API VERSION: 1.2 API SOURCE: NASA/JPL Horizons API ******************************************************************************* Revised: Jul 14, 2025 Hubble Space Telescope -48 http://hubblesite.org BACKGROUND: Launched: April 24, 1990 [from space shuttle Discovery (STS-31)] Deployed: April 25, 1990 NOTE: HST ephemeris data can be unreliable during times of the following space shuttle servicing missions Servicing Mission 1 : 1993 (December 02-14) Servicing Mission 2 : 1997 (February 11-21) Servicing Mission 3A: 1999 (December 19-28) Servicing Mission 3B: 2002 (March 01-12) Servicing Mission 4 : 2009 (May 11-25) HUBBLE SPACE TELESCOPE: Length : 43.5 ft (13.2 m) Weight : 24,500 lb (11,110 kg) Maximum Diameter: 14 ft (4.2 m) Data return : ~120 Gigabytes (GB)/week Generic orbit facts: Altitude : 569 km, or 353 miles Inclination : 28.5 deg. to equator Orbit period : 97 minutes Orbital speed: 28,000 kph (17500 mph) SPACECRAFT TRAJECTORY: The trajectory here is a concatenation of publicly released JSpOC two-line elements. These can usually only be propagated reliably "days" into the future, and are updated frequently to maintain accuracy. ******************************************************************************* ******************************************************************************* Ephemeris / API_USER Tue Jul 15 00:40:10 2025 Pasadena, USA / Horizons ******************************************************************************* Target body name: Hubble Space Telescope (spacecraft) (-48) {source: hst} Center body name: Earth (399) {source: DE441} Center-site name: El Berrueco ******************************************************************************* Start time : A.D. 2025-Jul-06 00:00:00.0000 UT Stop time : A.D. 2025-Jul-20 00:00:00.0000 UT Step-size : 10 minutes ******************************************************************************* Target pole/equ : undefined Target radii : undefined Center geodetic : 356.4134, 40.8833094, 1.06361 {E-lon(deg),Lat(deg),Alt(km)} Center cylindric: 356.4134,4829.88693,4153.33056 {E-lon(deg),Dxy(km),Dz(km)} Center pole/equ : ITRF93 {East-longitude positive} Center radii : 6378.137, 6378.137, 6356.752 km {Equator_a, b, pole_c} Target primary : Earth Vis. interferer : MOON (R_eq= 1737.400) km {source: DE441} Rel. light bend : Sun {source: DE441} 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 RTS-only print : NO EOP file : eop.250714.p251010 EOP coverage : DATA-BASED 1962-JAN-20 TO 2025-JUL-14. PREDICTS-> 2025-OCT-09 Units conversion: 1 au= 149597870.700 km, c= 299792.458 km/s, 1 day= 86400.0 s Table cut-offs 1: Elevation ( 0.0deg=YES),Airmass (>38.000=NO), Daylight (YES) Table cut-offs 2: Solar elongation ( 12.0,180.0=YES),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 Azi____(a-app)___Elev APmag S-brt r rdot delta deldot S-O-T /r S-T-O T-O-M/MN_Illu% RA_3sigma DEC_3sigma Sky_motion Sky_mot_PA RelVel-ANG *************************************************************************************************************************************************************************************************************************************************** $$SOE >..... Elevation Cut-off Requested .....< 2025-Jul-06 03:50 N 19 48 22.57 -39 14 54.4 210.424063 1.735823 n.a. n.a. 1.016654140191 -5.9176697 0.00001571105110 -4.5602454 160.6004 /L 19.3998 61.6/ 79.3942 n.a. n.a. 29942.099 100.19185 -38.72503 >..... Elevation Cut-off Requested .....< >..... Daylight Cut-off Requested .....< >..... Elevation Cut-off Requested .....< >..... Elevation Cut-off Requested .....< >..... Elevation Cut-off Requested .....< 2025-Jul-07 01:50 t 00 21 36.54 -32 30 57.0 135.214633 0.105980 n.a. n.a. 1.016644004692 -5.6266535 0.00001687863773 2.1938306 110.5881 /L 69.4118 103.4/ 85.9428 n.a. n.a. 34195.305 58.837928 17.457996 >..... Elevation Cut-off Requested .....< 2025-Jul-07 03:30 At 02 06 30.56 -26 10 59.9 130.441765 4.357130 n.a. n.a. 1.016628980291 -6.6132277 0.00001404822517 3.8884820 87.0970 /L 92.9029 121.9/ 86.3698 n.a. n.a. 36324.047 65.826400 32.227040 >..... Elevation Cut-off Requested .....< >..... Daylight Cut-off Requested .....< >..... Elevation Cut-off Requested .....< >..... Elevation Cut-off Requested .....< 2025-Jul-08 01:20 t 21 16 20.48 -46 49 50.5 168.535859 1.119548 n.a. n.a. 1.016637497840 -3.9761605 0.00001611569472 -1.4200592 144.6319 /L 35.3682 55.6/ 91.8205 n.a. n.a. 36765.444 72.969216 -11.20984 >..... Elevation Cut-off Requested .....< 2025-Jul-08 03:00 At 22 27 13.36 -39 39 27.8 172.632755 9.133142 n.a. n.a. 1.016625274281 -5.6038557 0.00001149434346 -0.6047088 134.8477 /L 45.1527 69.2/ 92.1228 n.a. n.a. 52229.321 80.767399 -4.759490 >..... Elevation Cut-off Requested .....< 2025-Jul-08 04:40 Ct 23 58 11.61 -36 18 42.0 174.152013 12.678146 n.a. n.a. 1.016610233135 -6.4387378 0.00001002827860 0.6704861 116.9555 /L 63.0447 86.0/ 92.4756 n.a. n.a. 59748.219 87.053885 5.2907262 >..... Elevation Cut-off Requested .....< >..... Daylight Cut-off Requested .....< >..... Elevation Cut-off Requested .....< >..... Elevation Cut-off Requested .....< 2025-Jul-09 02:30 r 18 39 08.48 -38 05 50.5 211.112587 2.620404 n.a. n.a. 1.016615160792 -4.0386166 0.00001510586503 -4.5101504 162.6961 /T 17.3031 15.1/ 96.4449 n.a. n.a. 31352.068 100.63947 -38.22858 >..... Elevation Cut-off Requested .....< 2025-Jul-09 04:10 Nr 19 47 32.64 -29 18 22.2 221.498442 6.501516 n.a. n.a. 1.016602729354 -5.5181911 0.00001281548481 -4.3063407 169.6133 /L 10.3874 26.9/ 96.6636 n.a. n.a. 37896.908 106.51887 -36.25811 >..... Elevation Cut-off Requested .....< >..... Daylight Cut-off Requested .....< >..... Elevation Cut-off Requested .....< >..... Elevation Cut-off Requested .....< 2025-Jul-10 00:30 t 23 18 23.48 -31 00 02.4 133.385942 0.560319 n.a. n.a. 1.016594488574 -3.6480466 0.00001653516949 2.5187473 125.9037 /L 54.0966 60.4/ 98.9916 n.a. n.a. 34345.581 59.366726 20.151789 >..... Elevation Cut-off Requested .....< 2025-Jul-10 02:10 t 01 03 46.67 -25 21 11.7 128.903537 4.167736 n.a. n.a. 1.016582721578 -5.1557327 0.00001415100318 4.1601352 102.1262 /L 77.8741 83.4/ 99.0803 n.a. n.a. 35006.570 66.665601 34.790072 >..... Elevation Cut-off Requested .....< 2025-Jul-10 03:50 Nt 02 34 53.25 -27 54 34.1 132.161176 3.522761 n.a. n.a. 1.016568345327 -5.9386576 0.00001455446637 4.9785174 84.5632 /L 95.4368 98.5/ 99.1791 n.a. n.a. 30223.985 73.915087 43.114377 >..... Elevation Cut-off Requested .....< >..... Daylight Cut-off Requested .....< >..... Elevation Cut-off Requested .....< 2025-Jul-11 00:00 t 20 12 18.52 -45 33 00.5 167.501315 2.161854 n.a. n.a. 1.016573358083 -1.7149029 0.00001538823073 -1.1825986 154.3235 /L 25.6763 20.2/ 99.7729 n.a. n.a. 38727.297 72.917153 -9.317356 >..... Elevation Cut-off Requested .....< 2025-Jul-11 01:40 t 21 28 36.67 -38 36 26.6 170.558475 9.880746 n.a. n.a. 1.016565348427 -3.6159096 0.00001114563455 -0.2142660 148.1475 /L 31.8531 26.7/ 99.7657 n.a. n.a. 54021.630 80.226962 -1.681296 >..... Elevation Cut-off Requested .....< 2025-Jul-11 03:20 At 23 01 34.81 -36 20 01.5 171.714386 12.374516 n.a. n.a. 1.016553576563 -5.0071172 0.00001013153985 1.1048667 130.5487 /L 49.4519 44.3/ 99.7560 n.a. n.a. 58710.771 86.405827 8.7390128 >..... Elevation Cut-off Requested .....< >..... Daylight Cut-off Requested .....< >..... Elevation Cut-off Requested .....< 2025-Jul-12 01:10 r 17 33 14.45 -37 07 33.0 211.144924 3.670950 n.a. n.a. 1.016540970879 -1.7379659 0.00001442355698 -4.3998665 151.5688 /T 28.4296 39.8/ 98.3527 n.a. n.a. 33314.042 100.92132 -37.14117 >..... Elevation Cut-off Requested .....< 2025-Jul-12 02:50 r 18 45 42.59 -29 21 55.4 220.252284 7.236828 n.a. n.a. 1.016532818682 -3.5321252 0.00001241675797 -4.0629988 168.4619 /T 11.5372 24.3/ 98.2435 n.a. n.a. 40254.901 106.99453 -33.91592 >..... Elevation Cut-off Requested .....< 2025-Jul-12 04:30 Cr 20 24 32.69 -30 42 10.8 219.795609 5.997488 n.a. n.a. 1.016521136811 -4.8321068 0.00001308304129 -2.7637610 164.1694 /L 15.8315 7.957/ 98.1184 n.a. n.a. 42660.733 113.88648 -22.27288 >..... Elevation Cut-off Requested .....< >..... Daylight Cut-off Requested .....< >..... Elevation Cut-off Requested .....< 2025-Jul-12 23:10 t 22 17 27.84 -29 14 27.1 131.009694 0.836621 n.a. n.a. 1.016510568775 -1.2857546 0.00001632793455 2.8955402 141.4164 /L 38.5843 16.4/ 94.9728 n.a. n.a. 34015.045 59.929618 23.334461 >..... Elevation Cut-off Requested .....< 2025-Jul-13 00:50 t 00 02 42.58 -24 29 05.2 127.058355 3.724028 n.a. n.a. 1.016503263388 -3.0798677 0.00001441219861 4.4488775 117.6784 /L 62.3222 37.6/ 94.7526 n.a. n.a. 33160.991 67.601417 37.601382 >..... Elevation Cut-off Requested .....< 2025-Jul-13 02:30 t 01 30 30.01 -28 23 02.2 131.755149 2.598677 n.a. n.a. 1.016492354017 -4.4459050 0.00001513488628 5.1195728 99.9187 /L 80.0816 56.6/ 94.5420 n.a. n.a. 28338.690 74.612045 44.639211 >..... Elevation Cut-off Requested .....< 2025-Jul-13 22:40 t 19 12 36.29 -44 02 08.4 165.632452 3.212822 n.a. n.a. 1.016474898648 0.6716683 0.00001469524127 -0.8453290 157.3154 /T 22.6836 48.0/ 89.4127 n.a. n.a. 40811.179 72.393840 -6.645580 >..... Elevation Cut-off Requested .....< 2025-Jul-14 00:20 t 20 35 03.49 -37 25 44.4 167.408575 10.477316 n.a. n.a. 1.016471730311 -1.2285184 0.00001087793321 0.2989466 159.3317 /L 20.6688 32.1/ 89.0554 n.a. n.a. 55323.779 79.209873 2.3587621 >..... Elevation Cut-off Requested .....< 2025-Jul-14 02:00 t 22 08 56.88 -36 23 28.6 168.499039 11.790291 n.a. n.a. 1.016464414205 -2.9597537 0.00001034657521 1.6207051 143.2326 /L 36.7683 23.0/ 88.7321 n.a. n.a. 56713.443 85.348351 12.874882 >..... Elevation Cut-off Requested .....< 2025-Jul-14 03:40 At 23 23 42.80 -42 54 31.6 174.394716 6.071069 n.a. n.a. 1.016453614503 -4.2842669 0.00001302395597 2.3567784 128.0729 /L 51.9277 33.2/ 88.4172 n.a. n.a. 43793.655 92.462420 18.874509 >..... Elevation Cut-off Requested .....< 2025-Jul-14 23:50 r 16 31 07.45 -36 22 23.8 210.396009 4.898960 n.a. n.a. 1.016432629222 0.7093329 0.00001367641239 -4.2144356 137.2371 /T 42.7610 91.4/ 81.4469 n.a. n.a. 35943.286 100.98250 -35.34336 >..... Elevation Cut-off Requested .....< 2025-Jul-15 01:30 r 17 48 00.40 -29 50 47.3 218.004096 8.080142 n.a. n.a. 1.016429379047 -1.1406774 0.00001198242432 -3.7164424 154.1418 /T 25.8566 76.8/ 80.9917 n.a. n.a. 43227.605 107.24835 -30.68844 >..... Elevation Cut-off Requested .....< 2025-Jul-15 03:10 Ar 19 28 33.45 -32 30 06.6 216.553070 5.923083 n.a. n.a. 1.016422078549 -2.8386313 0.00001310927337 -2.2801773 168.8731 /T 11.1270 56.5/ 80.5754 n.a. n.a. 43713.399 113.92497 -18.21592 >..... Elevation Cut-off Requested .....< 2025-Jul-15 21:50 t 21 18 50.16 -27 15 12.0 128.085100 0.881594 n.a. n.a. 1.016392095026 1.1751190 0.00001629330198 3.3174045 156.9037 /L 23.0971 43.6/ 72.8663 n.a. n.a. 33077.038 60.612585 26.990725 >..... Elevation Cut-off Requested .....< 2025-Jul-15 23:30 t 23 03 09.72 -23 36 52.3 124.961628 3.004198 n.a. n.a. 1.016389725516 -0.6505686 0.00001485970476 4.7444271 133.4580 /L 46.5428 25.0/ 72.1872 n.a. n.a. 30830.431 68.701577 40.590033 >..... Elevation Cut-off Requested .....< 2025-Jul-16 01:10 t 00 27 24.17 -28 52 38.7 131.162538 1.466116 n.a. n.a. 1.016383277974 -2.3960990 0.00001588728919 5.2656803 115.7152 /L 64.2853 29.2/ 71.5923 n.a. n.a. 26243.189 75.356468 46.256580 >..... Elevation Cut-off Requested .....< 2025-Jul-16 21:20 At 18 17 57.12 -42 12 24.3 162.716262 4.227393 n.a. n.a. 1.016341039942 2.9057552 0.00001406708639 -0.3832700 152.2929 /T 27.7056 96.1/ 62.6551 n.a. n.a. 42852.566 71.364059 -3.006023 >..... Elevation Cut-off Requested .....< 2025-Jul-16 23:00 t 19 46 52.54 -36 03 28.5 163.071809 10.808922 n.a. n.a. 1.016342581782 1.2663004 0.00001073421652 0.9434941 165.1881 /L 14.8115 79.3/ 61.8182 n.a. n.a. 55633.798 77.750161 7.4520056 >..... Elevation Cut-off Requested .....< 2025-Jul-17 00:40 t 21 20 03.07 -36 26 00.3 164.587488 10.870619 n.a. n.a. 1.016340162887 -0.5618617 0.00001071042007 2.2025681 154.3598 /L 25.6411 63.0/ 61.0770 n.a. n.a. 53572.977 83.935387 17.622557 >..... Elevation Cut-off Requested .....< 2025-Jul-17 02:20 t 22 28 29.41 -43 58 37.1 172.114070 4.704880 n.a. n.a. 1.016333636886 -2.3271519 0.00001378697890 2.7315658 139.4009 /L 40.5998 58.7/ 60.4298 n.a. n.a. 40549.724 91.355655 22.012365 >..... Elevation Cut-off Requested .....< 2025-Jul-17 20:50 Nr 14 43 05.86 -46 22 48.8 196.025802 0.120390 n.a. n.a. 1.016282532030 4.2364600 0.00001682037880 -3.8338167 114.3730 /T 65.6250 140.7/ 51.7545 n.a. n.a. 30534.411 93.071240 -31.69515 >..... Elevation Cut-off Requested .....< 2025-Jul-17 22:30 r 15 33 49.04 -35 53 28.2 208.623596 6.324999 n.a. n.a. 1.016287315307 3.0160424 0.00001287487554 -3.9249825 123.0633 /T 56.9348 142.4/ 50.7989 n.a. n.a. 39417.537 100.69691 -32.60960 >..... Elevation Cut-off Requested .....< 2025-Jul-18 00:10 r 16 55 27.28 -30 48 55.5 214.525119 8.993787 n.a. n.a. 1.016288816039 1.3613134 0.00001154008236 -3.2339563 140.0529 /T 39.9454 129.3/ 49.9346 n.a. n.a. 46763.126 107.09653 -26.36690 >..... Elevation Cut-off Requested .....< 2025-Jul-18 01:50 r 18 36 27.30 -34 42 33.0 212.461458 5.751234 n.a. n.a. 1.016286297633 -0.5004772 0.00001319264486 -1.6938215 158.9686 /T 21.0304 108.9/ 49.1754 n.a. n.a. 44489.239 113.48996 -13.42297 >..... Elevation Cut-off Requested .....< 2025-Jul-18 20:30 Nt 20 22 09.10 -25 06 47.1 124.715006 0.651005 n.a. n.a. 1.016234897889 3.4473530 0.00001646338659 3.7661362 171.9730 /L 8.0276 95.4/ 40.5878 n.a. n.a. 31482.351 61.531440 31.014883 >..... Elevation Cut-off Requested .....< 2025-Jul-18 22:10 t 22 04 41.46 -22 48 38.8 122.743059 2.014923 n.a. n.a. 1.016237167771 1.8348204 0.00001551098719 5.0313687 149.3696 /L 30.6313 74.0/ 39.5847 n.a. n.a. 28160.750 70.036182 43.621401 >..... Elevation Cut-off Requested .....< 2025-Jul-18 23:50 t 23 25 18.55 -29 24 32.9 130.454452 0.148628 n.a. n.a. 1.016235432059 -0.0546119 0.00001682152537 5.4087240 131.5989 /L 48.4018 63.8/ 38.6579 n.a. n.a. 24051.576 76.190195 47.881875 >..... Elevation Cut-off Requested .....< 2025-Jul-19 20:00 Ct 17 28 22.07 -39 59 20.6 158.644539 5.117615 n.a. n.a. 1.016166771735 4.7374646 0.00001354924982 0.2156506 143.1280 /T 36.8704 145.3/ 29.9183 n.a. n.a. 44520.663 69.915981 1.6980306 >..... Elevation Cut-off Requested .....< 2025-Jul-19 21:40 t 19 03 13.75 -34 27 26.8 157.683512 10.735411 n.a. n.a. 1.016172183556 3.5753836 0.00001076723371 1.6959522 161.9252 /T 18.0736 128.8/ 28.9422 n.a. n.a. 54391.200 76.042564 13.477540 >..... Elevation Cut-off Requested .....< 2025-Jul-19 23:20 t 20 33 43.54 -36 25 34.1 160.249508 9.593334 n.a. n.a. 1.016174343791 1.8919374 0.00001125887778 2.8126833 162.3558 /L 17.6447 112.0/ 28.0162 n.a. n.a. 49327.326 82.342423 22.737268 >..... Elevation Cut-off Requested .....< $$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. SOLAR PRESENCE (OBSERVING SITE) Time tag is followed by a blank, then a solar-presence condition code: '*' Daylight (refracted solar upper-limb on or above apparent horizon) 'C' Civil twilight/dawn 'N' Nautical twilight/dawn 'A' Astronomical twilight/dawn ' ' Night OR geocentric ephemeris LUNAR PRESENCE WITH TARGET RISE/TRANSIT/SET EVENT MARKER (OBSERVING SITE) The solar-presence code column is immediately followed by another marker: 'm' Refracted upper-limb of Moon on or above apparent horizon ' ' Refracted upper-limb of Moon below apparent horizon OR geocentric The lunar presence marker (an ongoing state) can be over-ridden by a target event marker if an event has occurred since the last output step: 'r' Rise (target body on or went above cut-off RTS elevation) 'e' Elevation max (target body maximum elevation angle has occurred) 't' Transit (target body at or passed through observer meridian) 's' Set (target body on or went below cut-off RTS elevation) RTS MARKERS (TVH) Rise and set are with respect to the reference ellipsoid true visual horizon defined by the elevation cut-off angle. Horizon dip and yellow-light refraction (Earth only) are considered. Accuracy is < or = to twice the requested search step-size. '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} '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 '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 '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 '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-M/MN_Illu%' = Target-Observer-Moon LUNAR ELONGATION angle and illuminated percentage. The apparent lunar elongation angle between target body center and Moon center, seen from the observing site, along with fraction of the lunar disk illuminated by the Sun. A negative lunar elongation angle indicates the target center is behind the Moon. Units: DEGREES & PERCENT 'RA_3sigma DEC_3sigma' = Uncertainty in Right-Ascension and Declination. Output values are the formal +/- 3 standard-deviations (sigmas) around nominal position. Units: ARCSECONDS '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 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/horizons_batch.txt scripts https://ssd.jpl.nasa.gov/ftp/ssd/SCRIPTS Author : Jon.D.Giorgini@jpl.nasa.gov ***************************************************************************************************************************************************************************************************************************************************