Skip Page Navigation
NASA JPL Caltech
NASA Logo - Jet Propulsion Laboratory + View the NASA Portal
+ Center for Near-Earth Object Studies
JPL Home Earth Solar System Stars & Galaxies Technology
JPL Solar System Dynamics

Significant website upgrade scheduled for September 27. More details available here.

JPL Small-Body Database Browser
Search: [ help ]  
18 Melpomene (A852 MA)
Classification: Main-belt Asteroid          SPK-ID: 2000018
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

[ show orbit diagram ]
Orbital Elements at Epoch 2459396.5 (2021-Jul-01.0) TDB
Reference: JPL 116 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2177342014557592 2.8991e-08  
a 2.296083226314816 2.2884e-09 au
q 1.796147378557196 6.6335e-08 au
i 10.13238480765174 3.5472e-06 deg
node 150.3618464413662 1.8819e-05 deg
peri 228.1075068848233 2.0518e-05 deg
M 132.602317867896 9.5379e-06 deg
tp 2458928.410951386679
3.3321e-05 TDB
period 1270.807782324547
n .2832843841587845 4.2351e-10 deg/d
Q 2.796019074072436 2.7867e-09 au
  Orbit Determination Parameters
   # obs. used (total)      5326  
   data-arc span      61719 days (168.98 yr)  
   first obs. used      1852-06-29  
   last obs. used      2021-06-22  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .45227  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Jul-08 10:25:15  

Additional Information
 Earth MOID = .812834 au 
 Jupiter MOID = 2.69903 au 
 T_jup = 3.543 
[ show covariance matrix ]

Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
absolute magnitude H 6.53   n/a MPO614063 IRAS observations used: 15
magnitude slope G 0.25   n/a PDS3 (MPC 17257) Fit
diameter diameter 139.594 km 2.452 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (  
rotation period rot_per 11.570 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List:
[Binzel, R.P.; Harris, A.W. (1980) Icarus 42, 43-45.]
[Zeigler, K.W.; Florence, W.B. (1985) Icarus 62, 512-517.]
[Lagerkvist, C.I.; Magnusson, P.; Williams, I.P.; Buontempo, M.E.; et al. (1988) Astron. Astrophys. Suppl. Ser. 73, 395-405.]
[Hoffmann, M.; Geyer, E.H. (1990) in Asteroids, Comets, Meteors III. C.-I. Lagerkvist, H. Rickman, B.A. Lindblad, M. Lindgren, eds. Uppsala, p. 111-114.]
[Torppa, J.; Kaasalainen, M.; Michalowski, T.; Kwiatkowski, T.; et al. (2003) Icarus 164, 346-383.]
[Behrend, R. (2011) Observatoire de Geneve web site,]
[Pilcher, F. (2013) Minor Planet Bull. 40, 33.]
[Pilcher, F. (2014) Minor Planet Bull. 41, 155-156.]
[Hanus, J.; Durech, J.; Oszkiewicz, D.A.; Behrend, R.; et al. (2016) Astron. Astrophys. 586, A108.]
[Hanus, J.; Viikinkoski, M.; Marchis, F.; Durech, J.; et al (2017) Astron. Astrophys. 601, A114.]
geometric albedo albedo 0.181   0.033 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (  
B-V BV 0.854   0.013 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=9; phase (min.=2.60, mean=19.31, max.=27.48) deg.
U-B UB 0.425   0.041 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=8; phase (min.=2.60, mean=18.73, max.=27.48) deg.
Tholen spectral type spec_T S   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 7 color indices; used ground-based radiometric albedo
SMASSII spectral type spec_B S   n/a EAR-A-5-DDR-TAXONOMY-V4.0 based on a high-resolution spectrum by Xu et al. (1995) or Bus and Binzel (2002)

18 Melpomene (A852 MA)          Discovered 1852-Jun-24 by Hind, J. R. at London
Reference: DISCOVERY.DBLast Updated: 2003-08-29
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
FirstGov 2021-Sep-22 09:58 UT
(server date/time)  
NASA Home Page
Site Manager:   Ryan S. Park
Webmaster  Alan B. Chamberlin