SiMDA»Main

Summary for : (2) Pallas

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	B	B	- \| -	B	2.91 ± 0.40 (A)	14 %	517.3 ± 16.1	3.1 %	2.11e+20 ± 2.13e+19	10 %	S	EVM
MBA	B	B	- \| -	B	2.92 ± 0.78 (C)	27 %	511.4 ± 10.4	2.0 %	2.04e+20 ± 5.30e+19	26 %	S	w.avg
MBA	B				2.86 ± 0.32 (A)	11 %	514.4 ± 19.1	3.7 %	2.04e+20 ± 4.00e+18	2 %	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
(2) Pallas	498.07 ± 18.79	3.8 %	STM	2004	D93		1.05	1
(2) Pallas	502.00 ± 6.00	1.2 %	Img-TE	2009	D54	2	6.53	2
(2) Pallas	544.00 ± 18.00	3.3 %	Img-TE	2009	D58		2.20	3
(2) Pallas	512.00 ± 6.00	1.2 %	KOALA	2010	D67		0.79	4
(2) Pallas	479.81 ± 20.18	4.2 %	STM	2010	D64	2	3.46	5
(2) Pallas	523.98 ± 20.83	4.0 %	NEATM	2010	D64		0.10	6
(2) Pallas	539.00 ± 28.00	5.2 %	MDM:LO	2011	D78		0.60	7
(2) Pallas	512.59 ± 4.98	1.0 %	STM	2011	D83		0.91	8
(2) Pallas	544.00 ± 42.91	7.9 %	NEATM	2011	D72		0.39	9
(2) Pallas	544.00 ± 60.70	11.2 %	NEATM	2011	D72	2	0.19	10
(2) Pallas	523.00 ± 10.00	1.9 %	ADAM	2017	D100		0.32	11

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).

ADAM : All-Data Asteroid Modeling. Img-TE : Triaxial ellipsoid model from images. KOALA : Combined lightcurve(s) + occultation(s) + disk-resolved image(s). MDM:LO : Multi-Data Modeling: Lightcurves + Occultations. NEATM : Near-Earth Asteroid Thermal Model. STM : Standard Thermal Model.

EVM diam. average D = (517.3 ± 16.08) km (ΔD/D = 3%, SNR = 32.17) Derived bulk density ρ = (2.91 ± 0.40) g/cm³ (Δρ/ρ = 14%, SNR = 7.3)

References

D54	(2009):	Drummond, J.D., Christou, J.C., Nelson, J., 2009. Triaxial ellipsoid dimensions and poles of asteroids from AO observations at the Keck-II telescope. Icarus 202, 147–159.
D58	(2009):	Schmidt, B.E., Thomas, P.C., Bauer, J.M., Li, J., McFadden, L.A., Mutchler, M.J., Radcliffe, S.C., Rivkin, A.S., Russell, C.T., Parker, J.W., Stern, S.A., 2009. The Shape and Surface Variation of 2 Pallas from the Hubble Space Telescope. Science 326, 275–278.
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.
D67	(2010):	Carry, B., Dumas, C., Kaasalainen, M., Berthier, J., Merline, W.J., Erard, S., Conrad, A.R., Drummond, J.D., Hestroffer, D., Fulchignoni, M., Fusco, T., 2010. Physical properties of (2) Pallas. Icarus 205, 460–472.
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.
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.
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
(2) Pallas	2.59e+20 ± 8.00e+19	31 %	Deflec	1974	M112	2	0.36	1
(2) Pallas	2.27e+20 ± 4.40e+19	19 %	Deflec	1975	M113	2	0.14	2
(2) Pallas	2.78e+20 ± 4.00e+19	14 %	FlyBy	1989	M116	2	2.83	3
(2) Pallas	3.16e+20 ± 9.94e+18	3 %	Deflec	1999	M17	12	112.21	4
(2) Pallas	2.41e+20 ± 5.17e+19	21 %	Deflec	2000	M21	2	0.34	5
(2) Pallas	2.33e+20 ± 5.97e+18	3 %	Deflec	2001	M23	12	13.94	6
(2) Pallas	2.14e+20 ± 7.56e+18	4 %	Deflec	2001	M29		0.19	7
(2) Pallas	1.99e+20 ± 1.99e+18	1 %	Deflec	2001	M25		34.61	8
(2) Pallas	2.06e+20 ± 3.98e+18	2 %	Deflec	2004	M39		1.40	9
(2) Pallas	2.04e+20 ± 5.97e+17	0 %	Deflec	2005	M49		126.20	10
(2) Pallas	2.04e+20 ± 5.57e+18	3 %	Deflec	2006	M56		1.45	11
(2) Pallas	2.11e+20 ± 7.96e+18	4 %	Deflec	2008	M72		0.00	12
(2) Pallas	2.04e+20 ± 1.99e+17	0 %	Ephem	2008	M70		1135.79	13
(2) Pallas	2.01e+20 ± 2.01e+19	10 %	Ephem	2009	M86		0.23	14
(2) Pallas	2.22e+20 ± 5.59e+18	3 %	Ephem	2010	M93		4.08	15
(2) Pallas	1.79e+20 ± 8.95e+18	5 %	Deflec	2010	M92	12	12.55	16
(2) Pallas	2.01e+20 ± 1.29e+19	6 %	Deflec	2011	M95		0.57	17
(2) Pallas	2.06e+20 ± 5.07e+18	2 %	Ephem	2011	M103		0.86	18
(2) Pallas	2.07e+20 ± 1.70e+19	8 %	Deflec	2011	M97		0.05	19
(2) Pallas	1.96e+20 ± 1.52e+19	8 %	Deflec	2011	M97		0.94	20
(2) Pallas	2.06e+20 ± 1.38e+19	7 %	Deflec	2011	M97		0.12	21
(2) Pallas	1.88e+20 ± 2.38e+19	13 %	Deflec	2011	M97		0.91	22
(2) Pallas	2.06e+20 ± 2.98e+18	1 %	Ephem	2011	M100		2.49	23
(2) Pallas	2.00e+20 ± 2.19e+18	1 %	OrbFitN	2014	M123		23.02	24
(2) Pallas	2.13e+20 ± 8.75e+18	4 %	Deflec	2017	M125	2	0.06	25
(2) Pallas	2.15e+20 ± 2.60e+19	12 %	Deflec	2017	M125	2	0.02	26
(2) Pallas	2.35e+20 ± 3.04e+19	13 %	Deflec	2017	M125	2	0.62	27
(2) Pallas	1.69e+20 ± 2.21e+19	13 %	Deflec	2017	M125	2	3.49	28
(2) Pallas	2.17e+20 ± 2.94e+19	14 %	Deflec	2017	M125	2	0.04	29
(2) Pallas	2.39e+20 ± 3.30e+19	14 %	Deflec	2017	M125	2	0.71	30
(2) Pallas	1.96e+20 ± 2.84e+19	14 %	Deflec	2017	M125	2	0.27	31
(2) Pallas	2.37e+20 ± 3.72e+19	16 %	Deflec	2017	M125	2	0.48	32
(2) Pallas	2.41e+20 ± 3.98e+19	17 %	Deflec	2017	M125	2	0.56	33
(2) Pallas	1.75e+20 ± 2.94e+19	17 %	Deflec	2017	M125	2	1.49	34
(2) Pallas	3.06e+20 ± 5.89e+19	19 %	Deflec	2017	M125	2	2.63	35
(2) Pallas	2.09e+20 ± 4.37e+19	21 %	Deflec	2017	M125	2	0.00	36
(2) Pallas	2.45e+20 ± 5.55e+19	23 %	Deflec	2017	M125	2	0.37	37
(2) Pallas	2.54e+20 ± 5.85e+19	23 %	Deflec	2017	M125	2	0.56	38
(2) Pallas	3.72e+20 ± 8.57e+19	23 %	Deflec	2017	M125	2	3.53	39
(2) Pallas	2.80e+20 ± 7.52e+19	27 %	Deflec	2017	M125	2	0.86	40
(2) Pallas	3.16e+20 ± 8.75e+19	28 %	Deflec	2017	M125	2	1.45	41
(2) Pallas	1.55e+20 ± 4.35e+19	28 %	Deflec	2017	M125	2	1.66	42
(2) Pallas	4.10e+20 ± 1.25e+20	31 %	Deflec	2017	M125	2	2.53	43
(2) Pallas	2.37e+20 ± 7.24e+19	31 %	Deflec	2017	M125	2	0.13	44
(2) Pallas	2.62e+20 ± 8.21e+19	31 %	Deflec	2017	M125	2	0.40	45
(2) Pallas	4.61e+20 ± 1.55e+20	34 %	Deflec	2017	M125	2	2.61	46
(2) Pallas	2.66e+20 ± 9.54e+19	36 %	Deflec	2017	M125	2	0.34	47
(2) Pallas	4.00e+20 ± 1.52e+20	38 %	Deflec	2017	M125	2	1.55	48
(2) Pallas	2.39e+20 ± 1.00e+20	42 %	Deflec	2017	M125	2	0.08	49
(2) Pallas	2.11e+20 ± 6.48e+18	3 %	Deflec	2017	M125	3	0.00	50
(2) Pallas	2.19e+20 ± 1.23e+18	1 %	Ephem	2019	M126		47.68	51

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). OrbFitN : Simultaneous multi-asteroid astrometric orbit solution (similar to 'Ephem').

EVM mass average M = (2.107 ± 0.213) × 10²⁰ kg (ΔM/M = 10%, SNR = 9.9) Derived bulk density ρ = (2.91 ± 0.40) g/cm³ (Δρ/ρ = 14%, SNR = 7.3)

References

M17	(1999):	Hilton, J.L., 1999. US Naval Observatory Ephemerides of the Largest Asteroids. Astronomical Journal 117, 1077–1086.
M21	(2000):	Michalak, G., 2000. Determination of asteroid masses — I. (1) Ceres, (2) Pallas and (4) Vesta. Astronomy and Astrophysics 360, 363–374.
M23	(2001):	Goffin, E., 2001. New determination of the mass of Pallas. Astronomy and Astrophysics 365, 627–630.
M25	(2001):	Pitjeva, E.V., 2001. Progress in the determination of some astronomical constants from radiometric observations of planets and spacecraft. Astronomy and Astrophysics 371, 760–765.
M29	(2001):	Standish, E.M., 2001. Suggested GM values for Ceres, Pallas, and Vesta. Technical Report. JPL Interoffice Memorandum.
M39	(2004):	Pitjeva, E.V., 2004. Estimations of masses of the largest asteroids and the main asteroid belt from ranging to planets, Mars orbiters and landers, in: J.-P. Paillé (Ed.), 35th COSPAR Scientific Assembly, p. 2014.
M49	(2005):	Pitjeva, E.V., 2005. High-Precision Ephemerides of Planets - EPM and Determination of Some Astronomical Constants. Solar System Research 39, 176–186.
M56	(2006):	Konopliv, A.S., Yoder, C.F., Standish, E.M., Yuan, D.N., Sjogren, W.L., 2006. A global solution for the Mars static and seasonal gravity, Mars orientation, Phobos and Deimos masses, and Mars ephemeris. Icarus 182, 23–50.
M70	(2008):	Fienga, A., Manche, H., Laskar, J., Gastineau, M., 2008. INPOP06: a new numerical planetary ephemeris. Astronomy and Astrophysics 477, 315–327.
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.
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.
M93	(2010):	Fienga, A., Manche, H., Kuchynka, P., Laskar, J., Gastineau, M., 2010. INPOP10a. Scientific Notes.
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.
M112	(1974):	Schubart, J., 1974. The Masses of the First Two Asteroids. Astronomy and Astrophysics 30, 289-292.
M113	(1975):	Schubart, J., 1975. The Mass of Pallas. Astronomy and Astrophysics, vol. 39, no. 1, Feb. 1975, p. 147, 148.
M116	(1989):	Standish, E. M., Hellings, R. W., 1989. A determination of the masses of Ceres, Pallas, and Vesta from their perturbations upon the orbit of Mars. Icarus, Volume 80, Issue 2, p. 326-333.
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 : (2) Pallas

Diameter estimates

Mass estimates