Near-Earth Asteroid Surface
Roughness Depends on Compositional Class
L. A. M. Benner, S. J. Ostro, C. Magri, M. C. Nolan, E. S Howell, Jon D. Giorgini,
J. L. Margot, M. W. Busch, M. K. Shepard, P. A. Taylor, and R. F. Jurgens
Abstract
Radar observations of 214 near-Earth asteroids (NEAs) reveal a very strong correlation
of circular polarization ratio with visible-infrared taxonomic class, establishing
distinct differences in the centimeter-to-several-decimeter structural complexity of
objects in different spectral classes. The correlation may be due to intrinsic
mechanical properties of different mineralogical assemblages but also may reflect
very different formation ages and collisional histories. The highest ratios are
measured for groups associated with achondrittic igneous rocky meteorites: the E class,
whose parent body may be 3103 Eger, and the V class, derived from the mainbelt
asteroid (and Dawn mission target) 4 Vesta.
Submitted to Icarus: February 2008
Revised: June 2008
Last update: 2009 Nov 12
http://echo.jpl.nasa.gov/~lance/scoc/scoc.html
The paper is available from Icarus at:
http://dx.doi.org/10.1016/j.icarus.2008.06.010
and was published in Icarus 198, 294-304 (2008).
OBJECTS NOT INCLUDED
Taxonomic
Asteroid H (mag) Class Reference
8567 1996 HW1 15.3 S M. D. Hicks, pers. comm., E.S. Howell, pers. comm., Birlan et al. 2009 (BAAS 41, 1061-1062)
35107 1991 VH 16.7 S Binzel et al. (2004)
54660 2000 UJ1 17.6 S M. D. Hicks and K. J. Lawrence, pers. comm.
68216 2001 CV26 16.2 S V. Reddy, pers. comm.
90403 2003 YE45 17.5 S M. D. Hicks, pers. comm.
136617 1994 CC 17.7 Sq M. D. Hicks et al., pers. comm.
136849 1998 CS1 17.7 Sq M. D. Hicks et al., pers. comm.
137032 1998 UO1 16.6 Sq M. D. Hicks, pers. comm.
143651 2003 QO104 15.9 S M. D. Hicks, pers. comm.
152664 1998 FW4 19.5 C M. D. Hicks, pers. comm.
159402 1999 AP10 16.4 L M. D. Hicks, S. C. Lowry, and P. R. Weissman, pers. comm.
164400 2005 GN59 17.4 Sq M. D. Hicks, pers. comm.
S E. S. Howell, pers. comm.
207398 2006 AS2 20.3 S M. D. Hicks, pers. comm.
208023 1999 AQ10 20.3 S Binzel et al. (2004)
K M. D. Hicks et al., pers. comm.
217796 2000 TO64 16.7 Sq M. D. Hicks and K. J. Lawrence, pers. comm.
217807 2000 XK44 17.7 S M. D. Hicks and K. J. Lawrence, pers. comm.
2000 CO101 18.9 Xk Binzel et al. 2004
2001 FE90 20.0 A (S?) M. D. Hicks et al., pers. comm.
2004 LV3 18.6 V M. D. Hicks, pers. comm.
2005 RC34 19.5 E V. Reddy and J. Emery, pers. comm; E. S. Howell, pers. comm., M. D. Hicks, pers. comm.
2008 BT18 18.2 V V. Reddy and J. Emery, pers. comm.
2008 EE5 19.1 Sl M. D. Hicks et al., pers. comm.
2008 EV5 20.0 C M. D. Hicks, K. J. Lawrence, B. J. Buratti pers. comm.
X V. Reddy, pers. comm.
2008 QS11 19.8 Xc M. D. Hicks, pers. comm.
2008 SV11 18.2 CX M. D. Hicks, pers. comm.
2008 UE7 20.4
2009 DO111 22.8
2009 DR3 21.5 S M. D. Hicks, pers. comm.
2009 KC3 18.1 C E. S. Howell, pers. comm.
N = 29
Of the targets in the list above, E. Howell, R. Vervack et al. have IRTF data
for 1998 UO1, 1999 AP10, 2001 FE90, 2003 QO104, and 2008 SV11.
Their spectral classes will be added above when they become available.
Binzel et al. also have IRTF spectra of 2008 SV11.
UPCOMING TARGETS
Proposed and/or scheduled for radar observations at Arecibo and Goldstone
through September, 2010
H Spectral Taxonomic Previous radar
Asteroid Date (mag) Class Reference detection?
2009 UN3 Feb 2010 17.7 No
2002 XY38 Feb 2010 22.9 No
2007 EF Feb 2010 20.8 No
88254 2001 FM129 Mar 2010 17.3 No
2004 FG11 Apr 2010 20.9 No
2005 YU55 Apr 2010 22.0 No
2002 JR100 May 2010 24.1 No
1999 MN Jun 2010 21.4 Yes
2007 XB10 Jun 2010 17.5 No
2002 BF25 Jul 2010 22.3 No
85989 1999 JD6 Jul 2010 16.9 K [need the reference] No
154029 2002 CY46 Aug 2010 16.3 No
6239 Minos Aug 2010 17.9 Yes
137032 1998 UO1 Sep 2010 16.6 Sq M. D. Hicks, pers. comm. Yes
Table 1: Ordered list
Last update: 2009 Nov 02
Spectral
Asteroid H (mag) Class SC/OC +- P (h)
======== ======= ====== ===== =====
433 Eros 11.2 S 0.28 0.06 5.27 Binzel et al. 2004
1036 Ganymed 9.5 S 0.18 0.06 10.31 Binzel et al. 2004
1566 Icarus 16.9 Q 0.5 0.2 2.273 Tholen 1989, Hicks et al. 1998
1580 Betulia 14.5 C 0.20 0.03 6.13 Tholen 1989, Rivkin et al. 2005
1620 Geographos 15.6 S 0.20 0.01 5.223 Binzel et al. 2004
1627 Ivar 13.2 S 0.21 0.01 4.797 Binzel et al. 2004, Davies et al. 2007
1685 Toro 14.2 S 0.15 0.05 10.196 Binzel et al. 2004
1862 Apollo 16.3 Q 0.33 0.01 3.066 BINARY Binzel et al. 2004
1866 Sisyphus 13.0 S 0.32 0.04 2.4 BINARY Binzel et al. 2004
1915 Quetzalcoatl 19.0 S 0.27 0.08 4.9 Tholen 1989
1917 Cuyo 13.9 S 0.21 0.03 2.69 Binzel et al. 2004
1981 Midas 15.5 V 0.65 0.13 5.22 Binzel et al. 2004
2062 Aten 16.8 S 0.39 0.06 40.77 Binzel et al. 2004
2063 Bacchus 17.1 Q 0.21 0.01 14.9 Binzel et al. 2004
2100 Ra-Shalom 16.1 K 0.25 0.04 19.797 Shepard et al. 2008
2101 Adonis 18.7 1.02 0.11
2201 Oljato 15.3 S 0.31 0.02 26. Binzel et al. 2004
3103 Eger 15.4 E 0.92 0.06 5.706 Gaffey et al. 1992, Binzel et al. 2004
3199 Nefertiti 14.8 S 0.47 0.04 3.021 Binzel et al. 2004
3200 Phaethon 14.6 B 0.25 0.02 3.604 Binzel et al. 2004
3757 1982 XB 19.0 S 0.27 0.05 9.005 Tholen 1989
3908 Nyx 17.4 V 0.75 0.03 4.426 Cruikshank et al. 1991, Binzel et al. 2004
4034 1986 PA 18.1 O 0.21 0.14 Binzel et al. 2004
4179 Toutatis 15.3 S 0.29 0.01 130 NPA Binzel et al. 2004, Davies et al. 2007
4183 Cuno 14.4 S 0.32 0.02 3.56 Binzel et al. 2004
4197 1982 TA 14.6 S 0.25 0.02 3.538 Binzel et al. 2004
4450 Pan 17.2 S 0.23 0.03 slow M. D. Hicks, pers. comm.
4486 Mithra 15.6 0.48 0.01 67.5 possibly NPA
4544 Xanthus 17.1 0.07 0.12
4660 Nereus 18.2 E 0.74 0.08 15.1 Delbo et al. 2003, Binzel et al. 2004
4769 Castalia 16.9 0.30 0.02 4.095
4953 1990 MU 14.1 Q 0.36 0.03 14.218 Hicks et al. 1998
5189 1990 UQ 17.3 0.37 0.05
5381 Sekhmet 16.5 V 0.52 0.02 ~3 BINARY Davies et al. 2007
5604 1992 FE 16.4 V 0.52 0.06 6.026 Binzel et al. 2004
5660 1974 MA 15.7 Q 0.37 0.15 17.5 Binzel et al. 2004
6037 1988 EG 18.7 S 0.32 0.02 2.76 Fevig and Fink 2007
6178 1986 DA 15.1 M 0.09 0.02 3.58 Ostro et al. 1991
6239 Minos 17.9 0.23 0.04 3.556
6489 Golevka 19.2 Q 0.23 0.02 6.026 Binzel et al. 2004, Davies et al. 2007
7025 1993 QA 18.0 0.28 0.03 2.506
7335 1989 JA 17.0 0.19 0.06
7341 1991 VK 16.7 Q 0.17 0.02 4.21 Binzel et al. 2004
7482 1994 PC1 16.8 S 0.27 0.04 2.6 Binzel et al. 2004
7753 1988 XB 18.6 B 0.18 0.02 Binzel et al. 2004
7822 1991 CS 17.4 S 0.28 0.01 2.389 Binzel et al. 2004
7889 1994 LX 15.3 V 0.57 0.05 2.741 Binzel et al. 2004
8014 1990 MF 18.7 0.19 0.04
8201 1994 AH2 16.3 O >> no SC/OC << 23.949 REFERENCE?
9856 1991 EE 17.4 S 0.24 0.02 3.045 Harris et al. 1998
10115 1992 SK 17.0 S 0.34 0.05 7.32 Binzel et al. 2004
11066 Sigurd 15.2 S 0.30 0.03 8.496 Binzel et al. 2004
11500 Tomaiyowit 18.4 S 0.37 0.03 73. Binzel et al. 2004 (1989 UR)
12711 Tukmit 16.0 S 0.27 0.05 3.484 Binzel et al. 2004 (1991 BB)
13651 1997 BR 17.6 S 0.16 0.04 33.644 Binzel et al. 2004
14827 Hypnos 18.2 C? 0.26 0.02 Ostro et al. 1989
16834 1997 WU22 15.4 S 0.20 0.10 9.345 Binzel et al. 2004
17511 1992 QN 16.9 X 1.10 0.19 5.99 Binzel et al. 2004
22753 1998 WT 17.4 S 0.25 0.03 Whitely 2001, Lazzarin et al. 2005
22771 1999 CU3 16.7 S 0.28 0.02 3.782 Binzel et al. 2004
23187 2000 PN9 15.9 S 0.24 0.02 2.53 I. N. Belskaya, pers. comm.
25143 Itokawa 19.0 S 0.27 0.04 12.132 Binzel et al. 2004, Davies et al. 2007
26663 2000 XK47 18.0 0.24 0.02
29075 1950 DA 16.8 M 0.14 0.03 2.122 Rivkin et al. 2005
30825 1990 TG1 14.7 S 0.27 0.03 2.624 F. DeMeo and R. P. Binzel, pers. comm.
33342 1998 WT24 17.9 E 0.97 0.10 3.697 Lazzarin et al. 2004
35396 1997 XF11 16.9 X 0.20 0.02 3.26 Binzel et al. 2004
37655 Illapa 17.7 C 0.20 0.04 2.66 M. D. Hicks, pers. comm.
38071 1999 GU3 19.4 0.36 0.07 216
52387 1993 OM7 17.4 0.27 0.02
52760 1998 ML14 17.6 S 0.30 0.03 14.98 Davies et al. 2007
53319 1999 JM8 15.0 P 0.19 0.01 168 NPA Benner et al. 2002, Binzel et al. 2004
54509 YORP 22.6 S 0.21 0.02 0.288 REFERENCE?
65803 Didymos 18.0 M 0.20 0.02 BINARY Binzel et al. 2004, Kitazato et al. 2004, Pravec et al. 2006
S De Leon et al. 2006, Added 2009 Sep.
65909 1998 FH12 19.1 0.16 0.03 ~3
66063 1998 RO1 18.0 S 0.24 0.05 2.5 BINARY Abell et al. 2005
66391 1999 KW4 16.5 S 0.45 0.11 2.765 BINARY A Binzel et al. 2004, Davies et al. 2004
0.45 0.20 18 BINARY B
68346 2001 KZ66 16.5 S 0.22 0.02 Lazzarin et al. 2005
68950 2002 QF15 16.2 S 0.23 0.02 29 F. DeMeo and R. P. Binzel, pers. comm.
69230 Hermes 17.5 S 0.19 0.02 13.89 BINARY Rivkin et al. 2004
85182 1991 AQ 17.1 0.22 0.03
85774 1998 UT18 19.1 C 0.25 0.01 ~34 Binzel et al. 2004
85938 1999 DJ4 18.5 Q 0.19 0.02 2.51 BINARY Binzel et al. 2004
87024 2000 JS66 18.6 X 0.73 0.08 Lazzarin et al. 2005
89136 2001 US16 20.2 0.39 0.05 12.4 NPA
99942 Apophis 19.7 Q 0.1 0.2 30.6 Binzel et al. 2006
100085 1992 UY4 17.6 P 0.20 0.02 12.9 Volquardsen et al. 2007
101955 1999 RQ36 20.8 B 0.18 0.01 4.29 Delbo et al. 2003
136770 1996 PC1 20.3 0.22 0.02
137924 2000 BD19 17.1 >> NO CW DATA <<
138127 2000 EE14 16.9 S >> no SC/OC << M. D. Hicks, pers. comm.
138175 2000 EE104 20.1 1.1 0.3
138258 2000 GD2 19.1 S 0.32 0.15 Binzel et al. 2004
138971 2001 CB21 18.4 0.20 0.02 3.302
141432 2002 CQ11 19.9 0.12 0.02
141593 2002 HK12 18.1 X 1.09 0.06 12.69 E. S. Howell, pers. comm.
144900 2004 VG64 18.2 S 0.25 0.02 F. DeMeo and R. P. Binzel, pers. comm.
144901 2004 WG1 17.4 0.17 0.01
152560 1991 BN 19.0 Q 0.27 0.04 Binzel et al. 2004
152770 1999 RR28 18.3 E 0.9 0.1 ~17 NPA? E. S. Howell, pers. comm.
153591 2001 SN263 16.9 P 0.16 0.01 fast TRIPLE R. P. Binzel, pers. comm.
154275 2002 SR41 20.2 >> CW DATA IS BAD <<
154276 2002 SY50 17.6 0.44 0.08 4.823
162000 1990 OS 19.3 0.23 0.03 BINARY
162039 1996 JG 19.1 0.19 0.04
162181 1999 LF6 18.2 S 0.25 0.01 48? M. D. Hicks and T. Barajas, pers. comm., Added 2009 Nov 01
162416 2000 EH26 21.3 0.23 0.07
163295 2002 HW 19.3 0.0 0.1
163692 2003 CY18 18.0 0.20 0.05
163732 2003 KP2 15.3 C 0.26 0.08 151 De Meo and Binzel 2007
164121 2003 YT1 16.2 V 0.61 0.06 2.34 BINARY Abell et al. 2005
S E. S. Howell, pers. comm. Added 2009 Oct.
164211 2004 JA27 19.3 Q 0.20 0.04 F. DeMeo and R. P. Binzel, pers. comm.
179806 2002 TD66 19.9 S 0.26 0.02 REFERENCE?
185851 2000 DP107 18.0 X 0.25 0.02 2.7755 BINARY Yang et al. 2003, Pravec et al. 2006
1989 AZ 19.4 0.13 0.04
1994 XD 19.1 0.21 0.05 BINARY
1998 BY7 21.4 0.35 0.04
1998 KY26 25.5 C 0.5 0.1 0.178 Ostro et al. 1999
1998 ST27 19.5 C 0.30 0.01 3.1 BINARY Abell et al. 2005
1999 FN19 22.4 S 0.22 0.05 3.5? Binzel et al. 2004
1999 FN53 18.4 0.19 0.07
1999 MN 21.4 0.21 0.05
1999 NW2 23.1 0.35 0.03
1999 TN13 23.6 >> No SC/OC <<
1999 TY2 23.3 S 0.34 0.15 0.121 REFERENCE?
2000 CE59 20.2 L 0.24 0.02
2000 ED14 20.7 0.28 0.12
2000 EW70 21.1 F 0.15 0.09 Whitely 2001
2000 LF3 21.6 0.19 0.02
2000 QW7 19.4 0.22 0.03 71.3
2000 RD53 19.9 0.21 0.05 14.96
2000 UG11 20.3 S 0.22 0.11 4.44 BINARY Kitazato et al. 2004
2000 UK11 25.0 0.38 0.05 0.266
2000 YA 23.7 S 0.16 0.02 0.666 Binzel et al. 2004
2000 YF29 20.2 S 0.23 0.01 Binzel et al. 2004
2001 AV43 24.4 0.01 0.10 0.17
2001 BE10 19.1 0.19 0.02 4.194
2001 BF10 22.3 0.27 0.03
2001 CP36 23.7 0.91 0.02
2001 EB18 19.1 0.23 0.05
2001 EC16 22.2 0.23 0.08
2001 FR85 24.5 0.17 0.01
2001 GQ2 20.0 0.27 0.06
2001 JV1 21.3 S >> NO CW DATA << REFERENCE?
2001 SE286 17.1 0.26 0.01 9.323
2001 SG276 17.7 0.18 0.03
2001 SP263 25.6 0.16 0.02
2001 UP 25.7 0.09 0.01
2001 WM15 25.0 0.83 0.02
2001 XX4 22.0 0.15 0.03
2001 YE4 20.5 0.61 0.11
2001 YP3 21.9 0.17 0.03
2002 AA29 24.1 0.26 0.07
2002 AL14 17.7 L 0.20 0.01 2.31 Binzel et al. 2004
2002 AV 20.7 K 0.10 0.01 Binzel et al. 2004
2002 AY1 20.6 0.21 0.02
2002 BG25 20.8 0.20 0.02
2002 BM26 20.0 P 0.20 0.03 2.7 BINARY Delbo et al. 2003, Binzel et al. 2004
2002 CE26 16.8 C 0.21 0.02 3.293 BINARY Shepard et al. 2006
2002 FC 18.8 0.35 0.08
2002 FD6 22.2 0.27 0.03
2002 KK8 20.5 0.50 0.05 BINARY
2002 NY40 19.2 S 0.33 0.07 19.982 Rivkin et al. 2003
2002 TD60 19.2 S 0.41 0.10 2.851 Lazzarin et al. 2005
2002 TS69 24.5 0.16 0.02
2002 TZ66 25.9 0.0 0.2
2002 VE68 20.3 1.0 0.2 13.5
2003 EP4 23.7 0.29 0.04
2003 GY 20.0 1.11 0.15
2003 HM 21.7 0.19 0.04
2003 HN16 22.0 0.41 0.04
2003 MS2 21.0 0.28 0.02
2003 QB30 26.4 0.37 0.02
2003 RU11 25.6 0.25 0.02
2003 SR84 25.2 >> NO SC ECHOES << 2.34
2003 SS84 21.8 0.72 0.05 BINARY
2003 TH2 22.8 1.48 0.4
2003 TL4 19.4 0.30 0.03 27.4
2003 UC20 18.1 C 0.21 0.03 Abe et al. 2007
2004 AD 24.5 0.45 0.15
2004 DC 18.0 0.9 0.05 BINARY
2004 FY31 21.9 0.09 0.03
2004 HX53 23.3 0.13 0.05
2004 RF84 18.2 0.10 0.01
2004 RQ10 20.9 0.31 0.15
2004 VB 20.7 0.16 0.05
2004 VW14 19.4 0.37 0.05
2004 XL14 21.2 C 0.49 0.01 F. DeMeo and R. P. Binzel, pers. comm.
2004 XP14 19.5 E 0.9 0.05 Reddy et al. 2006
2005 AB 17.5 C 0.15 0.04 3.34 BINARY Kumar et al. 2006, De Meo and Binzel 2007
2005 CR37 18.9 C? 0.32 0.03 6.49 Benner et al. 2006
2005 ED318 20.7 Q 0.36 0.02 F. DeMeo and R. P. Binzel, pers. comm.
2005 EK70 17.4 0.15 0.07
2005 EU2 23.1 0.26 0.06
2005 FA 25.2 0.45 0.08
2005 HB4 24.3 0.05 0.15
2005 JE46 17.8 0.38 0.01
2005 NB7 18.7 S 0.24 0.01 M. D. Hicks, pers. comm.
2005 OE3 20.3 0.38 0.03
2005 TD49 26.4 0.15 0.10
2005 TF49 19.1 0.73 0.06
2005 TU50 21.3 1.02 0.15
2005 WA1 21.5 0.28 0.10
2005 WC1 20.6 1.12 0.02 2.5?
2005 WJ56 18.1 E 0.92 0.15 days M. D. Hicks, pers. comm. V. Reddy, pers. comm.
2005 WK56 22.5 0.90 0.10
2005 XA 26.3 0.06 0.08
2006 AM4 21.8 Q 0.27 0.08 0.085 M. D. Hicks, pers. comm.
2006 BQ6 19.7 C 0.33 0.03 4.41 M. D. Hicks, pers. comm.
2006 GY2 18.7 0.21 0.02 BINARY
2006 QV89 25.3 0.0 0.25
2006 RH120 29.6 0.58 0.03 0.0458
2006 RZ 20.3 B 0.55 0.05 4.9 F. DeMeo and R. P. Binzel, pers. comm.
2006 UQ17 21.9 0.20 0.06
2006 VV2 16.8 S 0.27 0.02 2.43 BINARY V. Reddy, pers. comm.
2006 WB 22.8 0.38 0.03
2007 DT103 19.2 S 0.40 0.05 BINARY Hicks and Somers 2007
2007 EH 27.6 >> no SC/OC <<
2007 FY20 24.8 0.15 0.10
2007 TU24 20.2 S 0.37 0.01 M. D. Hicks, pers. comm.
2007 VD12 20.0 S 0.27 0.05 7.43 M. D. Hicks, pers. comm.
2007 XH16 19.6 0.38 0.01
N = 214 (counting both components of 1999 KW4 as one object)
Completeness: 214/218 = 0.986
1994 AH2, 1999 TN13, 2000 BD19, 2000 EE14, 2001 JV1, 2002 SR41, 2003 SR84, and 2007 EH are excluded
because SC/OC is not available.
We have spectral types for: 113/214 = 52.8% of the reduced sample (published in the paper)
Other spectral classes have been added since the paper was published and are indicated in bold.
Summary
-------
Reduced 214
Not available 8
---
Total 222
Table 2: Ranked list
Last update: 2009 October 29
SC/OC for objects observed at both Arecibo and Goldstone have
been averaged (indicated by "A & G"). Ratios reported for objects
observed at Goldstone are indicated by "G" and for objects observed at
Arecibo by "A."
Rank Object H Type SC/OC +/- Obs. Notes Reference
---- ------ - ---- ----- --- ---- ----- ---------
2003 TH2 22.8 1.48 0.4 A
2005 WC1 20.6 1.12 0.02 G
2003 GY 20.0 1.11 0.15 A
17511 1992 QN 16.9 X 1.10 0.19 G Benner et al. 1997
138175 2000 EE104 20.1 1.1 0.3 A Howell et al. 2001
141593 2002 HK12 18.1 X 1.09 0.06 A
2101 Adonis 18.7 1.02 0.11 A Benner et al. 1997
2005 TU50 21.3 1.02 0.15 A
2002 VE68 20.3 1.0 0.2 G
33342 1998 WT24 17.9 E 0.97 0.10 A G Busch et al. 2008
3103 Eger 15.4 E 0.92 0.06 A G 1986, 1991, 1996 Benner et al. 1997
2005 WJ56 18.1 E 0.92 0.15 A G
2001 CP36 23.7 0.91 0.02 A
152770 1999 RR28 18.3 E 0.9 0.1 A G
2004 DC 18.0 0.9 0.05 A G BINARY Taylor et al. 2006, 2008
2004 XP14 19.5 E 0.9 0.05 G Benner et al. 2006
2005 WK56 22.5 0.90 0.10 A
2001 WM15 25.0 0.83 0.02 A
3908 Nyx 17.4 V 0.75 0.03 A G Benner et al. 2002b
4660 Nereus 18.2 E 0.74 0.08 A Brozovic et al. 2008, submitted
87024 2000 JS66 18.6 X 0.73 0.08 A
2005 TF49 19.0 0.73 0.06 A
2003 SS84 21.8 0.72 0.05 G A BINARY
1981 Midas 15.5 V 0.65 0.13 A G 1987 Ostro et al. 1991b
164121 2003 YT1 16.2 V 0.61 0.06 A
S
2001 YE4 20.5 0.61 0.11 A
2006 RH120 29.6 0.58 0.03 G
7889 1994 LX 15.3 V 0.57 0.05 A
2006 RZ 20.3 B 0.55 0.05 G
5381 Sekhmet 16.5 V 0.52 0.02 A BINARY
5604 1992 FE 16.4 V 0.52 0.06 G A
1566 Icarus 16.9 Q 0.5 0.2 G 1996 Mahapatra et al. 1999
1998 KY26 25.5 C 0.5 0.1 G Ostro et al. 1999b
2002 KK8 20.5 0.50 0.05 A
2004 XL14 21.2 C 0.49 0.01 G
4486 Mithra 15.6 0.48 0.01 G
3199 Nefertiti 14.8 S 0.47 0.04 A Shepard et al. 2004
66391 1999 KW4 a 16.5 S 0.45 0.11 G A 2001 BINARY Ostro et al. 2006
66391 1999 KW4 b S 0.45 0.20 G A 2001 BINARY Ostro et al. 2006
2004 AD 24.5 0.45 0.15 A
2005 FA 25.2 0.45 0.08 A
154276 2002 SY50 17.6 0.44 0.08 G
2002 TD60 19.2 S 0.41 0.10 A
2003 HN16 22.0 0.41 0.04 A
2007 DT103 19.2 S 0.40 0.05 G BINARY
2062 Aten 16.8 S 0.39 0.06 G Benner et al. 1997
89136 2001 US16 20.2 0.39 0.05 G
2000 UK11 25.0 0.38 0.05 G
2005 JE46 17.8 0.38 0.01 G
2005 OE3 20.3 0.38 0.03 G
2006 WB 22.8 0.38 0.03 A
2007 XH16 19.7 0.38 0.01 A
5189 1990 UQ 17.3 0.37 0.05 G
5660 1974 MA 15.7 Q 0.37 0.15 A
11500 Tomaiyowit 18.4 S 0.37 0.03 G (1989 UR)
2003 QB30 26.4 0.37 0.02 A
2004 VW14 19.4 0.37 0.05 A
2007 TU24 20.2 S 0.37 0.01 G
4953 1990 MU 14.1 Q 0.36 0.03 G
38071 1999 GU3 19.4 0.36 0.07 G 1999 Pravec et al. 2000
2005 ED318 20.7 Q 0.36 0.02 G
1998 BY7 21.4 0.35 0.04 G
1999 NW2 23.1 0.35 0.03 G
2002 FC 18.8 0.35 0.08 G
10115 1992 SK 17.0 S 0.34 0.05 G Busch et al. 2006
1999 TY2 23.3 S 0.34 0.15 A
1862 Apollo 16.3 Q 0.33 0.01 A 1980 BINARY Ostro et al. 1991b
2002 NY40 19.2 S 0.33 0.07 A
2006 BQ6 19.7 C? 0.33 0.03 G
1866 Sisyphus 13.0 S 0.32 0.04 A Ostro et al. 1991b
4183 Cuno 14.4 S 0.32 0.02 A
6037 1988 EG 18.7 S 0.32 0.02 G
138257 2000 GD2 19.1 S 0.32 0.15 G
2005 CR37 18.9 C? 0.32 0.03 A Benner et al. 2006
2201 Oljato 15.3 S 0.31 0.02 A Ostro et al. 1991b
2004 RQ10 20.9 0.31 0.15 A
4769 Castalia 16.9 0.30 0.02 A G Ostro et al. 1991b
11066 Sigurd 15.2 S 0.30 0.03 A
52760 1998 ML14 17.6 S 0.30 0.03 G A Ostro et al. 2001
1998 ST27 19.5 C 0.30 0.01 A BINARY Benner et al., in prep.
2003 TL4 19.4 0.30 0.03 G
4179 Toutatis 15.3 S 0.29 0.01 G 1996 Ostro et al. 1999a
2003 EP4 23.7 0.29 0.04 A
433 Eros 11.2 S 0.28 0.06 G A 1975 & 1988 Magri et al. 2001
7025 1993 QA 18.0 0.28 0.03 G
7822 1991 CS 17.4 S 0.28 0.01 G Benner et al. 1999a
22771 1999 CU3 16.7 S 0.28 0.02 A 2003
2000 ED14 20.7 0.28 0.12 A
2003 MS2 21.0 0.28 0.02 G
2005 WA1 21.6 0.28 0.10 A
1915 Quetzalcoatl 19.0 S 0.27 0.08 A Shepard et al. 2004
3757 1982 XB 19.0 S 0.27 0.05 A Shepard et al. 2004
7482 1994 PC1 16.8 S 0.27 0.04 G
12711 Tukmit 16.0 S 0.27 0.05 A (1991 BB)
25143 Itokawa 19.0 S 0.27 0.04 A 2001 Ostro et al. 2004
30825 1990 TG1 14.6 S 0.27 0.03 A
52387 1993 OM7 17.4 0.27 0.02 A
152560 1991 BN 19.0 Q 0.27 0.04 A
2001 BF10 22.3 0.27 0.03 A
2001 GQ2 20.0 0.27 0.06 A
2002 FD6 22.2 0.27 0.03 G
2006 AM4 21.8 0.27 0.02 A
2006 VV2 16.8 S 0.27 0.02 A
2007 VD12 20.0 S 0.27 0.05 G
14827 Hypnos 18.2 C? 0.26 0.02 G Ostro et al. 1989
163732 2003 KP2 15.3 C 0.26 0.08 A
179806 2002 TD66 19.9 S 0.26 0.02 A
2001 SE286 17.1 0.26 0.01 A
2002 AA29 24.1 0.26 0.07 A Ostro et al. 2003
2005 EU2 23.1 0.26 0.06 A G
2100 Ra-Shalom 16.1 K 0.25 0.04 A 1981,1984,2000,2003 Shepard et al. 2000, 2007
3200 Phaethon 14.6 B 0.25 0.02 A
4197 1982 TA 14.6 S 0.25 0.02 G
22753 1998 WT 17.4 S 0.25 0.03 G 2005
85774 1998 UT18 19.1 C 0.25 0.01 A
144900 2004 VG64 18.2 S 0.25 0.02 A
162181 1999 LF6 18.2 S 0.25 0.01 A
185851 2000 DP107 18.0 X 0.25 0.02 G BINARY
2003 RU11 25.6 0.25 0.02 A
9856 1991 EE 17.4 S 0.24 0.02 A
66063 1998 RO1 18.0 S 0.24 0.05 A 2003 BINARY
23187 2000 PN9 15.9 S 0.24 0.02 A 2001
26663 2000 XK47 18.0 0.24 0.02 A
2000 CE59 20.2 0.24 0.02 A
2005 NB7 18.7 S 0.24 0.01 A
4450 Pan 17.2 S 0.23 0.03 A
6239 Minos 17.9 0.23 0.04 G
6489 Golevka 19.2 Q 0.23 0.02 G 1995 Hudson et al. 2000
68950 2002 QF15 16.2 S 0.23 0.02 A 2003
162000 1990 OS 19.3 0.23 0.03 A 1990 BINARY Ostro et al. 1991b
162416 2000 EH26 21.3 0.23 0.07 A
2000 YF29 20.2 S 0.23 0.01 A
2001 EB18 19.1 0.23 0.05 A
2001 EC16 22.2 0.23 0.08 G
68346 2001 KZ66 16.5 S 0.22 0.02 A
85182 1991 AQ 17.1 0.22 0.03 A
136770 1996 PC1 20.3 0.22 0.02 A
1999 FN19 22.4 S 0.22 0.05 G
2000 QW7 19.4 0.22 0.03 G
2000 UG11 20.3 S 0.22 0.11 G BINARY
1627 Ivar 13.2 S 0.21 0.01 A Ostro et al. 1990
1917 Cuyo 13.9 S 0.21 0.03 A G Ostro et al. 1991b
2063 Bacchus 17.1 Q 0.21 0.01 G Benner et al. 1999b
4034 1986 PA 18.1 O 0.21 0.14 A Shepard et al. 2004
54509 YORP 22.6 S 0.21 0.02 G A Taylor et al. 2007
1994 XD 19.1 0.21 0.05 A BINARY
1999 MN 21.4 0.21 0.05 A 2005
2000 RD53 19.9 0.21 0.05 G
2002 AY1 20.6 0.21 0.02 A
2002 CE26 16.8 C 0.21 0.02 A BINARY Shepard et al. 2006
2003 UC20 18.1 C 0.21 0.03 A
2006 GY2 18.7 0.21 0.02 G BINARY
1580 Betulia 14.5 C 0.20 0.03 A G 2002 Magri et al. 2007
1620 Geographos 15.6 S 0.20 0.01 A G 1983 & 1994 Ostro et al. 1996
16834 1997 WU22 15.4 S 0.20 0.10 A
35396 1997 XF11 16.9 X 0.20 0.02 G
37655 Illapa 17.7 C 0.20 0.04 G
65803 Didymos 18.0 M S 0.20 0.02 G BINARY
100085 1992 UY4 17.6 P 0.20 0.02 G A Benner et al., in prep.
138971 2001 CB21 18.4 0.20 0.02 A
163692 2003 CY18 18.0 0.20 0.05 A
164211 2004 JA27 19.5 Q 0.20 0.04 A
2002 AL14 17.7 L 0.20 0.01 A
2002 BG25 20.8 0.20 0.02 A
2002 BM26 20.0 P 0.20 0.03 A
2006 UQ17 21.9 0.20 0.06 A
7335 1989 JA 17.0 0.19 0.06 A G Mahapatra et al. 2002
8014 1990 MF 18.7 0.19 0.04 A Ostro et al. 1991b
53319 1999 JM8 15.0 P 0.19 0.01 G A Benner et al. 2002a
69230 Hermes 17.5 S 0.19 0.02 G BINARY
85938 1999 DJ4 18.5 Q 0.19 0.02 A BINARY
162039 1996 JG 19.1 0.19 0.04 G
1999 FN53 18.4 0.19 0.07 G
2000 LF3 21.6 0.19 0.02 A
2001 BE10 19.1 0.19 0.02 A
2003 HM 21.7 0.19 0.04 A
1036 Ganymed 9.5 S 0.18 0.06 A Ostro et al. 1991b
7753 1988 XB 18.6 B 0.18 0.02 A
101955 1999 RQ36 20.8 B 0.18 0.01 G
2001 SG276 17.7 0.18 0.03 A
7341 1991 VK 16.7 Q 0.17 0.02 A
144901 2004 WG1 17.4 0.17 0.01 A
2001 FR85 24.5 0.17 0.01 A
2001 YP3 21.9 0.17 0.03 A
13651 1997 BR 17.6 S 0.16 0.04 G
65909 1998 FH12 19.1 0.16 0.03 G
153591 2001 SN263 16.9 P 0.16 0.01 A
2000 YA 23.7 S 0.16 0.02 A
2001 SP263 25.6 0.16 0.02 A
2002 TS69 24.5 0.16 0.02 A
2004 VB 20.7 0.16 0.05 A
1685 Toro 14.2 S 0.15 0.05 A Ostro et al. 1983
2000 EW70 21.1 F 0.15 0.09 A
2005 AB 17.5 C 0.15 0.04 A BINARY
2001 XX4 22.0 0.15 0.03 A
2005 EK70 17.4 0.15 0.07 A
2005 TD49 26.4 0.15 0.10 A
2007 FY20 24.8 0.15 0.10 A
29075 1950 DA 16.8 M 0.14 0.03 A G Busch et al. 2007
1989 AZ 19.4 0.13 0.04 A
2004 HX53 23.3 0.13 0.05 A
141432 2002 CQ11 19.9 0.12 0.02 A
99942 Apophis 19.7 Q 0.1 0.2 A Giorgini et al. 2008
2002 AV 20.7 K 0.10 0.01 A
2004 RF84 18.2 0.10 0.01 A
6178 1986 DA 15.1 M 0.09 0.02 A Ostro et al. 1991a
2001 UP 25.7 0.09 0.01 A
2004 FY31 21.9 0.09 0.03 A
4544 Xanthus 17.1 0.07 0.12 A Benner et al. 1997
2005 XA 26.1 0.06 0.08 A
2005 HB4 24.3 0.05 0.15 A
2001 AV43 24.4 0.01 0.10 A
163295 2002 HW 19.3 0.0 0.10 A
2002 TZ66 25.9 0.0 0.2 A
2006 QV89 25.2 0.0 0.25 A
N = 214 (counting 1999 KW4 Alpha and Beta as one object)
Mean and rms dispersion = 0.336 +/- 0.248
Median = 0.26
The taxonomy adopted is that described by Tholen and Barucci (1989) and Bus et al. (2002).
The final version in the paper uses the Tholen system for simplicity; objects reported using the
Bus taxonomy have been converted to Tholen's.
Table 3: Spectral classes
Last update: 2008 August 01
NEAR-EARTH ASTEROIDS MAIN-BELT ASTEROIDS
Taxonomic <--------- SC/OC ---------> <--------- SC/OC -------->
Class Mean SD Range Number Mean SD Range Number
--------- ---- -- ----- ------ ---- -- ----- ------
C 0.285 0.120 0.40 17 0.098 0.056 0.22 25
E 0.892 0.079 0.23 6 0.67 0.226 0.32 2 **
F 0.15 ---- ---- 1 0.058 0.101 0.26 6
G 0.102 0.080 0.20 5
M 0.143 0.055 0.11 3 0.153 0.097 0.23 6
O 0.21 ----- ---- 1
P 0.188 0.019 0.04 4 0.096 0.062 0.18 9
S 0.270 0.079 0.40 70 0.198 0.094 0.35 27
V 0.603 0.088 0.23 6 0.28 ----- ---- 1
X 0.674 0.436 0.90 5
? 0.339 0.284 1.48 101
? = Taxonomy unknown
X = EMP (degenerate)
C = C- and B-types
S = S-, Q-, K-, L-, and R-types
Total = 214
** Hungaria and Nysa were observed by M. K. Shepard et al. 2007. Radar observations of
E-class asteroids 44 Nysa and 434 Hungaria. Icarus 195, 220-225.
The other MBA results are from Magri et al. 2007, A radar survey of mainbelt asteroids:
Arecibo observations of 55 objects during 1999-2003. Icarus 186, 126-151.
POST-PUBLICATION UPDATES
2009 Sep. 22: The table above does not include the reclassification of 65803 Didymos from
the M class to the S class.
2009 Nov. 02: Hicks and Barajas report that 1999 LF6 is an S-class object. That has been
updated in the SC/OC tables but is not reflected in the table of statistics above.
Abundances by spectral class and comparison with meteorite falls
Meteorite
Abundance in the NEA sample Fall Statistics
--------------------------- ---------------
C 16/107 = 15.0% 40/930 = 4.3% (CI, CM, & other carbonaceous chondrites)
E 6/107 = 5.6% 9/930 = 1.0%
F 1/107 = 0.9%
G 0/107 = 0.0%
M 3/107 = 2.8% 40/930 = 4.3% (Irons; excludes stony-irons)
O 1/107 = 0.9%
P 3/107 = 2.8%
S 66/107 = 61.7% 738/930 = 79.4% (H, L, LL ordinary chondrites; excluding E chondrites)
V 6/107 = 5.6% 60/930 = 6.5% (HEDs--all three groups)
X 5/107 = 4.7%
? 82/189 = 43.4%
Figure 1
Figure 2
Figure 3
Supplementary figures
|
Table COMET SC/OC
=================
Last updated: 2008 August 01
Comet Nucleus SC/OC Year Observatory
----- ------------- ---- -----------
2P/Encke No SC data 1980 Arecibo Kamoun et al. 1982, Harmon et al. 2004
0.21 +-0.04 2003 Arecibo Harmon and Nolan 2005
26P/Grigg-Skjellerup <0.3 1982 Arecibo Kamoun et al. 1999, Harmon et al. 2004
73P/Schwassmann-Wachmann 3 Nolan et al. 2006 (reported the detection by not SC/OC)
Fragment B 0.51 +-0.05 2006 Arecibo & Goldstone X-band result shown
Fragment C 0.06 +-0.05 2006 Arecibo & Goldstone X-band result shown
P/2005 JQ5 Catalina 3 0.49 +-0.05 2005 Arecibo Harmon et al. 2006
C/IRAS-Araki-Alcock 0.105+-0.005 1983 Arecibo Harmon et al. 1989, Harmon et al. 2004
0.25 1983 Goldstone Goldstein et al. 1984, Harmon et al. 2004
C/Sugano-Saigusa-Fujikawa 0.23 +-0.03 1983 Arecibo Harmon et al. 1999 Harmon et al. 2004
C/Hyakutake 0.49 +-0.10 1996 Goldstone Harmon et al. 1997 Harmon et al. 2004
C/1998 K5 LINEAR <0.5 1998 Arecibo Harmon et al. 1999 Harmon et al. 2004
C/2004 Q2 Machholz 0.59 +-0.04 2004 Arecibo Nolan et al. 2005
8P/Tuttle 0.35 +-???? 2008 Arecibo Harmon et al., Asteroids, Comets, and Meteors 2008 conference
Comet nucleus detections = 11 (73P/S-W 3 is treated as two comets)
Mean SC/OC = 0.353 +- 0.195
Range = 0.485
N = 6 (ignoring estimates without uncertainties, those that are only upper limits, and 73P/SW3, which hasn't
been reported yet).
Comets that did not yield nucleus detections:
1P/Halley 1985 Arecibo
C/2001 A2 LINEAR 2001 Arecibo
C/2002 06 Swan 2002 Arecibo
Selected comet references:
Harmon, J. K., and M. C. Nolan 2005. Radar observations of comet 2P/Encke during the 2003 apparition.
Icarus 176, 175-183.
Harmon, J. K., M. C. Nolan, S. J. Ostro, and D. B. Campbell 2004. Radar studies of comet nuclei and grain
comae. In Asteroids II, M. C. Festou, H. U. Keller, and H. A. Weaver, Eds., Tucson, Univ. of Arizona Press,
pp. 265-279.
Harmon, J. K., M. C. Nolan, J. L. Margot, D. B. Campbell, L. A. M. Benner, and J. D. Giorgini 2006. Radar
observations of comet P/2005 JQ5 (Catalina). Icarus 184, 285-288.
Nolan, M. C., D. B. Campbell, J. K. Harmon, E. S. Howell, and C. Magri, 2005. Arecibo radar detection of
the nucleus and coma of C/2004 Q2 (Machholz). In IAU Symposium 229, P14.21 [Abstract].