Summary for : 67P/C-G

DynT.TT.BT T.L B T.DDensity (g/cm^3)Δρ/ρDiameter (km)ΔD/DMass (kg)ΔM/MRefAvg.M
COM--- | --0.55 ± 0.05   (A)9 %3.3 ± 0.13.0 %9.97e+12 ± 2.51e+100 %SEVM
COM--- | --0.54 ± 0.34   (D)64 %3.3 ± 0.617.7 %9.97e+12 ± 3.56e+1236 %Sw.avg
COM-0.43 ± 0.37   (D)86 %3.0 ± 0.13.4 %1.50e+13 ± 6.00e+1240 %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:

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)

(Indirect) density estimates

Density (g/cm^3)Δρ/ρMethodYearRefN
0.23 ± 0.1460.9 %CNGF2005BD5

CNGF : Non-gravitational forces (comets).
References
BD5(2005):Davidsson, B.J.R., Gutierrez, P.J., 2005. Nucleus properties of Comet 67P/Churyumov Gerasimenko estimated from non-gravitational force modeling. Icarus 176, 453–477.

Diameter estimates

DesignationDiameter / Err (km)ΔD/DMethodYearRefNχ2Use
67P/C-G4.19 ± 0.256.0 % H-mag2006D3212 13.63 1
67P/C-G2.96 ± 0.041.4 % H-mag2006D2512 58.98 2
67P/C-G2.96 ± 0.103.4 % TPM2008D422 9.44 3
67P/C-G3.29 ± 0.000.0 % FlyBy2018D106 317.23 4

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. H-mag : Crude estimate from absolute magnitude. TPM : Thermophysical Model.


EVM diam. average D = (3.3 ± 0.10) km   (ΔD/D = 3%, SNR = 33.32) Derived bulk density ρ = (0.55 ± 0.05) g/cm3   (Δρ/ρ = 9%, SNR = 11.1)


References
D25(2006):Lamy, P.L., Toth, I., Weaver, H.A., Jorda, L., Kaasalainen, M., Gutiérrez, P.J., 2006. Hubble Space Telescope observations of the nucleus and inner coma of comet 67P/Churyumov-Gerasimenko. Astronomy and Astrophysics 458, 669–678.
D32(2006):Tancredi, G., Fernández, J.A., Rickman, H., Licandro, J., 2006. Nuclear magnitudes and the size distribution of Jupiter family comets. Icarus 182, 527–549.
D42(2008):Lamy, P.L., Toth, I., Groussin, O., Jorda, L., Kelley, M.S., Stansberry, J.A., 2008. Spitzer Space Telescope observations of the nucleus of comet 67P/Churyumov-Gerasimenko. Astronomy and Astrophysics 489, 777–785.
D106(2018):Pätzold, M.; Andert, T.P.; Hahn, M.; Barriot, J.P.; Asmar, S.W.; Häusler,B.; Bird, M.K.; Tellmann, S.; Oschlisniok, J.; Peter, K.; 2018. The Nucleus of comet 67P/Churyumov–Gerasimenko – Part I: The global view – nucleus mass, mass-loss, porosity, and implications, Monthly Notices of the Royal Astronomical Society, Volume 483, Issue 2, February 2019, Pages 2337–2346, https://doi.org/10.1093/mnras/sty3171

Mass estimates

DesignationMass / Err (kg)ΔM/MMethodYearRefNχ2Use
67P/C-G1.50e+13 ± 6.00e+1240 %CNGF 2009M8520.70 1
67P/C-G9.97e+12 ± 1.50e+080 %FlyBy 2018M1310.70 2

plot, average mass and derived density

All

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).

CNGF : Non-gravitational forces (comets). FlyBy : Spacecraft radio experiment (ranging etc. from flyby, orbiter or lander).


EVM mass average M = (9.972 ± 0.025) × 1012 kg   (ΔM/M = 0%, SNR = 396.6) Derived bulk density ρ = (0.55 ± 0.05) g/cm3   (Δρ/ρ = 9%, SNR = 11.1)


References
M85(2009):Sosa, A., Fernández, J.A., 2009. Cometary masses derived from nongravitational forces. Monthly Notices of the Royal Astronomical Society 393, 192–214.
M131(2018):Pätzold, M.; Andert, T.P.; Hahn, M.; Barriot, J.P.; Asmar, S.W.; Häusler,B.; Bird, M.K.; Tellmann, S.; Oschlisniok, J.; Peter, K.; 2018. The Nucleus of comet 67P/Churyumov–Gerasimenko – Part I: The global view – nucleus mass, mass-loss, porosity, and implications, Monthly Notices of the Royal Astronomical Society, Volume 483, Issue 2, February 2019, Pages 2337–2346, https://doi.org/10.1093/mnras/sty3171