******************************************************************************* JPL/HORIZONS 1P/Halley 2025-Dec-12 17:59:48 Rec #:90000030 Soln.date: 2025-Nov-21_15:57:34 # obs: 8518 (1835-1994) IAU76/J2000 helio. ecliptic osc. elements (au, days, deg., period=Julian yrs): EPOCH= 2439875.5 ! 1968-Jan-20.0000000 (TDB) RMSW= n.a. EC= .9679359956953212 QR= .5748638313743413 TP= 2446469.9736161465 OM= 59.09894720612437 W= 112.2414314637764 IN= 162.1905300439129 A= 17.92863504856929 MA= 274.3823371364693 ADIST= 35.28240626576424 PER= 75.915252807404 N= .012983244 ANGMOM= .018296559 DAN= 1.78543 DDN= .82795 L= 305.8544912 B= 16.4450919 MOID= .0745097 TP= 1986-Feb-08.4736161465 Comet physical (GM= km^3/s^2; RAD= km): GM= n.a. RAD= 5.5 M1= 5.5 M2= 13.6 k1= 8. k2= 5. PHCOF= .030 Comet non-gravitational force model (AMRAT=m^2/kg;A1-A3=au/d^2;DT=days;R0=au): AMRAT= 0. DT= 0. A1= 4.887055233121E-10 A2= 1.554720290005E-10 A3= 0. Standard model: ALN= .1112620426 NK= 4.6142 NM= 2.15 NN= 5.093 R0= 2.808 COMET comments 1: soln ref.= JPL#75, data arc: 1835-08-21 to 1994-01-11 2: k1=8.0, k2=5.0, phase coef.=0.03; ******************************************************************************* ******************************************************************************* Ephemeris / WWW_USER Fri Dec 12 17:59:48 2025 Pasadena, USA / Horizons ******************************************************************************* Target body name: 1P/Halley {source: JPL#75} Center body name: Earth (399) {source: DE441} Center-site name: GEOCENTRIC ******************************************************************************* Start time : A.D. 2134-Mar-24 00:00:00.0000 UT Stop time : A.D. 2134-Mar-30 00:00:00.0000 UT Step-size : 180 minutes ******************************************************************************* Target pole/equ : undefined Target radii : 5.5 km Center geodetic : 0.0, 0.0, -6378.137 {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 : ITRF93 {East-longitude positive} Center radii : 6378.137, 6378.137, 6356.752 km {Equator_a, b, pole_c} Target primary : Sun 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 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 (>38.000=NO), 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= 2439875.5 ! 1968-Jan-20.0000000 (TDB) RMSW= n.a. EC= .9679359956953212 QR= .5748638313743413 TP= 2446469.9736161465 OM= 59.09894720612437 W= 112.2414314637764 IN= 162.1905300439129 Equivalent ICRF heliocentric cartesian coordinates (au, au/d): X=-1.331029360169393E+01 Y= 2.541249958785733E+01 Z= 2.637549316318327E+00 VX= 1.418949944126011E-03 VY=-1.422475975617656E-03 VZ= 4.131321199969281E-05 Comet physical (GM= km^3/s^2; RAD= km): GM= n.a. RAD= 5.5 M1= 5.5 M2= 13.6 k1= 8. k2= 5. PHCOF= .030 Comet non-gravitational force model (AMRAT=m^2/kg;A1-A3=au/d^2;DT=days;R0=au): AMRAT= 0. DT= 0. A1= 4.887055233121E-10 A2= 1.554720290005E-10 A3= 0. Standard model: ALN= .1112620426 NK= 4.6142 NM= 2.15 NN= 5.093 R0= 2.808 ******************************************************************************* Date__(UT)__HR:MN r rdot ************************************************** $$SOE 2134-Mar-24 00:00 0.599346199482 -5.4108242 2134-Mar-24 03:00 0.598961624019 -5.2418272 2134-Mar-24 06:00 0.598589266010 -5.0723964 2134-Mar-24 09:00 0.598229156322 -4.9025447 2134-Mar-24 12:00 0.597881324892 -4.7322852 2134-Mar-24 15:00 0.597545800713 -4.5616310 2134-Mar-24 18:00 0.597222611826 -4.3905952 2134-Mar-24 21:00 0.596911785309 -4.2191914 2134-Mar-25 00:00 0.596613347267 -4.0474330 2134-Mar-25 03:00 0.596327322826 -3.8753338 2134-Mar-25 06:00 0.596053736118 -3.7029074 2134-Mar-25 09:00 0.595792610278 -3.5301678 2134-Mar-25 12:00 0.595543967431 -3.3571291 2134-Mar-25 15:00 0.595307828690 -3.1838052 2134-Mar-25 18:00 0.595084214140 -3.0102105 2134-Mar-25 21:00 0.594873142837 -2.8363593 2134-Mar-26 00:00 0.594674632800 -2.6622660 2134-Mar-26 03:00 0.594488701003 -2.4879451 2134-Mar-26 06:00 0.594315363368 -2.3134112 2134-Mar-26 09:00 0.594154634762 -2.1386790 2134-Mar-26 12:00 0.594006528989 -1.9637633 2134-Mar-26 15:00 0.593871058786 -1.7886788 2134-Mar-26 18:00 0.593748235817 -1.6134403 2134-Mar-26 21:00 0.593638070671 -1.4380630 2134-Mar-27 00:00 0.593540572856 -1.2625617 2134-Mar-27 03:00 0.593455750796 -1.0869515 2134-Mar-27 06:00 0.593383611829 -0.9112474 2134-Mar-27 09:00 0.593324162202 -0.7354646 2134-Mar-27 12:00 0.593277407069 -0.5596182 2134-Mar-27 15:00 0.593243350493 -0.3837233 2134-Mar-27 18:00 0.593221995438 -0.2077952 2134-Mar-27 21:00 0.593213343774 -0.0318491 2134-Mar-28 00:00 0.593217396271 0.1441000 2134-Mar-28 03:00 0.593234152604 0.3200366 2134-Mar-28 06:00 0.593263611348 0.4959458 2134-Mar-28 09:00 0.593305769983 0.6718122 2134-Mar-28 12:00 0.593360624892 0.8476207 2134-Mar-28 15:00 0.593428171362 1.0233562 2134-Mar-28 18:00 0.593508403588 1.1990035 2134-Mar-28 21:00 0.593601314676 1.3745475 2134-Mar-29 00:00 0.593706896642 1.5499732 2134-Mar-29 03:00 0.593825140415 1.7252656 2134-Mar-29 06:00 0.593956035846 1.9004098 2134-Mar-29 09:00 0.594099571706 2.0753908 2134-Mar-29 12:00 0.594255735691 2.2501937 2134-Mar-29 15:00 0.594424514431 2.4248039 2134-Mar-29 18:00 0.594605893488 2.5992066 2134-Mar-29 21:00 0.594799857367 2.7733872 2134-Mar-30 00:00 0.595006389521 2.9473312 $$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 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 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 COMMAND = '90000030' QUANTITIES = '19' START_TIME = '2134-Mar-24' STEP_SIZE = '3 hours' STOP_TIME = '2134-Mar-30'