******************************************************************************* Revised: Feb 20, 2024 New Horizons Spacecraft -98 http://pluto.jhuapl.edu/index.php NOTE: The trajectory here now includes post Pluto-encounter spacecraft reconstruction (documented as AAS 16-419, "New Horizons Orbit Determination Perfomance During Approach and Flyby of the Pluto System". Pelletier, et al.) That trajectory (od122) was later used along with satellite data through 1965-2018 to re-estimate the Pluto system satellite solution, plu058. When objects -98 (spacecraft) or 2486958 (TNO target) are used as target or coordinate centers, the trajectories listed below are used to derive relative positions. Schedule overview: 2006-Jan-19 ... launch (Atlas V551 1st stage, Centaur 2nd, STAR 48B 3rd 2006-Jun-13 ... Approaches 2002 JF56 to within 102,000 km at 04:06 CT 2007-Feb-28 ... Jupiter gravity assist (05:43 UTC, 2.3045(10)^6 km) 2015-Jul-14 ... Pluto Charon encounter @ 11:49:57 UTC 2016+ ... Kuiper Belt Object targeting 2019-Jan-1 ... Arrokoth (2014 MU69) flyby @ 05:33 UTC, 3500 km from center) Mission Objectives: * Map surface composition of Pluto and Charon * Characterize geology and morphology of Pluto and Charon * Characterize the neutral atmosphere of Pluto and its escape rate * Search for an atmosphere around Charon * Map surface temperatures on Pluto and Charon * Search for rings and additional satellites around Pluto * Conduct similar investigations of one or more Kuiper Belt Objects Spacecraft: 1025 lbs (465 kg), 8 feet wide (2.5 m), RTG powered Concatenated spacecraft trajectory (from NH navigation): USAGE NOTES: 1) To produce Horizons output relative to the Arrokoth (2014 MU69) flight-project target trajectory, specify coordinate center "@ 2486958" or "@ Arrokoth". 2) The reconstructed post Arrokoth-flyby target-body trajectory solution used is from "NavSBE_2014MU69_od159" File Start Stop ---------------------------------------- ----------------- ----------------- nh_pred_20060119_20070101_od021 2006-Jan-19 19:52 2006-Dec-31 23:58 nh_ref_20060119_20150925_v04 2007-Dec-31 23:58 2007-Mar-19 00:00 98_pred_20070319_20150101_od070 2007-Mar-19 00:00 2012-May-01 13:47 98_pred_20120501_20160913_od117 2012-May-01 13:47 2014-Dec-08 05:13 nh_recon_pluto_od122_v01 2014-Dec-08 05:13 2015-Sep-27 06:13 nh_recon_arrokoth_od147_v01 2015-Sep-27 06:13 2019-Feb-07 00:00 nh_pred_alleph_od151 2019-Feb-07 00:00 2021-Sep-30 23:58 98_pred_20211001_20300101_od159 2021-Sep-30 23:58 2030-Jan-01 11:56 ******************************************************************************* ******************************************************************************* Ephemeris / WWW_USER Sat Apr 27 10:52:48 2024 Pasadena, USA / Horizons ******************************************************************************* Target body name: New Horizons (spacecraft) (-98) {source: NH_merged} Center body name: Arrokoth (2486958) {source: NH_merged} Center-site name: BODYCENTRIC ******************************************************************************* Start time : A.D. 2022-Jan-01 10:00:00.0000 UT Stop time : A.D. 2022-Jan-02 00:00:00.0000 UT Step-size : 60 minutes ******************************************************************************* Target pole/equ : undefined Target radii : undefined Center geodetic : 0.0, 0.0, -11.0 {E-lon(deg),Lat(deg),Alt(km)} Center cylindric: 0.0, 0.0, 0.0 {E-lon(deg),Dxy(km),Dz(km)} Center pole/equ : IAU_ARROKOTH {East-longitude positive} Center radii : 11.0, 10.0, 3.5 km {Equator_a, b, pole_c} Target primary : Pluto Vis. interferer : None Rel. light bend : Sun {source: NH_merged} Rel. lght bnd GM: 1.3271E+11 km^3/s^2 Atmos refraction: NO (AIRLESS) RA format : HMS Time format : CAL Calendar mode : Mixed Julian/Gregorian EOP file : eop.240426.p240720 EOP coverage : DATA-BASED 1962-JAN-20 TO 2024-APR-26. PREDICTS-> 2024-JUL-19 Units conversion: 1 au= 149597870.700 km, c= 299792.458 km/s, 1 day= 86400.0 s Table cut-offs 1: Elevation (-90.0deg=NO ),Airmass n.a. , Daylight (NO ) Table cut-offs 2: Solar elongation ( 0.0,180.0=NO ),Local Hour Angle( 0.0=NO ) Table cut-offs 3: RA/DEC angular rate ( 0.0=NO ) ******************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************** Date__(UT)__HR:MN R.A._____(ICRF)_____DEC R.A.__(a-apparent)__DEC dRA*cosD d(DEC)/dt Azi____(a-app)___Elev dAZ*cosE d(ELV)/dt X_(sat-primary)_Y SatPANG L_Ap_Sid_Time a-mass mag_ex APmag S-brt Illu% Def_illu ang-sep/v Ang-diam ObsSub-LON ObsSub-LAT SunSub-LON SunSub-LAT SN.ang SN.dist NP.ang NP.dist hEcl-Lon hEcl-Lat r rdot delta deldot 1-way_down_LT VmagSn VmagOb S-O-T /r S-T-O T-O-I/IB_Illu% O-P-T PsAng PsAMV PlAng Cnst TDB-UT ObsEcLon ObsEcLat N.Pole-RA N.Pole-DC GlxLon GlxLat L_Ap_SOL_Time 399_ins_LT RA_3sigma DEC_3sigma SMAA_3sig SMIA_3sig Theta Area_3sig POS_3sigma RNG_3sigma RNGRT_3sig DOP_S_3sig DOP_X_3sig RT_delay_3sig Tru_Anom L_Ap_Hour_Ang phi PAB-LON PAB-LAT App_Lon_Sun RA_(ICRF-a-apparnt)_DEC I_dRA*cosD I_d(DEC)/dt Sky_motion Sky_mot_PA RelVel-ANG Lun_Sky_Brt sky_SNR UT1-UTC ******************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************** $$SOE 2022-Jan-01 10:00 18 19 02.25 -20 51 30.6 10 33 41.03 +50 34 57.4 -0.00153 0.006205 n.a. n.a. n.a. n.a. -458757. 327614.9 323.354 n.a. n.a. n.a. n.a. n.a. 98.74337 n.a. 599651.8/* n.a. n.a. n.a. n.a. n.a. 165.99 0.00 n.a. n.a. 287.3230 1.9752 52.06045934977 13.7589520 9.14907244146691 14.4833347 76.09051527 13.8272173 14.4833396 164.4236 /L 12.8719 n.a./ n.a. 6.4298 90.213 269.064 -0.81965 Sgr 69.183903 274.4519238 2.5072746 n.a. n.a. 10.764914 -2.589934 n.a. 367.263259 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 12.8727 280.8881 2.2554 n.a. 18 19 02.47 -20 51 30.5 0.006392 -3.68E-5 0.0001065 346.10878 89.953389 n.a. n.a. -0.11047 2022-Jan-01 11:00 18 19 02.25 -20 51 30.6 10 33 41.03 +50 34 57.4 -0.00153 0.006206 n.a. n.a. n.a. n.a. -458758. 327614.2 323.354 n.a. n.a. n.a. n.a. n.a. 98.74336 n.a. 599650.9/* n.a. n.a. n.a. n.a. n.a. 165.99 0.00 n.a. n.a. 287.3231 1.9752 52.06079043617 13.7589445 9.14942096065733 14.4833380 76.09341381 13.8272090 14.4833430 164.4235 /L 12.8719 n.a./ n.a. 6.4300 90.213 269.064 -0.81965 Sgr 69.183904 274.4519256 2.5072745 n.a. n.a. 10.764915 -2.589935 n.a. 367.264186 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 12.8728 280.8881 2.2554 n.a. 18 19 02.47 -20 51 30.5 0.006392 -3.68E-5 0.0001065 346.10877 89.953386 n.a. n.a. -0.11047 2022-Jan-01 12:00 18 19 02.25 -20 51 30.6 10 33 41.03 +50 34 57.4 -0.00153 0.006206 n.a. n.a. n.a. n.a. -458759. 327613.5 323.354 n.a. n.a. n.a. n.a. n.a. 98.74335 n.a. 599650.1/* n.a. n.a. n.a. n.a. n.a. 165.99 0.00 n.a. n.a. 287.3231 1.9752 52.06112152240 13.7589371 9.14976947992836 14.4833414 76.09631236 13.8272006 14.4833463 164.4233 /L 12.8720 n.a./ n.a. 6.4302 90.213 269.064 -0.81965 Sgr 69.183906 274.4519273 2.5072744 n.a. n.a. 10.764916 -2.589937 n.a. 367.265108 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 12.8728 280.8881 2.2554 n.a. 18 19 02.47 -20 51 30.5 0.006393 -3.68E-5 0.0001065 346.10875 89.953383 n.a. n.a. -0.11046 2022-Jan-01 13:00 18 19 02.25 -20 51 30.6 10 33 41.03 +50 34 57.4 -0.00153 0.006206 n.a. n.a. n.a. n.a. -458760. 327612.9 323.354 n.a. n.a. n.a. n.a. n.a. 98.74334 n.a. 599649.2/* n.a. n.a. n.a. n.a. n.a. 165.99 0.00 n.a. n.a. 287.3231 1.9752 52.06145260844 13.7589297 9.15011799927994 14.4833447 76.09921091 13.8271923 14.4833497 164.4232 /L 12.8720 n.a./ n.a. 6.4305 90.213 269.064 -0.81965 Sgr 69.183907 274.4519291 2.5072744 n.a. n.a. 10.764917 -2.589938 n.a. 367.266027 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 12.8728 280.8882 2.2554 n.a. 18 19 02.47 -20 51 30.5 0.006393 -3.68E-5 0.0001065 346.10874 89.953379 n.a. n.a. -0.11045 2022-Jan-01 14:00 18 19 02.25 -20 51 30.6 10 33 41.03 +50 34 57.4 -0.00153 0.006206 n.a. n.a. n.a. n.a. -458760. 327612.2 323.354 n.a. n.a. n.a. n.a. n.a. 98.74334 n.a. 599648.4/* n.a. n.a. n.a. n.a. n.a. 165.99 0.00 n.a. n.a. 287.3232 1.9752 52.06178369431 13.7589222 9.15046651871213 14.4833481 76.10210945 13.8271840 14.4833530 164.4231 /L 12.8720 n.a./ n.a. 6.4307 90.213 269.064 -0.81965 Sgr 69.183908 274.4519309 2.5072743 n.a. n.a. 10.764917 -2.589940 n.a. 367.266941 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 12.8729 280.8882 2.2555 n.a. 18 19 02.47 -20 51 30.5 0.006393 -3.68E-5 0.0001066 346.10872 89.953376 n.a. n.a. -0.11045 2022-Jan-01 15:00 18 19 02.25 -20 51 30.6 10 33 41.03 +50 34 57.4 -0.00153 0.006206 n.a. n.a. n.a. n.a. -458761. 327611.6 323.354 n.a. n.a. n.a. n.a. n.a. 98.74333 n.a. 599647.5/* n.a. n.a. n.a. n.a. n.a. 165.99 0.00 n.a. n.a. 287.3232 1.9752 52.06211478000 13.7589148 9.15081503822490 14.4833514 76.10500800 13.8271756 14.4833564 164.4229 /L 12.8721 n.a./ n.a. 6.4310 90.213 269.064 -0.81965 Sgr 69.183909 274.4519327 2.5072742 n.a. n.a. 10.764918 -2.589942 n.a. 367.267851 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 12.8729 280.8882 2.2555 n.a. 18 19 02.47 -20 51 30.5 0.006393 -3.68E-5 0.0001066 346.10871 89.953372 n.a. n.a. -0.11044 2022-Jan-01 16:00 18 19 02.25 -20 51 30.6 10 33 41.03 +50 34 57.4 -0.00153 0.006207 n.a. n.a. n.a. n.a. -458762. 327610.9 323.354 n.a. n.a. n.a. n.a. n.a. 98.74332 n.a. 599646.6/* n.a. n.a. n.a. n.a. n.a. 165.99 0.00 n.a. n.a. 287.3232 1.9752 52.06244586550 13.7589074 9.15116355781828 14.4833548 76.10790655 13.8271673 14.4833597 164.4228 /L 12.8721 n.a./ n.a. 6.4312 90.213 269.064 -0.81965 Sgr 69.183910 274.4519344 2.5072742 n.a. n.a. 10.764919 -2.589943 n.a. 367.268756 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 12.8729 280.8882 2.2555 n.a. 18 19 02.47 -20 51 30.5 0.006394 -3.68E-5 0.0001066 346.10870 89.953369 n.a. n.a. -0.11044 2022-Jan-01 17:00 18 19 02.26 -20 51 30.6 10 33 41.03 +50 34 57.4 -0.00154 0.006207 n.a. n.a. n.a. n.a. -458762. 327610.3 323.354 n.a. n.a. n.a. n.a. n.a. 98.74332 n.a. 599645.8/* n.a. n.a. n.a. n.a. n.a. 165.99 0.00 n.a. n.a. 287.3233 1.9752 52.06277695083 13.7589000 9.15151207749223 14.4833581 76.11080510 13.8271590 14.4833631 164.4226 /L 12.8721 n.a./ n.a. 6.4315 90.213 269.064 -0.81965 Sgr 69.183912 274.4519362 2.5072741 n.a. n.a. 10.764920 -2.589945 n.a. 367.269658 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 12.8730 280.8882 2.2555 n.a. 18 19 02.47 -20 51 30.5 0.006394 -3.68E-5 0.0001066 346.10868 89.953365 n.a. n.a. -0.11043 2022-Jan-01 18:00 18 19 02.26 -20 51 30.6 10 33 41.03 +50 34 57.4 -0.00154 0.006207 n.a. n.a. n.a. n.a. -458763. 327609.6 323.354 n.a. n.a. n.a. n.a. n.a. 98.74331 n.a. 599644.9/* n.a. n.a. n.a. n.a. n.a. 165.99 0.00 n.a. n.a. 287.3233 1.9752 52.06310803599 13.7588925 9.15186059724678 14.4833615 76.11370365 13.8271506 14.4833664 164.4225 /L 12.8722 n.a./ n.a. 6.4317 90.213 269.064 -0.81965 Sgr 69.183913 274.4519380 2.5072740 n.a. n.a. 10.764921 -2.589946 n.a. 367.270555 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 12.8730 280.8882 2.2555 n.a. 18 19 02.47 -20 51 30.5 0.006394 -3.68E-5 0.0001066 346.10867 89.953362 n.a. n.a. -0.11042 2022-Jan-01 19:00 18 19 02.26 -20 51 30.6 10 33 41.03 +50 34 57.5 -0.00154 0.006207 n.a. n.a. n.a. n.a. -458764. 327608.9 323.354 n.a. n.a. n.a. n.a. n.a. 98.74330 n.a. 599644.1/* n.a. n.a. n.a. n.a. n.a. 165.99 0.00 n.a. n.a. 287.3233 1.9752 52.06343912096 13.7588851 9.15220911708194 14.4833648 76.11660220 13.8271423 14.4833698 164.4223 /L 12.8722 n.a./ n.a. 6.4319 90.213 269.064 -0.81965 Sgr 69.183914 274.4519398 2.5072740 n.a. n.a. 10.764922 -2.589948 n.a. 367.271448 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 12.8731 280.8883 2.2555 n.a. 18 19 02.47 -20 51 30.5 0.006394 -3.68E-5 0.0001066 346.10866 89.953359 n.a. n.a. -0.11041 2022-Jan-01 20:00 18 19 02.26 -20 51 30.6 10 33 41.03 +50 34 57.5 -0.00154 0.006208 n.a. n.a. n.a. n.a. -458765. 327608.3 323.354 n.a. n.a. n.a. n.a. n.a. 98.74330 n.a. 599643.2/* n.a. n.a. n.a. n.a. n.a. 165.99 0.00 n.a. n.a. 287.3234 1.9752 52.06377020575 13.7588777 9.15255763699768 14.4833682 76.11950075 13.8271340 14.4833731 164.4222 /L 12.8722 n.a./ n.a. 6.4322 90.213 269.064 -0.81965 Sgr 69.183915 274.4519416 2.5072739 n.a. n.a. 10.764922 -2.589949 n.a. 367.272336 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 12.8731 280.8883 2.2555 n.a. 18 19 02.47 -20 51 30.5 0.006394 -3.68E-5 0.0001066 346.10864 89.953355 n.a. n.a. -0.11041 2022-Jan-01 21:00 18 19 02.26 -20 51 30.6 10 33 41.03 +50 34 57.5 -0.00154 0.006208 n.a. n.a. n.a. n.a. -458765. 327607.6 323.355 n.a. n.a. n.a. n.a. n.a. 98.74329 n.a. 599642.3/* n.a. n.a. n.a. n.a. n.a. 165.99 0.00 n.a. n.a. 287.3234 1.9752 52.06410129037 13.7588702 9.15290615699404 14.4833715 76.12239931 13.8271256 14.4833765 164.4220 /L 12.8723 n.a./ n.a. 6.4324 90.213 269.064 -0.81965 Sgr 69.183917 274.4519433 2.5072738 n.a. n.a. 10.764923 -2.589951 n.a. 367.273221 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 12.8731 280.8883 2.2555 n.a. 18 19 02.47 -20 51 30.5 0.006395 -3.68E-5 0.0001066 346.10863 89.953352 n.a. n.a. -0.11040 2022-Jan-01 22:00 18 19 02.26 -20 51 30.6 10 33 41.03 +50 34 57.5 -0.00154 0.006208 n.a. n.a. n.a. n.a. -458766. 327607.0 323.355 n.a. n.a. n.a. n.a. n.a. 98.74328 n.a. 599641.5/* n.a. n.a. n.a. n.a. n.a. 165.99 0.00 n.a. n.a. 287.3235 1.9752 52.06443237480 13.7588628 9.15325467707102 14.4833749 76.12529786 13.8271173 14.4833798 164.4219 /L 12.8723 n.a./ n.a. 6.4327 90.213 269.063 -0.81965 Sgr 69.183918 274.4519451 2.5072738 n.a. n.a. 10.764924 -2.589953 n.a. 367.274101 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 12.8732 280.8883 2.2555 n.a. 18 19 02.47 -20 51 30.5 0.006395 -3.68E-5 0.0001066 346.10861 89.953348 n.a. n.a. -0.11039 2022-Jan-01 23:00 18 19 02.26 -20 51 30.6 10 33 41.03 +50 34 57.5 -0.00154 0.006208 n.a. n.a. n.a. n.a. -458767. 327606.3 323.355 n.a. n.a. n.a. n.a. n.a. 98.74328 n.a. 599640.6/* n.a. n.a. n.a. n.a. n.a. 165.99 0.00 n.a. n.a. 287.3235 1.9752 52.06476345906 13.7588554 9.15360319722858 14.4833782 76.12819641 13.8271090 14.4833832 164.4217 /L 12.8724 n.a./ n.a. 6.4329 90.213 269.063 -0.81965 Sgr 69.183919 274.4519469 2.5072737 n.a. n.a. 10.764925 -2.589954 n.a. 367.274976 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 12.8732 280.8883 2.2555 n.a. 18 19 02.47 -20 51 30.5 0.006395 -3.68E-5 0.0001066 346.10860 89.953345 n.a. n.a. -0.11038 2022-Jan-02 00:00 18 19 02.26 -20 51 30.6 10 33 41.03 +50 34 57.5 -0.00154 0.006208 n.a. n.a. n.a. n.a. -458767. 327605.7 323.355 n.a. n.a. n.a. n.a. n.a. 98.74327 n.a. 599639.8/* n.a. n.a. n.a. n.a. n.a. 165.99 0.00 n.a. n.a. 287.3235 1.9752 52.06509454314 13.7588480 9.15395171746675 14.4833816 76.13109497 13.8271007 14.4833865 164.4216 /L 12.8724 n.a./ n.a. 6.4332 90.213 269.063 -0.81965 Sgr 69.183920 274.4519487 2.5072736 n.a. n.a. 10.764926 -2.589956 n.a. 367.275848 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 12.8732 280.8884 2.2555 n.a. 18 19 02.47 -20 51 30.5 0.006395 -3.68E-5 0.0001066 346.10859 89.953341 n.a. n.a. -0.11037 $$EOE ******************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************** Column meaning: TIME Times PRIOR to 1962 are UT1, a mean-solar time closely related to the prior but now-deprecated GMT. Times AFTER 1962 are in UTC, the current civil or "wall-clock" time-scale. UTC is kept within 0.9 seconds of UT1 using integer leap-seconds for 1972 and later years. Conversion from the internal Barycentric Dynamical Time (TDB) of solar system dynamics to the non-uniform civil UT time-scale requested for output has not been determined for UTC times after the next July or January 1st. Therefore, the last known leap-second is used as a constant over future intervals. Time tags refer to the UT time-scale conversion from TDB on Earth regardless of observer location within the solar system, although clock rates may differ due to the local gravity field and no analog to "UT" may be defined for that location. Any 'b' symbol in the 1st-column denotes a B.C. date. First-column blank (" ") denotes an A.D. date. CALENDAR SYSTEM Mixed calendar mode was active such that calendar dates after AD 1582-Oct-15 (if any) are in the modern Gregorian system. Dates prior to 1582-Oct-5 (if any) are in the Julian calendar system, which is automatically extended for dates prior to its adoption on 45-Jan-1 BC. The Julian calendar is useful for matching historical dates. The Gregorian calendar more accurately corresponds to the Earth's orbital motion and seasons. A "Gregorian-only" calendar mode is available if such physical events are the primary interest. NOTE: "n.a." in output means quantity "not available" at the print-time. 'R.A._____(ICRF)_____DEC' = Astrometric right ascension and declination of the target center with respect to the observing site (coordinate origin) in the reference frame of the planetary ephemeris (ICRF). Compensated for down-leg light-time delay aberration. Units: RA in hours-minutes-seconds of time, HH MM SS.ff{ffff} DEC in degrees-minutes-seconds of arc, sDD MN SC.f{ffff} 'R.A.__(a-apparent)__DEC' = Airless apparent right ascension and declination of the target center with respect to the center/site body's IAU 2015 equator (z-axis) and the meridian containing ICRF x-axis. Compensated for light-time, the gravitational deflection of light, stellar aberration, and IAU spin axis. Units: RA in hours-minutes-seconds of time, HH MM SS.ff{ffff} DEC in degrees-minutes-seconds of arc, sDD MN SC.f{ffff} 'dRA*cosD d(DEC)/dt' = The angular rate of change in aparent RA and DEC of the target. This is with respect to the non-inertial IAU76/80 Earth true equator and equinox of-date reference frame. d(RA)/dt is multiplied by the cosine of declination to provide a linear rate in the plane-of-sky. Units: ARCSECONDS PER HOUR 'Azi____(a-app)___Elev' = Airless apparent azimuth and elevation of target center. Compensated for light-time, the gravitational deflection of light, stellar aberration, precession and nutation. Azimuth is measured clockwise from north: North(0) -> East(90) -> South(180) -> West(270) -> North (360) Elevation angle is with respect to a plane perpendicular to the reference surface local zenith direction. TOPOCENTRIC ONLY. Units: DEGREES 'dAZ*cosE d(ELV)/dt' = The rate of change of target center apparent azimuth and elevation (airless). d(AZ)/dt is multiplied by the cosine of the elevation angle. TOPOCENTRIC ONLY. Units: ARCSECOND PER MINUTE 'X_(sat-primary)_Y SatPANG' = Satellite apparent differential coordinates in the plane-of-sky with respect to the primary body along with the satellite position angle. Differential coordinates are defined in RA as: X= ((RA_sat - RA_primary) * cosine(DEC_primary)) ... and in DEC as: Y= (DEC_sat - DEC_primary) Non-lunar satellites only. "SatPANG" is the counter-clockwise (CCW) position angle from the reference-frame of-date north-pole to a line from the primary center to the satellite center. Units: ARCSECONDS (X & Y), DEGREES (pos, angle) 'L_Ap_Sid_Time' = "Local Apparent Sidereal Time" -- non-Earth body. The angle measured westward in the body true equator-of-date plane from the meridian containing the body-fixed observer to the meridian containing the Earth equinox of J2000.0 (defined by intersection of the mean Earth equator of J2000.0 with the ecliptic of J2000.0). TOPOCENTRIC ONLY. Units: HH MM SS.ffff (hours-minutes-seconds) 'a-mass mag_ex' = RELATIVE optical airmass and visual magnitude extinction. Airmass is the ratio between the absolute optical airmass for the targets' refracted CENTER point to the absolute optical airmass at zenith. Also output is the estimated visual magnitude extinction due to the atmosphere, as seen by the observer. AVAILABLE ONLY FOR TOPOCENTRIC EARTH SITES WHEN THE TARGET IS ABOVE THE HORIZON. Units: none (airmass) and magnitudes (extinction). 'APmag S-brt' = The targets' approximate apparent visual magnitude and surface brightness. For planets and natural satellites, output is restricted to solar phase angles covered by observational data. Outside the observed phase angle range, "n.a." may be output to avoid extrapolation beyond the limit of model validity. For Earth-based observers, the estimated dimming due to atmospheric absorption (extinction) is available as a separate, requestable quantity. Surface brightness is the average airless visual magnitude of a square-arcsecond of the illuminated portion of the apparent disk. It is computed only if the target radius is known. Units: MAGNITUDES & MAGNITUDES PER SQUARE ARCSECOND 'Illu%' = Fraction of the target objects' assumed circular disk illuminated by Sun (phase), as seen by the observer. Units: PERCENT 'Def_illu' = Defect of illumination. The maximum angular width of the target body's assumed circular disk diameter NOT illuminated by the Sun. Units: ARCSECONDS 'ang-sep/v' = The angular separation between the center of the target object and the center of the (remote) primary body it revolves around, as seen by the observer, with target visibility code. Visibility codes (refers to limb-to-limb): /t = Transiting primary body disk /O = Occulted by primary body disk /p = Partial umbral eclipse /P = Occulted partial umbral eclipse /u = Total umbral eclipse /U = Occulted total umbral eclipse /- = Target is the primary body /* = None of above ("free and clear") The radius of both primary and target body is taken to be the equatorial value (maximum, given a triaxial shape). Atmospheric effects and oblateness aspect are NOT currently considered. Light-time is considered. Units: ARCSECONDS and visibility code 'Ang-diam' = The equatorial angular width of the target body full disk, if it were fully illuminated and visible to the observer. If the target body diameter is unknown "n.a." is output. Units: ARCSECONDS 'ObsSub-LON ObsSub-LAT' = Apparent planetodetic longitude and latitude of the center of the target disc seen by the OBSERVER at print-time. This is NOT exactly the same as the "nearest" sub-point for a non-spherical target shape (since the center of the disc might not be the point closest to the observer), but is generally very close if not a very irregular body shape. Down-leg light travel-time from target to observer is taken into account. Latitude is the angle between the equatorial plane and the line perpendicular to the reference ellipsoid of the body, so includes body oblateness. The reference ellipsoid is an oblate spheroid with a single flatness coefficient in which the y-axis body radius is taken to be the same value as the x-axis radius. Positive longitude is to the WEST for this target. Cartographic system is given in the header. Units: DEGREES DEGREES 'SunSub-LON SunSub-LAT' = Apparent sub-solar longitude and latitude of the Sun on the target. The apparent planetodetic longitude and latitude of the center of the target disc as seen from the Sun, as seen by the observer at print-time. This is NOT exactly the same as the "sub-solar" (nearest) point for a non-spherical target shape (since the center of the disc seen from the Sun might not be the closest point to the Sun), but is very close if not a highly irregular body shape. Light travel-time from Sun to target and from target to observer is taken into account. Latitude is the angle between the equatorial plane and the line perpendicular to the reference ellipsoid of the body. The reference ellipsoid is an oblate spheroid with a single flatness coefficient in which the y-axis body radius is taken to be the same value as the x-axis radius. Positive longitude is to the WEST for this target. Cartographic system is given in the header. Units: DEGREES DEGREES 'SN.ang SN.dist' = Targets' apparent sub-solar point position angle (counter-clockwise with respect to the direction of the true-of-date reference-frame north-pole) and its angular distance from the sub-observer point (center of disk) at print time. A negative distance indicates the sub-solar point is on the hidden hemisphere. Units: DEGREES and ARCSECONDS 'NP.ang NP.dist' = Targets' apparent north-pole position angle (counter-clockwise with respect to the direction of the true-of-date reference-frame north-pole) and its angular distance from the sub-observer point (center of disk) at observation time. A negative distance indicates the planets' north-pole is on the hidden hemisphere. Units: DEGREES and ARCSECONDS 'hEcl-Lon hEcl-Lat' = Geometric heliocentric J2000 ecliptic longitude and latitude of target center at the instant light leaves it to be observed at print time (print time minus down-leg light-time). Units: DEGREES 'r rdot' = The Sun's apparent range ("r", light-time aberrated) and range-rate ("rdot") relative to the target center, as seen by the observer. A positive "rdot" means the target center was moving away from the Sun, negative means moving toward the Sun. Units: AU and KM/S 'delta deldot' = Apparent range ("delta", light-time aberrated) and range-rate ("delta-dot") of the target center relative to the observer. A positive "deldot" means the target center is moving away from the observer, negative indicates movement toward the observer. Units: AU and KM/S '1-way_down_LT' = 1-way down-leg light-time from target center to observer. The elapsed time since light (observed at print-time) would have left or reflected off a point at the center of the target. Units: MINUTES 'VmagSn VmagOb' = Magnitude of target centers' velocity with respect to the Sun ("VmagSn") and the observer ("VmagOb") at the time light left the target center to be observed (print time minus down-leg light-time). These are absolute values of the velocity vectors (total speeds) and do NOT indicate direction of motion. Units: KM/S 'S-O-T /r' = Sun-Observer-Target apparent SOLAR ELONGATION ANGLE seen from the observers' location at print-time. The '/r' column provides a code indicating the targets' apparent position relative to the Sun in the observers' sky, as described below: Case A: For an observing location on the surface of a rotating body, that body rotational sense is considered: /T indicates target TRAILS Sun (evening sky: rises and sets AFTER Sun) /L indicates target LEADS Sun (morning sky: rises and sets BEFORE Sun) Case B: For an observing point that does not have a rotational model (such as a spacecraft), the "leading" and "trailing" condition is defined by the observers' heliocentric ORBITAL motion: * If continuing in the observers' current direction of heliocentric motion would encounter the targets' apparent longitude first, followed by the Sun's, the target LEADS the Sun as seen by the observer. * If the Sun's apparent longitude would be encountered first, followed by the targets', the target TRAILS the Sun. Two other codes can be output: /* indicates observer is Sun-centered (undefined) /? Target is aligned with Sun center (no lead or trail) The S-O-T solar elongation angle is numerically the minimum separation angle of the Sun and target in the sky in any direction. It does NOT indicate the amount of separation in the leading or trailing directions, which would be defined along the equator of a spherical coordinate system. Units: DEGREES 'S-T-O' = The Sun-Target-Observer angle; the interior vertex angle at target center formed by a vector from the target to the apparent center of the Sun (at reflection time on the target) and the apparent vector from target to the observer at print-time. Slightly different from true PHASE ANGLE (requestable separately) at the few arcsecond level in that it includes stellar aberration on the down-leg from target to observer. Units: DEGREES 'T-O-I/IB_Illu%' = Target-Observer-Interfering_body angle and illuminated fraction. The apparent elongation angle between target body center and the center of the "visually interfering body" (the largest other body in the system), seen from the observing-site, along with fraction of the IB disk that is illuminated by the Sun. A negative elongatione angle indicates the target center is behind the interfering body. Units: DEGREES and PERCENT 'O-P-T' = Observer-Primary-Target angle; apparent angle between a target satellite, its primarys' center and an observer at print time. Interior vertex angle at the primary. Units: DEGREES 'PsAng PsAMV' = The position angles of the extended Sun-to-target radius vector ("PsAng") and the negative of the targets' heliocentric velocity vector ("PsAMV"), as seen in the observers' plane-of-sky, measured counter-clockwise (east) from reference-frame north-pole. Primarily intended for ACTIVE COMETS, "PsAng" is an indicator of the comets' gas-tail orientation in the sky (being in the anti-sunward direction) while "PsAMV" is an indicator of dust-tail orientation. Units: DEGREES 'PlAng' = Angle between observer and target orbital plane, measured from center of target at the moment light seen at observation time leaves the target. Positive values indicate observer is above the objects' orbital plane, in the direction of reference-frame +z axis. Units: DEGREES 'Cnst' = Constellation ID; the 3-letter abbreviation for the name of the constellation containing the target centers' astrometric position, as defined by IAU (1930) boundary delineation. See documentation for list of abbreviations. 'TDB-UT' = Difference between the uniform Barycentric Dynamical time-scale and the Earth-rotation dependent Universal Time. Prior to 1962, the difference is with respect to UT1 (TDB-UT1) and the 0.002 second maximum amplitude distinction between TT and TDB is not maintained. For 1962 and later, the difference is with respect to UTC (TDB-UTC) and periodic terms less than 1.e-6 second are ignored. Values beyond the next July or January 1st may change if a leap-second is later required by the IERS. Values from the present date forward through the next ~78 days are predictions. Beyond that prediction interval, the last prediction is taken as a constant for all future dates. Units: SECONDS 'ObsEcLon ObsEcLat' = For a non-Earth observer, IAU76/80 standard epoch (J2000) Earth ecliptic longitude and latitude of the target centers' apparent position, with light-time, gravitational deflection of light, and stellar aberrations. Units: DEGREES 'N.Pole-RA N.Pole-DC' = ICRF right ascension and declination of the target body's north-pole direction at the time light left the body to be observed at print time. Target pole/rotation model is given in the header. Units: DEGREES 'GlxLon GlxLat' = Observer-centered Galactic System II (post WW II) longitude and latitude of the target centers' apparent position, with light-time, gravitational deflection of light, and stellar aberrations. Units: DEGREES 'L_Ap_SOL_Time' = Local Apparent SOLAR Time for observing site. This is the time indicated by a sundial. TOPOCENTRIC ONLY. Units: HH MM SS.ffff (sexagesimal angular hours) '399_ins_LT' = Instantaneous light-time of the station with respect to Earth center at print-time. The geometric (or "true") separation of site and Earth center, divided by the speed of light. Units: MINUTES 'RA_3sigma DEC_3sigma' = Uncertainty in Right-Ascension and Declination. Output values are the formal +/- 3 standard-deviations (sigmas) around nominal position. Units: ARCSECONDS 'SMAA_3sig SMIA_3sig Theta Area_3sig' = Plane-of-sky (POS) error ellipse data. These quantities summarize the targets' 3-dimensional 3-standard-deviation formal uncertainty volume projected into a reference plane perpendicular to the observers' line-of-sight. SMAA_3sig = Angular width of the 3-sigma error ellipse semi-major axis in POS. Units: ARCSECONDS. SMIA_3sig = Angular width of the 3-sigma error ellipse semi-minor axis in POS. Units: ARCSECONDS. Theta = Orientation angle of the error ellipse in POS; the clockwise angle from the direction of increasing RA to the semi-major axis of the error ellipse, in the direction of increasing DEC. Units: DEGREES. Area_3sig = Area of sky enclosed by the 3-sigma error ellipse. Units: ARCSECONDS ^ 2. 'POS_3sigma' = The Root-Sum-of-Squares (RSS) of the 3-standard deviation plane-of-sky error ellipse major and minor axes. This single pointing uncertainty number gives an angular distance (a circular radius) from the targets' nominal position in the sky that encompasses the error-ellipse. Units: ARCSECONDS. 'RNG_3sigma RNGRT_3sig' = Range and range rate (radial velocity) formal 3-standard-deviation uncertainties. Units: KM, KM/S 'DOP_S_3sig DOP_X_3sig RT_delay_3sig' = Doppler radar uncertainties at S-band (2380 MHz) and X-band (8560 MHz) frequencies, along with the round-trip (total) delay to first-order. Units: HERTZ and SECONDS 'Tru_Anom' = Apparent true anomaly angle of the targets' heliocentric orbit position; the angle in the targets' instantaneous orbit plane from the orbital periapse direction to the target, measured positively in the direction of motion. The position of the target is taken to be at the moment light seen by the observer at print-time would have left the center of the object. That is, the heliocentric position of the target used to compute the true anomaly is one down-leg light-time prior to the print-time. Units: DEGREES 'L_Ap_Hour_Ang' = Local apparent HOUR ANGLE of target at observing site. The angle between the observers' meridian plane, containing Earth's axis of-date and local zenith direction, and a great circle passing through Earth's axis-of-date and the targets' direction, measured westward from the zenith meridian to target meridian along the equator. Negative values are angular times UNTIL transit. Positive values are angular times SINCE transit. Exactly 24_hrs/360_degrees. EARTH TOPOCENTRIC ONLY. Units: sHH MM SS.fff (sexagesimal angular hours) 'phi PAB-LON PAB-LAT' = "phi" is the true PHASE ANGLE at the observers' location at print time. "PAB-LON" and "PAB-LAT" are the J2000 ecliptic longitude and latitude of the phase angle bisector direction; the outward directed angle bisecting the arc created by the apparent vector from Sun to target center and the astrometric vector from observer to target center. For an otherwise uniform ellipsoid, the time when its long-axis is perpendicular to the PAB direction approximately corresponds to lightcurve maximum (or maximum brightness) of the body. PAB is discussed in Harris et al., Icarus 57, 251-258 (1984). Units: DEGREES, DEGREES, DEGREES 'App_Lon_Sun' = The apparent target-centered longitude of the Sun ("apparent L_s") as seen at the target when the light recorded by the observer at print-time reflected off the target. It is referred to a coordinate system where the x-axis is the equinox direction defined by the targets' instantaneous IAU2015 pole direction and heliocentric orbit plane at reflection time, and is measured positively in an eastward direction (counter-clockwise around the positive pole of the solar system angular momentum vector). On bodies other than the Earth, the quantity can indicate boundary dates for the seasons: Northern hemisphere Southern hemisphere 0= Spring Equinox 0= Autumn Equinox 90= Summer Solstice 90= Winter Solstice 180= Autumn Equinox 180= Spring Equinox 270= Winter Solstice 270= Summer Solstice For Earth seasons, instead see quantity #31 ("ObsEcLon") as seen from the geocenter, with the Sun as a target. If the target has no associated spin-pole model (common for asteroids and comets), "n.a." will be output. Units: DEGREES 'RA_(ICRF-a-apparnt)_DEC' = Airless apparent right ascension and declination coordinates of the target in the ICRF reference frame, with down-leg light-time, gravitational deflection of light, and stellar aberration. Units: RA : HH MM SS.ff{ffff} (hours-minutes-seconds of time) DEC: DG MN SC.f{ffff} (degrees-minutes-seconds of arc) 'I_dRA*cosD I_d(DEC)/dt' = The angular rate of change in the targets' ICRF inertial reference-frame apparent RA and DEC, with light-time, gravitational light deflection, and stellar aberrations. d(RA)/dt is multiplied by the cosine of declination to provide a linear rate in the plane-of-sky. Units: ARCSECONDS PER HOUR 'Sky_motion Sky_mot_PA RelVel-ANG' = Total apparent angular rate of the target in the plane-of-sky. "Sky_mot_PA" is the position angle of the target's direction of motion in the plane-of-sky, measured counter-clockwise from the apparent of-date north pole direction. "RelVel-ANG" is the flight path angle of the target's relative motion with respect to the observer's line-of-sight, in the range [-90,+90], where positive values indicate motion away from the observer, negative values are toward the observer: -90 = target is moving directly toward the observer 0 = target is moving at right angles to the observer's line-of-sight +90 = target is moving directly away from the observer UNITS: ARCSECONDS/MINUTE, DEGREES, DEGREES 'Lun_Sky_Brt sky_SNR' = Sky brightness due to moonlight scattered by Earth's atmosphere at the target's position in the sky. "sky_SNR" is the visual signal-to-noise ratio (SNR) of the target's surface brightness relative to background sky. Output only for topocentric Earth observers when both the Moon and target are above the local horizon and the Sun is in astronomical twilight (or further) below the horizon, and the target is not the Moon or Sun. If all conditions are not met, "n.a." is output. Galactic brightness, local sky light-pollution and weather are NOT considered. Lunar opposition surge is considered. The value returned is accurate under ideal conditions at the approximately 8-23% level, so is a useful but not definitive value. If the target-body radius is also known, "sky_SNR" is output. This is the approximate visual signal-to-noise ratio of the target's brightness divided by lunar sky brightness. When sky_SNR < 1, the target is dimmer than the ideal moonlight-scattering background sky, so unlikely to be detectable at visual wavelengths. In practice, visibility requires sky_SNR > 1 and a detector sensitive enough to reach the target's magnitude, even if it isn't washed out by moonlight. When relating magnitudes and brightness values, keep in mind their logarithmic relationship m2-m1 = -2.5*log_10(b2/b1). UNITS: VISUAL MAGNITUDES / ARCSECOND^2, and unitless ratio 'UT1-UTC' = Difference between the UT1 and UTC timescales ("DUT1"). UT1 is the Earth-rotation dependent mean solar time on the Greenwich meridian sometimes referred to as GMT. UTC is a discontinuous timescale derived from the atomic TAI timescale, adjusted by leap seconds to provide a civil timescale maintained within 0.9 seconds of UT1. Therefore, the difference UT1-UTC will have discontinuities where leap-seconds are inserted in UTC. UTC is not well-defined prior to 1962, so "n.a." will be returned for earlier dates. The UT1 here is a JPL fit to measurements of the Earth rotation which can change rapidly and unpredictably at the 10^-4 second level due to tides and other factors affecting Earth rotation. Values for the 14 days prior to the present date are considered provisional and may change at up to the 0.002 second level as data accumulates, corresponding to about 1-meter (3-sigma) for an Earth equatorial site. Values from the present date forward through the next ~78 days are predictions. Beyond that prediction interval, the last prediction is taken as a constant for all future dates. Units: SECONDS Computations by ... Solar System Dynamics Group, Horizons On-Line Ephemeris System 4800 Oak Grove Drive, Jet Propulsion Laboratory Pasadena, CA 91109 USA General site: https://ssd.jpl.nasa.gov/ Mailing list: https://ssd.jpl.nasa.gov/email_list.html System news : https://ssd.jpl.nasa.gov/horizons/news.html User Guide : https://ssd.jpl.nasa.gov/horizons/manual.html Connect : browser https://ssd.jpl.nasa.gov/horizons/app.html#/x API https://ssd-api.jpl.nasa.gov/doc/horizons.html command-line telnet ssd.jpl.nasa.gov 6775 e-mail/batch https://ssd.jpl.nasa.gov/ftp/ssd/hrzn_batch.txt scripts https://ssd.jpl.nasa.gov/ftp/ssd/SCRIPTS Author : Jon.D.Giorgini@jpl.nasa.gov ******************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************** !$$SOF COMMAND = '-98' CENTER = '@2486958'