BINARY AND TERNARY NEAR-EARTH ASTEROIDS DETECTED BY RADAR


http://echo.jpl.nasa.gov/~lance/binary.neas.html
Last update: 2015 August 11           Added 2005 JF21

Known binary and ternary NEAs:
  Asteroid          H    Radar detection?
  1862 Apollo      16.2     Yes
  1866 Sisyphus    13.0     Yes              Brightest absolute magnitude among known binaries
  3671 Dionysus    16.3     No               Lightcurve discovery in May 1997
  5143 Heracles    14.0     Yes              Second brightest absolute magnitude
  5381 Sekhmet     16.5     Yes 
  5646 1990 TR     14.3     No               Lightcurve discovery in November 2012
  7088 Ishtar      16.7     No               Lightcurve discovery in December 2005
  7888 1993 UC     15.3     Yes
 31345 1998 PG     17.3     No               Lightcurve discovery in August 1998
 35107 1991 VH     16.9     Yes              Lightcurve discovery in February 1997
 65803 Didymos     18.0     Yes              Lightcurve discovery in November 2003
 66063 1998 RO1    17.9     Yes              Lightcurve discovery in September 2002
 66391 1999 KW4    16.5     Yes
 69230 Hermes      17.5     Yes              Components have comparable sizes
 85938 1999 DJ4    18.5     Yes              Lightcurve discovery in February 2004
 88710 2001 SL9    17.4     No               Lightcurve discovery in October 2001
136617 1994 CC     17.6     Yes              Triple
136993 1998 ST49   17.7     Yes
137170 1999 HF1    14.4     No               Lightcurve discovery in April 1999
138095 2000 DK79   15.8     Yes
153591 2001 SN263  16.9     Yes              Triple
153958 2002 AM31   18.2     Yes
162000 1990 OS     19.3     Yes
164121 2003 YT1    16.1     Yes
175706 1996 FG3    18.0     Yes              Lightcurve discovery in December 1998
185851 2000 DP107  18.1     Yes
276049 2002 CE26   16.8     Yes
285263 1998 QE2    17.1     Yes
311066 2004 DC     18.0     Yes
348400 2005 JF21   17.1     Yes
357439 2004 BL86   19.3     Yes              Lightcurve discovery in January 2015
363027 1998 ST27   19.5     Yes
363067 2000 CO101  19.1     Yes
363599 2004 FG11   21.0     Yes              Third faintest absolute magnitude 
374851 2006 VV2    16.8     Yes
385186 1994 AW1    17.3     Yes               Lightcurve discovery in January 1994
399307 1991 RJ2    18.9     No               Lightcurve discovery in November 2012
       1994 CJ1    21.3     Yes              Second faintest absolute magnitude; components have comparable sizes
       1994 XD     19.1     Yes
       2000 UG11   20.3     Yes
       2002 BM26   20.1     Yes
       2002 KK8    20.4     Yes
       2003 SS84   21.8     Yes              Faintest absolute magnitude among known binaries
       2005 AB     17.5     Yes               Lightcurve discovery in February 2005
       2005 NB7    18.8     Yes
       2006 GY2    18.7     Yes
       2007 DT103  19.2     Yes
       2007 LE     19.2     Yes
       2008 BT18   18.2     Yes
       2008 DG17   19.7     Yes
       2013 WT44   19.6     Yes
       2014 WZ120  20.4     Yes
       2014 YB35   18.9     Yes

N = 53

Radar discoveries:      38
Lightcurve discoveries: 15

Radar detections: 47/53 = 0.887

Absolute magnitudes were taken from Horizons and may differ from the delta-V lists on this website,
which were taken from the Minor Planet Center lists.

Not included: 162483 2000 PJ5, 2004 RZ164, and 2009 KD5: possible binaries, but unconfirmed.  
None has been observed with radar.


RADAR DETECTIONS IN CHRONOLOGICAL ORDER Radar Detection Discovery Order Asteroid a (AU) e i (deg) H (mag) Q (AU) q (AU) Date Observatory Technique ===== ======== ====== = ======= ======= ====== ====== ==== =========== ========= 1 1866 Sisyphus 1.894 0.539 41.2 13.0 2.914 0.873 Dec 1985 Arecibo Radar 2 185851 2000 DP107 TOO PHA 1.365 0.377 8.7 18.2 1.880 0.850 Sep 2000 Goldstone & Arecibo Radar Aug 2008 Arecibo & Goldstone 3 2000 UG11 TOO PHA 1.934 0.573 8.9 20.4 3.042 0.826 Nov 2000 Arecibo & Goldstone Radar 4 66391 1999 KW4 PHA 0.642 0.688 38.9 16.3 1.084 0.200 May 2001 Goldstone & Arecibo Radar Jun 2002 Arecibo 5 363027 1998 ST27 PHA 0.819 0.530 21.0 19.4 1.253 0.385 Oct 2001 Arecibo Radar Oct 2004 Arecibo 6 2002 BM26 TOO PHA 1.832 0.444 16.2 19.8 2.645 1.019 Feb 2002 Arecibo Radar 7 2002 KK8 TOO PHA 1.967 0.469 24.6 20.5 2.889 1.045 Jun 2002 Arecibo Radar 8 5381 Sekhmet 0.948 0.296 49.0 16.5 1.228 0.667 May 2003 Arecibo Radar 9 66063 1998 RO1 0.991 0.720 22.7 17.9 1.705 0.277 Sep 2003 Arecibo Photometry Sep 2004 Arecibo 10 2003 SS84 TOO PHA 1.932 0.572 5.5 21.7 3.037 0.827 Sep 2003 Arecibo & Goldstone Radar 11 69230 Hermes TOO PHA 1.654 0.624 6.1 17.5 2.686 0.622 Oct 2003 Arecibo & Goldstone Radar 12 162000 1990 OS PHA 1.680 0.463 1.1 20.0 2.458 0.902 Nov 2003 Arecibo Radar (Aug 1990 Goldstone Satellite not detected) 13 65803 Didymos PHA 1.642 0.383 3.4 17.9 2.275 1.013 Nov 2003 Arecibo, Goldstone Photometry, Radar 14 85938 1999 DJ4 PHA 1.851 0.483 9.2 18.4 2.745 0.957 Apr 2004 Arecibo Photometry 15 164121 2003 YT1 TOO PHA 1.110 0.292 44.1 16.2 1.434 0.785 May 2004 Arecibo Radar 16 276049 2002 CE26 2.233 0.559 47.4 16.5 3.481 0.984 Aug 2004 Arecibo Radar Possible triple 17 2005 AB TOO 3.217 0.656 8.2 17.3 5.325 1.107 Feb 2005 Arecibo Photometry 18 1994 XD TOO PHA 2.356 0.730 4.3 19.1 4.076 0.637 Jun 2005 Arecibo Radar 19 1862 Apollo PHA 1.471 0.560 6.4 16.3 2.295 0.647 Oct 2005 Arecibo Radar (Nov 1980 Arecibo Satellite not detected) 20 2006 GY2 TOO PHA 1.853 0.494 30.6 18.7 2.768 0.938 May 2006 Arecibo & Goldstone Radar 21 311066 2004 DC PHA 1.634 0.400 19.4 18.0 2.288 0.981 Jun 2006 Arecibo & Goldstone Radar 22 363599 2006 VV2 TOO PHA 2.388 0.602 23.6 16.6 3.826 0.949 Mar 2007 Goldstone & Arecibo Radar 23 2007 DT103 TOO PHA 2.210 0.574 5.4 19.4 3.480 0.941 Jul 2007 Goldstone Radar 24 153591 2001 SN263 1.987 0.478 6.7 16.9 2.938 1.037 Feb 2008 Arecibo Radar TRIPLE 25 2005 NB7 PHA 2.042 0.516 12.7 18.7 3.096 0.988 Apr 2008 Arecibo & Goldstone Radar 26 2008 BT18 TOO PHA 2.222 0.598 8.1 18.2 3.551 0.894 Jul 2008 Arecibo & Goldstone Radar 27 35107 1991 VH PHA 1.136 0.144 13.9 16.7 1.300 0.973 Jul 2008 Arecibo & Goldstone Photometry 28 136617 1994 CC PHA 1.638 0.417 4.7 17.7 2.321 0.955 Jun 2009 Goldstone & Arecibo Radar TRIPLE 29 363067 2000 CO101 PHA 1.075 0.090 15.3 19.0 1.172 0.979 Sep 2009 Arecibo Radar 30 175706 1996 FG3 PHA 1.054 0.350 2.0 18.0 1.423 0.685 Nov 2011 Arecibo Photometry 31 5143 Heracles 1.833 0.773 9.1 14.0 3.249 0.417 Dec 2011 Arecibo Radar 32 363599 2004 FG11 PHA 1.589 0.724 3.1 20.9 2.739 0.438 Apr 2012 Arecibo Radar 33 2007 LE PHA 1.839 0.517 29.5 19.2 2.790 0.889 May 2012 Goldstone Radar 34 153958 2002 AM31 PHA 1.704 0.452 4.6 18.2 2.475 0.935 Jul 2012 Arecibo Radar 35 136993 1998 ST49 2.311 0.593 24.5 17.7 3.681 0.939 Oct 2012 Arecibo Radar 36 2008 DG17 1.837 0.449 41.1 19.7 2.664 1.012 Feb 2013 Arecibo Radar 37 7888 1993 UC 2.434 0.664 26.1 15.3 4.053 0.817 Mar 2013 Arecibo Radar 38 285263 1998 QE2 PHA 2.421 0.571 12.9 17.1 3.805 1.039 May 2013 Goldstone Radar 39 138095 2000 DK79 PHA 1.777 0.414 60.7 15.8 2.513 1.040 Nov 2013 Arecibo Radar 40 2013 WT44 TOO PHA 2.259 0.568 12.2 19.6 3.542 0.975 Mar 2014 Goldstone Radar 41 1994 CJ1 PHA 1.489 0.325 2.3 21.3 1.973 1.005 Jun 2014 Arecibo Radar 42 2014 WZ120 TOO PHA 2.210 0.638 20.9 20.4 3.620 0.800 Nov 2014 Arecibo Radar 43 2005 YQ96 PHA 0.743 0.334 22.2 20.4 0.992 0.495 Dec 2014 Arecibo, Goldstone Radar 44 357439 2004 BL86 PHA 1.502 0.403 23.7 19.3 2.107 0.896 Jan 2015 Goldstone, Arecibo Photometry 45 2014 YB35 TOO PHA 1.875 0.483 12.7 18.9 2.780 0.969 Mar 2015 Goldstone Radar 46 385186 1994 AW1 PHA 1.105 0.075 24.1 17.5 1.188 1.021 Jul 2015 Goldstone, Arecibo Photometry 47 348400 2005 JF21 PHA 2.224 0.535 10.9 17.1 3.415 1.034 Aug 2015 Goldstone Radar "date" refers to the first radar apparition that showed evidence of a binary. 1990 OS was observed in 1990 but did not show evidence for a secondary until it was observed again in 2003. Similarly, Apollo was observed by radar in 1980 but its satellite was not detected until 2005. Consequently, radar observations that did not yield detections of secondaries are excluded from this list (e.g., 1990 OS at Goldstone in 2003, Apollo at Goldstone in 2005, and 2000 CO101 at Goldstone in 2009). With 2006 GY2, there was a suggestion of a satellite in Goldstone CW data on May 13, but it wasn't obviously a binary until radar imaging at Arecibo on May 15. May 16 Goldstone data also showed two objects. With Didymos, we did not realize that the Goldstone data showed both components until Sep. 2009. 2005 JF21 was detected by radar at Arecibo first but evidence for a satellite wasn't seen until the Goldstone observations about 2.5 weeks later. 1866 Sisyphus is now listed as a binary based on CW data obtained at Arecibo in December, 1985. The CW signature matches those subsequently seen many times with other binary NEAs. Attempts to detect the secondary with ranging observations in 1985 were unsuccessful. TOO indicates targets-of-opportunity. PHA = "Potentially Hazardous Asteroid" as defined by the Minor Planet Center Binaries and triples discovered by radar that have been targets-of-opportunity: 15/38 = 39.5% Percentage of radar binaries and triples classified as "Potentially Hazardous:" 36/47 = 76.6%
RADAR DETECTIONS ORDERED BY ASTEROID NUMBER AND PROVISIONAL DESIGNATION Asteroid a (AU) e i (deg) H (mag) Q (AU) q (AU) Order Date Observatory ======== ====== = ======= ======= ====== ====== ===== ==== =========== 1862 Apollo 1.471 0.560 6.4 16.3 2.295 0.647 PHA 19 Oct 2005 Arecibo 1866 Sisyphus 1.894 0.539 41.2 13.0 2.914 0.873 1 Dec 1985 Arecibo 5143 Heracles 1.833 0.773 9.1 14.0 3.249 0.417 31 Dec 2011 Arecibo 5381 Sekhmet 0.948 0.296 49.0 16.5 1.228 0.667 8 May 2003 Arecibo 7888 1993 UC 2.434 0.664 26.1 15.3 4.053 0.817 37 Mar 2013 Arecibo & Goldstone 35107 1991 VH 1.136 0.144 13.9 16.7 1.300 0.973 PHA 27 Jul 2008 Arecibo 65803 Didymos 1.642 0.383 3.4 17.9 2.275 1.013 PHA 13 Nov 2003 Arecibo & Goldstone 66063 1998 RO1 0.991 0.720 22.7 17.9 1.705 0.277 9 Sep 2003 Arecibo 66391 1999 KW4 0.642 0.688 38.9 16.3 1.084 0.200 PHA 4 May 2001 Goldstone & Arecibo 69230 Hermes 1.654 0.624 6.1 17.5 2.686 0.622 PHA 11 Oct 2003 Arecibo & Goldstone 85938 1999 DJ4 1.851 0.483 9.2 18.4 2.745 0.957 PHA 13 Apr 2004 Arecibo 136617 1994 CC 1.638 0.417 4.7 17.7 2.321 0.955 PHA 28 Jun 2009 Goldstone & Arecibo 136993 1998 ST49 2.311 0.593 24.5 17.7 3.681 0.939 35 Oct 2012 Arecibo 138095 2000 DK79 1.777 0.414 60.7 15.8 2.513 1.040 PHA 39 Nov 2013 Arecibo 153591 2001 SN263 1.987 0.478 6.7 16.9 2.938 1.037 24 Feb 2008 Arecibo 153958 2002 AM31 1.705 0.452 4.6 18.2 2.475 0.935 PHA 34 Jul 2012 Arecibo & Goldstone 162000 1990 OS 1.680 0.463 1.1 20.0 2.458 0.902 PHA 12 Nov 2003 Arecibo 164121 2003 YT1 1.110 0.292 44.1 16.2 1.434 0.785 PHA 15 May 2004 Arecibo 175706 1996 FG3 1.054 0.350 2.0 18.0 1.423 0.685 PHA 30 Nov 2011 Arecibo & Goldstone 185851 2000 DP107 1.365 0.377 8.7 18.2 1.880 0.850 PHA 2 Sep 2000 Goldstone & Arecibo 276049 2002 CE26 2.233 0.559 47.4 16.5 3.481 0.984 16 Aug 2004 Arecibo 285263 1998 QE2 2.421 0.571 12.9 17.1 3.805 1.039 PHA 38 May 2013 Goldstone & Arecibo 311066 2004 DC 1.634 0.400 19.4 18.0 2.288 0.981 PHA 21 Jun 2006 Arecibo & Goldstone 357439 2004 BL86 1.502 0.403 23.7 19.0 2.107 0.896 PHA 44 Jan 2015 Goldstone & Arecibo 363027 1998 ST27 0.819 0.530 21.0 19.4 1.253 0.385 PHA 5 Oct 2001 Arecibo 363067 2000 CO101 1.075 0.090 15.3 19.0 1.172 0.979 PHA 29 Sep 2009 Arecibo 363599 2004 FG11 1.589 0.724 3.1 20.9 2.739 0.438 PHA 32 Apr 2012 Arecibo 374851 2006 VV2 2.388 0.602 23.6 16.6 3.826 0.949 PHA 22 Mar 2007 Goldstone & Arecibo 385186 1994 AW1 1.105 0.075 24.1 17.5 1.188 1.105 PHA 46 Jul 2015 Goldstone, Arecibo 438400 2005 JF21 2.224 0.535 10.9 17.1 3.415 1.034 PHA 47 Aug 2015 Goldstone 1994 CJ1 1.489 0.325 2.3 21.3 1.973 1.005 PHA 41 Jun 2014 Arecibo 1994 XD 2.356 0.730 4.3 19.1 4.076 0.637 PHA 18 Jun 2005 Arecibo 2000 UG11 1.934 0.573 8.9 20.4 3.042 0.826 PHA 3 Nov 2000 Arecibo & Goldstone 2002 BM26 1.832 0.444 16.2 19.8 2.645 1.019 PHA 6 Feb 2002 Arecibo 2002 KK8 1.967 0.469 24.6 20.5 2.889 1.045 PHA 7 Jun 2002 Arecibo 2003 SS84 1.932 0.572 5.5 21.7 3.037 0.827 PHA 10 Sep 2003 Arecibo & Goldstone 2005 AB 3.217 0.656 8.2 17.3 5.325 1.107 17 Feb 2005 Arecibo 2005 NB7 2.042 0.516 12.7 18.7 3.096 0.988 PHA 25 Apr 2008 Arecibo & Goldstone 2005 YQ96 0.744 0.333 22.2 20.4 0.992 0.496 PHA 43 Dec 2014 Arecibo & Goldstone 2006 GY2 1.853 0.494 30.6 18.7 2.768 0.938 PHA 20 May 2006 Arecibo & Goldstone 2007 DT103 2.210 0.574 5.4 19.5 3.480 0.941 PHA 23 Jul 2007 Goldstone 2007 LE 1.839 0.517 29.5 19.2 2.790 0.889 PHA 33 May 2012 Goldstone & Arecibo 2008 BT18 2.222 0.598 8.1 18.2 3.551 0.894 PHA 26 Jul 2008 Arecibo 2008 DG17 1.837 0.449 41.1 19.7 2.664 1.101 36 Feb 2013 Arecibo 2013 WT44 2.259 0.568 12.2 19.6 3.542 0.975 PHA 40 Mar 2014 Goldstone 2014 WZ120 2.354 0.571 20.9 20.4 3.620 0.800 PHA 42 Nov 2014 Arecibo 2014 YB35 1.875 0.483 12.7 18.9 2.780 0.969 PHA 45 Mar 2015 Goldstone
CONFIRMED BINARY NEAS _NOT_ OBSERVED BY RADAR 3671 Dionysus 5646 1990 TR 7088 Ishtar 31345 1998 PG 88710 2001 SL9 137170 1999 HF1 399307 1991 RJ2
RADAR-DETECTED BINARY AND TERNARY NEAS RANKED BY ABSOLUTE MAGNITUDE Spectral Dprimary Asteroid H Class (km) 1866 Sisyphus 1972 XA 13.0 S ~8 RADAR DISCOVERY 5143 Heracles 1991 VL 14.0 0 RADAR DISCOVERY 137170 1999 HF1 14.4 X 7888 1993 UC 15.3 U RADAR DISCOVERY 138095 2000 DK79 15.8 RADAR DISCOVERY 164121 2003 YT1 16.1 V 1.0 RADAR DISCOVERY 1862 Apollo 1932 HA 16.2 Q 1.5 RADAR DISCOVERY 3671 Dionysus 1984 KD 16.3 C 5381 Sekhmet 1991 JY 16.5 V 1.0 RADAR DISCOVERY 66391 1999 KW4 16.5 S 1.5 RADAR DISCOVERY 7088 Ishtar 1992 AA 16.7 276049 2002 CE26 16.8 C 3.5 RADAR DISCOVERY 374851 2006 VV2 16.8 S 1.8 RADAR DISCOVERY 35107 1991 VH 16.9 S RADAR 153591 2001 SN263 16.9 B RADAR DISCOVERY 285263 1998 QE2 17.1 C 3 RADAR DISCOVERY 348400 2005 JF21 17.1 RADAR DISCOVERY 385186 1994 AW1 17.3 S 31345 1998 PG 17.3 Q 88710 2001 SL9 17.4 Q 69230 Hermes 1937 UB 17.5 S 0.6 RADAR DISCOVERY 2005 AB 17.5 C RADAR 385186 1994 AW1 17.5 S RADAR 136617 1994 CC 17.6 Q 0.7 RADAR DISCOVERY 136993 1998 ST49 17.7 RADAR DISCOVERY 66063 1998 RO1 17.9 S 0.6 RADAR 65803 Didymos 1996 GT 18.0 S 0.8 RADAR 311066 2004 DC 18.0 0.3 RADAR DISCOVERY 185851 2000 DP107 18.1 X 0.8 RADAR DISCOVERY 153958 2002 AM31 18.2 SqV RADAR DISCOVERY 175706 1996 FG3 18.2 C 1.8 RADAR 2008 BT18 18.2 S RADAR 85938 1999 DJ4 18.5 Q 0.42 RADAR 2006 GY2 18.7 0.45 RADAR DISCOVERY 2005 NB7 18.8 S 0.5 RADAR DISCOVERY 399307 1991 RJ2 18.9 2014 YB35 19.9 RADAR DISCOVERY 363067 2000 CO101 19.1 Xk 0.7 RADAR DISCOVERY 1994 XD 19.1 0.6 RADAR DISCOVERY 2007 DT103 19.2 S ~0.3 RADAR DISCOVERY 2007 LE 19.2 C ~0.45 RADAR DISCOVERY 162000 1990 OS 19.3 0.3 RADAR DISCOVERY 357439 2004 BL86 19.3 RADAR 363027 1998 ST27 19.5 C 0.8 RADAR DISCOVERY 2013 WT44 19.6 dark ~0.9 RADAR DISCOVERY 2008 DG17 19.7 RADAR DISCOVERY 2002 BM26 20.1 P 0.6 RADAR DISCOVERY 2000 UG11 20.3 S 0.23 RADAR DISCOVERY 2002 KK8 20.4 0.5 RADAR DISCOVERY 2005 YQ96 20.4 RADAR DISCOVERY 2014 WZ120 20.4 RADAR DISCOVERY 363599 2004 FG11 21.0 RADAR DISCOVERY 1994 CJ1 21.3 RADAR DISCOVERY 2003 SS84 21.8 0.12 RADAR DISCOVERY Here C includes C and B types and S includes S and Q types Note: absolute magnitudes are taken from Horizons. Values may differ by up to a few tenths of a magnitude from those listed on the Minor Planet Center's websites. Dprimary = diameter of the primary, as estimated from radar observations and/or shape modeling.
Spectral classes (all binaries and triples, not just radar detections): C XXXXX XXX E M P X S XXXXX XXXXX XXXXX XXX V XXX X XXX ? XXXXX XXXXX XX Abundance of Radar Binaries and Ternaries by Absolute Magnitude: ...This needs to be updated... (2013 Nov 18, not updated since Nov. 2012) Fraction of Radar Radar radar Fraction of H range NEAs binaries detections known binaries ------- ----- -------- ---------- -------------- H < 13.0 2 0 0.00 None known 13.0 <= H < 14.0 3 1 0.33 1/1 = 1.00 14.0 <= H < 15.0 8 0 0.00 0/1 = 0.00 15.0 <= H < 16.0 15 0 0.00 None known 16.0 <= H < 17.0 29 9 0.31 9/11 = 0.82 17.0 <= H < 18.0 41 3 0.073 3/6 = 0.50 18.0 <= H < 19.0 36 8 0.22 8/9 = 0.89 19.0 <= H < 20.0 37 5 0.14 5/5 = 1.00 20.0 <= H < 21.0 34 3 0.088 3/3 = 1.00 21.0 <= H < 22.0 20 1 0.050 1/1 = 1.00 22.0 <= H 47 0 0.00 None known
DELTA-V RANKINGS ================ Delta-v rankings for all NEA binaries and ternaries observed with radar and photometry. Not included; 2004 RZ164, a possible binary reported by Kwiatkowski et al., Astron. Astrophys. 462, 341-344 (2007) 2000 PJ5, a possible binary reported by Polishook and Brosch, Icarus 194, 111-124 (2008) 2009 KD5, a possible binary reported by Foster et al. Bull. Am. Astron. Soc. 42, 1055 (2010) [abstract] Number of NEAs in the MPC database = 12832 (2015 August 11) RADAR BINARY = Binary or ternary observed by radar, but not necessarily discovered by radar BINARY = Binary observed photometrically but not (yet) by radar SPACECRAFT RENDEZVOUS --------------------- DELTA-V (ASTEROID)/ PROVISIONAL DELTA-V DELTA-V FOR RANK PERCENTILE ASTEROID NAME DESIGNATION (KM/S) THE MOON MARS H (mag) a (AU) e i (deg) ==== ========== ============= =========== ======= ======== ==== ======= ====== === ====== 309 97.59 1994 CJ1 4.704 0.784 0.747 21.4 1.490 0.325 2.3 RADAR BINARY 732 94.30 (65803) Didymos 1996 GT 5.098 0.850 0.809 18.0 1.644 0.384 3.4 RADAR BINARY 1151 91.03 (136617) 1994 CC 5.379 0.896 0.854 17.7 1.638 0.417 4.7 RADAR BINARY 1624 87.34 (153958) 2002 AM31 5.627 0.938 0.893 18.3 1.703 0.452 4.6 RADAR BINARY 1743 86.42 (162000) 1990 OS 5.685 0.947 0.902 19.4 1.678 0.463 1.1 RADAR BINARY 2370 81.53 (153591) 2001 SN263 5.963 0.994 0.947 16.9 1.987 0.478 6.7 RADAR BINARY 2391 81.37 (185851) 2000 DP107 5.969 0.995 0.947 18.2 1.365 0.377 8.7 RADAR BINARY 2581 79.89 (85938) 1999 DJ4 6.032 1.005 0.958 18.6 1.853 0.483 9.1 RADAR BINARY 3639 71.64 (35107) 1991 VH 6.364 1.061 1.010 16.7 1.137 0.144 13.9 RADAR BINARY 3648 71.57 2014 YB35 6.367 1.061 1.011 19.0 1.877 0.483 12.6 RADAR BINARY 3666 71.43 2007 DT103 6.372 1.062 1.011 19.2 2.206 0.575 5.5 RADAR BINARY 4195 67.31 (399774) 2005 NB7 6.507 1.085 1.033 18.7 2.044 0.517 12.7 RADAR BINARY 4539 64.63 (348400) 2005 JF21 6.590 1.098 1.046 17.2 2.223 0.536 10.9 RADAR BINARY 4591 64.22 (175706) 1996 FG3 6.609 1.102 1.049 18.4 1.054 0.350 2.0 RADAR BINARY 4693 63.43 2003 SS84 6.634 1.106 1.053 21.8 1.931 0.571 5.5 RADAR BINARY 4814 62.48 (31345) 1998 PG 6.663 1.110 1.058 17.3 2.015 0.391 6.5 BINARY 4894 61.86 (7088) Ishtar 1992 AA 6.684 1.114 1.061 16.7 1.981 0.391 8.3 BINARY 4980 61.19 2008 BT18 6.706 1.118 1.064 18.3 2.222 0.593 8.1 RADAR BINARY 5153 59.84 2002 BM26 6.747 1.124 1.071 20.1 1.833 0.444 16.2 RADAR BINARY 5155 59.83 (3671) Dionysus 1984 KD 6.747 1.125 1.071 16.4 2.198 0.542 13.5 BINARY 5196 59.51 2013 WT44 6.757 1.126 1.073 19.3 2.260 0.568 12.2 RADAR BINARY 5511 57.05 (5646) 1990 TR 6.837 1.139 1.085 15.2 2.142 0.437 7.9 BINARY 5646 56.00 2000 UG11 6.876 1.146 1.091 20.4 1.929 0.573 8.9 RADAR BINARY 6158 52.01 (285263) 1998 QE2 7.023 1.170 1.115 17.3 2.423 0.572 12.9 RADAR BINARY 6571 48.79 (311066) 2004 DC 7.148 1.191 1.135 18.1 1.634 0.400 19.4 RADAR BINARY 6599 48.57 (399307) 1991 RJ2 7.159 1.193 1.136 18.9 2.208 0.429 8.9 BINARY 6770 47.24 (363067) 2000 CO101 7.218 1.203 1.146 19.1 1.076 0.090 15.3 RADAR BINARY 7333 42.85 2005 AB 7.457 1.243 1.184 17.5 3.216 0.656 8.2 RADAR BINARY 7371 42.56 (1862) Apollo 1932 HA 7.471 1.245 1.186 16.2 1.470 0.560 6.4 RADAR BINARY 8021 37.49 (69230) Hermes 1937 UB 7.777 1.296 1.234 17.5 1.655 0.624 6.1 RADAR BINARY 8491 33.83 1994 XD 8.073 1.345 1.281 19.1 2.346 0.734 4.3 RADAR BINARY 9031 29.62 (357439) 2004 BL86 8.458 1.410 1.343 19.3 1.502 0.403 23.8 RADAR BINARY 9062 29.38 2002 KK8 8.480 1.413 1.346 21.0 1.954 0.466 24.5 RADAR BINARY 9276 27.71 (374851) 2006 VV2 8.640 1.440 1.371 16.8 2.387 0.605 23.7 RADAR BINARY 9329 27.30 2014 WZ120 8.678 1.446 1.378 20.5 2.213 0.639 20.9 RADAR BINARY 9399 26.75 (136993) 1998 ST49 8.745 1.458 1.388 17.7 2.311 0.593 24.5 RADAR BINARY 9914 22.74 (363599) 2004 FG11 9.181 1.530 1.457 21.0 1.588 0.724 3.1 RADAR BINARY 10063 21.58 (88710) 2001 SL9 9.322 1.554 1.480 17.6 1.061 0.270 21.9 BINARY 10314 19.62 (7888) 1993 UC 9.584 1.597 1.521 15.1 2.436 0.664 26.1 RADAR BINARY 10327 19.52 (5143) Heracles 1991 VL 9.592 1.599 1.522 13.8 1.834 0.772 9.0 RADAR BINARY 10502 18.16 2007 LE 9.797 1.633 1.555 19.7 1.839 0.517 29.5 RADAR BINARY 10566 17.66 2006 GY2 9.879 1.647 1.568 18.8 1.858 0.496 30.6 RADAR BINARY 10834 15.57 (385186) 1994 AW1 10.237 1.706 1.625 17.6 1.105 0.076 24.1 RADAR BINARY 11938 6.97 2008 DG17 12.619 2.103 2.003 19.7 1.838 0.450 41.1 RADAR BINARY 12004 6.45 (1866) Sisyphus 1972 XA 12.829 2.138 2.036 12.4 1.894 0.538 41.2 RADAR BINARY 12019 6.34 (363027) 1998 ST27 12.905 2.151 2.048 19.5 0.819 0.530 21.1 RADAR BINARY 12055 6.06 (137170) 1999 HF1 13.032 2.172 2.069 14.5 0.819 0.462 25.7 BINARY 12290 4.22 (276049) 2002 CE26 14.079 2.347 2.235 16.8 2.235 0.559 47.3 RADAR BINARY 12599 1.82 (164121) 2003 YT1 16.470 2.745 2.614 16.2 1.110 0.292 44.1 RADAR BINARY 12728 0.81 (5381) Sekhmet 1991 JY 18.892 3.149 2.999 16.6 0.947 0.296 49.0 RADAR BINARY 12748 0.65 (138095) 2000 DK79 19.292 3.215 3.062 15.9 1.777 0.414 60.7 RADAR BINARY 12751 0.63 (66063) 1998 RO1 19.402 3.234 3.080 18.1 0.991 0.720 22.7 RADAR BINARY 12801 0.24 (66391) 1999 KW4 21.300 3.550 3.381 16.5 0.642 0.688 38.9 RADAR BINARY SPACECRAFT FLYBY ---------------- Provisional Delta-v H a e i Rank Percentile Asteroid number and name Designation (km/s) (mag) (AU) (deg) ==== ========== ======================== =========== ======= ===== ===== ===== ===== 424 96.70 (175706) 1996 FG3 4.020 18.4 1.054 0.350 2.0 RADAR BINARY 1438 88.79 (35107) 1991 VH 4.499 16.7 1.137 0.144 13.9 RADAR BINARY 1480 88.47 (363067) 2000 CO101 4.514 19.1 1.076 0.090 15.3 RADAR BINARY 1835 85.70 1994 CJ1 4.651 21.4 1.490 0.325 2.3 RADAR BINARY 2158 83.18 (185851) 2000 DP107 4.774 18.2 1.365 0.377 8.7 RADAR BINARY 2751 78.56 (65803) Didymos 1996 GT 4.998 18.0 1.644 0.384 3.4 RADAR BINARY 2996 76.65 (136617) 1994 CC 5.080 17.7 1.638 0.417 4.7 RADAR BINARY 3115 75.72 (1862) Apollo 1932 HA 5.113 16.2 1.470 0.560 6.4 RADAR BINARY 3202 75.05 (162000) 1990 OS 5.145 19.4 1.678 0.463 1.1 RADAR BINARY 3453 73.09 (153958) 2002 AM31 5.228 18.3 1.703 0.452 4.6 RADAR BINARY 4062 68.34 (88710) 2001 SL9 5.400 17.6 1.061 0.270 21.9 BINARY 4195 67.31 (363599) 2004 FG11 5.436 21.0 1.588 0.724 3.1 RADAR BINARY 4351 66.09 (69230) Hermes 1937 UB 5.481 17.5 1.655 0.624 6.1 RADAR BINARY 4544 64.59 (385186) 1994 AW1 5.527 17.6 1.105 0.076 24.1 RADAR BINARY 4838 62.30 (31345) 1998 PG 5.598 17.3 2.015 0.391 6.5 BINARY 5020 60.88 (7088) Ishtar 1992 AA 5.643 16.7 1.981 0.391 8.3 BINARY 5183 59.61 (85938) 1999 DJ4 5.681 18.6 1.853 0.483 9.1 RADAR BINARY 5347 58.33 (153591) 2001 SN263 5.719 16.9 1.987 0.478 6.7 RADAR BINARY 5477 57.32 2003 SS84 5.749 21.8 1.931 0.571 5.5 RADAR BINARY 6200 51.68 (5646) 1990 TR 5.887 15.2 2.142 0.437 7.9 BINARY 6323 50.72 2000 UG11 5.907 20.4 1.929 0.573 8.9 RADAR BINARY 6571 48.79 2014 YB35 5.952 19.0 1.877 0.483 12.6 RADAR BINARY 6826 46.80 (399307) 1991 RJ2 5.999 18.9 2.208 0.429 8.9 BINARY 7164 44.17 2007 DT103 6.069 19.2 2.206 0.575 5.5 RADAR BINARY 7199 43.90 (5143) Heracles 1991 VL 6.075 13.8 1.834 0.772 9.0 RADAR BINARY 7571 41.00 2002 BM26 6.154 20.1 1.833 0.444 16.2 RADAR BINARY 7575 40.97 (311066) 2004 DC 6.154 18.1 1.634 0.400 19.4 RADAR BINARY 7842 38.89 (399774) 2005 NB7 6.217 18.7 2.044 0.517 12.7 RADAR BINARY 7885 38.55 2008 BT18 6.225 18.3 2.222 0.593 8.1 RADAR BINARY 8274 35.52 (348400) 2005 JF21 6.309 17.2 2.223 0.536 10.9 RADAR BINARY 8613 32.88 1994 XD 6.389 19.1 2.346 0.734 4.3 RADAR BINARY 8986 29.97 2013 WT44 6.488 19.3 2.260 0.568 12.2 RADAR BINARY 8992 29.93 (3671) Dionysus 1984 KD 6.489 16.4 2.198 0.542 13.5 BINARY 9097 29.11 (357439) 2004 BL86 6.523 19.3 1.502 0.403 23.8 RADAR BINARY 9647 24.82 (285263) 1998 QE2 6.706 17.3 2.423 0.572 12.9 RADAR BINARY 10070 21.52 (137170) 1999 HF1 6.886 14.5 0.819 0.462 25.7 BINARY 10412 18.86 2005 AB 7.099 17.5 3.216 0.656 8.2 RADAR BINARY 10540 17.86 (363027) 1998 ST27 7.180 19.5 0.819 0.530 21.1 RADAR BINARY 10762 16.13 2002 KK8 7.334 21.0 1.954 0.466 24.5 RADAR BINARY 10848 15.46 2014 WZ120 7.405 20.5 2.213 0.639 20.9 RADAR BINARY 11325 11.74 (66391) 1999 KW4 7.877 16.5 0.642 0.688 38.9 RADAR BINARY 11332 11.69 (374851) 2006 VV2 7.883 16.8 2.387 0.605 23.7 RADAR BINARY 11345 11.59 (136993) 1998 ST49 7.905 17.7 2.311 0.593 24.5 RADAR BINARY 11457 10.72 2007 LE 8.017 19.7 1.839 0.517 29.5 RADAR BINARY 11600 9.60 2006 GY2 8.185 18.8 1.858 0.496 30.6 RADAR BINARY 11716 8.70 (7888) 1993 UC 8.337 15.1 2.436 0.664 26.1 RADAR BINARY 12115 5.59 (164121) 2003 YT1 9.168 16.2 1.110 0.292 44.1 RADAR BINARY 12350 3.76 2008 DG17 9.964 19.7 1.838 0.450 41.1 RADAR BINARY 12408 3.30 (1866) Sisyphus 1972 XA 10.188 12.4 1.894 0.538 41.2 RADAR BINARY 12525 2.39 (5381) Sekhmet 1991 JY 10.775 16.6 0.947 0.296 49.0 RADAR BINARY 12641 1.49 (276049) 2002 CE26 11.805 16.8 2.235 0.559 47.3 RADAR BINARY 12761 0.55 (138095) 2000 DK79 13.949 15.9 1.777 0.414 60.7 RADAR BINARY 12829 0.02 (66063) 1998 RO1 18.576 18.1 0.991 0.720 22.7 RADAR BINARY 12832 0.00 0.000 0.0 0.000 0.000 0.0 RADAR BINARY TISSERAND PARAMETER RANKINGS FOR BINARIES Tisserand Parameter is computed from T = aj/a + 2.0*cos(i)*sqrt((a/aj)*(1.0 - e*e)) where aj is the semimajor axis of Jupiter, a is the semimajor axis of an asteroid, i is the asteroid's inclination, and e is the asteroid's eccentricity. In general, most Jupiter-family (short period) comets have T < 3.0 and ~90% of numbered asteroids with a < 3.3 AU have T > 3. PROVISIONAL TISSERAND RANK PERCENTILE ASTEROID NAME DESIGNATION PARAMETER H (mag) a (AU) e i (deg) Q (AU) q (AU) ==== ========== ============= =========== ========= ======= ====== = ======= ====== ====== 276 97.85 2005 AB 2.792 17.5 3.216 0.656 8.2 5.326 1.106 RADAR BINARY 1061 91.73 (7888) 1993 UC 3.055 15.1 2.436 0.664 26.1 4.054 0.818 RADAR BINARY 1114 91.32 (276049) 2002 CE26 3.065 16.8 2.235 0.559 47.3 3.484 0.986 RADAR BINARY 1484 88.44 1994 XD 3.127 19.1 2.346 0.734 4.3 4.068 0.624 RADAR BINARY 1720 86.60 (374851) 2006 VV2 3.167 16.8 2.387 0.605 23.7 3.831 0.943 RADAR BINARY 2140 83.32 (136993) 1998 ST49 3.228 17.7 2.311 0.593 24.5 3.681 0.941 RADAR BINARY 2206 82.81 (285263) 1998 QE2 3.238 17.3 2.423 0.572 12.9 3.809 1.037 RADAR BINARY 2523 80.34 2014 WZ120 3.288 20.5 2.213 0.639 20.9 3.627 0.799 RADAR BINARY 2994 76.67 2013 WT44 3.362 19.3 2.260 0.568 12.2 3.544 0.976 RADAR BINARY 3137 75.55 2008 BT18 3.383 18.3 2.222 0.593 8.1 3.540 0.904 RADAR BINARY 3387 73.61 2007 DT103 3.419 19.2 2.206 0.575 5.5 3.474 0.938 RADAR BINARY 3407 73.45 (348400) 2005 JF21 3.424 17.2 2.223 0.536 10.9 3.415 1.031 RADAR BINARY 3446 73.15 (3671) Dionysus 1984 KD 3.429 16.4 2.198 0.542 13.5 3.389 1.007 BINARY 3585 72.06 (138095) 2000 DK79 3.448 15.9 1.777 0.414 60.7 2.513 1.041 RADAR BINARY 4007 68.77 (1866) Sisyphus 1972 XA 3.512 12.4 1.894 0.538 41.2 2.913 0.875 RADAR BINARY 4063 68.34 (399307) 1991 RJ2 3.519 18.9 2.208 0.429 8.9 3.155 1.261 BINARY 4412 65.62 (5646) 1990 TR 3.572 15.2 2.142 0.437 7.9 3.078 1.206 BINARY 4499 64.94 (5143) Heracles 1991 VL 3.582 13.8 1.834 0.772 9.0 3.250 0.418 RADAR BINARY 4564 64.43 (399774) 2005 NB7 3.592 18.7 2.044 0.517 12.7 3.101 0.987 RADAR BINARY 4838 62.30 2008 DG17 3.631 19.7 1.838 0.450 41.1 2.665 1.011 RADAR BINARY 4937 61.53 2002 KK8 3.649 21.0 1.954 0.466 24.5 2.865 1.043 RADAR BINARY 5133 60.00 2000 UG11 3.683 20.4 1.929 0.573 8.9 3.034 0.824 RADAR BINARY 5170 59.71 2003 SS84 3.690 21.8 1.931 0.571 5.5 3.034 0.828 RADAR BINARY 5194 59.52 2006 GY2 3.693 18.8 1.858 0.496 30.6 2.780 0.936 RADAR BINARY 5209 59.41 (153591) 2001 SN263 3.697 16.9 1.987 0.478 6.7 2.937 1.037 RADAR BINARY 5295 58.74 2007 LE 3.715 19.7 1.839 0.517 29.5 2.790 0.888 RADAR BINARY 5322 58.53 (31345) 1998 PG 3.720 17.3 2.015 0.391 6.5 2.803 1.227 BINARY 5465 57.41 (7088) Ishtar 1992 AA 3.750 16.7 1.981 0.391 8.3 2.756 1.206 BINARY 5682 55.72 2014 YB35 3.798 19.0 1.877 0.483 12.6 2.784 0.970 RADAR BINARY 5867 54.28 (85938) 1999 DJ4 3.840 18.6 1.853 0.483 9.1 2.748 0.958 RADAR BINARY 5963 53.53 2002 BM26 3.860 20.1 1.833 0.444 16.2 2.647 1.019 RADAR BINARY 6735 47.51 (69230) Hermes 1937 UB 4.020 17.5 1.655 0.624 6.1 2.688 0.622 RADAR BINARY 6807 46.95 (363599) 2004 FG11 4.037 21.0 1.588 0.724 3.1 2.738 0.438 RADAR BINARY 6984 45.57 (153958) 2002 AM31 4.072 18.3 1.703 0.452 4.6 2.473 0.933 RADAR BINARY 7114 44.56 (162000) 1990 OS 4.107 19.4 1.678 0.463 1.1 2.455 0.901 RADAR BINARY 7299 43.12 (311066) 2004 DC 4.153 18.1 1.634 0.400 19.4 2.288 0.980 RADAR BINARY 7456 41.90 (136617) 1994 CC 4.193 17.7 1.638 0.417 4.7 2.321 0.955 RADAR BINARY 7488 41.65 (65803) Didymos 1996 GT 4.201 18.0 1.644 0.384 3.4 2.275 1.013 RADAR BINARY 8092 36.94 (357439) 2004 BL86 4.364 19.3 1.502 0.403 23.8 2.107 0.897 RADAR BINARY 8280 35.47 (1862) Apollo 1932 HA 4.414 16.2 1.470 0.560 6.4 2.293 0.647 RADAR BINARY 8596 33.01 1994 CJ1 4.503 21.4 1.490 0.325 2.3 1.974 1.006 RADAR BINARY 9447 26.38 (185851) 2000 DP107 4.749 18.2 1.365 0.377 8.7 1.880 0.850 RADAR BINARY 10875 15.25 (164121) 2003 YT1 5.322 16.2 1.110 0.292 44.1 1.434 0.786 RADAR BINARY 11142 13.17 (35107) 1991 VH 5.474 16.7 1.137 0.144 13.9 1.301 0.973 RADAR BINARY 11268 12.19 (385186) 1994 AW1 5.547 17.6 1.105 0.076 24.1 1.189 1.021 RADAR BINARY 11526 10.18 (363067) 2000 CO101 5.709 19.1 1.076 0.090 15.3 1.173 0.979 RADAR BINARY 11529 10.15 (88710) 2001 SL9 5.710 17.6 1.061 0.270 21.9 1.347 0.775 BINARY 11624 9.41 (175706) 1996 FG3 5.779 18.4 1.054 0.350 2.0 1.423 0.685 RADAR BINARY 11659 9.14 (66063) 1998 RO1 5.809 18.1 0.991 0.720 22.7 1.705 0.277 RADAR BINARY 11907 7.21 (5381) Sekhmet 1991 JY 6.028 16.6 0.947 0.296 49.0 1.227 0.667 RADAR BINARY 12606 1.76 (363027) 1998 ST27 6.980 19.5 0.819 0.530 21.1 1.253 0.385 RADAR BINARY 12609 1.74 (137170) 1999 HF1 6.987 14.5 0.819 0.462 25.7 1.197 0.441 BINARY 12821 0.09 (66391) 1999 KW4 8.501 16.5 0.642 0.688 38.9 1.084 0.200 RADAR BINARY
Since completion of the upgrade At Arecibo (Jan. 1999): NEA binaries and ternaries with H < 22.0 (diameters > ~200 meters) detected by radar: 46/350 = 13.1% This does not include 2003 SS84, which is probably < 200 m in diameter. NEA ternaries with H < 22 detected by radar: 2/350 = 0.6% Note: the tabulations below include 1866 Sisyphus but do NOT include: 2004 RZ164, a possible binary reported by Kwiatkowski et al. (2007), or 2000 PJ5, a possible binary reported by Polishook and Brosch (2008). Percentage of all NEA binaries and ternaries discovered by radar: 38/53 = 71.7% Percentage of all NEA binaries and ternaries discovered photometrically: 14/53 = 26.4% Percentage of all NEA binaries and ternaries detected by radar: 47/53 = 88.7% Percentage of all NEA binaries and ternaries detected photometrically: 21/53 = 39.6% (the latter percentage doesn't include 2005 JF21...yet) (Lightcurves of 1998 ST27, Hermes, 2003 YT1, 2002 CE26, Apollo, Sisyphus, and 2000 CO101 do not show evidence for secondaries. The secondaries are probably too small. The lightcurve of 1994 CJ1 hasn't shown evidence for mutual events either.) Percentage of all NEA binaries and ternaries discovered at Arecibo: 28/53 = 52.8% Percentage of all NEA binaries and ternaries discovered at Goldstone: 10/53 = 18.9% Percentage of all NEA radar binaries and ternaries detected at Arecibo: 42/47 = 89.4% Percentage of all NEA radar binaries and ternaries detected at Goldstone: 22/47 = 45.8% Percentage of NEA radar binaries and ternaries that are "Potentially Hazardous:" 35/47 = 74.5% Percentage of NEA binaries and ternaries discovered by radar (including Sisyphus) that were targets-of-opportunity: 15/38 = 40.5% Ternaries: Percentage of NEA ternaries discovered by radar: 2/2 = 100% Percentage of NEA multiple systems detected by radar that are ternaries: 2/47 = 4.3% This is probably an underestimate due to low SNRs for many of the binary radar detections. This does not include 2002 CE26 or 2005 JF21, candidates but unconfirmed ternary systems. Photometry of 1999 KW4 in 1999 showed tentative evidence of mutual events, but the binary status of that object was not discovered until radar observations at Goldstone in 2001. 1998 RO1, Didymos, and 1999 DJ4, were strongly suspected of being binaries based on lightcurves prior to observations by radar. Photometry of 2006 VV2 suggested a binary in mid-March 2007 but not at the level required for an IAU Circular by the Binary Asteroid Photometric Survey. Its binary status became clear on March 27, 2007 based on observations at Goldstone. 1990 OS was first detected by radar in 1990 but was unrecognized as a binary system until November, 2003. 1862 Apollo was first detected by radar in 1980 but was unrecognized as a binary system until November, 2005. August, 2007 update: 1866 Sisyphus was suspected of being a binary in December, 1985 based on a narrow spike in CW data that did not move in frequency with the asteroid's 2.4 hour rotation period. Similar echo power spectra were not seen again with any asteroid until September, 2000 when 2000 DP107 was recognized as a binary based on both CW spectra and delay-Doppler imaging. Due to the narrow spikes observed in most known binaries, we now classify Sisyphus as a binary system. With an estimated diameter of about 8 km, Sisyphus is by far the largest binary NEA known. For additional lists of binary NEAs, their discovery history, and estimated physical properties, see Petr Pravec's website at: http://www.asu.cas.cz/~asteroid/binneas.htm#1 [THAT WEBSITE IS NOW OUTDATED]
FUTURE EARTH APPROACHES WITHIN 0.1 AU THROUGH 2099 FOR BINARY OR TERNARY NEAs This table also includes apparitions sufficiently close to yield detections for some objects even if Delta > 0.1 AU. Date Distance (AU) 1862 Apollo 2021 Dec 0.242 2023 May 0.213 2046 Nov 0.035 2048 May 0.050 2080 Nov 0.098 2082 May 0.033 1866 Sisyphus NONE Approaches within 0.51 AU in Dec. 2011 but the secondary is probably too small to detect photometrically. Sisyphus radar opportunities: 2032 Nov 0.470 Weak CW target: daily SNR ~15 2045 Nov 0.304 Coarse resolution imaging opportunity: daily SNR ~100 2058 Nov 0.154 Good imaging opportunity: daily SNR > 1000 2071 Nov 0.116 Good imaging opportunity: daily SNR > 1000 3671 Dionysus 2085 Jun 0.028 5143 Heracles 2039 Jul 0.058 5381 Sekhmet 2026 May 0.261 CW and coarse ranging 5646 1990 TR NONE within 0.2 au 7088 Ishtar NONE within 0.2 au 7888 1993 UC 2055 Mar 0.082 31345 1998 PG NONE within 0.2 au 35107 1991 VH 2020 Feb 0.307 Weak CW target 2025 Aug 0.078 2026 Jan 0.292 Weak CW target 2048 Aug 0.090 2065 Aug 0.045 2088 Aug 0.045 65803 Didymos 2022 Oct 0.071 2062 Oct 0.050 66063 1998 RO1 2076 Sep 0.098 66391 1999 KW4 2016 May 0.265 Weak CW target 2017 May 0.167 coarse imaging target 2018 May 0.078 2019 May 0.035 2020 Jun 0.180 CW and ranging 2036 May 0.016 2053 May 0.068 2054 May 0.046 2071 May 0.018 2088 May 0.087 2089 May 0.024 69230 Hermes 2040 Apr 0.028 2057 Apr 0.027 2069 Oct 0.086 2086 Oct 0.024 85938 1999 DJ4 2057 Mar 0.085 2062 May 0.087 88710 2001 SL9 2026 Apr 0.202 CW & ranging 136617 1994 CC 2032 Aug 0.111 Coarse-resolution imaging target 2053 Jul 0.073 2074 Jun 0.017 2095 Jun 0.034 136993 1998 ST49 ...None...within 0.2 au... 137170 1999 HF1 2022 Mar 0.182 2045 Mar 0.187 2065 Mar 0.175 138095 2000 DK79 2058 Nov 0.065 153591 2001 SN263 2022 Feb 0.101 153958 2002 AM31 2032 Jul 0.034 2052 Aug 0.070 2072 Sep 0.071 2092 Oct 0.086 162000 1990 OS 2027 Aug 0.131 2040 Sep 0.082 2053 Nov 0.020 2077 Oct 0.086 162483 2000 PJ5 2018 Jul 0.194 Possible binary; Polishook & Brosch 2008 2027 Jul 0.183 This object does not approach within 0.1 AU until at least 2100. 2049 Jul 0.176 2071 Jul 0.182 2080 Jul 0.196 2093 Jul 0.198) 164121 2003 YT1 2016 Oct 0.035 2018 May 0.260 CW and ranging 2023 Nov 0.059 2025 May 0.337 Weak CW 2066 Apr 0.068 2073 Apr 0.011 2085 Nov 0.040 175706 1996 FG3 2022 May 0.078 2024 Nov 0.180 2035 May 0.106 2037 Nov 0.129 2048 May 0.175 2050 Nov 0.057 2063 Nov 0.062 2086 Apr 0.057 2099 May 0.066 186851 2000 DP107 2016 Aug 0.179 CW and ranging 2067 Sep 0.042 2075 Sep 0.046 276049 2002 CE26 2024 Sep 0.201 CW and ranging 285263 1998 QE2 NONE within 0.2 au 311066 2004 DC 2077 Jun 0.027 357439 2004 BL86 2050 Jan 0.071 2061 Feb 0.195 2096 Jan 0.024 363027 1998 ST27 2021 Oct 0.189 Weak CW target 2024 Oct 0.024 2027 Oct 0.155 CW and ranging 2047 Oct 0.075 2050 Oct 0.092 2073 Oct 0.034 2096 Oct 0.044 363067 2000 CO101 2028 Sep 0.061 2057 Sep 0.025 2096 Sep 0.031 363599 2004 FG11 2016 Apr 0.050 2018 Apr 0.049 2020 Apr 0.049 2022 Apr 0.049 2024 Apr 0.052 2026 Apr 0.057 2028 Apr 0.064 2030 Apr 0.079 2032 Apr 0.098 2094 Apr 0.092 2096 Apr 0.052 374851 2006 VV2 2092 Mar 0.134 2129 Mar 0.166 2140 Apr 0.118 2177 Mar 0.032 385186 1994 AW1 2015 Jul 0.065 2022 Jul 0.112 2023 Jan 0.255 Weak CW 2058 Jul 0.065 2094 Jul 0.083 399307 1991 RJ2 None within 0.1 au through 2100 438400 2005 JF21 2015 Aug 0.051 2088 Aug 0.056 2181 Aug 0.069 1994 CJ1 2065 Apr 0.094 2134 Jul 0.094 1994 XD 2023 Jun 0.021 2041 Jun 0.015 2000 UG11 2067 Nov 0.081 2067 Nov 0.087 2002 BM26 2069 Jan 0.094 2002 KK8 2054 Jun 0.074 2003 SS84 2020 Feb 0.100 2054 Oct 0.047 (2004 RZ164 2074 Dec 0.053 Possible binary; Kwiatkowski et al. 2007) 2005 AB NONE within 0.2 au 2005 NB7 2046 Apr 0.029 2005 YQ96 2024 Jan 0.167 2030 Dec 0.104 2040 Jan 0.037 2056 Jan 0.055 2065 Jan 0.100 2071 Dec 0.157 2090 Jan 0.123 2096 Dec 0.151 2006 GY2 2044 May 0.029 2007 DT103 2089 Jul 0.066 2007 LE 2017 May 0.082 2008 BT18 2072 Feb 0.018 2008 DG17 2018 Feb 0.1002 2008 DG17 also makes close approaches within 0.15 AU of 15 Eunomia and 88 Thisbe 2013 WT44 2031 Mar 0.067 2048 Mar 0.149 2133 Mar 0.020 2150 Mar 0.062 2167 Apr 0.106 2014 WZ120 2014 Dec 0.047 2149 Nov 0.053 2014 YB35 2033 Mar 0.022 2051 Mar 0.093
Binary and Triple NEAs observed by radar: What can we estimate for each? Primary Spectral Object Orbit? Density? Shape? Class PI 1862 Apollo No No Maybe Q Benner 1866 Sisyphus No No No S Benner/Margot 5381 Sekhmet Maybe Maybe Maybe V Nolan 7888 1993 UC Maybe Maybe Maybe Brozovic 35107 1991 VH Yes Yes Yes S Margot In preparation 65803 Didymos Yes Yes Yes M Benner In preparation 66063 1998 RO1 Yes Yes Yes S Benner 66391 1999 KW4 Yes Yes Yes S Ostro/Benner PUBLISHED (2001 data) 69230 Hermes Yes Yes Yes S Margot In preparation 89538 1999 DJ4 Maybe Maybe Yes Q Benner In preparation 136617 1994 CC Yes Yes Yes ? Brozovic PUBLISHED 136993 1998 ST49 Maybe Maybe Yes Brozovic 138095 2000 DK79 Naidu 153591 2001 SN263 Yes Yes Yes P Nolan In preparation 153958 2002 AM31 Yes Yes Yes SqV Taylor In preparation 162000 1990 OS Yes Yes Yes ? Benner 164121 2003 YT1 Yes Yes Yes V Nolan 175706 1996 FG3 Yes Yes Yes C Benner 185851 2000 DP107 Yes Yes Yes X Margot PUBLISHED (2000 data); 2008 data submitted 285263 1998 QE2 Yes Yes Yes C Springmann In preparation 311066 2004 DC Yes Yes Yes ? Taylor In preparation 357439 2004 BL86 Yes Yes Yes V Benner 363027 1998 ST27 Yes Yes:Not unique Yes C Benner In preparation 363067 2000 CO101 Not yet Not yet Yes Xk Benner In preparation 363599 2004 FG11 Maybe Maybe Yes Taylor? 374851 2006 VV2 Yes Yes Yes S Benner/Nolan/Black/Busch In preparation 385186 1994 AW1 S Naidu 438400 2005 JF21 No No No Naidu 1994 CJ1 No No No Springmann 1994 XD No No No ? Benner 2000 UG11 Yes Yes Yes S Nolan/Benner In preparation 2002 BM26 P Nolan 2002 CE26 Yes Yes Yes C Shepard PUBLISHED 2002 KK8 ? Nolan 2003 SS84 Maybe Maybe Yes ? Nolan/Benner 2005 AB No No No C Benner 2005 NB7 Maybe Maybe Maybe S Shepard 2005 YQ96 Maybe Maybe Yes 2006 GY2 Yes Yes Yes ? Nolan/Benner 2007 DT103 No No No S Benner 2007 LE Maybe Maybe Maybe Brozovic 2008 BT18 No No Yes E Benner 2008 DG17 No No No Taylor 2013 WT44 Maybe Maybe Maybe dark Benner 2014 WZ120 No No No Nolan 2014 YB35 No No No Naidu
Published peer-reviewed papers on radar observations: Margot, J. L., M. C. Nolan, L. A. M. Benner, S.J. Ostro, R. F. Jurgens, J. D. Giorgini, M. A. Slade, and D. B. Campbell. Binary asteroids in the near-Earth object population. Science 296, 1445-1448. (2002). Shepard, M. K., J. Schlieder, B. Estes, C. Magri, M. C. Nolan, J.-L. Margot, S. J. Bus, E. L. Volquardsen, A. Rivkin, L. A. M. Benner, J. D. Giorgini, S. J. Ostro, and M. W. Busch. Radar, optical, and thermal observations of the binary near-Earth asteroid 2002 CE26. Icarus 184, 198-210 (2006). Ostro, S. J., J.-L. Margot, L. A. M. Benner, J. D. Giorgini, D. J. Scheeres, E. G. Fahnestock, S. B. Broschart, J. Bellerose, M. C. Nolan, C. Magri, P. Pravec, P. Scheirich, R. Rose, R. F. Jurgens, E. M. de Jong, and S. Suzuki. Radar imaging of binary near-Earth asteroid (66391) 1999 KW4. Science 314, 1276-1280 (DOI: 10.1126/science.1133622) (2006). Scheeres, D. J., E. G. Fahnestock, S. J. Ostro, J. L. Margot, L. A. M. Benner, S. B Broschart, J. Bellerose, J. D. Giorgini, M. C. Nolan, C. Magri, P. Pravec, P. Scheirich, R. Rose, R. F. Jurgens, E. M. de Jong, and S. Suzuki. Dynamical configuration of binary near-Earth asteroid (66391) 1999 KW4. Science 314, 1280-1283 (2006) Brozovic, M., L. A. M. Benner, M. C. Nolan, E. S. Howell, P. A. Taylor, C. Magri,, D. J. Scheeres, J. D. Giorgini, J. T. Pollock, P. Pravec, A. Galad, M. W. Busch, J. L. Margot, M. K. Shepard, D. E. Reichart, K. M. Ivarsen, J. B. Haislip, A. P. LaCluyze, J. Jao, M. A. Slade, K. J. Lawrence, and M. D. Hicks. Radar observations and physical modeling of triple near-Earth asteroid (136617) 1994 CC. Icarus 216, 241-256. Naidu et al. 2015. 2000 DP107 Margot et al. 2015. Asteroids IV chapter. Reviews of radar observations of binaries: Ostro, S. J., R. S. Hudson, L. A. M. Benner, J. D. Giorgini, C. Magri, J. L. Margot, and M. C. Nolan. Asteroid radar astronomy. In Asteroids III (W. F. Bottke, A. Cellino, P. Paolicchi, and R. P. Binzel, Eds.), Univ. of Arizona Press, Tucson, pp. 151-168. (2002) Merline, W. J., S. J. Weidenschilling, D. D. Durda, J. L. Margot, P. Pravec, and A. D. Storrs. Asteroids do have satellites. In Asteroids III (W. F. Bottke, A. Cellino, P. Paolicchi, and R. P. Binzel, Eds.), Univ. of Arizona Press, Tucson, pp. 289-312. (2002)
NEA Binary and Ternary systems with at least one companion that rotates more rapidly than its orbital period: 7/40 = 17.5% 35107 1991 VH 136617 1994 CC Outer satellite only 153591 2001 SN263 Outer satellite only 162000 1990 OS 164121 2003 YT1 363027 1998 ST27 348400 2005 JF21 2004 DC
CANDIDATE CONTACT BINARY NEAR-EARTH ASTEROIDS OBSERVED BY RADAR Arranged in order of increasing rotation period to the extent that it's known Last update: 2015 July 15 Approximate Rotation Asteroid H diameter (km) Period (h) Radar reference 4769 Castalia 16.9 1.0 4.0 Ostro et al. 1990, Hudson and Ostro 1994 275677 2000 RS11 19.1 ~0.5 4.4 unpublished 242643 2005 NZ6 17.4 2.3 ~5 unpublished 388188 2006 DP14 18.9 ~0.3 5.8 unpublished 68346 2001 KZ66 16.7 1.0 ~6 unpublished 2005 CR37 18.9 1.0 6.5 Benner et al. 2006 137126 1999 CF9 18.0 <1 6.7 unpublished 2014 UF206 18.8 ~1 6.83 unpublished 2007 VD12 20.0 0.5 7.4 unpublished 85989 1999 JD6 17.1 1.8 7.68 Warner et al. 2014 2002 AY1 20.8 ~0.2 ~8 unpublished 11066 Sigurd 15.2 3.0 8.5 Busch et al., in prep. 8567 1996 HW1 15.3 2.0 8.8 unpublished 179806 2002 TD66 20.2 0.3 9.5 unpublished 348306 2005 AY28 21.5 ~0.2 6-10 unpublished 2013 JR28 21.6 ~0.1 >10 unpublished 2000 YF29 20.3 0.5 <12 unpublished 25143 Itokawa 19.2 0.33 12.1 Ostro et al. 2004, 2005 2002 HK12 18.1 0.6 12.7 unpublished 2063 Bacchus 17.2 0.6 15.1 Benner et al. 1999 192642 1999 RD32 16.3 ~5 17.1 unpublished 152664 1998 FW4 19.7 ~0.3 ~18 unpublished 2002 NY40 19.0 ~0.4 20.0 unpublished 2014 HQ124 18.9 ~0.4 ~20 unpublished 398188 2010 LE15 19.5 0.44 ~20 unpublished Diameter from Mainzer et al. 2011 2003 UV11 19.5 ~0.4 ~24? Busch et al., submitted 2004 XL14 21.2 0.4 ~24 unpublished 2012 QG42 20.9 ~0.2 ~24 unpublished 52387 1993 OM7 17.8 1.0 >26 unpublished 2008 SV11 18.4 0.8 32.4 unpublished 2007 TU24 20.3 0.3 ~1-2 days unpublished 4450 Pan 17.1 1.0 2-3 days unpublished 144411 2003 EW9 16.6 1.1 49.9 unpublished 4486 Mithra 15.6 1.6 67.5 Brozovic et al. 2010 4179 Toutatis 15.3 2.4 5.4, 7.4 d Hudson et al. 1995, 2003 2002 FC 18.9 0.7 days unpublished 2004 RF84 18.4 2.4 weeks unpublished Fastest rotator: Castalia Slowest rotator: possibly 2004 RF84. The bandwidth is so narrow that it's hard to tell. Largest: 1999 RD32 ~5 km Smallest: 2013 JR28 ~0.1 km Toutatis and Itokawa are now included although they not considered contact binaries as defined in Benner et al. 2006. With the relaxed definition of a "contact binary," there could be other objects observed by radar that aren't on this list yet.

Lance Benner