******************************************************************************* JPL/HORIZONS 100P/Hartley 1 2025-Dec-12 18:00:54 Rec #:90000941 (+COV) Soln.date: 2025-Jul-31_12:12:40 # obs: 644 (1985-2022) IAU76/J2000 helio. ecliptic osc. elements (au, days, deg., period=Julian yrs): EPOCH= 2457114.5 ! 2015-Apr-02.0000000 (TDB) RMSW= n.a. EC= .4137581146698033 QR= 2.009747344211878 TP= 2457480.5926919873 OM= 37.76447817720789 W= 181.8748336121175 IN= 25.58407100879231 A= 3.42818791100179 MA= 303.1542233018788 ADIST= 4.846628477791702 PER= 6.3475353901581 N= .155277005 ANGMOM= .028996109 DAN= 4.8448 DDN= 2.01006 L= 219.4556018 B= -.8095013 MOID= 1.00286996 TP= 2016-Apr-02.0926919873 Comet physical (GM= km^3/s^2; RAD= km): GM= n.a. RAD= n.a. M1= 9.9 M2= 16.2 k1= 23.5 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= 2.140716165304E-9 A2= -9.588984772563E-11 A3= -6.447836011648E-10 Standard model: ALN= .1112620426 NK= 4.6142 NM= 2.15 NN= 5.093 R0= 2.808 COMET comments 1: soln ref.= JPL#40, data arc: 1985-06-13 to 2022-08-15 2: k1=23.5, k2=5., phase coef.=0.03; ******************************************************************************* ******************************************************************************* Ephemeris / WWW_USER Fri Dec 12 18:00:54 2025 Pasadena, USA / Horizons ******************************************************************************* Target body name: 100P/Hartley 1 {source: JPL#40} Center body name: Earth (399) {source: DE441} Center-site name: GEOCENTRIC ******************************************************************************* Start time : A.D. 2028-Dec-15 00:00:00.0000 UT Stop time : A.D. 2028-Dec-17 00:00:00.0000 UT Step-size : 180 minutes ******************************************************************************* Target pole/equ : undefined Target radii : undefined 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= 2457114.5 ! 2015-Apr-02.0000000 (TDB) RMSW= n.a. EC= .4137581146698033 QR= 2.009747344211878 TP= 2457480.5926919873 OM= 37.76447817720789 W= 181.8748336121175 IN= 25.58407100879231 Equivalent ICRF heliocentric cartesian coordinates (au, au/d): X=-1.132535287763902E+00 Y= 1.908627034236831E+00 Z= 2.287137281576278E+00 VX=-6.708989265361092E-03 VY=-6.403841507424820E-03 VZ=-3.656064151870987E-03 Comet physical (GM= km^3/s^2; RAD= km): GM= n.a. RAD= n.a. M1= 9.9 M2= 16.2 k1= 23.5 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= 2.140716165304E-9 A2= -9.588984772563E-11 A3= -6.447836011648E-10 Standard model: ALN= .1112620426 NK= 4.6142 NM= 2.15 NN= 5.093 R0= 2.808 ******************************************************************************* Date__(UT)__HR:MN r rdot ************************************************** $$SOE 2028-Dec-15 00:00 2.019028161973 -0.0204046 2028-Dec-15 03:00 2.019026922473 -0.0139325 2028-Dec-15 06:00 2.019026150231 -0.0074604 2028-Dec-15 09:00 2.019025845249 -0.0009883 2028-Dec-15 12:00 2.019026007526 0.0054838 2028-Dec-15 15:00 2.019026637063 0.0119559 2028-Dec-15 18:00 2.019027733857 0.0184279 2028-Dec-15 21:00 2.019029297907 0.0249000 2028-Dec-16 00:00 2.019031329211 0.0313720 2028-Dec-16 03:00 2.019033827765 0.0378439 2028-Dec-16 06:00 2.019036793566 0.0443158 2028-Dec-16 09:00 2.019040226611 0.0507877 2028-Dec-16 12:00 2.019044126893 0.0572594 2028-Dec-16 15:00 2.019048494408 0.0637311 2028-Dec-16 18:00 2.019053329150 0.0702027 2028-Dec-16 21:00 2.019058631113 0.0766743 2028-Dec-17 00:00 2.019064400289 0.0831457 $$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 = '100P' QUANTITIES = '19' START_TIME = '2028-Dec-15' STEP_SIZE = '3 hours' STOP_TIME = '2028-Dec-17'