(549948) 2011 WL₂

Discovery[1]
Discovered by	LINEAR
Discovery site	Lincoln Laboratory ETS
Discovery date	16 November 2011
Designations
MPC designation	(549948) 2011 WL2
Alternative designations	2011 WL2
Minor planet category	Apollo NEO, PHA
Orbital characteristics[2]
Epoch 13 January 2016 (JD 2457400.5)
Uncertainty parameter 2
Observation arc	386 days (1.06 yr)
Aphelion	1.3833510 AU (206.94636 Gm)
Perihelion	0.7723798 AU (115.54637 Gm)
Semi-major axis	1.0778654 AU (161.24637 Gm)
Eccentricity	0.283417
Orbital period (sidereal)	1.12 yr (408.74 d)
Average orbital speed	28.10406 km/s
Mean anomaly	336.9187°
Mean motion	0° 52m 50.734s /day
Inclination	14.12974°
Longitude of ascending node	212.9462°
Argument of perihelion	88.83006°
Earth MOID	0.00141998 AU (212,426 km)
Jupiter MOID	3.83997 AU (574.451 Gm)
Physical characteristics
Mean diameter	190–420 m[3]
Absolute magnitude (H)	20.8[2]

(549948) 2011 WL₂ is a sub-kilometer asteroid, classified as a near-Earth object and potentially hazardous asteroid of the Apollo group. It was discovered on 16 November 2011, by astronomers with the LINEAR at the Lincoln Laboratory ETS near Socorro, New Mexico, in the United States.

Orbit

2011 WL₂ is a potentially hazardous asteroid (PHA), but has a well determined orbit with a 10 year observation arc. 2011 WL₂ will pass at a distance of 0.0056 AU (840,000 km; 520,000 mi) from Earth on 25 October 2077.^[2] For comparison, the distance to the Moon is about 0.0026 AU (384,400 km). 2011 WL₂ appears on the list of PHA close approaches issued by the Minor Planet Center (MPC), with the next close approach in the year 2038.^[4]

The Jupiter Tisserand invariant, used to distinguish different kinds of orbits, is 5.7.^[2]