2010 TD54

2010 TD₅₄ is a tiny asteroid and fast rotator, classified as a near-Earth object of the Apollo group, approximately 5 meters in diameter. It was first observed by the Mount Lemmon Survey in October 2010, when the asteroid crossed through the Earth-moon system and had a close encounter with Earth.^[4]

2010 TD₅₄

Orbital diagram of 2010 TD54 during its near-Earth encounter on 12 Oct 2010
Discovery[1]
Discovered by	Mount Lemmon Srvy.
Discovery site	Mount Lemmon Obs.
Discovery date	9 October 2010
Designations
MPC designation	2010 TD54
Minor planet category	NEO · Apollo[1][2]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 6
Observation arc	3 days
Aphelion	3.2396 AU
Perihelion	0.7020 AU
Semi-major axis	1.9708 AU
Eccentricity	0.6438
Orbital period (sidereal)	2.77 yr (1,011 days)
Mean anomaly	159.97°
Mean motion	0° 21m 22.32s / day
Inclination	4.3045°
Longitude of ascending node	18.607°
Argument of perihelion	76.068°
Earth MOID	0.000178 AU 0.0693 LD
Physical characteristics
Dimensions	5 m[3] 5–10 m[4]
Synodic rotation period	0.01167 h (dated)[5] 0.0229317 h[3][a]
Geometric albedo	0.20 (assumed)[3]
Spectral type	Srv[6]
Absolute magnitude (H)	28.9[1]

Orbit and classification

2010 TD₅₄ orbits the Sun at a distance of 0.7–3.2 AU once every 2 years and 9 months (1,011 days). Its orbit has an eccentricity of 0.64 and an inclination of 4° with respect to the ecliptic.^[1]

The body's observation arc begins with its first observations by the Mount Lemmon Survey and only spans over a period of 3 days until 12 October 2010. It has been observed since then.^[2]

Close approach

2010 TD₅₄ made its closest approach at 10:51, 12 October 2010 UTC (6:51 EDT a.m.) at 0.000346 AU (51,800 km; 32,200 mi). It is one of the closest known approaches of an asteroid to Earth, at which time the object appeared at a magnitude of 14. It was first observed by of the Catalina Sky Survey's telescopes north of Tucson, Arizona on 9 October 2010.^[4]

It has an Earth minimum orbit intersection distance of 0.000178086 AU (26,600 km; 16,600 mi), which corresponds to 0.0693 lunar distance.^[1] It was removed from the Sentry Risk Table on 11 October 2010.^[7] The asteroid may have passed 0.0009 AU (135,000 km; 83,700 mi) from Earth in October 1979, but the nominal orbit suggests it passed millions of kilometres from Earth in 1979.^[1]

Physical characteristics

2010 TD₅₄ is a stony asteroid, characterized as a Srv subtype.^[6]

Rotation period

In November 2010, a rotational light curve of 2010 TD₅₄ was obtained from photometric observations, which showed that the asteroid is a fast rotator. Light curve analysis gave a well-defined rotation period of 0.0229317 hours (1 minute and 23 seconds) with a brightness amplitude of 0.92 magnitude (U=3). A high amplitude typically indicates that the body has an irregular, elongated rather than spherical shape.^[a] This result supersedes a previously obtained lightcurve with a shorter period of 0.01167 hours (U=1).^[5]

Diameter and albedo

The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 5 metres (16 feet) based on an absolute magnitude of 28.9.^[3] NASA's press release gave an estimated diameter of 5 to 10 meters (16 to 33 feet).^[4]

See also

• List of asteroid close approaches to Earth, for other close approaches
• List of asteroid close approaches to Earth in 2010

Notes

1. Ryan (2011) web: rotation period 0.0229317±0.0000002 hours with a brightness amplitude of 0.92±0.03 mag. Summary figures for (2010 TD54) at the LCDB and Bill Ryan at Magdalena Ridge Observatory