Summary for : (25143) Itokawa

DynT.TT.BT T.L B T.DDensity (g/cm^3)Δρ/ρDiameter (km)ΔD/DMass (kg)ΔM/MRefAvg.M
NEA--- | --0.63 ± 0.99   (E)156 %0.5 ± 0.252.0 %3.50e+10 ± 1.05e+093 %SEVM
NEA--- | --0.24 ± 0.16   (D)68 %0.7 ± 0.122.8 %3.50e+10 ± 1.05e+093 %Sw.avg
NEAS1.91 ± 0.21   (A)11 %0.3 ± 0.03.1 %3.50e+10 ± 1.00e+093 %C?

Average asteroid densities (g/cm^3):
C = 1.3 ± 0.6, B = 2.4 ± 0.5, S = 2.7 ± 0.5, M = 3.5 ± 1.0, P = 2.8 ± 1.6, X = 1.9 ± 0.8, Xc = 4.9 ± 0.9, Xk = 4.2 ± 0.7 (Ref)

Additional resources:
3D Model | JPL New Horizons | Minor Planet Center | Wikipedia (these auto-generated links might not work)

Note: The density estimates have been ranked from (A) to (E), corresponding to the relative error: (B) less than 20%, (C) between 20 and 50%, (D) between 50 and 100%, and (E) more than 100%. (A) stands for (presumably) reliable estimates (accuracy better than 20%), based on more than 5 mass estimates and 5 diameter estimates, or a spacecraft encounter. Apparently unrealistic densities (ρ > 8) are tagged with (X).

EVM: average by using the Expected Value Method (Ref). w.avg: weighted average (with w = 1/err^2).

T.T: Tholen Tax Class. T.B: Bus & Binzel Tax Class. T T.L: S3OS2 Lazarro (Tholen) Tax Class. T.L B: S3OS2 Lazarro (Bus & Binzel) Tax Class. T.D: DeMeo Tax Class.

Ref: S = SiMDA, C = Carry (2012)

Diameter estimates

DesignationDiameter / Err (km)ΔD/DMethodYearRefNχ2Use
(25143) Itokawa0.83 ± 0.011.2 % STM2004D9212 1275.24 1
(25143) Itokawa0.91 ± 0.011.1 % NEATM2004D9212 1910.61 2
(25143) Itokawa0.32 ± 0.039.4 % TPM2005D1812 25.97 3
(25143) Itokawa0.36 ± 0.038.3 % Radar2005D2012 14.16 4
(25143) Itokawa0.32 ± 0.013.1 % FlyBy2006D36 233.77 5
(25143) Itokawa0.31 ± 0.0412.9 % NEATM2011D7112 16.58 6

plot, average diameter and derived density

All

Notes (N):
1: This estimate is discarded for the average diameter (and derived density) calculation in Carry (2012).
2: This estimate is discarded for the average diameter (and derived density) calculation in SiMDA (catalog).

FlyBy : Images from spacecraft encounter. NEATM : Near-Earth Asteroid Thermal Model. Radar : Radar imaging. STM : Standard Thermal Model. TPM : Thermophysical Model.


EVM diam. average D = (0.5 ± 0.25) km   (ΔD/D = 52%, SNR = 1.92) Derived bulk density ρ = (0.63 ± 0.99) g/cm3   (Δρ/ρ = 156%, SNR = 0.6)


References
D18(2005):Müller, T.G., Sekiguchi, T., Kaasalainen, M., Abe, M., Hasegawa, S., 2005. Thermal infrared observations of the Hayabusa spacecraft target asteroid 25143 Itokawa. Astronomy and Astrophysics 443, 347–355.
D20(2005):Ostro, S.J., Benner, L.A.M., Magri, C., Giorgini, J.D., Rose, R., Jurgens, R.F., Yeomans, D.K., Hine, A.A., Nolan, M.C., Scheeres, D.J., Broschart, S.B., Kaasalainen, M., Margot, J., 2005. Radar observations of Itokawa in 2004 and improved shape estimation. Meteoritics and Planetary Science 40, 1563–1574.
D36(2006):Fujiwara, A., Kawaguchi, J., Yeomans, D.K., Abe, M., Mukai, T., Okada, T., Saito, J., Yano, H., Yoshikawa, M., Scheeres, D.J., Barnouin-Jha, O.S., Cheng, A.F., Demura, H., Gaskell, G.W., Hirata, N., Ikeda, H., Kominato, T., Miyamoto, H., Nakamura, R., Sasaki, S., Uesugi, K., 2006. The Rubble-Pile Asteroid Itokawa as Observed by Hayabusa. Science 312, 1330–1334.
D71(2011):Mueller, M., Delbo, M., Hora, J.L., Trilling, D.E., Bhattacharya, B., Bottke, W.F., Chesley, S., Emery, J.P., Fazio, G., Harris, A.W., Mainzer, A., Mommert, M., Penprase, B., Smith, H.A., Spahr, T.B., Stansberry, J.A., Thomas, C.A., 2011. ExploreNEOs. III. Physical Characterization of 65 Potential Spacecraft Target Asteroids. Astronomical Journal 141, 109.
D92(2004):Delbo, M., 2004. Thermal Infrared Asteroid Diameters and Albedo. NASA Planetary Data System. MSX-A-SPIRIT3-5-SBN0003-MIMPS-V1.0.

Mass estimates

DesignationMass / Err (kg)ΔM/MMethodYearRefNχ2Use
(25143) Itokawa3.50e+10 ± 1.05e+093 %FlyBy 2006M600.00 1

Notes (N):
1: This estimate is discarded for the average mass (and derived density) calculation in Carry (2012).
2: This estimate is discarded for the average mass (and derived density) calculation in SiMDA (catalog).
3: This estimate is an average of individual solutions listed before under the same reference (e.g. M125).

FlyBy : Spacecraft radio experiment (ranging etc. from flyby, orbiter or lander).


EVM mass average M = (3.500 ± 0.105) × 1010 kg   (ΔM/M = 3%, SNR = 33.3) Derived bulk density ρ = (0.63 ± 0.99) g/cm3   (Δρ/ρ = 156%, SNR = 0.6)


References
M60(2006):Fujiwara, A., Kawaguchi, J., Yeomans, D.K., Abe, M., Mukai, T., Okada, T., Saito, J., Yano, H., Yoshikawa, M., Scheeres, D.J., Barnouin-Jha, O.S., Cheng, A.F., Demura, H., Gaskell, G.W., Hirata, N., Ikeda, H., Kominato, T., Miyamoto, H., Nakamura, R., Sasaki, S., Uesugi, K., 2006. The Rubble-Pile Asteroid Itokawa as Observed by Hayabusa. Science 312, 1330–1334.