Near-Earth Asteroid Elongations from Radar Observations
Last modified: 2010 Sep 14
Pole-on elongations estimated from convex hulls, three-dimensional shape reconstructions, or
bandwidth extrema from observations that do not permit hull or shape inversions due to
insufficient SNR and/or rotational coverage. For the non-principal axis rotator Toutatis,
we list the ratio of the long
to the intermediate axis from its shape model. For objects described in more than one
paper, the most recent estimate of the elongation is cited (e.g., Castalia, Geographos,
and Itokawa).
Pole-on Inversion
Asteroid elongation method Reference
-------- ---------- --------- ---------
1620 Geographos 2.5 3-D model Hudson and Ostro 1999
11066 Sigurd 2.5 bandwidth extrema Benner et al. 2004
4179 Toutatis 2.4 3-D model Hudson and Ostro 1995
8567 1996 HW1 2.3 3-D model Magri et al., in preparation.
433 Eros 2.2 3-D, hull Mitchell et al. 1998, Ostro et al. 1990b
1627 Ivar 2.1 hull Ostro et al. 1990a
2063 Bacchus 2.1 3-D model Benner et al. 1999b
25143 Itokawa 1.9 3-D model Ostro et al.. 2005
2005 CR37 1.9 bandwidth extrema Benner et al., 2006
4183 Cuno 1.7 bandwidth extrema Benner et al. 2001
4769 Castalia 1.6 3-D model Hudson and Ostro 1994
1685 Toro 1.5 ellipsoid fit Ostro et al. 1983
3103 Eger 1.5 bandwidth extrema Benner et al. 1997
4660 Nereus 1.5 3-D model Brozovic et al. 2009
10115 1992 SK 1.5 3-D model Busch et al. 2006
4486 Mithra 1.4 3-D model Brozovic et al. 2010
6178 1986 DA 1.4 hull Ostro et al. 1991
6489 Golevka 1.4 3-D model Hudson et al. 2000
1862 Apollo 1.3 hull Ostro et al., 2002
2010 AL30 1.3 bandwidth extrema In preparation
2100 Ra-Shalom 1.2 hull Shepard et al. 2000
3908 Nyx 1.2 hull, 3-D Benner et al. 2002b
4197 1982 TA 1.2 hull * unpublished *
7822 1991 CS 1.2 hull Benner et al. 1999a
66391 1999 KW4 1.2 3-D model (secondary) Ostro et al, 2006
1998 KY26 1.2 hull Ostro et al. 1999
1999 JM8 1.2 bandwidth extrema Benner et al., 2002a
1999 RQ36 1.2 3-D model Hudson et al. 2000
1998 ML14 1.1 3-D model Ostro et al. 2001
1580 Betulia 1.1 3-D model Magri et al. 2007
29075 1950 DA 1.1 3-D models (both) Busch et al. 2007
33342 1998 WT24 1.1 3-D model Busch et al.. 2008
54509 YORP 1.1 3-D model Taylor et al. 2007
66391 1999 KW4 1.0 3-D model (primary) Ostro et al 2006
2002 CE26 1.0 3-D model (primary) Shepard et al., 2006
2004 DC 1.0 3-D model (primary) Taylor 2009
2008 EV5 1.0 3-D model Busch et al., in preparation
N = 37
Mean and rms dispersion = 1.49 +/- 0.46
Future updates:
35107 1991 VH in preparation
65803 Didymos Benner et al. in preparation
101955 1999 RQ36 Nolan et al. in preparation
136617 1994 CC Brozovic et al., in preparation
185851 2000 DP107 in preparation
2000 CO101
2009 KC3 Taylor et al., in preparation
MANY other data sets are available that should yield hulls and/or 3-D reconstructions.
REFERENCES
----------
Benner, L. A. M., S. J. Ostro, J. D. Giorgini, R. F. Jurgens, D. L. Mitchell, R. Rose,
K. D. Rosema, M. A. Slade, R. Winkler, D. K. Yeomans, D. B. Campbell, J. F.
Chandler, and I. I. Shapiro 1997. Radar detection of near-Earth asteroids 2062 Aten,
2101 Adonis, 3103 Eger, 4544 Xanthus, and 1992 QN. Icarus 130, 296-312.
Benner, L. A. M., S. J. Ostro, K. D. Rosema, J. D. Giorgini, D. Choate, R. F. Jurgens
R. Rose, M. A. Slade, M. L. Thomas, R. Winkler, and D. K. Yeomans. 1999a. Radar
observations of asteroid 7822 (1991 CS). Icarus 137, 247-259.
Benner, L. A. M., R. S. Hudson, S. J. Ostro, K. D. Rosema, J. D. Giorgini, D. K.
Yeomans, R. F. Jurgens, D. L. Mitchell, R. Winkler, R. Rose, M. A. Slade, M. L.
Thomas, and P. Pravec. 1999b. Radar observations of asteroid 2063 Bacchus.
Icarus 139, 309-327.
Benner, L. A. M., M. C. Nolan, J.-L. Margot, J. D. Giorgini, R. S. Hudson, R. F. Jurgens,
and S. J. Ostro 2001. Recent radar observations of four near-Earth asteroids.
Bull. Am. Astron. Soc. 33, 918. [abstract]
Benner, L. A. M., S. J. Ostro, M. C. Nolan, J. L. Margot, J. D. Giorgini, R. S. Hudson, R. F. Jurgens,
M. A. Slade, E.S Howell, D. B. Campbell, and D. K. Yoemans 2002. Radar observations of
asteroid 1999 JM8. Meteorit. Planet. Sci. 37, 779-792.
Benner, L. A. M., S. J. Ostro, R. S. Hudson, K. D. Rosema, R. F. Jurgens, D. K. Yeomans,
D. B. Campbell, J. F. Chandler, and I. I. Shapiro 2002b. Radar observations of asteroid
3908 Nyx. Icarus 158, 379-388.
Benner, L. A. M. et al. 2004. Radar imaging of contact binary near-Earth asteroid
11066 Sigurd. Bull. Am. Astron. Soc. 36, 1697. [abstract]
Benner, L. A. M., M. C. Nolan, S. J. Ostro, J. D. Giorgini, C. Magri, and J. L. Margot 2006.
Near-Earth asteroid 2005 CR37: Radar images of a candidate contact binary. Icarus 182, 474-481.
Brozovic, M., S. J. Ostro, L. A. M. Benner, J. D. Giorgini, R. F. Jurgens, R. Rose, M. C. Nolan,
A. A. Hine, C. Magri, D. J. Scheeres, and J. L. Margot. 2009. Radar observations and a physical
model of asteroid 4660 Nereus, a prime space mission target. Icarus 201, 153-166.
Brozovic, M., L. A. M. Bener, C. Magri, S. J. Ostro, D. J. Scheeres, J. D. Giorgini, M. C. Nolan,
J. L. Margot, R. F. Jurgens, and R. Rose 2010. Radar observations and a physical model of contact
binary asteroid 4486 Mithra. Icarus 208, 207-20.
Busch, M. W., S. J. Ostro, L. A. M. Benner, J. D. Giorgini, R. F. Jurgens, R. Rose, C. Magri,
P. Pravec, D. J. Scheeres, and S. B. Broschart 2006. Radar and optical observations and physical
modeling of near-Earth asteroid 10115 (1992 SK). Icarus 181, 145-155.
Busch, M. W., J. D. Giorgini, S. J. Ostro, L. A. M. Benner, R. F. Jurgens, R. Rose, M. D. Hicks,
P. Pravec, P. Kusnirak, M. J. Ireland, D. J. Scheeres, S. B. Broschart, C. Magri, M. C. Nolan,
and A. A. Hine 2007. Physical modeling of near-Earth asteroid (29075) 1950 DA. Icarus 190,
608-621.
Busch, M. W., L. A. M. Benner, S. J. Ostro, J. D. Giorgini, R. F. Jurgens, R. Rose, D. J. Scheeres,
C. Magri, J. L. Margot, M. C. Nolan, and A. A. Hine 2008. Physical properties of near-Earth
asteroid (33342) 1998 WT24. Icarus 195, 614-621.
Busch, M. W., S. J. Ostro, L. A. M. Benner, M. Brozovic, J. D. Giorgini, J. S. Jao,
D. J. Scheeres, C. Magri, M. C. Nolan, E. S. Howell, P. A. Taylor, J. L. Margot,
and W. Brisken 2010. Radar observations and the shape of near-Earth asteroid 2008 EV5.
(In preparation)
Hudson, R. S., and S. J. Ostro 1994. Shape of asteroid 4769 Castalia (1989 PB) from
inversion of radar images. Science 263, 940-943.
Hudson, R. S., and S. J. Ostro 1995. Shape and non-principal axis spin state of asteroid
4179 Toutatis. Science 270, 84-86.
Hudson, R. S., and S. J. Ostro 1999. Physical model of asteroid 1620 Geographos from radar
and optical data. Icarus 140, 369-378.
Hudson, R. S., S. J. Ostro, R. F. Jurgens, K. D. Rosema, J. D. Giorgini, R. Winkler,
R. Rose, D. Choate, R. A. Cormier, C. R. Franck, R. Frye, D. Howard, D. Kelley,
R. Littlefair, M. A. Slade, L. A. M. Benner, M. L. Thomas, D. L. Mitchell, P. W.
Chodas, D. K. Yeomans, D. J. Scheeres, P. Palmer, A. Zaitsev, Y. Koyama, A.
Nakamura, A. W. Harris, and M. N. Meshkov 2000. Radar observations and physical
modeling of asteroid 6489 Golevka. Icarus 148, 37-51.
Hudson, R. S., S. J. Ostro, and L. A. M. Benner 2000. Recent delay-Doppler radar
asteroid modeling results: 1999 RQ36 and craters on Toutatis. Bull. Am. Astron.
Soc. 32, 1001. [abstract]
Magri, C., S. J. Ostro, D. J. Scheeres, M. C. Nolan, J. D. Giorgini, L. A. M. Benner, and J. L. Margot,
2007. Radar observations and a physical model of asteroid 1580 Betulia. Icarus 186, 152-177.
Magri, C., E. S. Howell, M. C. Nolan, P. A. Taylor, Y. R. Fernandez, M. Mueller, R. J. Vervack,
L. A. M. Benner, J. D. Giorgini, S. J. Ostro, D. J. Scheeres, M. D. Hicks, H. Rhoades, J. M. Somers,
N. M. Gaftonyuk, V. V. Kouprianov, Y. N. Krugly, I. E. Molotov, V. Benishek, V. Protich-Benishek,
A. Galad, D. Higgins, P. Kusnirak, and D. P. Pray 2010. Observations and a physical model of
near-Earth asteorid (8567) 1996 HW1. (In preparation)
Mitchell, D. L., R. S. Hudson, S. J. Ostro, and K. D. Rosema 1998. Shape of asteroid
433 Eros from inversion of Goldstone radar Doppler spectra. Icarus 131, 4-14.
Ostro, S. J., D. B. Campbell, and I. I. Shapiro 1983. Radar observations of asteroid
1685 Toro. Astron. J. 88, 565-576.
Ostro, S. J., D. B. Campbell, A. A. Hine, I. I. Shapiro, J. F. Chandler, C. L. Werner,
and K. D. Rosema 1990a. Radar images of asteroid 1627 Ivar. Astron. J. 99, 2012-2018.
Ostro, S. J., K. D. Rosema, and R. F. Jurgens 1990b. The shape of Eros. Icarus 84,
334-351.
Ostro, S. J., D. B. Campbell, J. F. Chandler, A. A. Hine, R. S. Hudson, K. D. Rosema, and
I. I. Shapiro 1991. Asteroid 1986 DA: Radar evidence for a metallic composition.
Science 252, 1399-1404.
Ostro, S. J., P. Pravec, L. A. M. Benner, R. S. Hudson, L. Sarounova, M. D. Hicks, D. L.
Rabinowitz, J. V. Scotti, D. J. Tholen, M. Wolf, R. F. Jurgens, M. L. Thomas, J. D.
Giorgini, P. W. Chodas, D. K. Yeomans, R. Rose, R. Frye, K. D. Rosema, R. Winkler,
and M. A. Slade 1999b. Radar and optical observations of asteroid 1998 KY26.
Science 285, 557-559.
Ostro, S. J., R. S. Hudson, L. A. M. Benner, M. C. Nolan, J. D. Giorgini, D. J. Scheeres,
R. F. Jurgens, and R. Rose 2001. Radar observations of asteroid 1998 ML14. Meteoritics
Planet. Sci. 36, 1225-1236.
Ostro, S. J., K. D. Rosema, D. B. Campbell, and I. I. Shapiro 2001. Radar observations of
asteroid 1862 Apollo. Icarus 156, 580-583.
Ostro, S. J., L. A. M. Benner, C. Magri, J. D. Giorgini, R. Rose, R. F. Jurgens, D. K. Yeomans,
A. A. Hine, M. C. Nolan, D. J. Scheeres, S. B. Broschart, M. Kaasalainen, and J. L. Margot 2005.
Radar observations of Itokawa in 2004 and improved shape estimation. Meteorit. Planet. Sci.
40, 1563-1574.
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 2006. Radar imaging of binary near-Earth
asteroid (66391) 1999 KW4. Science 314, 1276-1280.
Shepard, M. K., S. J. Ostro, L. A. M. Benner, A. W. Harris, K. D. Rosema, I. I. Shapiro,
J. F. Chandler, and D. B. Campbell 2000. Radar observations of 2100 Ra-Shalom.
Icarus 147, 520-529.
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 2006. Radar, optical, and thermal observations of binary near-Earth
asteroid 2002 CE26. Icarus 184, 198-210.
Taylor, P. A., J. L. Margot, D. Vokrouhlicky, D. J. Scheeres, P. Pravec, S. C. Lowry,
A. Fitzsimmons, M. C. Nolan, S. J. Ostro, L. A. M. Benner, J. D. Giorgini, and C. Magri
2007. Spin rate of asteroid (54509) 2000 PH5 increasing due to the YORP effect.
Science 316, 274-277.
Taylor, P. A. 2009. Tidal Interactions in Binary Asteroid Systems. Ph.D. Thesis, Cornell University.