SiMDA»Main

Summary for : (21) Lutetia

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	M	Xk	X \| X	Xc	3.41 ± 0.93 (C)	27 %	101.9 ± 6.7	6.6 %	1.89e+18 ± 3.54e+17	19 %	S	EVM
MBA	M	Xk	X \| X	Xc	2.97 ± 1.05 (C)	35 %	103.1 ± 5.2	5.0 %	1.71e+18 ± 5.44e+17	32 %	S	w.avg
MBA	Xk				3.44 ± 0.52 (A)	15 %	98.0 ± 5.0	5.1 %	1.70e+18 ± 1.00e+16	1 %	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

Designation	Diameter / Err (km)	ΔD/D	Method	Year	Ref	N	χ²	Use
(21) Lutetia	95.76 ± 4.09	4.3 %	STM	2004	D93	12	2.25	1
(21) Lutetia	100.00 ± 11.00	11.0 %	Radar	2008	D45	12	0.03	2
(21) Lutetia	110.50 ± 3.50	3.2 %	TPM	2009	D57	12	6.04	3
(21) Lutetia	105.19 ± 7.69	7.3 %	Img-TE	2010	D62	12	0.18	4
(21) Lutetia	100.00 ± 5.00	5.0 %	KOALA	2010	D61	12	0.14	5
(21) Lutetia	82.67 ± 2.57	3.1 %	STM	2010	D64	2	55.97	6
(21) Lutetia	104.21 ± 7.11	6.8 %	NEATM	2010	D64	2	0.11	7
(21) Lutetia	98.00 ± 5.00	5.1 %	FlyBy	2011	D84		0.61	8
(21) Lutetia	108.37 ± 1.27	1.2 %	STM	2011	D83	12	25.97	9

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. Img-TE : Triaxial ellipsoid model from images. KOALA : Combined lightcurve(s) + occultation(s) + disk-resolved image(s). NEATM : Near-Earth Asteroid Thermal Model. Radar : Radar imaging. STM : Standard Thermal Model. TPM : Thermophysical Model.

EVM diam. average D = (101.9 ± 6.74) km (ΔD/D = 7%, SNR = 15.11) Derived bulk density ρ = (3.41 ± 0.93) g/cm³ (Δρ/ρ = 27%, SNR = 3.7)

References

D45	(2008):	Shepard, M.K., Clark, B.E., Nolan, M.C., Howell, E.S., Magri, C., Giorgini, J.D., Benner, L.A.M., Ostro, S.J., Harris, A.W., Warner, B.D., Pray, D.P., Pravec, P., Fauerbach, M., Bennett, T., Klotz, A., Behrend, R., Correia, H., Coloma, J., Casulli, S., Rivkin, A.S., 2008. A radar survey of M- and X-class asteroids. Icarus 195, 184–205.
D57	(2009):	Delbo, M., Tanga, P., 2009. Thermal inertia of main belt asteroids smaller than 100 km from IRAS data. Planetary and Space Science 57, 259–265.
D61	(2010):	Carry, B., Kaasalainen, M., Leyrat, C., Merline, W.J., Drummond, J.D., Conrad, A.R., Weaver, H.A., Tamblyn, P.M., Chapman, C.R., Dumas, C., Colas, F., Christou, J.C., Dotto, E., Perna, D., Fornasier, S., Bernasconi, L., Behrend, R., Vachier, F., Kryszczynska, A., Polinska, M., Fulchignoni, M., Roy, R., Naves, R., Poncy, R., Wiggins, P., 2010b. Physical properties of the ESA Rosetta target asteroid (21) Lutetia. II. Shape and flyby geometry. Astronomy and Astrophysics 523, A94.
D62	(2010):	Drummond, J.D., Conrad, A., Merline, W.J., Carry, B., Chapman, C.R., Weaver, H.A., Tamblyn, P.M., Christou, J.C., Dumas, C., 2010. Physical properties of the ESA Rosetta target asteroid (21) Lutetia. I. The triaxial ellipsoid dimensions, rotational pole, and bulk density. Astronomy and Astrophysics 523, A93.
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.
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.
D84	(2011):	Sierks, H., Lamy, P., Barbieri, C., Koschny, D., Rickman, H., Rodrigo, R., A'Hearn, M.F., Angrilli, F., Barucci, A., Bertaux, J.L., Bertini, I., Besse, S., Carry, B., Cremonese, G., Da Deppo, V., Davidsson, B., Debei, S., De Cecco, M., De Leon, J., Ferri, F., Fornasier, S., Fulle, M., Hviid, S.F., Gaskell, G.W., Groussin, O., Gutierrez, P.J., Jorda, L., Kaasalainen, M., Keller, H.U., Knollenberg, J., Kramm, J.R., Kührt, E., Küppers, M., Lara, L.M., Lazzarin, M., Leyrat, C., Lopez Moreno, J.L., Magrin, S., Marchi, S., Marzari, F., Massironi, M., Michalik, H., Moissl, R., Naletto, G., Preusker, F., Sabau, L., Sabolo, W., Scholten, F., Snodgrass, C., Thomas, N., Tubiana, C., Vernazza, P., Vincent, J.B., Wenzel, K.P., Andert, T., Pätzold, M., Weiss, B.P., 2011. Images of asteroid (21) Lutetia: A remnant planetesimal from the early Solar System. Science 334, 487–490.
D93	(2004):	Tedesco, E.F., Noah, P.V., Noah, M.C., Price, S.D., 2004. IRAS Minor Planet Survey. NASA Planetary Data System. IRAS-A-FPA-3-RDR-IMPS-V6.0.

Mass estimates

Designation	Mass / Err (kg)	ΔM/M	Method	Year	Ref	N	χ²	Use
(21) Lutetia	2.57e+18 ± 2.39e+17	9 %	Deflec	2008	M72	12	8.08	1
(21) Lutetia	2.61e+18 ± 8.75e+17	34 %	Deflec	2008	M72	12	0.68	2
(21) Lutetia	2.06e+18 ± 5.97e+17	29 %	Ephem	2009	M80	12	0.08	3
(21) Lutetia	2.08e+18 ± 2.08e+17	10 %	Ephem	2009	M86	12	0.83	4
(21) Lutetia	2.54e+18 ± 2.33e+18	92 %	Ephem	2010	M93	12	0.08	5
(21) Lutetia	1.70e+18 ± 1.40e+16	1 %	FlyBy	2011	M104		185.31	6
(21) Lutetia	9.31e+17 ± 2.56e+18	275 %	Deflec	2011	M97	12	0.14	7
(21) Lutetia	1.67e+18 ± 1.23e+18	74 %	Ephem	2011	M100	12	0.03	8
(21) Lutetia	1.73e+18 ± 6.45e+17	37 %	Ephem	2019	M126	2	0.06	9

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

EVM mass average M = (1.891 ± 0.354) × 10¹⁸ kg (ΔM/M = 19%, SNR = 5.3) Derived bulk density ρ = (3.41 ± 0.93) g/cm³ (Δρ/ρ = 27%, SNR = 3.7)

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.
M93	(2010):	Fienga, A., Manche, H., Kuchynka, P., Laskar, J., Gastineau, M., 2010. INPOP10a. Scientific Notes.
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.
M104	(2011):	Pätzold, M., Andert, T., Asmar, S.W., Anderson, J.D., Barriot, J.P., Bird, M.K., Husler, B., Hahn, M., Tellmann, S., Sierks, H., Lamy, P., Weiss, B.P., 2011. Asteroid 21 Lutetia: Low Mass, High Density. Science 334, 491.
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 : (21) Lutetia

Diameter estimates

Mass estimates