Last updated

Damocloids are a class of minor planets such as 5335 Damocles and 1996 PW that have Halley-type or long-period highly eccentric orbits typical of periodic comets such as Halley's Comet, but without showing a cometary coma or tail. David Jewitt defines a damocloid as an object with a Jupiter Tisserand invariant (TJ) of 2 or less, [1] [lower-alpha 1] while Akimasa Nakamura defines this group with the following orbital elements: [2]


However, this definition that does not focus on Jupiter excludes objects such as (127546) 2002 XU93, 2003 WG166, and 2004 DA62. [3]

Using the Tisserand's parameter with respect to Jupiter of 2 or less, there are currently 220 damocloid candidates as of January 2022. [4] Of these objects, 189 have orbital observation arcs greater than 30 days providing reasonably decent orbits. [1] [5] Their average radius is eight kilometers assuming an albedo of 0.04. The albedos of four damocloids have been measured, and they are among the darkest objects known in the Solar System. Damocloids are reddish in color, but not as red as many Kuiper-belt objects or centaurs. Other damocloids include: 2013 BL76 , 2012 DR30 , 2008 KV42 , (65407) 2002 RP120 , and 20461 Dioretsa.

Retrograde objects such as Halley's Comet and damocloid (343158) 2009 HC82 can have relative velocities to Earth of 81 km/s (290,000 km/h). [6]


Damocloids are thought to be nuclei of Halley-type comets that have lost all their volatile materials due to outgassing and become dormant. Such comets probably originate from the Oort cloud. This hypothesis is strengthened by the fact that a number of objects thought to be damocloids (and assigned minor-planet provisional designations) subsequently showed a coma and were confirmed to be comets: C/2001 OG108 (LONEOS), C/2002 CE10 (LINEAR), C/2002 VQ94 (LINEAR), C/2004 HV60 (Spacewatch) and possibly others. Another strong indication of cometary origin is the fact that some damocloids have retrograde orbits, unlike any other minor planets. (Objects with an inclination beyond 90 degrees up to 180 degrees are in a retrograde orbit and orbit in the opposite direction of other objects.)


As of August 2021 this list from the JPL SBDB contains 20 numbered and 268 unnumbered bodies that meet Akimasa Nakamura's criteria for being classified as a damocloid, that is, either a retrograde orbit, or the following orbital elements: q < 5.2 AU, a > 8.0 AU, and e > 0.75(also see § top). Tisserand's parameter with respect to Jupiter (TJupiter) is also given. [lower-alpha 1] Akimasa Nakamura's criteria and a TJupiter of less than 2 are largely equivalent as only a few listed bodies do not meet the defined TJupiter threshold. Most damocloids are also listed on MPC's list of other unusual minor planets. [7] The orbital data is sourced from JPL-numbered and -unnumbered element files. [8] The list includes A/-designated objects (introduced in 2017) that were mistakenly identified as a comet, but are actually minor planets. However it excludes hyperbolic bodies such as A/2019 G4 as well as ʻOumuamua and 2I/Borisov, two interstellar objects.

Designation a
e i
Orbital criteria and classes q
Unusual Catalog Refs
Cls Retro TJupiter [lower-alpha 1] TJ2
5335 Damocles 11.850.86661.6 CEN 1.158Green check.svg1.5922.11 LoMP MPC  · JPL
(15504) 1999 RG33 9.370.77435CEN1.948Green check.svg2.1216.63 unusual LoMP MPC  · JPL
20461 Dioretsa 23.880.901160.4CENGreen check.svg-1.534Green check.svg2.3745.39 unusual LoMP MPC  · JPL
(65407) 2002 RP120 53.660.954119.3 TNO Green check.svg-0.844Green check.svg2.46104.86 unusual LoMP MPC  · JPL
(154783) 2004 PA44 14.230.763.3 CEN 2.5133.4225.04 unusual LoMP MPC  · JPL
(330759) 2008 SO218 8.120.562170.3CENGreen check.svg-1.397Green check.svg3.5612.69 unusual LoMP MPC  · JPL
(336756) 2010 NV1 278.330.966140.7 TNO Green check.svg-2.903Green check.svg9.42547.23 LoMP MPC  · JPL
(342842) 2008 YB3 11.580.442105.1 CEN Green check.svg-0.246Green check.svg6.4716.7 LoMP MPC  · JPL
343158 Marsyas 2.530.807154.4 NEO Green check.svg1.317Green check.svg0.494.57 LoMP MPC  · JPL
(434620) 2005 VD 6.670.251172.9 CEN Green check.svg-1.394Green check.svg58.34 unusual LoMP MPC  · JPL
(459870) 2014 AT28 10.90.401165.5CENGreen check.svg-2.090Green check.svg6.5315.27 LoMP MPC  · JPL
(468861) 2013 LU28 191.630.954125.3 TNO Green check.svg-2.069Green check.svg8.74374.53 LoMP MPC  · JPL
(471325) 2011 KT19 35.70.33110.2TNOGreen check.svg-1.560Green check.svg23.947.5 LoMP MPC  · JPL
514107 Kaʻepaokaʻawela 5.130.378163.1 other Green check.svg-0.745Green check.svg3.197.07 LoMP MPC  · JPL
(518151) 2016 FH13 24.540.61593.6 CEN Green check.svg-0.005Green check.svg9.4539.62 LoMP MPC  · JPL
(523797) 2016 NM56 71.460.853144 TNO Green check.svg-3.061Green check.svg10.53132.38 LoMP MPC  · JPL
(523800) 2017 KZ31 54.30.798161.7TNOGreen check.svg-3.601Green check.svg10.9697.63 LoMP MPC  · JPL
(528219) 2008 KV42 42.030.497103.4TNOGreen check.svg-1.021Green check.svg21.1562.92 LoMP MPC  · JPL
(582301) 2015 RM306 246.870.954176TNOGreen check.svg-4.117Green check.svg11.46482.29 LoMP MPC  · JPL
(585899) 2020 HM9883.60.841137.9TNOGreen check.svg-3.151Green check.svg13.26153.94 LoMP MPC  · JPL
1996 PW 265.490.99130.1TNO1.708Green check.svg2.49528.5 unusual MPC  · JPL
1997 MD1026.490.94359.4 CEN 0.960Green check.svg1.5151.47 MPC  · JPL
1998 QJ111.240.81523.7CEN2.0232.0820.41 unusual MPC  · JPL
1998 WU2415.130.90742.5CEN1.404Green check.svg1.4128.85 MPC  · JPL
1999 LE31 8.170.468151.5CENGreen check.svg-1.309Green check.svg4.3511.99 MPC  · JPL
1999 XS35 17.770.94819.5 NEO 1.405Green check.svg0.9334.62 MPC  · JPL
2000 AB22952.320.95668.2 TNO 0.790Green check.svg2.31102.33 unusual MPC  · JPL
2000 DG8 10.770.793129.3 CEN Green check.svg-0.627Green check.svg2.2319.31 unusual MPC  · JPL
2000 HE4623.660.9158.6CENGreen check.svg-1.510Green check.svg2.3744.95 unusual MPC  · JPL
2000 KP6590.210.96345.6 TNO 1.630Green check.svg3.34177.07 unusual MPC  · JPL
2002 AR9175.230.96517.6TNO1.965Green check.svg2.62147.84 unusual MPC  · JPL
2002 RN109 564.680.99558.5TNO1.069Green check.svg2.671126.68 unusual MPC  · JPL
2003 UY28333.10.89518.9TNO2.2833.4662.74 MPC  · JPL
2003 WN18814.390.84626.8 CEN 1.946Green check.svg2.2226.56 unusual MPC  · JPL
2004 CM11133.280.8494.7 TNO 2.8185.0261.55 MPC  · JPL
2004 NN8100.430.977165.6TNOGreen check.svg-1.781Green check.svg2.36198.5 unusual MPC  · JPL
2004 PB5910.450.8734 CEN 1.879Green check.svg1.3319.57 MPC  · JPL
2004 VM411.560.8829.2CEN1.838Green check.svg1.3721.76 MPC  · JPL
2005 HL311.290.83135.6CEN1.794Green check.svg1.9120.67 unusual MPC  · JPL
2005 NP825.870.478130.5CENGreen check.svg-0.327Green check.svg3.078.67 MPC  · JPL
2005 OE63.240.95267.5 TNO 0.901Green check.svg3.05123.43 unusual MPC  · JPL
2005 PF2613.540.89223.2 CEN 1.727Green check.svg1.4725.61 MPC  · JPL
2005 SB22329.410.90591.5CENGreen check.svg0.124Green check.svg2.7956.03 unusual MPC  · JPL
2005 TJ509.160.584110.3CENGreen check.svg-0.180Green check.svg3.8114.51 unusual MPC  · JPL
2005 UH52517.780.90814.2CEN1.797Green check.svg1.6433.91 MPC  · JPL
2005 VX3 838.420.995112.4 TNO Green check.svg-0.948Green check.svg4.11672.73 unusual MPC  · JPL
2006 BZ8 9.60.803165.3 CEN Green check.svg-1.024Green check.svg1.8917.31 unusual MPC  · JPL
2006 BV12429.570.9369CEN1.829Green check.svg1.8857.26 MPC  · JPL
2006 EX5242.120.939150.2 TNO Green check.svg-1.571Green check.svg2.5681.68 unusual MPC  · JPL
2006 LM1 32.190.885172.1TNOGreen check.svg-2.133Green check.svg3.760.67 MPC  · JPL
2006 RG125.680.921133.5 CEN Green check.svg-0.992Green check.svg2.0449.32 unusual MPC  · JPL
2006 RJ2 9.670.76164.7CENGreen check.svg-1.172Green check.svg2.3217.02 unusual MPC  · JPL
2006 SO13419.520.8324.2CEN2.4093.2835.77 unusual MPC  · JPL
2007 BJ638.580.81111CEN2.0811.6215.54 MPC  · JPL
2007 DA61445.810.99476.5 TNO 0.484Green check.svg2.66888.96 unusual MPC  · JPL
2007 TG25021.290.92610.6 CEN 1.747Green check.svg1.5841 MPC  · JPL
2007 VJ20024.350.9417.2CEN1.664Green check.svg1.4347.27 MPC  · JPL
2007 VW2665.440.39108.3 other Green check.svg0.364Green check.svg3.327.57 MPC  · JPL
2008 BN1830.340.91428.8 TNO 1.889Green check.svg2.6158.07 unusual MPC  · JPL
2008 SE8219.350.83617.4 CEN 2.2883.1735.53 unusual MPC  · JPL
2008 UW445.690.61796CENGreen check.svg0.742Green check.svg2.189.2 MPC  · JPL
2008 WA9514.010.87860.2CEN1.151Green check.svg1.726.31 unusual MPC  · JPL
2009 AU1623.540.91769.9CEN0.804Green check.svg1.9545.13 unusual MPC  · JPL
2009 DD4748.870.954107.4 TNO Green check.svg-0.440Green check.svg2.2395.5 MPC  · JPL
2009 FW2311.520.85586.4 CEN 0.548Green check.svg1.6721.37 unusual MPC  · JPL
2009 KK3120.040.92322.8CEN1.653Green check.svg1.5538.54 MPC  · JPL
2009 QY612.470.833137.8CENGreen check.svg-0.852Green check.svg2.0822.87 unusual MPC  · JPL
2009 SE813.260.90218CEN1.706Green check.svg1.325.21 MPC  · JPL
2009 WX19931.30.9558.7 TNO 1.603Green check.svg1.4161.2 MPC  · JPL
2009 YS620.160.919147.8 CEN Green check.svg-1.052Green check.svg1.6338.7 MPC  · JPL
2010 AK11110.70.79226.2CEN2.0572.2219.17 MPC  · JPL
2010 BK118 378.150.984143.9 TNO Green check.svg-2.454Green check.svg6.11750.19 MPC  · JPL
2010 CG5531.720.91146.1TNOGreen check.svg-1.538Green check.svg2.8660.57 unusual MPC  · JPL
2010 CA10010.960.888.1 CEN 1.842Green check.svg1.3220.6 MPC  · JPL
2010 DC39108.970.98310.5 TNO 1.691Green check.svg1.83216.1 unusual MPC  · JPL
2010 EB4631.630.952156.6TNOGreen check.svg-1.215Green check.svg1.561.75 MPC  · JPL
2010 EJ10421.610.941.4 CEN 1.574Green check.svg2.1641.06 MPC  · JPL
2010 ER14410.890.8278.8CEN2.0831.8819.91 MPC  · JPL
2010 EV15923.070.92718.6CEN1.726Green check.svg1.6944.45 MPC  · JPL
2010 EQ1692.090.09392 MBA Green check.svg2.4491.892.28 MPC  · JPL
2010 EX17549.390.94629.2 TNO 1.844Green check.svg2.6596.14 unusual MPC  · JPL
2010 GW6462.460.941105.2TNOGreen check.svg-0.533Green check.svg3.69121.23 unusual MPC  · JPL
2010 GW147173.90.96999.9TNOGreen check.svg-0.462Green check.svg5.39342.42 unusual MPC  · JPL
2010 HK12614.450.897121.6 CEN Green check.svg-0.414Green check.svg1.527.4 MPC  · JPL
2010 JX1624.220.89816.9CEN2.0332.4745.96 MPC  · JPL
2010 JH12470.080.96353.4 TNO 1.262Green check.svg2.63137.54 unusual MPC  · JPL
2010 JC14714.60.76241.6 CEN 1.979Green check.svg3.4825.72 unusual MPC  · JPL
2010 JB18444.840.93218.7 TNO 2.1383.0786.62 unusual MPC  · JPL
2010 JA19110.020.79315.1 CEN 2.1532.0817.96 MPC  · JPL
2010 LG616.280.783123.8CENGreen check.svg0.069Green check.svg1.3611.19 MPC  · JPL
2010 LN1352169.280.99964.7 TNO 0.699Green check.svg1.724336.84 unusual MPC  · JPL
2010 MK1914.860.80525.6 CEN 2.1602.926.81 MPC  · JPL
2010 OR126.980.924143.9CENGreen check.svg-1.219Green check.svg2.0651.89 unusual MPC  · JPL
2010 OU10017.290.89115.2CEN1.901Green check.svg1.8932.7 MPC  · JPL
2010 OM10126.10.918118.8CENGreen check.svg-0.657Green check.svg2.1450.06 unusual MPC  · JPL
2010 OT12828.670.90325.8CEN1.996Green check.svg2.7854.56 MPC  · JPL
2010 PK1618.820.90527.7CEN1.711Green check.svg1.7935.85 MPC  · JPL
2010 PO5813.180.78121.4CENGreen check.svg-0.643Green check.svg2.923.46 unusual MPC  · JPL
2010 RA1722.910.93911.3CEN1.646Green check.svg1.444.41 MPC  · JPL
2011 BP14111.340.8644.5CEN1.940Green check.svg1.5421.15 MPC  · JPL
2011 FB10721.060.9243.7CEN1.780Green check.svg1.640.52 MPC  · JPL
2011 GN2715.750.4153.4CENGreen check.svg-2.522Green check.svg9.4522.06 MPC  · JPL
2011 MM4 21.260.473100.5CENGreen check.svg-0.404Green check.svg11.231.33 MPC  · JPL
2011 OR17288.790.989110.4 TNO Green check.svg-0.745Green check.svg3.12574.45 unusual MPC  · JPL
2011 SP2519.580.884109.3 CEN Green check.svg-0.334Green check.svg2.2836.88 unusual MPC  · JPL
2011 SH2108.10.79816.2CEN2.0871.6414.56 MPC  · JPL
2011 UT3688.940.7823.9CEN2.0811.9615.92 MPC  · JPL
2011 UR40218.560.77824.6CEN2.4394.1233 unusual MPC  · JPL
2011 WS4137.660.945141.6 TNO Green check.svg-1.239Green check.svg2.0673.26 unusual MPC  · JPL
2012 DT4245.160.9691.2TNO1.582Green check.svg1.4288.9 MPC  · JPL
2012 HD262.790.959146.7TNOGreen check.svg-1.555Green check.svg2.55123.03 unusual MPC  · JPL
2012 KA51484.170.9970.9TNO0.906Green check.svg4.89963.46 unusual MPC  · JPL
2012 TF7211.140.8645.3 CEN 1.934Green check.svg1.5120.76 MPC  · JPL
2012 TT729.580.865.1CEN1.920Green check.svg1.3417.83 MPC  · JPL
2012 TQ11113.440.8848CEN1.877Green check.svg1.5625.32 MPC  · JPL
2012 TL13929.890.882160CENGreen check.svg-1.950Green check.svg3.5356.26 MPC  · JPL
2012 VG9410.570.838.5CEN2.0661.819.34 MPC  · JPL
2012 YO66.310.478106.9CENGreen check.svg0.262Green check.svg3.299.33 unusual MPC  · JPL
2012 YE89.290.588136.1CENGreen check.svg-0.996Green check.svg3.8314.74 unusual MPC  · JPL
2013 BN2759.150.974101.8 TNO Green check.svg-0.225Green check.svg1.55116.75 MPC  · JPL
2013 BL76 958.560.99198.6TNOGreen check.svg-0.528Green check.svg8.371908.74 MPC  · JPL
2013 CY16710.310.8485.9 CEN 1.989Green check.svg1.5719.05 MPC  · JPL
2013 DG4136.580.995.3 TNO 1.443Green check.svg1.3271.85 MPC  · JPL
2013 HS15058.040.95197.1TNOGreen check.svg-0.164Green check.svg2.82113.27 unusual MPC  · JPL
2013 JD411.990.86372.9 CEN 0.883Green check.svg1.6422.34 MPC  · JPL
2013 LA2 5.680.466175.1CENGreen check.svg-0.926Green check.svg3.038.33 MPC  · JPL
2013 LD1681.490.969154.7 TNO Green check.svg-1.708Green check.svg2.54160.45 unusual MPC  · JPL
2013 LG2917.050.79115.4 CEN 2.4423.5730.54 unusual MPC  · JPL
2013 NS1112.580.786130.4CENGreen check.svg-0.831Green check.svg2.6922.47 unusual MPC  · JPL
2013 PS2111.010.83611.3CEN2.0391.8120.22 MPC  · JPL
2013 RA9619.840.925.2CEN1.783Green check.svg1.5838.1 MPC  · JPL
2013 SM9934.030.9114.3 TNO 2.2063.0665 MPC  · JPL
2013 YG488.170.75261.3 CEN 1.430Green check.svg2.0314.31 unusual MPC  · JPL
2014 CW1432.90.869170.8 TNO Green check.svg-2.297Green check.svg4.3161.48 MPC  · JPL
2014 HM5912.720.8869.6 CEN 1.841Green check.svg1.4523.99 MPC  · JPL
2014 HX6413.470.8934.4CEN1.831Green check.svg1.4425.5 MPC  · JPL
2014 HS678.990.8546.5CEN1.938Green check.svg1.3116.68 MPC  · JPL
2014 HT9413.220.8945.6CEN1.814Green check.svg1.425.03 MPC  · JPL
2014 HA99146.830.9914.3 TNO 1.484Green check.svg1.46292.21 MPC  · JPL
2014 HJ1049.240.8449.5 CEN 1.971Green check.svg1.4417.04 MPC  · JPL
2014 HU11010.380.8426.8CEN2.0131.6419.12 MPC  · JPL
2014 HW11319.980.9288.8CEN1.708Green check.svg1.4538.52 MPC  · JPL
2014 HC11413.160.8899.8CEN1.832Green check.svg1.4624.86 MPC  · JPL
2014 JJ5770.29195.9CENGreen check.svg0.514Green check.svg4.979.04 unusual MPC  · JPL
2014 MH5544.840.992.4 TNO Green check.svg0.010Green check.svg4.585.18 unusual MPC  · JPL
2014 PP6921.370.94193.7 NEO Green check.svg0.155Green check.svg1.2541.48 MPC  · JPL
2014 QZ11112.180.86515.8 CEN 1.903Green check.svg1.6422.72 MPC  · JPL
2014 QW2438.260.7618.1CEN2.1871.9814.53 MPC  · JPL
2014 QU25012.330.8679.1CEN1.937Green check.svg1.6423.02 MPC  · JPL
2014 QP48218.810.9183.8CEN1.781Green check.svg1.5436.07 MPC  · JPL
2014 SQ33928.840.903128.6CENGreen check.svg-1.078Green check.svg2.7954.89 unusual MPC  · JPL
2014 UG612.40.8897.1CEN1.821Green check.svg1.3723.43 MPC  · JPL
2014 UU2611.60.8741.5CEN1.898Green check.svg1.4621.75 MPC  · JPL
2014 UK7022.470.72169.3CENGreen check.svg-2.602Green check.svg6.2938.64 MPC  · JPL
2014 UV11413.860.71171CENGreen check.svg-1.895Green check.svg4.0223.7 unusual MPC  · JPL
2014 UC2419.580.7567.4CEN2.3042.3416.83 MPC  · JPL
2014 WK3468.370.8419.2CEN1.976Green check.svg1.3315.41 MPC  · JPL
2014 XS371.970.955101.5 TNO Green check.svg-0.368Green check.svg3.26140.67 unusual MPC  · JPL
2015 AO4421.940.835139.9 CEN Green check.svg-1.491Green check.svg3.6240.26 unusual MPC  · JPL
2015 AM10712.790.8757.1CEN1.916Green check.svg1.6123.97 MPC  · JPL
2015 BH3118.660.71294.4CENGreen check.svg0.462Green check.svg2.4914.83 unusual MPC  · JPL
2015 BE3849.350.8080.3CEN2.1361.816.91 MPC  · JPL
2015 BH52616.730.8778.3CEN2.0132.0531.4 MPC  · JPL
2015 EV4523.960.9287.2CEN1.800Green check.svg1.7246.2 MPC  · JPL
2015 FK37456.590.989156.1 TNO Green check.svg-2.506Green check.svg4.96908.23 unusual MPC  · JPL
2015 KJ8711.980.8868.2 CEN 1.828Green check.svg1.3722.58 MPC  · JPL
2015 RK24580.60.96691.7 TNO Green check.svg0.002Green check.svg2.76158.45 unusual MPC  · JPL
2015 RE27720.20.7641.6 CEN 2.7974.7635.64 unusual MPC  · JPL
2015 TP1014.210.90237.9CEN1.492Green check.svg1.3927.03 MPC  · JPL
2015 TN17854.150.95691.2 TNO Green check.svg0.057Green check.svg2.39105.91 unusual MPC  · JPL
2015 TN23914.520.88214.1 CEN 1.886Green check.svg1.7227.32 MPC  · JPL
2015 TM2408.070.83610.5CEN1.989Green check.svg1.3214.82 MPC  · JPL
2015 TV27510.930.80513.4CEN2.1502.1319.73 MPC  · JPL
2015 TS350144.420.96558 TNO 1.501Green check.svg5.05283.78 unusual MPC  · JPL
2015 XX35114.470.853159.2 CEN Green check.svg-1.267Green check.svg2.1326.81 unusual MPC  · JPL
2015 XR38436.440.902157.5 TNO Green check.svg-1.967Green check.svg3.5769.32 unusual MPC  · JPL
2015 YY1819.350.83118.2 CEN Green check.svg-0.748Green check.svg3.2835.42 unusual MPC  · JPL
2016 AT28163.070.95722.2 TNO 1.945Green check.svg2.69123.45 unusual MPC  · JPL
2016 CD9329.10.93612.2 CEN 1.810Green check.svg1.8756.32 MPC  · JPL
2016 CO26447.630.937129.7 TNO Green check.svg-1.245Green check.svg3.0192.25 unusual MPC  · JPL
2016 DF27.20.538167.1 CEN Green check.svg-1.209Green check.svg3.3211.07 unusual MPC  · JPL
2016 EJ20366.610.959171 TNO Green check.svg-1.922Green check.svg2.72130.49 unusual MPC  · JPL
2016 GE5310.770.8750.6 CEN 1.877Green check.svg1.3520.19 MPC  · JPL
2016 GF7021.020.93514.1CEN1.633Green check.svg1.3740.67 MPC  · JPL
2016 GM83139.370.9893.5 TNO 1.567Green check.svg1.54277.19 MPC  · JPL
2016 GV8323.250.93811.8 CEN 1.657Green check.svg1.4445.06 MPC  · JPL
2016 GE9313.780.91817.2 NEO 1.614Green check.svg1.1426.42 MPC  · JPL
2016 GZ12010.720.83110.5 CEN 2.0541.8119.63 MPC  · JPL
2016 JK2413.030.66152.3CENGreen check.svg-1.706Green check.svg4.4321.63 MPC  · JPL
2016 LS13.340.606114.3CENGreen check.svg-0.660Green check.svg5.2621.42 unusual MPC  · JPL
2016 NL10013.90.7621.9CEN2.3443.3324.46 unusual MPC  · JPL
2016 PN6631.020.906105.2 TNO Green check.svg-0.373Green check.svg2.959.13 unusual MPC  · JPL
2016 SP68.540.8284.9 CEN 2.0401.4715.61 MPC  · JPL
2016 TK29.20.55192.4CENGreen check.svg0.475Green check.svg4.1314.27 unusual MPC  · JPL
2016 TP937.390.554138.3CENGreen check.svg-0.778Green check.svg3.311.49 unusual MPC  · JPL
2016 US10935.690.94887.2 TNO 0.226Green check.svg1.8569.52 MPC  · JPL
2016 UA1403.610.526117.8 MBA Green check.svg0.780Green check.svg1.715.51 MPC  · JPL
2016 UK21229.620.952.3 CEN 1.662Green check.svg1.4857.77 MPC  · JPL
2016 UN23230.390.86211.2 TNO 2.5764.256.59 MPC  · JPL
2016 UN23324.860.9371.4 CEN 1.741Green check.svg1.5848.14 MPC  · JPL
2016 UG2458.470.832.3CEN2.0361.4415.5 MPC  · JPL
2016 VH1210.30.8344.6CEN2.0511.718.89 MPC  · JPL
2016 VY1711.150.85148.5CENGreen check.svg-0.847Green check.svg1.6720.62 unusual MPC  · JPL
2016 WS114.350.88253CEN1.304Green check.svg1.6927 unusual MPC  · JPL
2016 XK310.290.8134.4CEN1.868Green check.svg1.9618.63 MPC  · JPL
2016 YB135.450.407139.8 other Green check.svg-0.474Green check.svg3.247.67 MPC  · JPL
2017 AX1328.690.883137.2 CEN Green check.svg-1.435Green check.svg3.3554.03 unusual MPC  · JPL
2017 BA4817.570.90419.9CEN1.776Green check.svg1.6933.45 MPC  · JPL
2017 CW32186.350.984152.4 TNO Green check.svg-1.852Green check.svg2.95369.75 unusual MPC  · JPL
2017 DQ10624.650.94611.2 CEN 1.596Green check.svg1.3347.97 MPC  · JPL
2017 EM433.150.9283.4 TNO 0.383Green check.svg2.6463.66 MPC  · JPL
2017 GD843.250.94774.9TNO0.603Green check.svg2.2984.22 unusual MPC  · JPL
2017 JB632.780.883160.9TNOGreen check.svg-2.063Green check.svg3.8261.74 unusual MPC  · JPL
2017 MZ467.320.95365.8TNO0.974Green check.svg3.19131.45 unusual MPC  · JPL
2017 MB7 1311.870.99755.8TNO1.475Green check.svg4.462619.28 unusual MPC  · JPL
2017 NM214.60.622101.3 CEN Green check.svg-0.156Green check.svg5.5223.67 MPC  · JPL
2017 OX6858.90.97194.8 TNO Green check.svg-0.046Green check.svg1.73116.07 unusual MPC  · JPL
2017 PY2417.380.92571.8 CEN 0.733Green check.svg1.3133.44 MPC  · JPL
2017 QO3334.550.857148.8 TNO Green check.svg-2.121Green check.svg4.9464.16 unusual MPC  · JPL
2017 QW469.020.8015.1 CEN 2.1471.7916.25 MPC  · JPL
2017 RR211.620.78287.1CEN0.542Green check.svg2.5320.71 unusual MPC  · JPL
2017 SV13 9.660.792113.3CENGreen check.svg-0.119Green check.svg2.0117.3 unusual MPC  · JPL
2017 SN33239.430.992152.1 TNO Green check.svg-1.464Green check.svg1.85477.02 unusual MPC  · JPL
2017 SZ11834.080.9542.5TNO1.684Green check.svg1.5666.6 MPC  · JPL
2017 UW51125.750.975144.2TNOGreen check.svg-1.729Green check.svg3.14248.36 unusual MPC  · JPL
2017 UX5130.060.74790.5 CEN Green check.svg0.147Green check.svg7.6152.5 MPC  · JPL
2017 UR52317.810.996108.3 NEO Green check.svg-0.416Green check.svg1.24634.38 MPC  · JPL
2017 YL28.920.76627.9 CEN 2.0722.0915.76 unusual MPC  · JPL
2017 YL4152.420.97289 TNO 0.080Green check.svg4.26300.57 unusual MPC  · JPL
2018 AS1812.930.87263 CEN 1.105Green check.svg1.6624.21 MPC  · JPL
2018 DE4320.92581.3 TNO 0.446Green check.svg2.3961.62 unusual MPC  · JPL
2018 DF495.810.98368.2TNO0.635Green check.svg1.6190.02 MPC  · JPL
2018 KH393.930.96146.9TNO1.672Green check.svg3.71184.15 unusual MPC  · JPL
2018 MP8370.070.9968.3TNO0.909Green check.svg3.83736.31 unusual MPC  · JPL
2018 PQ188.950.8081.2 CEN 2.1271.7216.19 MPC  · JPL
2018 PL2819.510.86274.1CEN0.804Green check.svg2.6936.33 unusual MPC  · JPL
2018 SQ13154.080.98191 TNO Green check.svg-0.002Green check.svg2.97305.19 unusual MPC  · JPL
2018 TL68.150.788170.9 CEN Green check.svg-0.881Green check.svg1.7214.57 unusual MPC  · JPL
A/2018 V3121.440.989165 TNO Green check.svg-1.339Green check.svg1.34241.54 MPC  · JPL
2018 WB17.250.694152.3 CEN Green check.svg-0.787Green check.svg2.2212.27 unusual MPC  · JPL
2019 CR14.460.594160.3CENGreen check.svg-2.166Green check.svg5.8723.04 MPC  · JPL
2019 EJ324.20.956139.6 NEO Green check.svg-0.754Green check.svg1.0847.32 MPC  · JPL
A/2019 G2699.850.997159.2 TNO Green check.svg-1.746Green check.svg2.291397.41 MPC  · JPL
A/2019 G317.150.834156.8 CEN Green check.svg-1.540Green check.svg2.8531.45 MPC  · JPL
2019 HC48.790.555134.3CENGreen check.svg-0.918Green check.svg3.9113.66 unusual MPC  · JPL
2019 KE711.670.702108.3CENGreen check.svg-0.224Green check.svg3.4819.86 unusual MPC  · JPL
2019 KN1912.420.76514.8CEN2.3422.9121.93 MPC  · JPL
A/2019 O257.370.83193.3 TNO Green check.svg-0.121Green check.svg9.68105.05 MPC  · JPL
A/2019 O432.880.889115.1TNOGreen check.svg-0.817Green check.svg3.6462.12 MPC  · JPL
2019 PN225.110.92113 CEN Green check.svg-0.465Green check.svg2.0148.22 unusual MPC  · JPL
A/2019 Q259.680.979159 NEO Green check.svg-1.205Green check.svg1.26118.11 MPC  · JPL
A/2019 T138.240.888120.9 TNO Green check.svg-1.143Green check.svg4.2872.2 MPC  · JPL
2019 YJ637.390.93122TNO1.948Green check.svg2.5672.22 unusual MPC  · JPL
A/2020 A125.940.936149 CEN Green check.svg-1.152Green check.svg1.6750.2 MPC  · JPL
A/2020 B152.320.96718.5 TNO 1.641Green check.svg1.75102.88 MPC  · JPL
2020 BZ127.690.922165.5 NEO Green check.svg-0.237Green check.svg0.614.79 MPC  · JPL
2020 EP10.50.76476.4 CEN 0.927Green check.svg2.4818.51 unusual MPC  · JPL
2020 FH2414.40.77328.6CEN2.2163.2725.52 unusual MPC  · JPL
A/2020 H9341.710.992137.9 TNO Green check.svg-1.458Green check.svg2.58680.84 MPC  · JPL
2020 HB1116.60.709147.3 CEN Green check.svg-1.808Green check.svg4.8428.36 unusual MPC  · JPL
2020 KD613.070.87238.7CEN1.612Green check.svg1.6824.47 unusual MPC  · JPL
2020 KH77.940.502106.1CENGreen check.svg0.061Green check.svg3.9511.94 unusual MPC  · JPL
2020 KU734.880.88103.8 TNO Green check.svg-0.440Green check.svg4.265.57 unusual MPC  · JPL
2020 ML156.080.95582.5TNO0.349Green check.svg2.54109.62 unusual MPC  · JPL
A/2020 M45092.510.999160.1TNOGreen check.svg-2.843Green check.svg5.9510179.07 MPC  · JPL
2020 OR56.240.376166.6 CEN Green check.svg-1.139Green check.svg3.898.58 unusual MPC  · JPL
2020 OS56.90.684155.8CENGreen check.svg-0.779Green check.svg2.1811.63 unusual MPC  · JPL
2020 OP728.370.89479.5CEN0.565Green check.svg353.75 unusual MPC  · JPL
2020 QN6674.790.99376.8 TNO 0.627Green check.svg4.821344.75 unusual MPC  · JPL
2020 QO619.130.87580.5 CEN 0.579Green check.svg2.3935.88 MPC  · JPL
2020 SJ518.180.85677.4CEN0.709Green check.svg2.6233.74 unusual MPC  · JPL
2020 SV7917.520.8845.7CEN2.0032.0333.02 unusual MPC  · JPL
2020 TK920.440.878105.6CENGreen check.svg-0.254Green check.svg2.4938.4 unusual MPC  · JPL
2020 VS67.730.773161.2CENGreen check.svg-0.791Green check.svg1.7513.71 unusual MPC  · JPL
2020 XQ723.540.91832.5CEN1.647Green check.svg1.9445.14 MPC  · JPL
2020 YR3 501.830.967169.3 TNO Green check.svg-4.896Green check.svg16.49987.16 MPC  · JPL
2021 CT37.60.435160.4 CEN Green check.svg-1.366Green check.svg4.2910.91 unusual MPC  · JPL
2021 DL135.410.889148.6 TNO Green check.svg-1.892Green check.svg3.9366.88 unusual MPC  · JPL
2021 DN222.120.8210.8 CEN 2.5553.9940.25 unusual MPC  · JPL
A/2021 E2216.270.989167.5 TNO Green check.svg-1.802Green check.svg2.29430.26 MPC  · JPL
A/2021 E4733.10.994116.4TNOGreen check.svg-1.181Green check.svg4.681461.53 MPC  · JPL
A/2021 F1239.470.996107.3 NEO Green check.svg-0.346Green check.svg1477.95 MPC  · JPL
2021 FQ210.810.79254.9 CEN 1.492Green check.svg2.2419.37 MPC  · JPL
A/2021 G25022.170.99948.5 TNO 1.834Green check.svg4.9810039.37 MPC  · JPL
2021 GQ5786.210.96125.1TNOGreen check.svg-1.252Green check.svg3.46168.96 unusual MPC  · JPL
2021 KL924.640.9442.3 CEN 1.652Green check.svg1.3947.89 MPC  · JPL
2021 LB1825.640.869129CENGreen check.svg-1.179Green check.svg3.3647.92 MPC  · JPL
Designation a
e i
Orbital criteria and classes q
Unusual Catalog Refs
Cls Retro TJupiter TJ2
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  1. 1 2 3 The Jupiter Tisserand invariant or Tisserand's parameter with respect to Jupiter can be derived from Jupiter's semi-major axis (aJ) and the minor planet's orbital elements (a, e and i) as follows: [lower-alpha 2]
    aJ/a + 2(cosi) × a/aJ × (1-e2)
    In order to agree with the data displayed at the JPL Small-Body Database from which the orbital elements are sourced, [lower-alpha 3] the calculation of the Tisserand invariant uses a value of 5.203363 AU for Jupiter's osculating semi-major axis (aJ). Also, the degrees of the objects inclination need to be converted into the radian equivalent such as in:
    ($a_j / $a) + (2 * cos(deg2rad($i))) * sqrt(($a/$a_j) * (1 - $e * $e)).

See also

Related Research Articles

(65407) 2002 RP120, provisional designation 2002 RP120, is a trans-Neptunian object and damocloid from the outer Solar System. Its orbit is retrograde and comet-like, and has a high eccentricity. It was discovered on 4 September 2002 by astronomers with the LONEOS survey at Anderson Mesa Station, Arizona, in the United States. The unusual object measures approximately 14.6 kilometers (9.1 miles) in diameter and is likely elongated in shape. It is a slow rotator and potentially a tumbler as well. The object was probably ejected from the ecliptic by Neptune.

20461 Dioretsa is a centaur and damocloid on a retrograde, cometary-like orbit from the outer Solar System. It was discovered on 8 June 1999, by members of the LINEAR team at the Lincoln Laboratory Experimental Test Site near Socorro, New Mexico, United States. The highly eccentric unusual object measures approximately 14 kilometers in diameter. It was named Dioretsa, the word "asteroid" spelled backwards.

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Tisserand's parameter is a value calculated from several orbital elements of a relatively small object and a larger "perturbing body". It is used to distinguish different kinds of orbits. The term is named after French astronomer Félix Tisserand, and applies to restricted three-body problems in which the three objects all differ greatly in mass.

20898 Fountainhills, provisional designation 2000 WE147, is a dark asteroid in a cometary orbit (ACO) from the outermost regions of the asteroid belt, approximately 37 kilometers (23 miles) in diameter. It was discovered on 30 November 2000, by American amateur astronomer Charles W. Juels at the Fountain Hills Observatory in Arizona, United States. The D-type asteroid has a rotation period of 12.84 hours. It was named for the city of Fountain Hills, Arizona, in the United States.

7604 Kridsadaporn

7604 Kridsadaporn, provisional designation 1995 QY2, is an unusual, carbonaceous asteroid and Mars-crosser on a highly eccentric orbit from the outer regions of the asteroid belt, approximately 12 kilometers (7.5 miles) in diameter. It was discovered on 31 August 1995, by Australian astronomer Robert McNaught at Siding Spring Observatory near Coonabarabran, Australia. Due to its particular orbit, the C-type asteroid belongs to MPC's list of "other" unusual objects, and has been classified as an "asteroid in cometary orbit", or ACO. The asteroid was named in memory of Thai astronomer Kridsadaporn Ritsmitchai.

<span class="nowrap">(528219) 2008 KV<sub>42</sub></span>

(528219) 2008 KV42 (provisionally designated:2008 KV42, and nicknamed Drac) is a trans-Neptunian object and the first one with a retrograde orbit to be discovered. This retrograde motion with an orbital inclination of 103° suggests that it is the missing link between its source in the Hills cloud and Halley-type comets, thus providing further insight into the evolution of the outer Solar System. The object measures approximately 77 kilometers (48 miles) in diameter. With a semi-major axis of 42 AU, it takes about 269 years to complete an orbit around the Sun.

(434620) 2005 VD, provisional designation 2005 VD, is a centaur and damocloid on a retrograde orbit from the outer Solar System, known for having the second most highly inclined orbit of any small Solar System body, second to 2013 LA2. It was the most highly inclined known object between 2005 and 2013. The unusual object measures approximately 6 kilometers in diameter.

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<span class="nowrap">1999 LE<sub>31</sub></span>

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1996 PW

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2007 BP102 is a high inclination centaur and damocloid from the outer regions of the Solar System, approximately 34 kilometers in diameter. It was first observed by astronomers at the Mauna Kea Observatories on 24 January 2007.

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(342842) 2008 YB3, provisional designation: 2008 YB3, is a sizable centaur and retrograde damocloid from the outer Solar System, approximately 67 kilometers (42 miles) in diameter. It was discovered on 18 December 2008, by astronomers with the Siding Spring Survey at the Siding Spring Observatory in Australia. The minor planet was numbered in 2012 and has since not been named.

(468861) 2013 LU28, provisional designation 2013 LU28 is a highly eccentric trans-Neptunian object, retrograde centaur and damocloid from the outer regions of the Solar System. It was discovered on 8 June 2013 by astronomers with the Mount Lemmon Survey at the Mount Lemmon Observatory in Arizona, United States. The object is unlikely a dwarf planet as it measures approximately 110 kilometers (68 miles) in diameter. It was numbered in 2016 and has not been named since.

2011 MM4, provisional designation: 2011 MM4, is a sizable centaur and retrograde damocloid from the outer Solar System, approximately 64 kilometers (40 miles) in diameter. It was discovered on 24 June 2011, by astronomers with the Pan-STARRS 1 at the Haleakala Obs. in Hawaii.

In planetary science, the term unusual minor planet, or unusual object, is used for a minor planet that possesses an unusual physical or orbital characteristic. For the Minor Planet Center (MPC), which operates under the auspices of the International Astronomical Union, any non-classical main-belt asteroid, which account for the vast majority of all minor planets, is an unusual minor planet. These include the near-Earth objects and Trojans as well as the distant minor planets such as centaurs and trans-Neptunian objects. In a narrower sense, the term is used for a group of bodies – including main-belt asteroids, Mars-crossers, centaurs and otherwise non-classifiable minor planets – that show a high orbital eccentricity, typically above 0.5 and/or a perihelion of less than 6 AU. Similarly, an unusual asteroid (UA) is an inner Solar System object with a high eccentricity and/or inclination but with a perihelion larger than 1.3 AU, which does exclude the near-Earth objects.


  1. 1 2 Jewitt, David (August 2013). "The DAMOCLOIDS". UCLA, Department of Earth and Space Sciences. Retrieved 14 February 2014. (2013 list / 2011 list / 2010 list)
  2. Akimasa Nakamura and bas (2 May 2009). "List of Damocloids (Oort cloud asteroids)". Lowell Observatory. Retrieved 15 February 2017.
  3. Jewitt, David (2005). "A first look at the Damocloids" (PDF). The Astronomical Journal. 129 (1): 530–538. Bibcode:2005AJ....129..530J. doi: 10.1086/426328 . Retrieved 13 February 2011.
  4. "JPL Small-Body Database Search Engine: asteroids and T-Jupiter <= 2". JPL Solar System Dynamics. Retrieved 3 July 2021. Search parameters used: Limited by object type/group: Asteroids and T-Jupiter <= 2
  5. "JPL Small-Body Database Search Engine: asteroids and T-Jupiter <= 2 and data-arc span > 30 (d)". JPL Solar System Dynamics. Retrieved 1 June 2019.
  6. "NEO Close-Approaches (Between 1900 and 2200)". NASA/JPL Near-Earth Object Program. Archived from the original on 13 December 2012. Retrieved 22 June 2012. (sorted by descending relative velocity, dist<0.5AU = "215,221 close-Earth approaches")
  7. "List Of Other Unusual Objects". Minor Planet Center. Retrieved 1 June 2019.
  8. "JPL Small-Body Orbital Elements – ASCII Files". JPL Solar System Dynamics. Retrieved 16 June 2021.
  9. Alvarez-Candal, A. (January 2013). "SDSS photometry of asteroids in cometary orbits" (PDF). Astronomy and Astrophysics. 549: A34. arXiv: 1211.4351 . Bibcode:2013A&A...549A..34A. doi:10.1051/0004-6361/201220274. ISSN   0004-6361.