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21065 Jamesmelka (1991 NM)
Classification: Main-belt Asteroid          SPK-ID: 2021065
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 44 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2082756820957255 2.0999e-08  
a 3.135937595121971 1.5226e-08 au
q 2.482798053488313 6.8765e-08 au
i 16.59643172918931 4.2504e-07 deg
node 249.6754109172297 1.3164e-06 deg
peri 27.26930204231835 2.8672e-06 deg
M 147.2163790326906 5.6483e-06 deg
tp 2458567.025240612173
(2019-Mar-24.52524061)
2.9081e-05 TDB
period 2028.381049321345
5.55
1.4773e-05
4.045e-08
d
yr
n .1774814451754263 1.2926e-09 deg/d
Q 3.789077136755628 1.8397e-08 au
  Orbit Determination Parameters
   # obs. used (total)      2048  
   data-arc span      10860 days (29.73 yr)  
   first obs. used      1991-07-10  
   last obs. used      2021-04-03  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .43239  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Aug-25 14:56:47  

Additional Information
 Earth MOID = 1.47814 au 
 Jupiter MOID = 1.35838 au 
 T_jup = 3.115 
[ 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 12.85   n/a E2021B10  
diameter diameter 15.452 km 0.218 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  
geometric albedo albedo 0.107   0.010 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  

21065 Jamesmelka           Discovered 1991 July 10 by E. F. Helin at Palomar.
James Melka (b. 1942) is an amateur astronomer who has observed and imaged Mars during nine apparitions from 1971 through 2012. He recorded the initial clouds of the 1971 and 2007 planet-wide dust storms and used Mars Global Surveyor images to identify three craters containing massive black sand dunes.
NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character)
Reference: MPC batch dated 2013-08-21Last Updated: 2014-08-13

[ 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
1966-Jan-12 10:32 < 00:01 Jupiter 1.44251413931767 1.4425134318905 1.44251484674878 4.23266174331695 4.09158351332704 2439137.938806316 0.972846558317001 137.890877645742 14.4822062978873 76.2667176403229 11813236.5526755 T 44 CATAB v2.0g-lin.ifort 2021-Aug-25 14:59:15 2021-Aug-25 14:59
1976-Sep-25 23:22 < 00:01 Jupiter 1.60172409982629 1.60172329299885 1.60172490666018 4.22820337911188 4.10122729773138 2443047.473313573 0.831942670471049 169.678452649929 4.83937807181023 -76.2318724660225 22098290.3111146 T 44 CATAB v2.0g-lin.ifort 2021-Aug-25 14:59:15 2021-Aug-25 14:59
2050-Feb-27 23:49 < 00:01 Jupiter 1.99864584124616 1.99864493615791 1.99864674633498 3.33750711826578 3.20801455160379 2469865.492079474 0.999473227945359 79.8869733862577 31.3535350189962 -55.2504728949994 8199468.46093853 T 44 CATAB v2.0g-lin.ifort 2021-Aug-25 14:59:15 2021-Aug-25 14:59
2060-Sep-14 23:48 < 00:01 Jupiter 1.38260180634605 1.3826015022915 1.38260211040391 4.25403691251068 4.10750182698553 2473717.491452924 0.894697773002603 148.188360110211 10.005299853818 85.5660025901516 13876327.5011196 T 44 CATAB v2.0g-lin.ifort 2021-Aug-25 14:59:15 2021-Aug-25 14:59
2071-May-10 16:11 00:02 Jupiter 1.75664612016287 1.75664451880519 1.75664772152853 4.17620342673826 4.05910233634664 2477607.174300734 1.52807356164699 205.977296612626 6.10957170074271 -66.8502764754172 22538637.9658331 T 44 CATAB v2.0g-lin.ifort 2021-Aug-25 14:59:15 2021-Aug-25 14:59
2144-Oct-07 12:39 00:03 Jupiter 1.84590448835708 1.84590102815154 1.84590794856557 3.64712429558048 3.51906009469862 2504420.027010665 3.46013997016556 212.016192339381 34.9520295060878 28.1330399239232 22371745.6114468 T 44 CATAB v2.0g-lin.ifort 2021-Aug-25 14:59:15 2021-Aug-25 14:59
2155-May-27 00:34 00:03 Jupiter 1.38641321774667 1.38641292385039 1.386413511703 4.26493545335099 4.1191970098623 2508303.523319553 2.78977526120922 532.133856797498 6.86268932003468 -88.71835044154 16222709.5772156 T 44 CATAB v2.0g-lin.ifort 2021-Aug-25 14:59:15 2021-Aug-25 14:59
2165-Dec-17 23:41 00:04 Jupiter 1.92932637098974 1.92932206867675 1.9293306733205 4.16319568980464 4.05637132798038 2512161.486843857 4.27656772500624 365.305529621686 7.75529963311615 -53.5424368119711 21869902.5236579 T 44 CATAB v2.0g-lin.ifort 2021-Aug-25 14:59:15 2021-Aug-25 14:59

Alternate Designations
 1991 NM = 1998 WJ21 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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