******************************************************************************* JPL/HORIZONS Dimorphos (Didymos I) 120065803 Updated: 2024-Mar-01 Solution (s542) date: 2023-Sep-19 This is the DART mission's post-impact reconstructed trajectory for Dimorphos, -satellite- of the 65803 Didymos system & the IMPACTED TARGET. The trajectory data includes the pre- and post-impact ephemeris for Dimorphos. For surface cartographic locations, pre- and post-impact Dimorphos rotation models are used automatically. To use Dimorphos as a coordinate origin, set center to "@ 120065803". DART impact was on 26-Sep-2022 @ 23:14:24.183 UTC, equivalent to 2022-Sep-26 23:15:33.365359 TDB. Related objects: DART spacecraft : -135 (mission navigation) LICIACube spacecraft : -210 (mission navigation) Didymos system barycenter : 20065803 (JPL s205 mission reconstruction) 65803; (latest JPL ground-based solution) Didymos primary body : 920065803 (JPL s542 reconstruction) Dimorphos physical parameters: Radii ~ (0.09078 x 0.06932 x 0.06131) km, 145.6 m volume equivalent diam. Volume ~ 0.001616 km^3 GM_Dimo ~ 2.98047E-10 km^3/s^2 Possible Dimorphos mass-ejection (0.1-0.5%) is not reflected here, perhaps measured later by follow-on ESA mission Hera. Pre-impact Dimorphos spin pole (ICRF at J2000.0 epoch, east long. positive) RA = 69.32686 deg. (310.0 deg. ecliptic longitude) DEC = -72.72455 deg. (-80.6 deg. ecliptic latitude) PM = 73.07056508 deg., 724.7243883 deg/day, 1.0271E-06 deg^2/day^2 (period is 11.92177 hrs) Post-impact Dimorphos spin pole A dynamic frame where the X axis points from Dimorphos center to Didymos center. The Z axis is parallel to the pre-impact Z axis. RA = 69.32686 deg. (310.0 deg. ecliptic longitude) DEC = -72.72455 deg. (-80.6 deg. ecliptic latitude) Name Start (TDB) Stop (TDB) --------------------------------------- ----------------- ----------------- didymos_system_s542_v01 2000-Jan-01 00:00 2024-Dec-31 00:00 ******************************************************************************* ******************************************************************************* Ephemeris / WWW_USER Fri Dec 12 18:04:19 2025 Pasadena, USA / Horizons ******************************************************************************* Target body name: Dimorphos (120065803) {source: dart_v03_hrzn} Center body name: Didymos (system barycenter) (20065803) {source: dart_v03_hrzn} Center-site name: BODY CENTER ******************************************************************************* Start time : A.D. 2022-Sep-26 23:15:00.0000 TDB Stop time : A.D. 2022-Sep-26 23:16:00.0000 TDB Step-size : 1 minutes ******************************************************************************* 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 radii : (undefined) Keplerian GM : 2.5388026650186694E+02 km^3/d^2 Output units : KM-D, deg, Julian Day Number (Tp) Calendar mode : Mixed Julian/Gregorian Output type : GEOMETRIC osculating elements Output format : 10 Reference frame : Ecliptic of J2000.0 ******************************************************************************* JDTDB EC QR IN OM W Tp N MA TA A AD PR ******************************************************************************* $$SOE 2459849.468750000 = A.D. 2022-Sep-26 23:15:00.0000 TDB EC= 1.817322127594282E-02 QR= 1.173392283428905E+00 IN= 1.706142441823245E+02 OM= 4.000615911425209E+01 W = 1.743779242295275E+02 Tp= 2459849.468750000000 N = 6.987544279176083E+02 MA= 3.599999999559759E+02 TA= 3.599999999543386E+02 A = 1.195111305635602E+00 AD= 1.216830327842299E+00 PR= 5.152024597151439E-01 2459849.469444444 = A.D. 2022-Sep-26 23:16:00.0000 TDB EC= 1.287171378130064E-02 QR= 1.143741908805864E+00 IN= 1.706142441823245E+02 OM= 4.000615911425206E+01 W = 3.387007736755753E+00 Tp= 2459849.235465401318 N = 7.319905060586098E+02 MA= 1.712704383214097E+02 TA= 1.714907916481004E+02 A = 1.158655794564544E+00 AD= 1.173569680323225E+00 PR= 4.918096573935279E-01 $$EOE ******************************************************************************* TIME Barycentric Dynamical Time ("TDB" or T_eph) output was requested. This continuous coordinate time is equivalent to the relativistic proper time of a clock at rest in a reference frame co-moving with the solar system barycenter but outside the system's gravity well. It is the independent variable in the solar system relativistic equations of motion. TDB runs at a uniform rate of one SI second per second and is independent of irregularities in Earth's rotation. 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. REFERENCE FRAME AND COORDINATES Ecliptic at the standard reference epoch Reference epoch: J2000.0 X-Y plane: adopted Earth orbital plane at the reference epoch Note: IAU76 obliquity of 84381.448 arcseconds wrt ICRF X-Y plane X-axis : ICRF Z-axis : perpendicular to the X-Y plane in the directional (+ or -) sense of Earth's north pole at the reference epoch. Symbol meaning [1 day=86400.0 s]: JDTDB Julian Day Number, Barycentric Dynamical Time EC Eccentricity, e QR Periapsis distance, q (km) IN Inclination w.r.t X-Y plane, i (degrees) OM Longitude of Ascending Node, OMEGA, (degrees) W Argument of Perifocus, w (degrees) Tp Time of periapsis (Julian Day Number) N Mean motion, n (degrees/day) MA Mean anomaly, M (degrees) TA True anomaly, nu (degrees) A Semi-major axis, a (km) AD Apoapsis distance (km) PR Sidereal orbit period (day) ABERRATIONS AND CORRECTIONS Geometric osculating elements have NO corrections or aberrations applied. 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 ******************************************************************************* !$$SOF CENTER = '@20065803' COMMAND = 'Dimorphos' OUT_UNITS = 'KM-D' START_TIME = '2022-09-26 23:15' STEP_SIZE = '1 minute' STOP_TIME = '2022-09-26 23:16' TABLE_TYPE = 'ELEMENTS'