(66391) Moshup and Squannit

Asteroids with Satellites Database--Johnston's Archive

(66391) Moshup and Squannit

compiled by Wm. Robert Johnston
last updated 9 October 2021

--Orbital and physical data--

(See this page for definitions of quantities; source codes in brackets, see this link for full references; *A, *D, and *E indicate assumed, derived, and estimated values, respectively.)

dynamical type, primary: NEA, Aten (PHA)
orbital data, primary (osculating elements) [JPL] :
semimajor axis a: 0.64236506676 AU
orbital period P: 0.51485042406 yr
(= 188.04911739 d)
eccentricity e: 0.6883655944
perihelion distance q: 0.2001830557 AU
aphelion distance Q: 1.0845470778 AU
inclination i: 38.87991326°
argument of perihelion ω: 192.6452137°
ascending node Ω: 244.90164572°
mean anomaly M: 152.0353763°
perihelion passage T_P: 2021 Apr 12.5830047
Epoch: 2021 Jul 01
data arc: 1998-2021 (3686 obs.)
Earth MOID: 0.0133541 AU
Jupiter Tisserand invariant T_J: 8.497

orbital data, secondary:

binary dynamical type: A [P07f]
semimajor axis a_s: 2.548 ± 0.015 km [O06a]
separation/primary radius a_s/r_p: 3.9 [*D]
separation/Hill radius a_s/r_H: 0.11 [*D]
orbital period P_s: 0.7274013 ± 0.0000017 d [S21c]
eccentricity e_s: <0.006 [S21c]
inclination i_s: 156.1° ± 2° [O06a]
ascending node Ω_s: 105.4° ± 3° [O06a]
argument of pericenter ω_s: 319.7° ± 182° [O06a]
pericenter passage T_P: 2001 May 26.41± 0.88 [O06a]
normalized ang. mom. α_L: 1.06 [P07f]

other data, system (combined):

absolute mag. H: 16.59 [MPC]
16.74 ± 0.22 [S21c]
slope parameter G: (0.24) [*A]
effective diameter d_E: 1.44 ± 0.04 km [*D]
geometric albedo: 0.162 ± 0.034 [S21c]
color index U-B: ?
color index B-V: ?
taxonomic type: S: (SMASSII) [JPL]
mass m: 2.49x10¹² ± 5.4x10¹⁰ kg [O06a]
density ρ: 1.3 ± 0.7/0.4 g/cm³[S21c]
Hill radius r_H: 22 km [*D]
other data, primary:

diameter d_p: 1.317 ± 0.04 km [O06a]
dimensions : 1.532 x 1.495 x 1.347 km [O06a]
axial ratios a/b, b/c: 1.02, 1.11 [*D]
rotation period RP_p: 2.7645 ± 0.0003 h [O06a]
amplitude in mag., rotational ΔM: 0.13 [H03a]
pole direction Β, λ: ? , ?
densityρ_p: 1.97± 0.24/O06a g/cm³ [O06a]

other data, secondary:

diameter d_s: 0.59 ± 0.04 km [S21c]
dimensions : 0.571 x 0.463 x 0.349km [O06a]
axial ratios a/b, b/c: 1.23;1.33 [*D]
diameter ratio d_s/d_p: 0.42 ± 0.03 [S21c]
component mag. difference ΔM: 1.88 ± 0.16 [*D]
rotation period RP_s: 17.45763 h [S21c]

-- (66391) Moshup and Squannit --discovery and notes:

Primary discovered 1999 May 20 from Socorro, New Mexico, USA by LINEAR Program. Alternate designation(s): 1999 KW4 . Linked to prediscovery observations from 1998 May 29. Permanent number assigned 2003 Sep 10.

Named 2019 Aug 27 for the Native American mythological giant [MPC115894].

Companion discovered 2001 May 21 using radar and lightcurve observations. Announced 2001 May 23. Permanent designation I Squannit, assigned 2019 Aug 27; named for the Native American mythological leader [MPC115894].

Shape model published [O06a].

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:

Takahashi, Yu & Scheeres, D. J. 2014, Icarus Morphology driven density distribution estimation for small bodies
Hirabayashi, M. & Scheeres, D. J. 2014, Lunar and Planetary Science Conference Interior Stress Within the NEO Binary System 1999 KW4
Taylor, Patrick A. & Margot, Jean-Luc 2014, Icarus Tidal end states of binary asteroid systems with a nonspherical component
Frouard, Julien 2013, AAS/Division of Dynamical Astronomy Meeting Evolution of Small Binary Asteroids with the Binary YORP Effect
Nolan, Michael C., Magri, C., Benner, L. A. M., Hergenrother, C. W., Howell, E. S., Hudson, R. S., Giorgini, J. D., Lauretta, D. S., & Margot, J. L. 2012, AAS/Division for Planetary Sciences Meeting Abstracts The Shape of OSIRIS-REx Mission Target 1999 RQ36 from RADAR and Lightcurve Data
McMahon, Jay W. & Scheeres, D. J. 2012, AAS/Division for Planetary Sciences Meeting Abstracts Binary-YORP Coefficients for Known Asteroid Shapes
Benner, Lance A. M., Brozovic, M., Giorgini, J. D., Lawrence, K. J., Taylor, P. A., Nolan, M. C., Howell, E. S., Busch, M. W., Margot, J., Naidu, S. P., Magri, C., & Shepard, M. K. 2012, AAS/Division for Planetary Sciences Meeting Abstracts Arecibo and Goldstone Radar Observations of Binary Near-Earth Asteroid and Marco Polo-R Mission Target (175706) 1996 FG3
Naidu, Shantanu, Nolan, Michael, Margot, Jean-Luc, Busch, . M. W., Fang, J., Taylor, P. A., Howell, E. S., Giorgini, J. D., Benner, L. A. M., Brozovic, M., & Magri, C. 2012, 39th COSPAR Scientific Assembly Binary Near-Earth Asteroid 2000 DP107, A Prime Spacecraft Target
Nolan, M. C., Magri, C., Benner, L. A. M., Giorgini, J. D., Hergenrother, C. W., Howell, E. S., Hudson, R. S., Lauretta, D. S., & Margot, J.-L. 2012, LPI Contributions The Shape of OSIRIS-REx Mission Target 1999 RQ36 from Radar and Lightcurve Data
McMahon, Jay W. & Scheeres, D. 2012, AAS/Division of Dynamical Astronomy Meeting Effect of Small Scale Surface Topology on Near-Earth Asteroid YORP and bYORP Coefficients
Fang, Julia & Margot, Jean-Luc 2012, The Astronomical Journal Binary Asteroid Encounters with Terrestrial Planets: Timescales and Effects
Fang, Julia & Margot, Jean-Luc 2012, The Astronomical Journal Near-Earth Binaries and Triples: Origin and Evolution of Spin-Orbital Properties
Brozović, Marina, Benner, Lance A. M., Taylor, Patrick A., Nolan, Michael C., Howell, Ellen S., Magri, Christopher, Scheeres, Daniel J., Giorgini, Jon D., Pollock, Joseph T., Pravec, Petr, Galád, Adrián, Fang, Julia, Margot, Jean-Luc, Busch, Michael W., Shepard, Michael K., Reichart, Daniel E., Ivarsen, Kevin M., Haislip, Joshua B., LaCluyze, Aaron P., Jao, Joseph, Slade, Martin A., Lawrence, Kenneth J., & Hicks, Michael D. 2011, Icarus Radar and optical observations and physical modeling of triple near-Earth Asteroid (136617) 1994 CC
Tardivel, S. & Scheeres, D. J. 2011, EPSC-DPS Joint Meeting 2011 Robust deployment of landers to asteroid surfaces
Busch, Michael W., Ostro, Steven J., Benner, Lance A. M., Brozovic, Marina, Giorgini, Jon D., Jao, Joseph S., Scheeres, Daniel J., Magri, Christopher, Nolan, Michael C., Howell, Ellen S., Taylor, Patrick A., Margot, Jean-Luc, & Brisken, Walter 2011, Icarus Radar observations and the shape of near-Earth ASTEROID 2008 EV5
McMahon, Jay W. & Scheeres, D. J. 2011, Bulletin of the American Astronomical Society Dynamical limits on planar libration-orbit coupling around an oblate primary with application to byorp evolution
McMahon, Jay W. 2011, Ph.D. Thesis An Analytical Theory for the Perturbative Effect of Solar Radiation Pressure on Natural and Artificial Satellites
McMahon, Jay & Scheeres, Daniel 2010, Icarus Detailed prediction for the BYORP effect on binary near-Earth Asteroid (66391) 1999 KW4 and implications for the binary population
Scheeres, Daniel J., Hartzell, C. M., Sanchez, P., & Swift, M. 2010, Bulletin of the American Astronomical Society Scaling Forces to the Asteroid Surface: The Role of Cohesion
McMahon, Jay & Scheeres, D. 2010, Bulletin of the American Astronomical Society Measuring the Binary YORP Effect and the Influence of Librations on Binary Asteroid Evolution
Busch, Michael W., Ostro, S. J., Benner, L. A. M., Scheeres, D. J., Giorgini, J. D., Brozovic, M., Nolan, M. C., Howell, E. S., Taylor, P. A., Margot, J., Magri, C., Jao, J. S., & Brisken, W. 2010, Bulletin of the American Astronomical Society Radar Observations and the Shape of 2008 EV5: Ridges and Craters on Near-Earth Asteroids
Brozovic, Marina, Benner, L. A. M., Nolan, M. C., Howell, E. S., Magri, C., Giorgini, J. D., Taylor, P. A., Margot, J. L., Busch, M. W., Shepard, M. K., Scheeres, D. J., & Carter, L. M. 2010, Bulletin of the American Astronomical Society Radar Images And Shape Model Of A Triple Asteroid (136617) 1994CC
Jimenez, Nicholas, Howell, E. S., Nolan, M. C., Taylor, P. A., Benner, L. A. M., Brozovic, M., Giorgini, J. D., Vervack, R. J., Fernandez, Y. R., Mueller, M., Margot, J., & Shepard, M. K. 2010, Bulletin of the American Astronomical Society Radar Shape Modeling of Binary Near-Earth Asteroid 2000 CO101
Benner, Lance A. M., Margot, J., Nolan, M. C., Giorgini, J. D., Brozovic, M., Scheeres, D. J., Magri, C., & Ostro, S. J. 2010, Bulletin of the American Astronomical Society Radar Imaging and a Physical Model of Binary Asteroid 65803 Didymos
Pravec, Petr & Scheirich, P. 2010, Bulletin of the American Astronomical Society Binary System Candidates for Detection of BYORP
Kreslavsky, Mikhail A. & Nimmo, F. 2010, Bulletin of the American Astronomical Society Critical Spin as a Possible Origin of the Iapetus Ridge
McMahon, Jay & Scheeres, Daniel 2010, Celestial Mechanics and Dynamical Astronomy Secular orbit variation due to solar radiation effects: a detailed model for BYORP
Winter, Othon, de Melo, Cristiano F., & Macau, Elbert E. N. 2010, 38th COSPAR Scientific Assembly Low-cost Mission to NEO Binary 1999 KW4
McMahon, Jay & Scheeres, D. 2009, AAS/Division for Planetary Sciences Meeting Abstracts #41 Predictions For The Effects Of BYORP On 1999 KW4
Benner, Lance A. M., Brozovic, M., Giorgini, J. D., Nolan, M. C., Magri, C., Ostro, S. J., Jao, J. S., Lawrence, K. J., Margot, J. L., Busch, M. W., Shepard, M. K., Howell, E. S., Taylor, P. A., & Carter, L. M. 2009, AAS/Division for Planetary Sciences Meeting Abstracts #41 Arecibo and Goldstone Radar Images of Near-Earth Asteroid (136849) 1998 CS1
Schwartz, Stephen R., Richardson, D. C., Michel, P., & Walsh, K. J. 2009, AAS/Division for Planetary Sciences Meeting Abstracts #41 Modeling Cohesion in Gravitational Aggregates with Variable Bond Strengths
Fahnestock, Eugene G. & Scheeres, Daniel J. 2009, Icarus Binary asteroid orbit expansion due to continued YORP spin-up of the primary and primary surface particle motion
Richardson, Derek C., Schwartz, S. R., Walsh, K. J., & Michel, P. 2009, AAS/Division of Dynamical Astronomy Meeting #40 Testing Cohesion in Gravitational Aggregates
Fahnestock, Eugene G. 2009, AAS/Division of Dynamical Astronomy Meeting #40 Allocation of Angular Momentum Changes Accompanying Lofting Particle Motion in Binary Asteroid Systems
Scheirich, P. & Pravec, P. 2009, Icarus Modeling of lightcurves of binary asteroids
Harris, Alan W., Fahnestock, Eugene G., & Pravec, Petr 2009, Icarus On the shapes and spins of “rubble pile” asteroids
Scheeres, Daniel J., Gaskell, R. W., & Sanchez, P. 2009, Bulletin of the American Astronomical Society Density Inhomogeneity, YORP and Itokawa
Fahnestock, Eugene Gregory 2009, Ph.D. Thesis The full two-body-problem: Simulation, analysis, and application to the dynamics, characteristics, and evolution of binary asteroid systems
Scheeres, D. J., Gaskell, R. W., & Sanchez, P. 2008, AGU Fall Meeting Abstracts YORP and Density Inhomogeneity within Itokawa
Fahnestock, Eugene G. & Scheeres, D. J. 2008, Bulletin of the American Astronomical Society Primary Surface Particle Motion as a Mechanism for YORP-Driven Binary Asteroid Evolution
Richardson, Derek C., Schwartz, S. R., Michel, P., & Walsh, K. J. 2008, Bulletin of the American Astronomical Society Modeling Cohesion in Gravitational Aggregates
Nesvorný, David & Vokrouhlický, David 2008, The Astronomical Journal Analytic Theory for the Yarkovsky-O Effect on Obliquity
Minton, David A. 2008, Icarus The topographic limits of gravitationally bound, rotating sand piles
Harris, Alan W., Fahnestock, E. G., & Pravec, P. 2008, AAS/Division of Dynamical Astronomy Meeting #39 Regulation of Primary Spin Rate of Asynchronous Binary Asteroids by "Tidal Saltation"
Fahnestock, Eugene G. & Scheeres, D. J. 2008, AAS/Division of Dynamical Astronomy Meeting #39 YORP-Driven Expansion of Binary Asteroid Systems
Fahnestock, Eugene G. & Scheeres, Daniel J. 2008, Icarus Simulation and analysis of the dynamics of binary near-Earth Asteroid (66391) 1999 KW4
Fahnestock, Eugene & Scheeres, D. 2007, Bulletin of the American Astronomical Society Ejecta Dynamics and Regolith Transport within Binary Asteroid Systems
Benner, Lance A., Busch, M. W., Nolan, M. C., Ostro, S. J., Giorgini, J. D., Rose, R., Jao, J. S., Black, G. J., Carter, L. M., Slade, M. A., Jurgens, R. F., & Hine, A. A. 2007, Bulletin of the American Astronomical Society Radar Images Of Binary Near-earth Asteroid 2006 VV2
Fahnestock, Eugene G. & Scheeres, D. J. 2007, AAS/Division of Dynamical Astronomy Meeting #38 The Dynamics of 1999 KW4 and Similar Binary Near-Earth Asteroids
Davies, John K., Harris, Alan W., Rivkin, Andrew S., Wolters, Stephen D., Green, Simon F., McBride, Neil, Mann, Rita K., & Kerr, Tom H. 2007, Icarus Near-infrared spectra of 12 Near-Earth Objects
Scheeres, D. J., Fahnestock, E. G., Ostro, S. J., Margot, J.-L., Benner, L. A. M., Broschart, S. B., Bellerose, J., Giorgini, J. D., Nolan, M. C., Magri, C., Pravec, P., Scheirich, P., Rose, R., Jurgens, R. F., De Jong, E. M., & Suzuki, S. 2006, Science Dynamical Configuration of Binary Near-Earth Asteroid (66391) 1999 KW4
Ostro, Steven. J., Margot, Jean-Luc, Benner, Lance A. M., Giorgini, Jon D., Scheeres, Daniel J., Fahnestock, Eugene G., Broschart, Stephen B., Bellerose, Julie, Nolan, Michael C., Magri, Christopher, Pravec, Petr, Scheirich, Petr, Rose, Randy, Jurgens, Raymond F., De Jong, Eric M., & Suzuki, Shigeru 2006, Science Radar Imaging of Binary Near-Earth Asteroid (66391) 1999 KW4
Scheeres, Daniel J., Fahnestock, E. G., Ostro, S. J., Margot, J. L., Benner, L. A., Broschart, S. B., Bellerose, J., Giorgini, J. D., Nolan, M. C., Magri, C., Pravec, P., Scheirich, P., Rose, R., Jurgens, R. F., Suzuki, S., & DeJong, E. M. 2006, Bulletin of the American Astronomical Society Dynamical Investigation of Asteroid 66391 (1999 KW4)
Ostro, Steven J., Margot, J. L., Benner, L. A., Giorgini, J. D., Scheeres, D. J., Fahnestock, E. G., Broschart, S. B., Bellerose, J., Nolan, M. C., Magri, C., Pravec, P., Scheirich, P., Rose, R., Jurgens, R. F., Suzuki, S., & de Jong, E. M. 2006, Bulletin of the American Astronomical Society Radar Investigation of Asteroid 66391 (1999 KW4)
Vokrouhlický, D., Čapek, D., Chesley, S. R., & Ostro, S. J. 2005, Icarus Yarkovsky detection opportunities. II. Binary systems
Scheeres, D. J. & Ostro, S. J. 2004, Bulletin of the American Astronomical Society Regolith Mechanics on Binary Asteroids
Margot, J. L. 2003, Bulletin of the American Astronomical Society Candidate Asteroids for Discerning General Relativity and Solar Oblateness
Krugly, Yu. N., Belskaya, I. N., Chiorny, V. G., Shevchenko, V. G., & Gaftonyuk, N. M. 2002, Asteroids, Comets, and Meteors: ACM 2002 CCD photometry of near-Earth asteroids in 2001
Sinnott, Roger W. 2001, Sky and Telescope Rare Flyby of 1999 KW4
Benner, L. A. M., Ostro, S. J., Giorgini, J. D., Jurgens, R. F., Margot, J. L., & Nolan, M. C. 2001, International Astronomical Union Circular 1999 KW4
Foglia, Sergio 2001, Astronomia. La rivista dell' Unione Astrofili Italiani Avvicinamento alla Terra degli asteroidi 1999 KW4 e 1998 WT24
Benner, L. A. M., Ostro, S. J., Giorgini, J. D., Jurgens, R. F., Margot, J. L., & Nolan, M. C. 2001, IAU Circ., 7632, 1 (2001). Edited by Marsden, B. G. 1999 KW4
Pravec, P. & Sarounova, L. 2001, IAU Circ., 7633, 2 (2001). Edited by Marsden, B. G. 1999 KW4
Holvorcem, P. R. & Williams, G. V. 2000, Minor Planet Electronic Circ., 2000-H37 (2000). 1999 KW4
Ticha, J., Tichy, M., Zhu, J., Teng, X. M., Sarounova, L., Lopez, A., Pacheco, R., Balam, D. D., Hergenrother, C. W., Gleason, A. E., Blythe, M., Shelly, F., Bezpalko, M., Elowitz, M., Stuart, J., Viggh, H., Sayer, R., & Williams, G. V. 1999, Minor Planet Electronic Circ., 1999-K28 (1999). 1999 KW4

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Last modified 9 October 2021.
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