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NEO Discovery Statistics

NEAR-EARTH ASTEROID DISCOVERY STATISTICS

Some entries in the following charts and tables are dependent upon a diameter that is roughly inferred from the object’s estimated absolute magnitude (H) and its assumed reflectivity, or albedo. The absolute magnitude (H) of a near-Earth asteroid (NEA) is a measure of the object's brightness one astronomical unit from the sun and Earth and at zero phase angle (i.e., the angle between the sun and Earth, as seen from the NEA, is zero). The absolute magnitude (H) for a particular NEA is computed from the observed apparent magnitudes of the object at various times when the phase angles and the distances from the sun and Earth are known. An effective diameter is the diameter of a hypothetical spherical NEA that would provide the same apparent brightness as the observed NEA, whose actual shape is unknown.

Since most NEAs do not have a known reflectivity, or albedo, this albedo must be estimated before the H values, representing intrinsic brightness, can be converted to an approximate diameter. Pravec et al (2012) determined that, for their sample of 583 main-belt asteroids and NEAs, the mean albedos and their standard deviations are 0.057 (±0.013) for the Tholen/Bus/DeMeo C/G/B/F/P/D types and 0.197 (±0.051) for the S/A/L types. Since the albedos for NEAs are most likely to be either approximately 6% for asteroids of the C-type and associated taxonomic classes or 20% for asteroids of the more populous S-type and associated taxonomic classes, we have used an approximate mean value of 14% albedo and an H value of 17.75 to represent a one kilometer spherical NEA. Since the determined H values are uncertain, and likely biased by a few tenths (see Pravec et al., 2012, Icarus) and the single 14% albedo is only a rough mean representing a bimodal albedo distribution, the estimated numbers of one kilometer and larger sized objects in the tables below are very rough. However, these statistics are useful for monitoring the annual NEA discovery progress.

Using near-infrared data provided by the WISE spacecraft in 2010 and early 2011, Mainzer et al (2011) were able to determine diameters and albedos for 250 NEAs with a minimum uncertainty of 10% and 20% respectively. Hence they were able to determine the albedo distribution of these objects with known diameters and this distribution was then used to compute diameters for previously known NEOs with known H values but unknown diameters or albedos. They provided an estimate of 981 (±19) NEAs as the total population of NEAs one kilometer and larger. At the time of their analysis (Spring 2011), they also estimated that 911 (±17) of these large NEAs had already been discovered. While this latter estimate is both higher and more accurate than the estimated numbers given for Spring 2011 in the following tables, this statistical technique cannot be easily employed for day-to-day estimates of the population of NEAs one kilometer and larger. In the following tables, we will continue to use the simpler method described in the previous paragraph.

Mainzer, A. et al. (2011). NEOWISE observations of near-Earth objects: Preliminary Results. Astrophysical Journal. 743:156.
Pravec, P., A.W. Harris, P. Kusnirak, A. Galad, K. Hornoch (2012). Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations. Icarus (submitted 6/2012).
Stuart, J.S. (2003). Observational constraints on the number, albedos, sizes and impact hazards of the near-Earth asteroids. Ph.D. thesis, MIT.

All Asteroids

Table: Number of Near-Earth Asteroid Discoveries at Half-Year Intervals: All Asteroids

Table 1. NEAs Discovered by Site

Half Year
Intervals
LINEAR
(704)
NEAT
(566,608,644)
Spacewatch
(691,291)
LONEOS
(699)
Catalina
(703,E12,G96)
Pan-STARRS
(F51)
NEOWISE
(C51)
OtherCumulative
Total
 1995 (1)001400004334
 1995 (2)001201002349
 1996 (1)151800004377
 1996 (2)051000002394
 1997 (1)321000004413
 1997 (2)149400007447
 1998 (1)4491911007528
 1998 (2)9221562005650
 1999 (1)75012611001755
 1999 (2)8707719003878
 2000 (1)10821421130041040
 2000 (2)15014121700081241
 2001 (1)942872200021394
 2001 (2)18364152000041680
 2002 (1)15857161410061932
 2002 (2)130896700052169
 2003 (1)10230233300092366
 2003 (2)13337332270082606
 2004 (1)167194114250062878
 2004 (2)13772925600063142
 2005 (1)778292211500103403
 2005 (2)5930541919300103768
 2006 (1)44445131950034072
 2006 (2)52175461990054405
 2007 (1)3842072010034678
 2007 (2)7402552660075055
 2008 (1)7404312810055459
 2008 (2)66043028000115859
 2009 (1)51032026000186220
 2009 (2)58031031500176641
 2010 (1)29021025808797045
 2010 (2)7502203461737147556
 2011 (1)410170328683128025
 2011 (2)2901502521040238448
 2012 (1)260130352120078966
 2012 (2)2901302771310269442
 2013 (1)301302881510189915
 2013 (2)0012031520812910480
 2014 (1)00803322411614611223
 2014 (2)0080285380243811958
 2015 (1)*00101702316612372
* Incomplete half-year (based on discovery data through 2015-Mar-30 06:05 local)

Large Asteroids

Table: Number of Near-Earth Asteroid Discoveries at Half-Year Intervals: Large Asteroids

Table 2. Large NEAs Discovered by Site

Half Year
Intervals
LINEAR
(704)
NEAT
(566,608,644)
Spacewatch
(691,291)
LONEOS
(699)
Catalina
(703,E12,G96)
Pan-STARRS
(F51)
NEOWISE
(C51)
OtherCumulative
Total
 1995 (1)00300002176
 1995 (2)00400001181
 1996 (1)02200000185
 1996 (2)02000000187
 1997 (1)01300001192
 1997 (2)23100002200
 1998 (1)74210002216
 1998 (2)242130003249
 1999 (1)160244000275
 1999 (2)230112002304
 2000 (1)332114001346
 2000 (2)372350004397
 2001 (1)238040000432
 2001 (2)225040001464
 2002 (1)294230001503
 2002 (2)1910010001534
 2003 (1)143260002561
 2003 (2)175142001591
 2004 (1)155123001618
 2004 (2)910112000641
 2005 (1)100219001664
 2005 (2)645010001690
 2006 (1)30219000705
 2006 (2)102012000720
 2007 (1)20309001735
 2007 (2)50107000748
 2008 (1)20109000760
 2008 (2)30104000768
 2009 (1)10109000779
 2009 (2)60006002793
 2010 (1)00004030800
 2010 (2)10002030806
 2011 (1)20005100814
 2011 (2)00106300824
 2012 (1)00009100834
 2012 (2)10005200842
 2013 (1)00004000846
 2013 (2)00003201852
 2014 (1)00002420860
 2014 (2)00001310865
 2015 (1)*00000400869
* Incomplete half-year (based on discovery data through 2015-Mar-30 06:05 local)
NOTE: In the year 2010, the "Other" site category was exclusively WISE.
A separate table of WISE discoveries is
available.

Data compiled by Alan Chamberlin.

NUMBER OF NEOS
With over 90% of the near-Earth objects larger than one kilometer already discovered, the NEO Program is now focusing on finding 90% of the NEO population larger than 140 meters. A separate table containing WISE discoveries for NEAs and comets is available.

The chart below shows the cumulative total known near-Earth asteroids versus time. The blue area shows all near-Earth asteroids while the red area shows only large near-Earth asteroids (those with diameters roughly one kilometer and larger).
Table: Number of Known Near-Earth Asteroids Over Time
(click on the chart above for a larger version)

The chart below shows the total known near-Earth asteroids per size bin. Diameters are estimated using an assumed average albedo for NEAs. The first size bin represents NEAs smaller than 30m in diameter. The second represents NEAs with diameters from 30m to 100m, and so on.
Known Near-Earth Asteroids by Size Bin
Data shown in the chart above represent known NEAs as of the date shown in the bottom-right corner of the chart.

The table below shows the total number of NEOs known at selected dates. The most recent date at the top of the table is generally not the date the table was updated, but rather the discovery date of the most recently discovered NEO. Numbers for large asteroids (PHA-KM and NEA-KM) are rough estimates (see introductory note above). This table is updated daily using discovery data published by the Minor Planet Center.

----------------------------------------------------------------------------
   Date      NEC  Atira  Aten Apollo  Amor  PHA-KM  PHA  NEA-KM  NEA    NEO
----------  ----  ----- ----- ------ -----  ------ ----  ------ -----  -----
2015-03-28    96     15   913   6713  4731     152 1572     869 12372  12468
2015-03-01    96     15   905   6617  4699     151 1559     868 12236  12332
2015-02-01    96     14   898   6535  4662     151 1547     868 12109  12205
2015-01-01    95     14   889   6456  4599     151 1534     865 11958  12053
2014-12-01    95     14   880   6392  4562     151 1525     863 11848  11943
2014-11-01    95     14   874   6318  4499     151 1516     860 11705  11800
2014-10-01    94     14   867   6228  4436     151 1511     860 11545  11639
2014-09-01    94     14   861   6175  4381     151 1505     860 11431  11525
2014-08-01    94     14   856   6122  4308     151 1496     860 11300  11394
2014-07-01    94     14   854   6079  4276     151 1486     860 11223  11317
2014-06-01    94     14   845   6042  4219     150 1478     856 11120  11214
2014-05-01    94     14   838   5975  4172     150 1465     854 10999  11093
2014-04-01    94     14   826   5859  4063     150 1457     853 10762  10856
2014-03-01    94     13   819   5803  4036     150 1452     853 10671  10765
2014-02-01    94     13   811   5758  3998     150 1445     853 10580  10674
2014-01-01    94     13   804   5705  3958     150 1441     852 10480  10574
2013-12-01    94     13   799   5650  3932     150 1437     852 10394  10488
2013-11-01    94     13   798   5578  3906     150 1429     852 10295  10389
2013-10-01    94     12   786   5519  3844     149 1422     848 10161  10255
2013-09-01    94     12   780   5462  3789     149 1418     847 10043  10137
2013-08-01    94     12   778   5431  3752     149 1412     847  9973  10067
2013-07-01    94     12   773   5403  3727     149 1405     846  9915  10009
2013-06-01    94     12   770   5373  3709     149 1399     844  9864   9958
2013-05-01    94     11   765   5334  3688     149 1392     844  9798   9892
2013-04-01    94     11   760   5293  3657     149 1383     843  9721   9815
2013-03-01    94     11   755   5245  3628     149 1374     843  9639   9733
2013-02-01    93     11   750   5206  3601     149 1370     843  9568   9661
2013-01-01    93     11   743   5125  3563     149 1356     842  9442   9535
2012-12-01    93     11   735   5072  3532     149 1345     842  9350   9443
2012-11-01    92     10   727   5018  3495     149 1337     839  9250   9342
2012-10-01    92     10   721   4943  3439     149 1326     837  9113   9205
2012-09-01    92     10   717   4910  3409     149 1323     836  9046   9138
2012-08-01    92     10   712   4884  3376     149 1318     835  8982   9074
2012-07-01    91     10   711   4878  3367     149 1314     834  8966   9057
2012-06-01    91     10   706   4853  3343     149 1305     831  8912   9003
2012-05-01    91     10   704   4820  3319     149 1300     828  8853   8944
2012-04-01    91     10   702   4769  3292     149 1294     827  8773   8864
2012-03-01    91     10   696   4689  3265     149 1288     825  8660   8751
2012-02-01    91     10   686   4642  3224     149 1282     825  8562   8653
2012-01-01    91     10   676   4573  3189     149 1273     824  8448   8539
2011-12-01    91     10   672   4541  3164     149 1266     820  8387   8478
2011-11-01    91     10   669   4500  3130     147 1256     817  8309   8400
2011-10-01    91     10   662   4438  3085     146 1245     816  8195   8286
2011-09-01    90     10   661   4403  3032     146 1239     815  8106   8196
2011-08-01    90     10   661   4387  3006     146 1236     814  8064   8154
2011-07-01    89     10   659   4374  2982     146 1232     814  8025   8114
2011-06-01    89     10   659   4357  2957     146 1226     813  7983   8072
2011-05-01    89     10   656   4331  2934     146 1217     811  7931   8020
2011-04-01    89     10   645   4282  2905     146 1210     809  7842   7931
2011-03-01    89     10   634   4219  2881     146 1201     807  7744   7833
2011-02-01    89     10   624   4173  2863     146 1190     807  7670   7759
2011-01-01    89     10   618   4098  2830     146 1174     806  7556   7645
2010-12-01    89      9   609   4043  2799     146 1165     806  7460   7549
2010-11-01    89      9   598   3974  2753     146 1159     806  7334   7423
2010-10-01    89      9   588   3918  2714     146 1145     806  7229   7318
2010-09-01    89      9   582   3871  2649     146 1140     804  7111   7200
2010-08-01    89      9   579   3857  2638     146 1137     801  7083   7172
2010-07-01    89      9   574   3835  2627     146 1135     800  7045   7134
2010-06-01    88      9   568   3804  2605     146 1127     799  6986   7074
2010-05-01    87      9   560   3760  2586     145 1114     797  6915   7002
2010-04-01    87      9   552   3714  2569     145 1108     797  6844   6931
2010-03-01    87      9   544   3677  2543     144 1099     796  6773   6860
2010-02-01    87      9   540   3623  2518     144 1087     795  6690   6777
2010-01-01    87      9   535   3597  2500     144 1084     793  6641   6728
2009-12-01    87      9   531   3576  2490     144 1079     791  6606   6693
2009-11-01    86      9   520   3500  2461     144 1071     788  6490   6576
2009-10-01    86      9   511   3445  2428     144 1067     786  6393   6479
2009-09-01    86      9   506   3392  2381     144 1057     784  6288   6374
2009-08-01    86      9   504   3372  2354     144 1055     783  6239   6325
2009-07-01    86      9   504   3362  2345     143 1053     779  6220   6306
2009-06-01    85      9   501   3351  2334     142 1050     778  6195   6280
2009-05-01    85      9   499   3324  2320     142 1041     776  6152   6237
2009-04-01    85      9   496   3292  2306     142 1037     773  6103   6188
2009-03-01    85      9   491   3231  2287     142 1025     773  6018   6103
2009-02-01    85      9   487   3172  2261     141 1013     770  5929   6014
2009-01-01    85      9   481   3128  2241     141 1004     768  5859   5944
2008-12-01    84      9   480   3086  2212     141  994     767  5787   5871
2008-11-01    84      9   474   3038  2190     141  986     765  5711   5795
2008-10-01    84      8   467   2976  2139     140  976     764  5590   5674
2008-09-01    83      8   464   2945  2104     140  966     763  5521   5604
2008-08-01    83      8   461   2931  2090     140  961     762  5490   5573
2008-07-01    83      8   459   2914  2078     140  952     760  5459   5542
2008-06-01    83      8   455   2903  2070     140  949     759  5436   5519
2008-05-01    83      8   451   2873  2052     140  943     758  5384   5467
2008-04-01    83      8   449   2826  2023     140  940     757  5306   5389
2008-03-01    83      7   440   2758  1998     139  930     750  5203   5286
2008-02-01    83      7   428   2698  1968     138  916     748  5101   5184
2008-01-01    83      7   426   2671  1951     138  908     748  5055   5138
2007-12-01    83      7   423   2636  1934     138  898     745  5000   5083
2007-11-01    83      7   411   2578  1898     138  888     741  4894   4977
2007-10-01    82      7   397   2529  1856     138  877     740  4789   4871
2007-09-01    82      7   390   2491  1824     137  870     739  4712   4794
2007-08-01    82      7   388   2480  1814     136  865     735  4689   4771
2007-07-01    82      7   388   2476  1807     136  864     735  4678   4760
2007-06-01    82      7   383   2454  1798     135  855     733  4642   4724
2007-05-01    82      7   382   2441  1787     135  851     731  4617   4699
2007-04-01    82      7   381   2415  1770     135  847     727  4573   4655
2007-03-01    82      6   375   2375  1747     135  840     725  4503   4585
2007-02-01    82      6   367   2342  1731     134  832     721  4446   4528
2007-01-01    82      6   359   2322  1718     134  823     720  4405   4487
2006-12-01    81      6   354   2296  1700     134  820     718  4356   4437
2006-11-01    81      5   344   2247  1677     133  808     712  4273   4354
2006-10-01    79      5   337   2217  1645     133  798     710  4204   4283
2006-09-01    79      5   330   2180  1618     132  789     706  4133   4212
2006-08-01    79      5   328   2163  1605     132  784     706  4101   4180
2006-07-01    79      5   327   2152  1588     132  782     705  4072   4151
2006-06-01    79      5   326   2141  1575     132  779     705  4047   4126
2006-05-01    79      5   325   2113  1548     132  769     701  3991   4070
2006-04-01    78      5   321   2086  1533     132  759     699  3945   4023
2006-03-01    78      5   319   2071  1514     132  758     698  3909   3987
2006-02-01    78      5   316   2036  1497     132  750     695  3854   3932
2006-01-01    78      5   312   1981  1470     131  741     690  3768   3846
2005-12-01    78      5   302   1949  1449     130  730     687  3705   3783
2005-11-01    77      5   297   1907  1423     129  720     682  3632   3709
2005-10-01    76      4   289   1851  1383     128  708     671  3527   3603
2005-09-01    76      4   286   1817  1364     128  703     668  3471   3547
2005-08-01    76      4   283   1803  1348     128  697     667  3438   3514
2005-07-01    76      4   279   1783  1337     127  690     664  3403   3479
2005-06-01    76      4   275   1768  1317     127  686     659  3364   3440
2005-05-01    75      4   274   1751  1303     125  680     656  3332   3407
2005-04-01    75      4   268   1726  1285     123  667     652  3283   3358
2005-03-01    75      4   263   1686  1259     122  656     648  3212   3287
2005-02-01    75      4   262   1663  1251     121  652     645  3180   3255
2005-01-01    75      4   258   1639  1241     121  645     641  3142   3217
2004-12-01    74      3   249   1607  1220     121  637     633  3079   3153
2004-11-01    74      3   245   1587  1214     120  628     628  3049   3123
2004-10-01    73      3   238   1559  1206     119  617     626  3006   3079
2004-09-01    72      3   230   1521  1181     119  609     625  2935   3007
2004-08-01    72      3   226   1501  1159     118  602     621  2889   2961
2004-07-01    72      3   226   1494  1155     116  599     618  2878   2950
2004-06-01    72      3   223   1464  1142     115  588     615  2832   2904
2004-05-01    72      2   218   1445  1127     115  582     611  2792   2864
2004-04-01    72      2   215   1415  1115     111  572     604  2747   2819
2004-03-01    72      2   206   1379  1097     111  565     595  2684   2756
2004-02-01    71      2   204   1364  1090     110  560     594  2660   2731
2004-01-01    71      2   202   1330  1072     108  550     591  2606   2677
2003-12-01    71      2   196   1298  1060     105  537     583  2556   2627
2003-11-01    71      2   193   1277  1047     105  530     577  2519   2590
2003-10-01    70      2   188   1250  1024     105  522     575  2464   2534
2003-09-01    70      2   185   1229   991     103  513     568  2407   2477
2003-08-01    70      2   185   1217   978     100  508     564  2382   2452
2003-07-01    69      2   184   1210   970     100  505     561  2366   2435
2003-06-01    69      2   182   1194   958     100  500     555  2336   2405
2003-05-01    67      2   180   1180   952      99  498     553  2314   2381
2003-04-01    67      2   175   1160   941      99  491     547  2278   2345
2003-03-01    67      2   170   1141   930      99  484     543  2243   2310
2003-02-01    67      1   169   1121   924      99  479     539  2215   2282
2003-01-01    67      1   167   1094   907      98  469     534  2169   2236
2002-12-01    67      1   163   1067   887      98  467     532  2118   2185
2002-11-01    67      1   160   1052   870      97  461     528  2083   2150
2002-10-01    66      1   158   1028   847      96  455     520  2034   2100
2002-09-01    64      1   155   1007   828      95  449     511  1991   2055
2002-08-01    64      1   154    991   805      93  438     508  1951   2015
2002-07-01    63      1   152    981   798      92  431     503  1932   1995
2002-06-01    63      1   148    962   790      90  422     497  1901   1964
2002-05-01    63      1   144    944   779      89  413     486  1868   1931
2002-04-01    63      1   142    926   766      89  406     484  1835   1898
2002-03-01    62      1   136    899   752      88  396     481  1788   1850
2002-02-01    62      1   131    876   736      87  387     471  1744   1806
2002-01-01    62      1   124    842   713      87  374     464  1680   1742
2001-12-01    62      1   121    806   694      83  360     455  1622   1684
2001-11-01    60      1   120    778   679      82  353     451  1578   1638
2001-10-01    60      1   114    752   656      81  344     447  1523   1583
2001-09-01    60      1   110    723   622      80  333     436  1456   1516
2001-08-01    59      1   109    701   602      80  327     433  1413   1472
2001-07-01    58      1   108    696   589      80  326     432  1394   1452
2001-06-01    57      1   108    686   579      78  323     425  1374   1431
2001-05-01    56      1   107    674   568      76  316     417  1350   1406
2001-04-01    56      1   105    662   559      75  307     413  1327   1383
2001-03-01    56      1   101    647   545      73  298     406  1294   1350
2001-02-01    56      1    98    636   534      72  295     401  1269   1325
2001-01-01    56      1    94    621   525      72  292     397  1241   1297
2000-12-01    56      1    93    607   513      71  286     390  1214   1270
2000-11-01    56      1    90    583   496      70  283     381  1170   1226
2000-10-01    56      1    87    573   482      70  279     374  1143   1199
2000-09-01    56      1    81    555   456      69  272     366  1093   1149
2000-08-01    56      1    79    537   440      67  263     357  1057   1113
2000-07-01    56      1    77    532   430      65  260     346  1040   1096
2000-06-01    56      1    76    527   424      64  256     343  1028   1084
2000-05-01    56      1    76    514   410      64  251     335  1001   1057
2000-04-01    55      1    73    499   397      63  245     328   970   1025
2000-03-01    55      1    64    483   386      61  233     316   934    989
2000-02-01    55      1    62    466   375      61  223     309   904    959
2000-01-01    55      1    57    452   368      61  217     304   878    933
1999-12-01    54      1    56    442   359      59  209     297   858    912
1999-11-01    54      1    54    429   345      59  205     287   829    883
1999-10-01    54      1    54    413   331      58  200     283   799    853
1999-09-01    52      1    54    397   315      56  192     279   767    819
1999-08-01    52      1    54    397   313      56  192     279   765    817
1999-07-01    52      1    54    392   308      55  190     275   755    807
1999-06-01    52      1    51    385   298      55  186     272   735    787
1999-05-01    51      1    49    373   292      51  178     262   715    766
1999-04-01    51      1    48    360   285      50  174     255   694    745
1999-03-01    51      1    47    350   280      50  172     254   678    729
1999-02-01    51      1    47    340   275      50  169     251   663    714
1999-01-01    51      1    45    335   269      50  166     249   650    701
1998-12-01    51      1    41    325   260      50  162     240   627    678
1998-11-01    51      1    38    311   251      48  154     235   601    652
1998-10-01    51      1    36    306   245      48  152     231   588    639
1998-09-01    51      1    29    293   232      47  140     225   555    606
1998-08-01    51      1    29    283   221      45  133     219   534    585
1998-07-01    51      1    29    279   219      43  129     216   528    579
1998-06-01    51      1    29    273   212      42  127     213   515    566
1998-05-01    51      1    29    264   206      42  124     209   500    551
1998-04-01    51      1    27    256   197      42  117     208   481    532
1998-03-01    51      1    27    244   189      42  112     204   461    512
1998-02-01    51      0    26    240   189      41  110     203   455    506
1998-01-01    51      0    26    235   186      41  108     200   447    498
1997-01-01    51      0    22    206   166      39   97     187   394    445
1996-01-01    51      0    20    178   151      37   86     181   349    400
1995-01-01    51      0    19    163   134      36   83     171   316    367
1994-01-01    49      0    15    140   114      32   70     153   269    318
1993-01-01    49      0    13    117    98      30   64     139   228    277
1992-01-01    49      0    11    103    84      28   61     122   198    247
1991-01-01    47      0     9     76    73      23   49     104   158    205
1990-01-01    47      0     8     63    62      20   42      89   133    180
1980-01-01    43      0     3     27    22      12   17      44    52     95
1970-01-01    41      0     0     13    14       8   10      24    27     68
1960-01-01    40      0     0     10    10       7    8      18    20     60
1950-01-01    40      0     0      7     6       4    5      12    13     53
1940-01-01    35      0     0      3     6       2    3       8     9     44
1930-01-01    33      0     0      0     5       0    0       5     5     38
1920-01-01    31      0     0      0     3       0    0       3     3     34
1910-01-01    29      0     0      0     1       0    0       1     1     30
1900-01-01    27      0     0      0     1       0    0       1     1     28

Note: "NEC" are Near-Earth comets. "PHA-KM" and "NEA-KM" are PHAs and NEAs with diameters roughly one kilometer and larger. Other definitions, such as Apollo, are on the NEO groups page.

Data compiled by Alan Chamberlin.

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