API VERSION: 1.2 API SOURCE: NASA/JPL Horizons API ******************************************************************************* JPL/HORIZONS 138971 (2001 CB21) 2025-Dec-12 17:58:20 Rec #: 138971 (+COV) Soln.date: 2025-Dec-12_05:25:05 # obs: 2378 (2001-2025) IAU76/J2000 helio. ecliptic osc. elements (au, days, deg., period=Julian yrs): EPOCH= 2458802.5 ! 2019-Nov-15.00 (TDB) Residual RMS= .26793 EC= .333436119388179 QR= .6894745217598415 TP= 2458940.7952386406 OM= 353.7280712926391 W= 271.7949525553146 IN= 7.898765894606268 A= 1.034371261051516 MA= 230.4323346022429 ADIST= 1.37926800034319 PER= 1.05202 N= .93689173 ANGMOM= .016494025 DAN= .90987 DDN= .92907 L= 265.5402053 B= -7.8948654 MOID= .0235528 TP= 2020-Apr-01.2952386406 Asteroid physical parameters (km, seconds, rotational period in hours): GM= n.a. RAD= n.a. ROTPER= 3.303 H= 18.52 G= .150 B-V= n.a. ALBEDO= n.a. STYP= n.a. ASTEROID comments: 1: soln ref.= JPL#369, PHA OCC=0 radar( 1 delay, 1 Dop.) 2: source=ORB ******************************************************************************* ******************************************************************************* Ephemeris / API_USER Fri Dec 12 17:58:20 2025 Pasadena, USA / Horizons ******************************************************************************* Target body name: 138971 (2001 CB21) {source: JPL#369} Center body name: DART (spacecraft) (-135) {source: DART_V03_HRZN} Center-site name: BODYCENTRIC ******************************************************************************* Start time : A.D. 2022-Mar-01 00:00:00.0000 UT Stop time : A.D. 2022-Mar-03 00:00:00.0000 UT Step-size : 60 minutes ******************************************************************************* Target pole/equ : undefined Target radii : undefined Center geodetic : 0.0, 0.0, 0.0 {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 : ICRF Center radii : undefined Target primary : Sun Vis. interferer : None Rel. light bend : Sun {source: DART_V03_HRZN} Rel. lght bnd GM: 1.3271E+11 km^3/s^2 Small-body perts: Yes {source: SB441-N16} Atmos refraction: NO (AIRLESS) RA format : HMS Time format : CAL Calendar mode : Mixed Julian/Gregorian EOP file : eop.251212.p260310 EOP coverage : DATA-BASED 1962-JAN-20 TO 2025-DEC-12. PREDICTS-> 2026-MAR-09 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 ) ******************************************************************************* Initial IAU76/J2000 heliocentric ecliptic osculating elements (au, days, deg.): EPOCH= 2458802.5 ! 2019-Nov-15.00 (TDB) Residual RMS= .26793 EC= .333436119388179 QR= .6894745217598415 TP= 2458940.7952386406 OM= 353.7280712926391 W= 271.7949525553146 IN= 7.898765894606268 Equivalent ICRF heliocentric cartesian coordinates (au, au/d): X=-5.167180525538249E-01 Y= 1.027267371101613E+00 Z= 6.152973768059268E-01 VX=-1.050657136396584E-02 VY=-6.386673605183421E-03 VZ=-4.066448887858143E-03 Asteroid physical parameters (km, seconds, rotational period in hours): GM= n.a. RAD= n.a. ROTPER= 3.303 H= 18.52 G= .150 B-V= n.a. ALBEDO= n.a. STYP= n.a. ********************************************************************************************************** Date__(UT)__HR:MN R.A._____(ICRF)_____DEC APmag S-brt delta deldot S-O-T /r ********************************************************************************************************** $$SOE 2022-Mar-01 00:00 07 00 06.82 +07 12 03.9 15.950 n.a. 1.7487288171E+07 -0.6421465 115.9850 /L 2022-Mar-01 01:00 06 59 42.48 +07 09 55.9 15.953 n.a. 1.7485005126E+07 -0.6261020 115.8381 /L 2022-Mar-01 02:00 06 59 18.16 +07 07 47.9 15.956 n.a. 1.7482779805E+07 -0.6100802 115.6912 /L 2022-Mar-01 03:00 06 58 53.84 +07 05 39.7 15.960 n.a. 1.7480612127E+07 -0.5940813 115.5443 /L 2022-Mar-01 04:00 06 58 29.53 +07 03 31.5 15.963 n.a. 1.7478502008E+07 -0.5781053 115.3974 /L 2022-Mar-01 05:00 06 58 05.23 +07 01 23.2 15.966 n.a. 1.7476449367E+07 -0.5621523 115.2506 /L 2022-Mar-01 06:00 06 57 40.94 +06 59 14.7 15.969 n.a. 1.7474454120E+07 -0.5462224 115.1038 /L 2022-Mar-01 07:00 06 57 16.65 +06 57 06.2 15.973 n.a. 1.7472516184E+07 -0.5303156 114.9570 /L 2022-Mar-01 08:00 06 56 52.38 +06 54 57.6 15.976 n.a. 1.7470635476E+07 -0.5144321 114.8103 /L 2022-Mar-01 09:00 06 56 28.11 +06 52 48.9 15.979 n.a. 1.7468811912E+07 -0.4985719 114.6635 /L 2022-Mar-01 10:00 06 56 03.84 +06 50 40.1 15.983 n.a. 1.7467045407E+07 -0.4827350 114.5168 /L 2022-Mar-01 11:00 06 55 39.59 +06 48 31.2 15.986 n.a. 1.7465335879E+07 -0.4669215 114.3702 /L 2022-Mar-01 12:00 06 55 15.35 +06 46 22.3 15.989 n.a. 1.7463683241E+07 -0.4511316 114.2235 /L 2022-Mar-01 13:00 06 54 51.11 +06 44 13.2 15.993 n.a. 1.7462087410E+07 -0.4353652 114.0769 /L 2022-Mar-01 14:00 06 54 26.88 +06 42 04.1 15.996 n.a. 1.7460548300E+07 -0.4196225 113.9304 /L 2022-Mar-01 15:00 06 54 02.66 +06 39 54.9 16.000 n.a. 1.7459065827E+07 -0.4039035 113.7838 /L 2022-Mar-01 16:00 06 53 38.45 +06 37 45.6 16.003 n.a. 1.7457639904E+07 -0.3882083 113.6373 /L 2022-Mar-01 17:00 06 53 14.25 +06 35 36.2 16.006 n.a. 1.7456270445E+07 -0.3725370 113.4908 /L 2022-Mar-01 18:00 06 52 50.06 +06 33 26.7 16.010 n.a. 1.7454957366E+07 -0.3568895 113.3444 /L 2022-Mar-01 19:00 06 52 25.87 +06 31 17.2 16.013 n.a. 1.7453700579E+07 -0.3412661 113.1980 /L 2022-Mar-01 20:00 06 52 01.70 +06 29 07.6 16.017 n.a. 1.7452499999E+07 -0.3256666 113.0516 /L 2022-Mar-01 21:00 06 51 37.53 +06 26 57.9 16.020 n.a. 1.7451355538E+07 -0.3100913 112.9053 /L 2022-Mar-01 22:00 06 51 13.38 +06 24 48.1 16.024 n.a. 1.7450267110E+07 -0.2945402 112.7590 /L 2022-Mar-01 23:00 06 50 49.23 +06 22 38.3 16.027 n.a. 1.7449234628E+07 -0.2790133 112.6127 /L 2022-Mar-02 00:00 06 50 25.10 +06 20 28.4 16.031 n.a. 1.7448258004E+07 -0.2635106 112.4665 /L 2022-Mar-02 01:00 06 50 00.97 +06 18 18.4 16.034 n.a. 1.7447337150E+07 -0.2480324 112.3203 /L 2022-Mar-02 02:00 06 49 36.85 +06 16 08.3 16.038 n.a. 1.7446471979E+07 -0.2325785 112.1741 /L 2022-Mar-02 03:00 06 49 12.75 +06 13 58.2 16.041 n.a. 1.7445662403E+07 -0.2171491 112.0280 /L 2022-Mar-02 04:00 06 48 48.65 +06 11 48.0 16.045 n.a. 1.7444908334E+07 -0.2017443 111.8819 /L 2022-Mar-02 05:00 06 48 24.56 +06 09 37.8 16.048 n.a. 1.7444209683E+07 -0.1863640 111.7359 /L 2022-Mar-02 06:00 06 48 00.49 +06 07 27.5 16.052 n.a. 1.7443566362E+07 -0.1710083 111.5899 /L 2022-Mar-02 07:00 06 47 36.42 +06 05 17.1 16.055 n.a. 1.7442978282E+07 -0.1556774 111.4439 /L 2022-Mar-02 08:00 06 47 12.37 +06 03 06.7 16.059 n.a. 1.7442445353E+07 -0.1403712 111.2980 /L 2022-Mar-02 09:00 06 46 48.32 +06 00 56.2 16.062 n.a. 1.7441967487E+07 -0.1250899 111.1521 /L 2022-Mar-02 10:00 06 46 24.29 +05 58 45.6 16.066 n.a. 1.7441544595E+07 -0.1098334 111.0063 /L 2022-Mar-02 11:00 06 46 00.26 +05 56 35.0 16.069 n.a. 1.7441176585E+07 -0.0946018 110.8605 /L 2022-Mar-02 12:00 06 45 36.25 +05 54 24.3 16.073 n.a. 1.7440863370E+07 -0.0793952 110.7147 /L 2022-Mar-02 13:00 06 45 12.25 +05 52 13.6 16.077 n.a. 1.7440604858E+07 -0.0642135 110.5690 /L 2022-Mar-02 14:00 06 44 48.26 +05 50 02.8 16.080 n.a. 1.7440400960E+07 -0.0490570 110.4234 /L 2022-Mar-02 15:00 06 44 24.28 +05 47 52.0 16.084 n.a. 1.7440251586E+07 -0.0339255 110.2777 /L 2022-Mar-02 16:00 06 44 00.31 +05 45 41.1 16.088 n.a. 1.7440156644E+07 -0.0188193 110.1322 /L 2022-Mar-02 17:00 06 43 36.35 +05 43 30.1 16.091 n.a. 1.7440116045E+07 -0.0037383 109.9866 /L 2022-Mar-02 18:00 06 43 12.41 +05 41 19.1 16.095 n.a. 1.7440129696E+07 0.0113175 109.8412 /L 2022-Mar-02 19:00 06 42 48.47 +05 39 08.1 16.099 n.a. 1.7440197507E+07 0.0263479 109.6957 /L 2022-Mar-02 20:00 06 42 24.55 +05 36 57.0 16.102 n.a. 1.7440319388E+07 0.0413530 109.5504 /L 2022-Mar-02 21:00 06 42 00.64 +05 34 45.9 16.106 n.a. 1.7440495245E+07 0.0563326 109.4050 /L 2022-Mar-02 22:00 06 41 36.74 +05 32 34.7 16.110 n.a. 1.7440724989E+07 0.0712868 109.2597 /L 2022-Mar-02 23:00 06 41 12.86 +05 30 23.5 16.113 n.a. 1.7441008526E+07 0.0862154 109.1145 /L 2022-Mar-03 00:00 06 40 48.98 +05 28 12.2 16.117 n.a. 1.7441345766E+07 0.1011185 108.9693 /L $$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} 'APmag S-brt' = The asteroids' approximate apparent airless visual magnitude and surface brightness using the standard IAU H-G system magnitude model: APmag = H + 5*log10(delta) + 5*log10(r) - 2.5*log10((1-G)*phi_1 + G*phi_2) For solar phase angles >90 deg, the error could exceed 1 magnitude. For phase angles >120 degrees, output values are rounded to the nearest integer to indicate error could be large and unknown. 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 '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: KM 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 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 **********************************************************************************************************