SiMDA»Main

Summary for : (9) Metis

Dyn	T.T	T.B	T T.L B	T.D	Density (g/cm^3)	Δρ/ρ	Diameter (km)	ΔD/D	Mass (kg)	ΔM/M	Ref	Avg.M
MBA	S	-	T \| T	-	3.85 ± 1.25 (C)	32 %	161.3 ± 12.3	7.6 %	8.45e+18 ± 1.95e+18	23 %	S	EVM
MBA	S	-	T \| T	-	3.34 ± 1.49 (C)	45 %	157.6 ± 13.8	8.8 %	6.84e+18 ± 2.46e+18	36 %	S	w.avg
MBA	S				3.60 ± 0.87 (C)	24 %	164.5 ± 7.7	4.7 %	8.39e+18 ± 1.67e+18	20 %	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)

Object is a Gaia target for mass determination !

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

Designation	Diameter / Err (km)	ΔD/D	Method	Year	Ref	N	χ²	Use
(9) Metis	154.66 ± 4.25	2.7 %	STM	2004	D94		2.43	1
(9) Metis	181.00 ± 1.50	0.8 %	Img	2006	D34	1	172.73	2
(9) Metis	152.41 ± 0.01	0.0 %	STM	2010	D64	2	787846.25	3
(9) Metis	178.11 ± 0.02	0.0 %	NEATM	2010	D64	2	707611.52	4
(9) Metis	169.00 ± 20.00	11.8 %	MDM:LO	2011	D78		0.15	5
(9) Metis	166.47 ± 2.07	1.2 %	TPM	2011	D83		6.27	6
(9) Metis	204.52 ± 3.67	1.8 %	NEATM	2011	D72	12	138.78	7
(9) Metis	190.78 ± 4.90	2.6 %	NEATM	2011	D72	12	36.23	8
(9) Metis	168.00 ± 3.00	1.8 %	ADAM	2017	D100		5.01	9

plot, average diameter and derived density

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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).

ADAM : All-Data Asteroid Modeling. Img : Apparent size in disk-resolved imaging. MDM:LO : Multi-Data Modeling: Lightcurves + Occultations. NEATM : Near-Earth Asteroid Thermal Model. STM : Standard Thermal Model. TPM : Thermophysical Model.

EVM diam. average D = (161.3 ± 12.28) km (ΔD/D = 8%, SNR = 13.14) Derived bulk density ρ = (3.85 ± 1.25) g/cm³ (Δρ/ρ = 32%, SNR = 3.1)

References

D34	(2006):	Marchis, F., Kaasalainen, M., Hom, E.F.Y., Berthier, J., Enriquez, J., Hestroffer, D., Le Mignant, D., de Pater, I., 2006. Shape, size and multiplicity of main-belt asteroids. Icarus 185, 39–63.
D64	(2010):	Ryan, E.L., Woodward, C.E., 2010. Rectified Asteroid Albedos and Diameters from IRAS and MSX Photometry Catalogs. Astronomical Journal 140, 933–943.
D72	(2011):	Masiero, J.R., Mainzer, A.K., Grav, T., Bauer, J.M., Cutri, R.M., Dailey, J., Eisenhardt, P.R.M., McMillan, R.S., Spahr, T.B., Skrutskie, M.F., Tholen, D., Walker, R.G., Wright, E.L., DeBaun, E., Elsbury, D., Gautier, IV, T., Gomillion, S., Wilkins, A., 2011. Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters. Astrophysical Journal 741, 68.
D78	(2011):	Ďurech, J., Kaasalainen, M., Herald, D., Dunham, D., Timerson, B., Hanuš, J., Frappa, E., Talbot, J., Hayamizu, T., Warner, B.D., Pilcher, F., Galád, A., 2011. Combining asteroid models derived by lightcurve inversion with asteroidal occultation silhouettes. Icarus 214, 652–670.
D83	(2011):	Usui, F., Kuroda, D., Müller, T.G., Hasegawa, S., Ishiguro, M., Ootsubo, T., Ishihara, D., Kataza, H., Takita, S., Oyabu, S., Ueno, M., Matsuhara, H., Onaka, T., 2011. Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey. Publications of the Astronomical Society of Japan 63, 1117–1138.
D94	(2004):	Tedesco, E.F., Egan, M.P., Price, S.D., 2004. MSX Infrared Minor Planet Survey. NASA Planetary Data System. MSX-A-SPIRIT3-5-SBN0003-MIMPS-V1.0.
D100	(2017):	Hanuš, J., Viikinkoski, M., Marchis, F., et al., 2017. Volumes and bulk densities of forty asteroids from ADAM shape modeling. Astronomy and Astrophysics 601, A114 (2017). DOI: 10.1051/0004-6361/201629956

Mass estimates

Designation	Mass / Err (kg)	ΔM/M	Method	Year	Ref	N	χ²	Use
(9) Metis	1.13e+19 ± 2.78e+18	25 %	Deflec	2008	M72		1.05	1
(9) Metis	2.29e+18 ± 1.99e+18	87 %	Ephem	2009	M80	12	9.59	2
(9) Metis	8.50e+18 ± 8.50e+17	10 %	Ephem	2009	M86		0.00	3
(9) Metis	2.96e+19 ± 1.66e+19	56 %	Deflec	2010	M92	12	1.62	4
(9) Metis	1.13e+19 ± 2.19e+18	19 %	Deflec	2011	M95		1.69	5
(9) Metis	6.52e+18 ± 2.15e+18	33 %	Ephem	2011	M103		0.81	6
(9) Metis	8.12e+18 ± 2.05e+18	25 %	Deflec	2011	M97		0.03	7
(9) Metis	9.08e+18 ± 1.34e+18	15 %	Deflec	2011	M97		0.22	8
(9) Metis	9.00e+18 ± 1.33e+18	15 %	Deflec	2011	M97		0.17	9
(9) Metis	1.60e+19 ± 3.02e+18	19 %	Deflec	2011	M97	12	6.25	10
(9) Metis	5.95e+18 ± 9.95e+17	17 %	Ephem	2011	M100		6.32	11
(9) Metis	4.97e+18 ± 3.98e+17	8 %	OrbFitN	2014	M123		76.46	12
(9) Metis	6.74e+18 ± 8.25e+17	12 %	Deflec	2017	M125	2	4.30	13
(9) Metis	9.58e+18 ± 1.55e+18	16 %	Deflec	2017	M125	2	0.53	14
(9) Metis	7.58e+18 ± 2.21e+18	29 %	Deflec	2017	M125	2	0.16	15
(9) Metis	1.01e+19 ± 3.36e+18	33 %	Deflec	2017	M125	2	0.25	16
(9) Metis	2.09e+19 ± 7.18e+18	34 %	Deflec	2017	M125	2	3.00	17
(9) Metis	9.19e+18 ± 3.50e+18	38 %	Deflec	2017	M125	2	0.04	18
(9) Metis	8.85e+18 ± 3.40e+18	38 %	Deflec	2017	M125	2	0.01	19
(9) Metis	1.08e+19 ± 4.85e+18	45 %	Deflec	2017	M125	2	0.24	20
(9) Metis	7.78e+18 ± 6.44e+17	8 %	Deflec	2017	M125	3	1.10	21
(9) Metis	8.17e+18 ± 8.93e+17	11 %	Ephem	2019	M126		0.10	22

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).

Deflec : Orbital deflection (close encounter) of one or several test asteroids (classical LSQ). Ephem : Planetary ephemeris solution. OrbFitN : Simultaneous multi-asteroid astrometric orbit solution (similar to 'Ephem').

EVM mass average M = (8.451 ± 1.950) × 10¹⁸ kg (ΔM/M = 23%, SNR = 4.3) Derived bulk density ρ = (3.85 ± 1.25) g/cm³ (Δρ/ρ = 32%, SNR = 3.1)

References

M72	(2008):	Baer, J., Milani, A., Chesley, S.R., Matson, R.D., 2008. An Observational Error Model, and Application to Asteroid Mass Determination, in: Bulletin of the American Astronomical Society, p. 493.
M80	(2009):	Fienga, A., Laskar, J., Morley, T., Manche, H., Kuchynka, P., Le Poncin-Lafitte, C., Budnik, F., Gastineau, M., Somenzi, L., 2009. INPOP08, a 4-D planetary ephemeris: from asteroid and time-scale computations to ESA Mars Express and Venus Express contributions. Astronomy and Astrophysics 507, 1675–1686.
M86	(2009):	Folkner, W.M., Williams, J.G., Boggs, D.H., 2009. The planetary and lunar ephemeris de 421. IPN Progress Report 42, 1–34.
M92	(2010):	Somenzi, L., Fienga, A., Laskar, J., Kuchynka, P., 2010. Determination of asteroid masses from their close encounters with Mars. Planetary and Space Science 58, 858–863.
M95	(2011):	Baer, J., Chesley, S.R., Matson, R.D., 2011. Astrometric Masses of 26 Asteroids and Observations on Asteroid Porosity. Astronomical Journal 141, 143–155.
M97	(2011):	Zielenbach, W., 2011. Mass Determination Studies of 104 Large Asteroids. Astronomical Journal 142, 120–128.
M100	(2011):	Fienga, A., Kuchynka, P., Laskar, J., Manche, H., Gastineau, M., 2011. Asteroid mass determinations with INPOP planetary ephemerides. EPSC-DPS Joint Meeting 2011 , 1879.
M103	(2011):	Konopliv, A.S., Asmar, S.W., Folkner, W.M., Karatekin, Ö., Nunes, D.C., Smrekar, S.E., Yoder, C.F., Zuber, M.T., 2011. Mars high resolution gravity fields from MRO, Mars seasonal gravity, and other dynamical parameters. Icarus 211, 401–428.
M123	(2014):	Goffin, E., 2014. Astrometric asteroid masses: a simultaneous determination. Astronomy & Astrophysics, Volume 565, id.A56, 8 pp.
M125	(2017):	Baer, J., Chesley, S.R., 2017. Simultaneous Mass Determination for Gravitationally Coupled Asteroids. The Astronomical Journal, Volume 154, Issue 2, article id. 76, 11 pp.
M126	(2019):	Fienga, A., et. al, 2019. INPOP19a planetary ephemeris. Notes Scientifiques et Techniques de l'Institut de mécanique céleste,

Size, Mass and Density of Asteroids (SiMDA)

Summary for : (9) Metis

Diameter estimates

Mass estimates