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65803 Didymos (1996 GT)
Classification: Apollo [NEO, PHA]          SPK-ID: 2065803
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

[ show orbit diagram ]
Orbital Elements at Epoch 2459396.5 (2021-Jul-01.0) TDB
Reference: JPL 181 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .383697480609711 2.7422e-09  
a 1.644394196638894 2.9335e-09 au
q 1.013444286259321 5.1199e-09 au
i 3.407705711883407 1.3274e-06 deg
node 73.19943499617158 9.6759e-06 deg
peri 319.3188680163129 1.1002e-05 deg
M 136.6502277847489 3.5113e-06 deg
tp 2459104.141860697233
(2020-Sep-11.64186070)
7.1631e-06 TDB
period 770.2067669787134
2.11
2.061e-06
5.643e-09
d
yr
n .4674069554233733 1.2507e-09 deg/d
Q 2.275344107018468 4.0591e-09 au

Additional Model Parameters
 Parameter Value Uncertainty (1-sigma) 
A2 [EST] -1.885839515169381E-14 7.227E-15
ALN [SET] 1. n/a
NK [SET] 0. n/a
NM [SET] 2. n/a
NN [SET] 0. n/a
R0 [SET] 1. n/a
  Orbit Determination Parameters
   # obs. used (total)      1046  
   # delay obs. used      5  
   # Doppler obs. used      0  
   data-arc span      9066 days (24.82 yr)  
   first obs. used      1996-04-11  
   last obs. used      2021-02-05  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .37476  
   source      ORB  
   producer      Steve Chesley  
   solution date      2021-Feb-13 14:47:32  

Additional Information
 Earth MOID = .0401437 au 
 Jupiter MOID = 3.1682 au 
 T_jup = 4.201 
[ show covariance matrix ]

Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
absolute magnitude H 18.07   n/a MPCxxxxx  
diameter diameter 0.78 km 0.08 Richardson et al., 2016, "Dynamical and Physical Properties of 65803 Didymos", LPSC Abstract (submitted) uncertainty is published as "10%"
bulk density density 2.1 g/cm^3 0.6 Richardson et al., 2016, "Dynamical and Physical Properties of 65803 Didymos", LPSC Abstract (submitted) uncertainty is published as "30%"
rotation period rot_per 2.2593 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List:
[Pravec, P.; et al. (2003) IAUC 8244. (65803)]
[Kitazato, K.; Abe, M.; Mito, H. (2005) Asia-Oceana Geophys. Soc. abstract 58-PS-A1183.]
[Pravec, P.; et al. (2006) Icarus 181, 63-93.]
SMASSII spectral type spec_B Xk   n/a Binzel et al. (2004) Meteorit. Planet. Sci. 39, 351-366  

65803 Didymos           Discovered 1996 Apr. 11 by Spacewatch at Kitt Peak.
Greek for "twin", this rapid-rotator Amor possesses a satellite with an orbital period of 11.9 hr. Suspicions arose in the Goldstone delay-Doppler echoes, and these were confirmed with the optical light curve analysis, along with Arecibo radar imaging on 2003 Nov. 23. The name was suggested by J. Montani.
NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character)
Reference: 20040713/MPCPages.arcLast Updated: 2004-07-14

[ hide close-approach data ]
Close-Approach Data   ...sorted by Date/Time (TDB)
Date/Time (TDB) Time Uncertainty
(days_HH:MM)
Body Nominal Distance (au) Minimum Distance (au) Maximum Distance (au) V-relative (km/s) V-infinity (km/s) JD (TDB) Time Uncertainty (minutes) Semi-major axis (km) Semi-minor axis (km) range-LOV angle (deg) N-sigma BP Orbit Ref. Reference Modified
1901-Feb-04 17:19 < 00:01 Mars 0.0521602421330093 0.0521587295699813 0.0521617547493532 8.97851939946255 8.97790806813149 2415420.221294188 0.19997239824962 112.430006088303 5.40493747361238 -47.9394446056709 1056931.34241741 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
1902-Sep-29 14:52 00:01 Earth 0.0799440182184454 0.0799419609079938 0.0799460755690458 6.3526975071322 6.34744885665181 2416022.119503972 1.05078143194944 136.072163426113 2.09808925846787 41.1373631868882 2864264.4635103 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
1921-Aug-29 07:37 < 00:01 Earth 0.377501321576552 0.377497231994845 0.377505411159418 16.3363845847825 16.3359525251671 2422930.817671783 0.377693960531129 206.542179474489 2.64752734771587 9.13448393234498 2788576.5266505 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
1922-Jan-05 01:06 < 00:01 Earth 0.496118674593753 0.496115659842022 0.496121689349038 4.5323735008625 4.53118839301789 2423059.545919353 0.67520247332013 164.285992952062 6.31888240577009 23.9752327190631 1520943.37910872 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
1923-Dec-02 12:31 < 00:01 Earth 0.208571109492593 0.208566937802903 0.208575281182508 11.5154611245969 11.5143516999935 2423756.021826532 0.40939711641285 208.314864074654 0.976286333797121 3.13502933768819 1379000.40684477 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
1942-Oct-09 18:28 < 00:01 Earth 0.0603071391024962 0.0603067441319681 0.0603075340761987 5.45300049226745 5.44489216816206 2430642.269465380 0.441729046555936 29.4621689300837 1.67555117811774 48.2339393275607 3329807.93651723 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
1961-Aug-23 14:30 < 00:01 Earth 0.484760014714618 0.484756584644099 0.484763444785468 19.4785186813619 19.4782364971013 2437535.104414538 0.274768222831999 172.204582829266 2.66863323717972 6.66754120653038 2716998.8604427 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
1963-Nov-21 10:06 < 00:01 Earth 0.0868621243380769 0.0868587129456738 0.0868655357380148 7.59078799049596 7.58674585659508 2438354.920686858 0.71901612462678 174.832963483376 0.635194204370982 13.4497307356431 3586677.6670692 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
1967-Oct-08 21:37 < 00:01 Mars 0.0534339402504106 0.053430894232184 0.0534369862918852 9.32368534657406 9.3231106815468 2439772.400431850 0.235685648624817 161.752478375295 4.88718622639046 20.1194653964959 552424.867788145 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
1982-Sep-14 01:39 < 00:01 Earth 0.178552216838432 0.178550414095474 0.178554019583512 10.1208290359611 10.1193544752435 2445226.568447707 0.250047875283251 95.0076386704945 2.64972806594418 18.917424664578 2609302.46198312 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
1984-Dec-14 04:28 < 00:01 Earth 0.408755375434349 0.408753677072273 0.408757073796448 17.5225328335747 17.5221608218673 2446048.685926935 0.130784194263315 84.7699412047244 0.77852348554891 2.52043846406733 2905778.07549599 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
1989-Jul-02 06:03 < 00:01 Mars 0.0543953942682999 0.0543948496877499 0.0543959388567191 8.98951610333349 8.98893061008375 2447709.752161144 0.079702635654564 43.0729591091791 5.93490210364891 -51.6003664281654 1066023.62484568 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
2003-Nov-12 23:24 < 00:01 Earth 0.0480175533627746 0.0480175526865932 0.0480175540389559 6.01219256046928 6.00295593823194 2452956.474736669 0.00132889288403365 0.717043791044362 0.0326535741311214 -89.4562649166988 47488745.3092911 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
2022-Oct-04 09:48 < 00:01 Earth 0.0712330671104591 0.071232865163592 0.0712332690578283 5.99364441650716 5.98740037161963 2459856.908091790 0.14326827993535 13.9318301802628 2.02377529653472 44.3712922465583 3230113.61768717 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
2041-Sep-01 08:51 < 00:01 Earth 0.354010288509466 0.354008367884558 0.354012209134676 15.6173552581592 15.6168733151507 2466763.868442381 0.179114399640556 97.1623385965518 2.7576158444948 9.71632831987295 2700267.25154879 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
2042-Jan-03 18:33 < 00:01 Earth 0.479445742342521 0.479444275710081 0.479447208976542 4.07364101460229 4.07227654810837 2466888.272583622 0.368748459744901 85.0906125157965 7.36086441866598 31.0656695615204 1389936.32837261 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
2042-Feb-28 18:54 < 00:01 Mars 0.0434478477622485 0.0434474560587149 0.0434482395091505 8.63609072096918 8.63532769395315 2466944.287247759 0.132979917995345 74.9111318801274 6.30256457178209 -75.6598253425997 994496.417245797 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
2043-Dec-05 07:59 < 00:01 Earth 0.231773274668278 0.231770925188883 0.231775624147712 12.2086437339378 12.2077020648185 2467588.832542150 0.217828955050444 117.247403891159 0.873318068258966 2.35233363723435 1295145.04893196 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
2062-Oct-20 02:37 00:03 Earth 0.0496511160474077 0.0496492555531057 0.049652976577497 5.1406484914992 5.13019871338059 2474482.608719224 2.83326014593635 114.172637871049 1.07658812224557 35.7239360241604 3545239.70610173 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
2081-Aug-28 15:18 00:02 Earth 0.425775428454814 0.425753700364027 0.425797156566294 17.7514432216974 17.7510906865624 2481370.137799142 1.88241995193913 1093.56432963378 2.6954989494216 7.79413333880294 2689810.29492526 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
2083-Nov-29 13:10 00:03 Earth 0.147282528965992 0.147259425444779 0.147305632507165 9.58180656911337 9.57991833204599 2482193.048828604 2.93556946155878 1155.2482375301 0.792673315081431 4.39028561698182 1632333.6480011 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
2102-Sep-19 18:45 00:03 Earth 0.152366143741735 0.152348434047647 0.152383853780392 9.15774297623065 9.1558332077692 2489061.281524555 3.0169648688535 954.188208968144 2.62867067826897 22.2873234440442 2616910.20361463 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
2104-Dec-17 19:37 00:01 Earth 0.432824145540293 0.432805529011544 0.432842762070322 18.2390090286732 18.2386715054524 2489881.317447468 1.39047699504723 929.08491226848 0.878708213975103 2.34503544610614 2506248.79087394 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
2123-Nov-04 05:43 < 00:01 Earth 0.0391461053354425 0.0391459974979247 0.039146213173412 5.22969889845073 5.21666757469596 2496776.738298201 0.325780085240744 8.63924814985254 1.05984075915324 -51.9240065807594 6118251.50864647 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
2142-Sep-01 14:53 00:02 Earth 0.3925872939281 0.392565924106826 0.392608663776065 16.7477641951548 16.7473589437451 2503653.120362550 1.83900967594252 1077.77668685978 2.65267806044378 8.6238684830326 2751585.9264284 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
2144-Jul-31 12:01 00:02 Mars 0.0313159196654597 0.0313016632797457 0.0313301834758715 8.82720717910276 8.82617145714872 2504352.001037717 1.56677497137851 1041.11194360852 4.82584048547345 46.9221924450429 700885.315081019 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
2144-Dec-02 23:10 00:03 Earth 0.178177376080553 0.178154029151718 0.178200723018756 10.5567865435515 10.555369911062 2504476.464954837 2.6581531161887 1165.9982382919 0.959513235811529 3.31148210350167 1246322.55943222 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
2163-Sep-17 16:09 00:03 Earth 0.181566310324897 0.181542380610248 0.181590240392127 10.1715741999809 10.1701313548419 2511339.172905123 3.40684874471515 1258.22956223648 2.58023141596712 18.5177206002706 2607349.40751686 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
2165-Dec-17 03:04 00:02 Earth 0.397015701038901 0.396990745710136 0.39704065637015 17.1989205318095 17.1985303128098 2512160.627577911 1.9570104106998 1245.40423085597 1.32008259197507 2.32085284862724 1511451.26204304 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
2166-Apr-20 17:05 00:02 Mars 0.0458230293095714 0.0458189585222274 0.0458271067450889 8.32342193027835 8.32267127581718 2512285.211955014 1.72146284420216 894.150383061179 5.91245141476761 76.8716804691959 1132734.92111414 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
2180-May-01 04:42 00:01 Mars 0.0765825453493573 0.0765674025959061 0.0765976884043512 7.21259281960278 7.21207449647674 2517409.696076001 1.09171963825482 792.23063125323 4.89959714287122 -17.602914698061 747918.898068308 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
2184-Oct-14 10:09 00:07 Earth 0.05741429088619 0.0574074091582602 0.0574211733446071 5.43871445906388 5.43017486590334 2519036.923210525 6.94904640692308 471.412476091899 1.54392965852188 43.3564160877663 3133013.82200302 T 181 CATAB v2.0g-lin.ifort 2021-Jun-11 09:52:02 2021-Jun-11 09:52
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