******************************************************************************* Revised: April 22, 2021 Neptune 899 PHYSICAL DATA (update 2021-May-03): Mass x10^24 (kg) = 102.409 Density (g/cm^3) = 1.638 Equat. radius (1 bar) = 24766+-15 km Volume, 10^10 km^3 = 6254 Vol. mean radius (km) = 24624+-21 Polar radius (km) = 24342+-30 Geometric Albedo = 0.41 Flattening = 0.0171 Sid. rot. period (III)= 16.11+-0.01 hr Sid. rot. rate (rad/s) = 0.000108338 Mean solar day, h =~16.11 h GM (km^3/s^2) = 6835099.97 GM 1-sigma (km^3/s^2) = +-10 Equ. grav, ge (m/s^2) = 11.15 Pol. grav, gp (m/s^2) = 11.41+-0.03 Visual magnitude V(1,0)= -6.87 Vis. mag. (opposition)= +7.84 Obliquity to orbit = 28.32 deg Sidereal orbit period = 164.788501027 y Sidereal orbit period = 60189 d Mean daily motion = 0.006020076dg/d Mean orbit velocity = 5.43 km/s Atmos. temp. (1 bar) = 72+-2 K Escape speed (1 bar) = 23.5 km/s Aroche(ice)/Rp = 2.98 Hill's sphere rad., Rp = 4700 Perihelion Aphelion Mean Solar Constant (W/m^2) 1.54 1.49 1.51 Maximum Planetary IR (W/m^2) 0.52 0.52 0.52 Minimum Planetary IR (W/m^2) 0.52 0.52 0.52 ******************************************************************************* ******************************************************************************* Ephemeris / WWW_USER Fri Dec 12 18:08:07 2025 Pasadena, USA / Horizons ******************************************************************************* Target body name: Neptune (899) {source: nep097_merged} Center body name: Earth (399) {source: nep097_merged} Center-site name: GEOCENTRIC ******************************************************************************* Start time : A.D. 2042-Aug-20 00:00:00.0000 UT Stop time : A.D. 2042-Sep-15 00:00:00.0000 UT Step-size : 180 minutes ******************************************************************************* Target pole/equ : IAU_NEPTUNE {West-longitude positive} Target radii : 24764.0, 24764.0, 24341.0 km {Equator_a, b, pole_c} 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: nep097_merged} Rel. lght bnd GM: 1.3271E+11 km^3/s^2 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 ) ******************************************************************************* Date__(UT)__HR:MN r rdot ************************************************** $$SOE 2042-Aug-20 00:00 29.80647594687 0.0005549 2042-Aug-20 03:00 29.80647598518 0.0005038 2042-Aug-20 06:00 29.80647601924 0.0004370 2042-Aug-20 09:00 29.80647604793 0.0003556 2042-Aug-20 12:00 29.80647607033 0.0002630 2042-Aug-20 15:00 29.80647608567 0.0001606 2042-Aug-20 18:00 29.80647609334 0.0000507 2042-Aug-20 21:00 29.80647609289 -0.0000638 2042-Aug-21 00:00 29.80647608407 -0.0001805 2042-Aug-21 03:00 29.80647606681 -0.0002976 2042-Aug-21 06:00 29.80647604110 -0.0004143 2042-Aug-21 09:00 29.80647600702 -0.0005295 2042-Aug-21 12:00 29.80647596472 -0.0006415 2042-Aug-21 15:00 29.80647591453 -0.0007474 2042-Aug-21 18:00 29.80647585701 -0.0008441 2042-Aug-21 21:00 29.80647579292 -0.0009292 2042-Aug-22 00:00 29.80647572314 -0.0010018 2042-Aug-22 03:00 29.80647564859 -0.0010605 2042-Aug-22 06:00 29.80647557045 -0.0011016 2042-Aug-22 09:00 29.80647548987 -0.0011283 2042-Aug-22 12:00 29.80647540786 -0.0011410 2042-Aug-22 15:00 29.80647532547 -0.0011388 2042-Aug-22 18:00 29.80647524381 -0.0011207 2042-Aug-22 21:00 29.80647516403 -0.0010866 2042-Aug-23 00:00 29.80647508728 -0.0010366 2042-Aug-23 03:00 29.80647501470 -0.0009714 2042-Aug-23 06:00 29.80647494736 -0.0008917 2042-Aug-23 09:00 29.80647488624 -0.0007993 2042-Aug-23 12:00 29.80647483220 -0.0006963 2042-Aug-23 15:00 29.80647478588 -0.0005857 2042-Aug-23 18:00 29.80647474774 -0.0004701 2042-Aug-23 21:00 29.80647471808 -0.0003509 2042-Aug-24 00:00 29.80647469714 -0.0002287 2042-Aug-24 03:00 29.80647468510 -0.0001049 2042-Aug-24 06:00 29.80647468190 0.0000163 2042-Aug-24 09:00 29.80647468743 0.0001361 2042-Aug-24 12:00 29.80647470144 0.0002508 2042-Aug-24 15:00 29.80647472344 0.0003572 2042-Aug-24 18:00 29.80647475275 0.0004527 2042-Aug-24 21:00 29.80647478850 0.0005354 2042-Aug-25 00:00 29.80647482973 0.0006043 2042-Aug-25 03:00 29.80647487542 0.0006590 2042-Aug-25 06:00 29.80647492454 0.0006992 2042-Aug-25 09:00 29.80647497604 0.0007249 2042-Aug-25 12:00 29.80647502885 0.0007357 2042-Aug-25 15:00 29.80647508190 0.0007310 2042-Aug-25 18:00 29.80647513402 0.0007100 2042-Aug-25 21:00 29.80647518402 0.0006722 2042-Aug-26 00:00 29.80647523067 0.0006176 2042-Aug-26 03:00 29.80647527285 0.0005486 2042-Aug-26 06:00 29.80647530962 0.0004677 2042-Aug-26 09:00 29.80647534007 0.0003742 2042-Aug-26 12:00 29.80647536349 0.0002734 2042-Aug-26 15:00 29.80647537941 0.0001666 2042-Aug-26 18:00 29.80647538741 0.0000543 2042-Aug-26 21:00 29.80647538715 -0.0000621 2042-Aug-27 00:00 29.80647537838 -0.0001811 2042-Aug-27 03:00 29.80647536099 -0.0003005 2042-Aug-27 06:00 29.80647533503 -0.0004180 2042-Aug-27 09:00 29.80647530074 -0.0005310 2042-Aug-27 12:00 29.80647525854 -0.0006366 2042-Aug-27 15:00 29.80647520906 -0.0007320 2042-Aug-27 18:00 29.80647515314 -0.0008149 2042-Aug-27 21:00 29.80647509171 -0.0008847 2042-Aug-28 00:00 29.80647502569 -0.0009420 2042-Aug-28 03:00 29.80647495598 -0.0009869 2042-Aug-28 06:00 29.80647488355 -0.0010166 2042-Aug-28 09:00 29.80647480956 -0.0010305 2042-Aug-28 12:00 29.80647473510 -0.0010296 2042-Aug-28 15:00 29.80647466130 -0.0010118 2042-Aug-28 18:00 29.80647458943 -0.0009762 2042-Aug-28 21:00 29.80647452076 -0.0009235 2042-Aug-29 00:00 29.80647445643 -0.0008560 2042-Aug-29 03:00 29.80647439745 -0.0007761 2042-Aug-29 06:00 29.80647434462 -0.0006855 2042-Aug-29 09:00 29.80647429868 -0.0005857 2042-Aug-29 12:00 29.80647426025 -0.0004776 2042-Aug-29 15:00 29.80647422988 -0.0003627 2042-Aug-29 18:00 29.80647420799 -0.0002428 2042-Aug-29 21:00 29.80647419490 -0.0001194 2042-Aug-30 00:00 29.80647419080 0.0000060 2042-Aug-30 03:00 29.80647419577 0.0001313 2042-Aug-30 06:00 29.80647420962 0.0002511 2042-Aug-30 09:00 29.80647423184 0.0003632 2042-Aug-30 12:00 29.80647426187 0.0004671 2042-Aug-30 15:00 29.80647429903 0.0005606 2042-Aug-30 18:00 29.80647434253 0.0006422 2042-Aug-30 21:00 29.80647439147 0.0007116 2042-Aug-31 00:00 29.80647444497 0.0007683 2042-Aug-31 03:00 29.80647450209 0.0008114 2042-Aug-31 06:00 29.80647456177 0.0008393 2042-Aug-31 09:00 29.80647462287 0.0008504 2042-Aug-31 12:00 29.80647468414 0.0008440 2042-Aug-31 15:00 29.80647474432 0.0008202 2042-Aug-31 18:00 29.80647480219 0.0007802 2042-Aug-31 21:00 29.80647485662 0.0007253 2042-Sep-01 00:00 29.80647490658 0.0006566 2042-Sep-01 03:00 29.80647495114 0.0005761 2042-Sep-01 06:00 29.80647498961 0.0004878 2042-Sep-01 09:00 29.80647502129 0.0003882 2042-Sep-01 12:00 29.80647504548 0.0002808 2042-Sep-01 15:00 29.80647506168 0.0001670 2042-Sep-01 18:00 29.80647506948 0.0000483 2042-Sep-01 21:00 29.80647506859 -0.0000730 2042-Sep-02 00:00 29.80647505895 -0.0001938 2042-Sep-02 03:00 29.80647504070 -0.0003109 2042-Sep-02 06:00 29.80647501421 -0.0004217 2042-Sep-02 09:00 29.80647498000 -0.0005246 2042-Sep-02 12:00 29.80647493869 -0.0006182 2042-Sep-02 15:00 29.80647489098 -0.0007015 2042-Sep-02 18:00 29.80647483766 -0.0007736 2042-Sep-02 21:00 29.80647477958 -0.0008333 2042-Sep-03 00:00 29.80647471766 -0.0008795 2042-Sep-03 03:00 29.80647465293 -0.0009110 2042-Sep-03 06:00 29.80647458650 -0.0009259 2042-Sep-03 09:00 29.80647451970 -0.0009218 2042-Sep-03 12:00 29.80647445380 -0.0009010 2042-Sep-03 15:00 29.80647438998 -0.0008642 2042-Sep-03 18:00 29.80647432937 -0.0008121 2042-Sep-03 21:00 29.80647427303 -0.0007465 2042-Sep-04 00:00 29.80647422187 -0.0006688 2042-Sep-04 03:00 29.80647417671 -0.0005805 2042-Sep-04 06:00 29.80647413830 -0.0004819 2042-Sep-04 09:00 29.80647410736 -0.0003737 2042-Sep-04 12:00 29.80647408455 -0.0002569 2042-Sep-04 15:00 29.80647407041 -0.0001340 2042-Sep-04 18:00 29.80647406527 -0.0000083 2042-Sep-04 21:00 29.80647406920 0.0001168 2042-Sep-05 00:00 29.80647408207 0.0002388 2042-Sep-05 03:00 29.80647410359 0.0003568 2042-Sep-05 06:00 29.80647413345 0.0004684 2042-Sep-05 09:00 29.80647417098 0.0005699 2042-Sep-05 12:00 29.80647421555 0.0006636 2042-Sep-05 15:00 29.80647426657 0.0007479 2042-Sep-05 18:00 29.80647432327 0.0008204 2042-Sep-05 21:00 29.80647438470 0.0008788 2042-Sep-06 00:00 29.80647444980 0.0009216 2042-Sep-06 03:00 29.80647451738 0.0009477 2042-Sep-06 06:00 29.80647458623 0.0009565 2042-Sep-06 09:00 29.80647465509 0.0009481 2042-Sep-06 12:00 29.80647472275 0.0009234 2042-Sep-06 15:00 29.80647478807 0.0008838 2042-Sep-06 18:00 29.80647485006 0.0008311 2042-Sep-06 21:00 29.80647490778 0.0007659 2042-Sep-07 00:00 29.80647496034 0.0006879 2042-Sep-07 03:00 29.80647500680 0.0005972 2042-Sep-07 06:00 29.80647504637 0.0004972 2042-Sep-07 09:00 29.80647507835 0.0003875 2042-Sep-07 12:00 29.80647510216 0.0002710 2042-Sep-07 15:00 29.80647511741 0.0001511 2042-Sep-07 18:00 29.80647512397 0.0000308 2042-Sep-07 21:00 29.80647512190 -0.0000876 2042-Sep-08 00:00 29.80647511141 -0.0002022 2042-Sep-08 03:00 29.80647509282 -0.0003116 2042-Sep-08 06:00 29.80647506656 -0.0004147 2042-Sep-08 09:00 29.80647503312 -0.0005101 2042-Sep-08 12:00 29.80647499312 -0.0005962 2042-Sep-08 15:00 29.80647494731 -0.0006708 2042-Sep-08 18:00 29.80647489659 -0.0007318 2042-Sep-08 21:00 29.80647484202 -0.0007774 2042-Sep-09 00:00 29.80647478474 -0.0008065 2042-Sep-09 03:00 29.80647472597 -0.0008185 2042-Sep-09 06:00 29.80647466696 -0.0008138 2042-Sep-09 09:00 29.80647460885 -0.0007933 2042-Sep-09 12:00 29.80647455276 -0.0007580 2042-Sep-09 15:00 29.80647449973 -0.0007087 2042-Sep-09 18:00 29.80647445075 -0.0006458 2042-Sep-09 21:00 29.80647440681 -0.0005694 2042-Sep-10 00:00 29.80647436885 -0.0004800 2042-Sep-10 03:00 29.80647433778 -0.0003789 2042-Sep-10 06:00 29.80647431437 -0.0002681 2042-Sep-10 09:00 29.80647429923 -0.0001502 2042-Sep-10 12:00 29.80647429279 -0.0000279 2042-Sep-10 15:00 29.80647429525 0.0000960 2042-Sep-10 18:00 29.80647430663 0.0002191 2042-Sep-10 21:00 29.80647432681 0.0003393 2042-Sep-11 00:00 29.80647435553 0.0004553 2042-Sep-11 03:00 29.80647439245 0.0005667 2042-Sep-11 06:00 29.80647443727 0.0006734 2042-Sep-11 09:00 29.80647448940 0.0007688 2042-Sep-11 12:00 29.80647454804 0.0008537 2042-Sep-11 15:00 29.80647461237 0.0009261 2042-Sep-11 18:00 29.80647468140 0.0009833 2042-Sep-11 21:00 29.80647475395 0.0010238 2042-Sep-12 00:00 29.80647482882 0.0010476 2042-Sep-12 03:00 29.80647490483 0.0010554 2042-Sep-12 06:00 29.80647498085 0.0010480 2042-Sep-12 09:00 29.80647505580 0.0010259 2042-Sep-12 12:00 29.80647512863 0.0009892 2042-Sep-12 15:00 29.80647519828 0.0009377 2042-Sep-12 18:00 29.80647526369 0.0008718 2042-Sep-12 21:00 29.80647532384 0.0007921 2042-Sep-13 00:00 29.80647537777 0.0007000 2042-Sep-13 03:00 29.80647542466 0.0005971 2042-Sep-13 06:00 29.80647546379 0.0004860 2042-Sep-13 09:00 29.80647549474 0.0003710 2042-Sep-13 12:00 29.80647551731 0.0002538 2042-Sep-13 15:00 29.80647553137 0.0001359 2042-Sep-13 18:00 29.80647553695 0.0000187 2042-Sep-13 21:00 29.80647553412 -0.0000964 2042-Sep-14 00:00 29.80647552312 -0.0002078 2042-Sep-14 03:00 29.80647550426 -0.0003135 2042-Sep-14 06:00 29.80647547804 -0.0004112 2042-Sep-14 09:00 29.80647544514 -0.0004982 2042-Sep-14 12:00 29.80647540642 -0.0005720 2042-Sep-14 15:00 29.80647536291 -0.0006308 2042-Sep-14 18:00 29.80647531572 -0.0006738 2042-Sep-14 21:00 29.80647526599 -0.0007014 2042-Sep-15 00:00 29.80647521478 -0.0007145 $$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 = '899' QUANTITIES = '19' START_TIME = '2042-08-20' STEP_SIZE = '3 hours' STOP_TIME = '2042-09-15'