66391 Moshup
Template:Short description Template:Infobox planet
66391 Moshup Template:IPAc-en, provisional designation Template:Mp, is a binary asteroid, classified as a near-Earth object and potentially hazardous asteroid of the Aten group, approximately 1.3 kilometers in diameter. It was discovered on 20 May 1999, by Lincoln Near-Earth Asteroid Research (LINEAR) at the Lincoln Laboratory's Experimental Test Site in Socorro, New Mexico, United States.<ref name="MPC-object" /> It is a Mercury-crosser that comes extremely close to the Sun at a perihelion of 0.2 AU.
Orbit
The asteroid orbits the Sun at a distance of 0.2–1.1 AU once every 6.18 months (188 days). Its orbit has an eccentricity of 0.69 and an inclination of 39° with respect to the ecliptic.<ref name="jpldata" /> A first precovery was taken by 2MASS at the Fred Lawrence Whipple Observatory in 1998, extending the body's observation arc by one year prior to its official discovery observation at Socorro.<ref name="MPC-object" />
As a potentially hazardous asteroid, it has an Earth minimum orbital intersection distance of Template:Convert, or 5.4 lunar distances.<ref name="jpldata" /> On 25 May 2036, it will pass Template:Convert from Earth.<ref name=jpl-close />
Numbering and naming
This minor planet was numbered by the Minor Planet Center on 10 September 2003. It was named from Mohegan legend, after Moshup, a giant who lived in the coastal areas of New England. The asteroid's companion is named Squannit, after the wife of Moshup and a medicine woman of the Makiawisug (little people). The official Template:MoMP was published by the Minor Planet Center on 27 August 2019 (Template:Small).<ref name="MPC-Circulars-Archive" />
Physical characteristics
In the SMASS classification, the asteroid a characterized as a stony S-type asteroid.<ref name="jpldata" />
Satellite
Moshup has a minor-planet moon orbiting it. The moon, named Squannit Template:IPAc-en, is approximately 360 metres in diameter, and orbits its primary every 16 hours at a mean distance of 2.6 kilometers. The presence of a companion was suggested by photometric observations made by Pravec and Šarounová and was confirmed by radar observations from Arecibo, announced on 23 May 2001 (also see below).<ref name="Pravec-2006" /><ref name="Johnstonsarchive" /> Based on radar imaging, Squannit's dimensions are estimated to be Template:Val meters.<ref name="Ostro-2006" />
Diameter and shape
According to radiometric observations from Arecibo Observatory, the asteroid has an effective mean diameter of 1.317 kilometers.<ref name="Ostro-2006" /> The observations were taken from May 21–23, 2001, by Lance A. M. Benner, Steven J. Ostro, Jon D. Giorgini, Raymond F. Jurgens, Jean-Luc Margot and Michael C. Nolan.<ref name="Ostro-2006" />
The Collaborative Asteroid Lightcurve Link adopts a diameter of 1.3 kilometers and derives an albedo 0.26 with an absolute magnitude of 16.5.<ref name="lcdb" />
The shapes of the two bodies and their dynamics are complex.<ref>NASA Jet Propulsion Laboratory Asteroid Radar Research Template:Webarchive, retrieved May 3, 2007</ref> With a dimension of approximately Template:Val kilometers for a simple triaxial ellipsoid, the asteroid has an oblate shape, which is dominated by an equatorial ridge at the body's potential-energy minimum. This bizarre property of the equatorial region means that it is close to breakup: raising a particle a meter above the surface would put it into orbit. As seen in the image above, the gravitational effects between the moon and the asteroid create a gigantic mountain extending in the equatorial plane around the entire asteroid. It was the first asteroid to be described as "muffin-shaped",<ref>Template:Cite web</ref> which is now understood to be a very common shape for asteroids in critical rotation,<ref name="JewittWeaver2018">Template:Cite journal</ref> including 101955 Bennu and 162173 Ryugu.
Lightcurves
During 19–27 June 2000, a rotational lightcurve of this asteroid was obtained from photometric observations by Petr Pravec and Lenka Šarounová at Ondřejov Observatory. Lightcurve analysis gave a rotation period of 2.7650 hours with a brightness variation of 0.12 magnitude (Template:Small).<ref name="Pravec-2006" />
See also
References
External links
- Margot, Jean-Luc, Radar observations of Template:Mp November 1999, retrieved July 2016
- Near-Earth Asteroid Is Two Chunks In One, NASA Jet Propulsion Laboratory, May 2001
- Asteroids with Satellites, Robert Johnston, johnstonsarchive.net
- 1999 KW4 orbit and observations at IAU Minor Planet Center
- Template:NeoDys
- Template:JPL small body
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