) + ... 0 Declination ----------- delta = 64.4969 + 0.00028 T - 0.0382 cos(J3) - 0.01 cos(J4) - 0.0013 cos(J5) + ... 0 Prime meridian -------------- W = 200.3970 + 203.48895843 d - 0.0800 sin(J3) - 0.0210 sin(J4) - 0.0027 sin(J5) + ... \begindata BODY501999_POLE_RA = ( 268.0590 -0.017 0. ) BODY501999_POLE_DEC = ( 64.4969 0.00028 0. ) BODY501999_PM = ( 200.3970 203.48895843 0. ) BODY501999_LONG_AXIS = ( 0. ) BODY501999_NUT_PREC_RA = ( 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.0886 0.0233 0.0029 0. -0.0008 0. 0.0023 ) BODY501999_NUT_PREC_DEC = ( 0. 0. 0. 0. 0. 0. 0. 0. 0. -0.0382 -0.0100 -0.0013 0. 0.0003 0. -0.0010 ) BODY501999_NUT_PREC_PM = ( 0. 0. 0. 0. 0. 0. 0. 0. 0. -0.0800 -0.0210 -0.0027 0. 0.0007 0. -0.0020 ) BODY501999_NUT_PREC_ANGLES = ( 99.360714 4850.4046 175.895369 1191.9605 300.323162 262.5475 114.012305 6070.2476 49.511251 64.3000 73.32 91472.9 146.64 182945.8 24.62 45137.2 49.24 90274.4 259.686 -4850.7 184.097 -1191.8 59.999 -261.79 59.519 -261.73 308.856 -64.286 309.328 -64.229 273.900 -52829.0 113.496 6069.9 8.194 -2384.1 298.928 -3034.7 244.217 -1453.6 119.999 -523.51 8.375 -326.01 257.712 -128.57 ) \begintext Europa Old values: Values were from the IAU2015 report [2]. Current values: The values come from Yseboodt & Baland (2026) [1] and the NOE orbital theory. \begindata BODY502999_POLE_RA = ( 268.0850 -0.0169 0. ) BODY502999_POLE_DEC = ( 64.5068 0.0003 0. ) BODY502999_PM = ( 35.9187 101.37472463 0. ) BODY502999_LONG_AXIS = ( 0. ) BODY502999_NUT_PREC_RA = ( 0. 0. 0. 0. 0. 0. 0. 0. 0. -0.0049 1.2082 0.0591 0. 0. 0.0129 0.0007 0.0013 -0.0115 0.0007 -0.0011 ) BODY502999_NUT_PREC_DEC = ( 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.0021 -0.5200 -0.0254 0. 0. -0.0055 -0.0003 -0.0005 0.0025 -0.0003 0.0002 ) BODY502999_NUT_PREC_PM = ( 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.0044 -1.0906 -0.0534 0. 0. -0.0116 -0.0007 -0.0011 0.0116 -0.0006 0.0011 ) BODY502999_NUT_PREC_ANGLES = ( 99.360714 4850.4046 175.895369 1191.9605 300.323162 262.5475 114.012305 6070.2476 49.511251 64.3000 73.32 91472.9 146.64 182945.8 24.62 45137.2 49.24 90274.4 259.686 -4850.7 184.097 -1191.8 59.999 -261.79 59.519 -261.73 308.856 -64.286 309.328 -64.229 273.900 -52829.0 113.496 6069.9 8.194 -2384.1 298.928 -3034.7 244.217 -1453.6 119.999 -523.51 8.375 -326.01 257.712 -128.57 ) \begintext Ganymede Old values: Values were from the IAU2015 report [2]. Current values: The values come from Yseboodt & Baland (2026) [1] and the NOE orbital theory. \begindata BODY503999_POLE_RA = ( 268.2049 -0.0167 0. ) BODY503999_POLE_DEC = ( 64.5663 0.0041 0. ) BODY503999_PM = ( 44.1615 50.317607704 0. ) BODY503999_LONG_AXIS = ( 0. ) BODY503999_NUT_PREC_RA = ( 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. -0.1129 0.5025 0. 0. 0.0907 0. 0.0010 0. -0.0010 0.0009 -0.0020 -0.0007 ) BODY503999_NUT_PREC_DEC = ( 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.0485 -0.2158 0. 0. -0.0390 0. -0.0004 0. 0.0004 -0.0002 0.0004 0.0002 ) BODY503999_NUT_PREC_PM = ( 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.1019 -0.4538 0. 0. -0.0819 0. -0.0009 0. 0.0009 -0.0009 0.0020 0.0007 ) BODY503999_NUT_PREC_ANGLES = ( 99.360714 4850.4046 175.895369 1191.9605 300.323162 262.5475 114.012305 6070.2476 49.511251 64.3000 73.32 91472.9 146.64 182945.8 24.62 45137.2 49.24 90274.4 259.686 -4850.7 184.097 -1191.8 59.999 -261.79 59.519 -261.73 308.856 -64.286 309.328 -64.229 273.900 -52829.0 113.496 6069.9 8.194 -2384.1 298.928 -3034.7 244.217 -1453.6 119.999 -523.51 8.375 -326.01 257.712 -128.57 ) \begintext Callisto Old values: Values were from the IAU2015 report [2]. Current values: The values come from Yseboodt & Baland (2026) [1] and the NOE orbital theory. \begindata BODY504999_POLE_RA = ( 268.7352 -0.0157 0. ) BODY504999_POLE_DEC = ( 64.8188 0.00086 0. ) BODY504999_PM = ( 259.7765 21.571072689 0. ) BODY504999_LONG_AXIS = ( 0. ) BODY504999_NUT_PREC_RA = ( 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.1473 0.9183 0. 0. 0. 0. 0. 0. 0. -0.0021 -0.0067 ) BODY504999_NUT_PREC_DEC = ( 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. -0.0626 -0.3907 0. 0. 0. 0. 0. 0. 0. 0.0005 0.0014 ) BODY504999_NUT_PREC_PM = ( 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. -0.1333 -0.8310 0. 0. 0. 0. 0. 0. 0. 0.0021 0.0067 ) BODY504999_NUT_PREC_ANGLES = ( 99.360714 4850.4046 175.895369 1191.9605 300.323162 262.5475 114.012305 6070.2476 49.511251 64.3000 73.32 91472.9 146.64 182945.8 24.62 45137.2 49.24 90274.4 259.686 -4850.7 184.097 -1191.8 59.999 -261.79 59.519 -261.73 308.856 -64.286 309.328 -64.229 273.900 -52829.0 113.496 6069.9 8.194 -2384.1 298.928 -3034.7 244.217 -1453.6 119.999 -523.51 8.375 -326.01 257.712 -128.57 ) \begintext Auxiliary Body Frames ------------------------------------------------------------------------------- This frame kernel defines a set of custom, body-fixed reference frames for selected Jovian satellites. The frames defined here are intended to serve as mission- or user-specific frames, allowing for the introduction of fixed rotational offsets and time-varying body rotation. The name convention includes the prefix JUICE_ROB (Royal Observatory of Belgium) in order to differenciate them from the IAU ones. This kernel defines the following frames: Frame Name Frame ID Center ------------------ -------- ------- JUICE_ROB_IO 1501999 501999 JUICE_ROB_EUROPA 1502999 502999 JUICE_ROB_GANYMEDE 1503999 503999 JUICE_ROB_CALLISTO 1504999 504999 All frames defined in this kernel are: - Body-fixed - Time-varying - Centered on the associated target body \begindata FRAME_JUICE_ROB_IO = 1501999 FRAME_1501999_NAME = 'JUICE_ROB_IO' FRAME_1501999_CLASS = 2 FRAME_1501999_CLASS_ID = 501999 FRAME_1501999_CENTER = 501999 BODY501999_FRAME = 1501999 FRAME_JUICE_ROB_EUROPA = 1502999 FRAME_1502999_NAME = 'JUICE_ROB_EUROPA' FRAME_1502999_CLASS = 2 FRAME_1502999_CLASS_ID = 502999 FRAME_1502999_CENTER = 502999 BODY502999_FRAME = 1502999 FRAME_JUICE_ROB_GANYMEDE = 1503999 FRAME_1503999_NAME = 'JUICE_ROB_GANYMEDE' FRAME_1503999_CLASS = 2 FRAME_1503999_CLASS_ID = 503999 FRAME_1503999_CENTER = 503999 BODY503999_FRAME = 1503999 FRAME_JUICE_ROB_CALLISTO = 1504999 FRAME_1504999_NAME = 'JUICE_ROB_CALLISTO' FRAME_1504999_CLASS = 2 FRAME_1504999_CLASS_ID = 504999 FRAME_1504999_CENTER = 504999 BODY504999_FRAME = 1504999 \begintext NAIF ID Codes -- Definitions ============================================================================== This section contains name to NAIF ID of the centers for the auxiliary frames included in the PCK. Name ID --------------------- ------- JUICE_ROB_IO 501999 JUICE_ROB_EUROPA 502999 JUICE_ROB_GANYMEDE 503999 JUICE_ROB_CALLISTO 504999 \begindata NAIF_BODY_NAME += ( 'JUICE_ROB_IO' ) NAIF_BODY_CODE += ( 501999 ) NAIF_BODY_NAME += ( 'JUICE_ROB_EUROPA' ) NAIF_BODY_CODE += ( 502999 ) NAIF_BODY_NAME += ( 'JUICE_ROB_GANYMEDE' ) NAIF_BODY_CODE += ( 503999 ) NAIF_BODY_NAME += ( 'JUICE_ROB_CALLISTO' ) NAIF_BODY_CODE += ( 504999 ) \begintext End of file