2006 QQ23

2006 QQ₂₃^[a] is a sub-kilometre asteroid, classified as a near-Earth object of the Aten group that is potentially hazardous only as the orbit evolves over millennia. It was first observed on 21 August 2006 by the Siding Spring Survey.^[1][2] On 10 August 2019, the object safely passed 7.4 million kilometres (4.6 million miles) from Earth.^[5][6] With a 12 year observation arc it has a well determined orbit and is not a threat for the foreseeable future.^[5]

2006 QQ₂₃

Discovery[1]
Discovered by	SSS
Discovery site	Siding Spring Obs.
Discovery date	21 August 2006 (first observed)
Designations
MPC designation	2006 QQ23
Minor planet category	Aten · NEO · PHA[1][2]
Orbital characteristics[2]
Epoch 27 April 2019 (JD 2458600.5)
Uncertainty parameter 0[2] · 1[1]
Observation arc	12.95 yr (4,730 d)
Aphelion	1.0321 au
Perihelion	0.5748 au
Semi-major axis	0.8035 au
Eccentricity	0.2846
Orbital period (sidereal)	263 d
Mean anomaly	47.558°
Mean motion	1° 22m 6.6s / day
Inclination	3.4316°
Longitude of ascending node	4.8313°
Argument of perihelion	124.78°
Earth MOID	0.0338 au (13.2 LD)
Mercury MOID	0.2325 au[1]
Venus MOID	0.0501 au[1]
Mars MOID	0.3592 au[1]
Physical characteristics
Mean diameter	250 m (est. at 0.26)[3][4] 570 m (est. at 0.05)[3][4]
Absolute magnitude (H)	20.1[1][2]

Discovery

2006 QQ₂₃ was first observed on 21 August 2006^[7] by the Siding Spring Survey, at the Siding Spring Observatory in Australia.^[1][2]

Orbit and classification

2019 flyby of 2006 QQ₂₃ at 13.2 lunar distances.^[2]

2006 QQ₂₃ is classified as an Aten asteroid, which means that it is a near-Earth asteroid that crosses Earth's orbit at two points and has an orbital period of less than a year. Because it will come within 0.05 au of the Earth (MOID) and has an absolute magnitude (H) brighter than 22,^[8] 2006 QQ₂₃ is labelled as a potentially hazardous object.^[1][2] With a 12 year observation arc it has a well determined orbit and is not a threat for the foreseeable future.^[5]

It orbits the Sun at a distance of 0.57–1.03 au in less than 9 months (263 days; semi-major axis of 0.80 au). Its orbit has an eccentricity of 0.28 and an inclination of 3.4° with respect to the ecliptic.^[2] The body's observation arc begins with its first observation at the Siding Spring Observatory on 21 August 2006.^[1]

Close approach in 2019

On 10 August 2019 at 7:23 am UTC,^[6] 2006 QQ₂₃ safely passed 0.04977 au (7,445,000 km) from Earth;^[7][9] travelling at around 4.67 km/s (16,800 km/h)^[7][10] The asteroid was recovered on 14 July 2019, which extended the observation arc from 8 years to 12 years, and therefore it had a very small uncertainty in the 2019 approach.^[1] The uncertainty region in the close approach was ±60 km.^[5][b]

Physical characteristics

Based on its absolute magnitude of 20.1,^[1] 2006 QQ₂₃ is estimated to have a diameter of 250–570 metres using an assumed albedo between 0.05 (carbonaceous) and 0.26 (siliceous).^[3][4]

Notes

1. The name 2006 QQ₂₃ is its provisional designation which is based on the date it was discovered: 2006 for the year, "Q" for half-month of August 16–31, and "Q₂₃" for the 17th discovery in the 23rd reiteration of the alphabet (excluding "I"), making it the 592nd object discovered in the second half of August 2006.
2. Archive of JPL 19 (2019-08-06 solution) using 2019-08-10 close approach data: (max distance: 0.04977 − min distance: 0.0497692) × 149597870.7 km = 119.6 km.