2011 UB256 - Misplaced Pages

2011 UB₂₅₆
Discovery
Discovered by	Pan-STARRS
Discovery date	29 October 2011
Designations
MPC designation	2011 UB₂₅₆
Minor planet category	Martian L5
Orbital characteristics
Epoch 31 May 2020 (JD 2459000.5)
Uncertainty parameter 0
Observation arc	6265 days (17.15 yr)
Aphelion	1.631894031 AU (244.1278722 Gm)
Perihelion	1.4154896 AU (211.75423 Gm)
Semi-major axis	1.523691798 AU (227.9410486 Gm)
Eccentricity	0.0710132
Orbital period (sidereal)	1.88 yr (686.980044 d)
Mean anomaly	180.60444°
Mean motion	0° 31 26.518 /day
Inclination	24.30270°
Longitude of ascending node	58.781126°
Argument of perihelion	7.58178°
Earth MOID	0.428887 AU (64.1606 Gm)
Jupiter MOID	3.5641 AU (533.18 Gm)
Physical characteristics
Mean diameter	300 m
Geometric albedo	0.5-0.05 (assumed)
Absolute magnitude (H)	19.9

2011 UB₂₅₆ is a small asteroid and Mars trojan orbiting near the L₅ point of Mars (60 degrees behind Mars on its orbit).

Discovery, orbit and physical properties

2011 UB₂₅₆ was first observed on 29 October 2011 by the Pan-STARRS 1 telescope system at Haleakala; the Apache Point-Sloan Digital Sky Survey had imaged this object on 31 March 2003 without identifying it as an asteroid. Its orbit is characterized by low eccentricity (0.071), moderate inclination (24.3°) and a semi-major axis of 1.52 AU. Upon discovery, it was classified as Mars-crosser by the Minor Planet Center. Its orbit is well determined as it is currently (January 2021) based on 64 observations with a data-arc span of 6265 days. 2011 UB₂₅₆ has an absolute magnitude of 19.9 which gives a characteristic diameter of 300 m.

Mars trojan and orbital evolution

Recent calculations indicate that it is a stable L₅ Mars trojan. It may not be a member of the so-called Eureka family.

Mars trojan

L₄ (leading):

(121514) 1999 UJ7 †

L₅ (trailing):

References

^ "JPL Small-Body Database Browser: (2011 UB256)". Jet Propulsion Laboratory. Retrieved 12 January 2021.
^ Christou, Apostolos A.; Borisov, Galin; Dell'Oro, Aldo; Jacobson, Seth A.; Cellino, Alberto; Unda-Sanzana, Eduardo (January 2020). "Population control of Mars Trojans by the Yarkovsky & YORP effects". Icarus. 335 (1): 113370 (34 pages). arXiv:1907.12858. Bibcode:2020Icar..33513370C. doi:10.1016/j.icarus.2019.07.004. S2CID 198985887.
Christou, Apostolos A.; Borisov, Galin; Dell'Oro, Aldo; Cellino, Alberto; Devogèle, Maxime (January 2021). "Composition and origin of L₅ Trojan asteroids of Mars: Insights from spectroscopy". Icarus. 354 (1): 113994 (22 pages). arXiv:2010.10947. Bibcode:2021Icar..35413994C. doi:10.1016/j.icarus.2020.113994. S2CID 224814529.
de la Fuente Marcos, Carlos; de la Fuente Marcos, Raúl (March 2021). "Using Mars co-orbitals to estimate the importance of rotation-induced YORP break-up events in Earth co-orbital space". Monthly Notices of the Royal Astronomical Society. 501 (4): 6007–6025. arXiv:2101.02563. Bibcode:2021MNRAS.501.6007D. doi:10.1093/mnras/stab062.
^ MPC data on 2011 SP189

Further reading

Three new stable L5 Mars Trojans de la Fuente Marcos, C., de la Fuente Marcos, R. 2013, Monthly Notices of the Royal Astronomical Society: Letters, Vol. 432, Issue 1, pp. 31–35.
Orbital clustering of Martian Trojans: An asteroid family in the inner solar system? Christou, A. A. 2013, Icarus, Vol. 224, Issue 1, pp. 144–153.

External links

2011 UB₂₅₆ data at MPC.
2011 UB256 at AstDyS-2, Asteroids—Dynamic Site
- Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
2011 UB256 at ESA–space situational awareness
- Ephemerides · Observations · Orbit · Physical properties · Summary
2011 UB256 at the JPL Small-Body Database
- Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters

Mars

Outline of Mars

Geography

Atmosphere	Circulation Climate Dust devil tracks Methane
Regions	Arabia Terra Cerberus (Mars) Cydonia Eridania Lake Iani Chaos Olympia Undae Planum Australe Planum Boreum Quadrangles Sinus Meridiani Tempe Terra Terra Cimmeria Terra Sabaea Tharsis Undae Ultimi Scopuli Vastitas Borealis
Physical features	"Canals" (list) Canyons Catenae Chaos terrain Craters Fossae Gullies Mensae Labyrinthi Mountains by height Observed rocks Outflow channels Plains Valley network Valleys Gravity
Geology	Brain terrain Carbonates Chaos terrain Color Composition Concentric crater fill Dark slope streak Dichotomy Fretted terrain Geysers Glaciers Groundwater Gullies Lakes Lava tubes Lobate debris apron Marsquake Meteorites on Earth on Mars Mud cracks North Polar Basin Ocean theory Ore resources Polar caps polar wander Recurring slope lineae (RSL) Ring mold craters Rootless cones Seasonal flows Soil Spherules Surface "Swiss cheese" feature Terrain softening Tharsis bulge Volcanism Water Yardangs
History	Amazonian Hesperian Noachian Observation history Classical albedo features

Astronomy

Moons	Phobos Stickney crater Limtoc crater Monolith Deimos Swift crater Voltaire crater
Transits	Solar eclipses on Mars Satellite transits Phobos Deimos Planetary transits Earth Mercury
Asteroids	Impacts Mars-crossers 2007 WD5 Trojans 5261 Eureka 1998 VF₃₁ 1999 UJ₇ 2007 NS₂
Comets	C/2013 A1 (Siding Spring)
General	Orbit

Exploration

Concepts	Flyby Orbiter Landing Rover Sample return Human mission Permanent settlement Colonization Terraforming
Missions	List of missions to Mars
Advocacy	The Mars Project The Case for Mars Inspiration Mars Foundation Mars Institute Mars Society Mars race

Portal:

Solar System

Small Solar System bodies

Minor planets

Designation Groups List Moon Meanings of names
Asteroid	Active Aten asteroid Asteroid belt Family Jupiter trojan Near-Earth Spectral types
Distant minor planet	Centaur Neptune trojan Damocloid Trans-Neptunian object Detached Kuiper belt Oort cloud Scattered disc

Comets

Other

Categories:

Discovery, orbit and physical properties

Mars trojan and orbital evolution

Mars trojan

See also

References

External links