******************************************************************************* JPL/HORIZONS 1P/Halley 2025-Dec-12 17:54:45 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 17:54:45 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. 2061-Jul-28 17:00:00.0000 UT Stop time : A.D. 2061-Jul-28 18:00:00.0000 UT Step-size : 1 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 2061-Jul-28 17:00 0.592782035489 -0.0193834 2061-Jul-28 17:01 0.592782027911 -0.0184047 2061-Jul-28 17:02 0.592782020725 -0.0174259 2061-Jul-28 17:03 0.592782013932 -0.0164472 2061-Jul-28 17:04 0.592782007532 -0.0154685 2061-Jul-28 17:05 0.592782001524 -0.0144897 2061-Jul-28 17:06 0.592781995909 -0.0135110 2061-Jul-28 17:07 0.592781990686 -0.0125322 2061-Jul-28 17:08 0.592781985856 -0.0115535 2061-Jul-28 17:09 0.592781981418 -0.0105747 2061-Jul-28 17:10 0.592781977373 -0.0095960 2061-Jul-28 17:11 0.592781973720 -0.0086172 2061-Jul-28 17:12 0.592781970460 -0.0076385 2061-Jul-28 17:13 0.592781967593 -0.0066597 2061-Jul-28 17:14 0.592781965118 -0.0056810 2061-Jul-28 17:15 0.592781963036 -0.0047022 2061-Jul-28 17:16 0.592781961346 -0.0037235 2061-Jul-28 17:17 0.592781960049 -0.0027447 2061-Jul-28 17:18 0.592781959145 -0.0017660 2061-Jul-28 17:19 0.592781958633 -0.0007872 2061-Jul-28 17:20 0.592781958513 0.0001915 2061-Jul-28 17:21 0.592781958786 0.0011703 2061-Jul-28 17:22 0.592781959452 0.0021490 2061-Jul-28 17:23 0.592781960510 0.0031278 2061-Jul-28 17:24 0.592781961961 0.0041065 2061-Jul-28 17:25 0.592781963804 0.0050853 2061-Jul-28 17:26 0.592781966040 0.0060640 2061-Jul-28 17:27 0.592781968669 0.0070428 2061-Jul-28 17:28 0.592781971690 0.0080215 2061-Jul-28 17:29 0.592781975103 0.0090003 2061-Jul-28 17:30 0.592781978909 0.0099790 2061-Jul-28 17:31 0.592781983108 0.0109578 2061-Jul-28 17:32 0.592781987699 0.0119365 2061-Jul-28 17:33 0.592781992683 0.0129153 2061-Jul-28 17:34 0.592781998059 0.0138940 2061-Jul-28 17:35 0.592782003828 0.0148728 2061-Jul-28 17:36 0.592782009990 0.0158515 2061-Jul-28 17:37 0.592782016544 0.0168302 2061-Jul-28 17:38 0.592782023491 0.0178090 2061-Jul-28 17:39 0.592782030830 0.0187877 2061-Jul-28 17:40 0.592782038562 0.0197665 2061-Jul-28 17:41 0.592782046686 0.0207452 2061-Jul-28 17:42 0.592782055203 0.0217240 2061-Jul-28 17:43 0.592782064112 0.0227027 2061-Jul-28 17:44 0.592782073414 0.0236815 2061-Jul-28 17:45 0.592782083109 0.0246602 2061-Jul-28 17:46 0.592782093196 0.0256390 2061-Jul-28 17:47 0.592782103675 0.0266177 2061-Jul-28 17:48 0.592782114548 0.0275965 2061-Jul-28 17:49 0.592782125812 0.0285752 2061-Jul-28 17:50 0.592782137470 0.0295540 2061-Jul-28 17:51 0.592782149520 0.0305327 2061-Jul-28 17:52 0.592782161962 0.0315115 2061-Jul-28 17:53 0.592782174797 0.0324902 2061-Jul-28 17:54 0.592782188025 0.0334689 2061-Jul-28 17:55 0.592782201645 0.0344477 2061-Jul-28 17:56 0.592782215658 0.0354264 2061-Jul-28 17:57 0.592782230063 0.0364052 2061-Jul-28 17:58 0.592782244861 0.0373839 2061-Jul-28 17:59 0.592782260051 0.0383627 2061-Jul-28 18:00 0.592782275634 0.0393414 $$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 = '2061-Jul-28 17:00' STEP_SIZE = '1 min' STOP_TIME = '2061-Jul-28 18:00'