2020 SO

2020 SO
	The orbit of 2020 SO around Earth and Sun from Nov. 2020 to Mar. 2021
Discovery
Discovered by	Pan-STARRS 1
Discovery site	Haleakalā Obs.
Discovery date	17 September 2020
Designations
MPC designation	2020 SO
Alternative designations	P116rK2
Minor planet category	NEO · Apollo (May 2020); Atira (Dec 2020)
Orbital characteristics
	Epoch 17 December 2020 (JD 2459200.5)
	Uncertainty parameter 2
Observation arc	167 days
Earliest precovery date	19 August 2020
Aphelion	0.988 AU
Perihelion	0.985 AU
Semi-major axis	0.986 AU
Eccentricity	0.00181
Orbital period (sidereal)	0.98 yr (357.9 d)
Mean anomaly	276.388°
Mean motion	1° 0m 21.877s / day
Inclination	0.1389°
Longitude of ascending node	216.656°
Argument of perihelion	311.989°
Earth MOID	0.01628 AU (May 2020); 0.00106 AU (Dec 2020)
Physical characteristics
Mean diameter	6–12 m (assumed)
Synodic rotation period	0.0026080±0.0000001 h; or 9.39 s
Apparent magnitude	22.4 (at discovery); 14.1 (1 Dec 2020)
Absolute magnitude (H)	27.66±0.34; 28.43

2020 SO^[a] is a near-Earth object identified to be the Centaur upper stage used on 20 September 1966 to launch the Surveyor 2 spacecraft. The object was discovered by the Pan-STARRS 1 survey at the Haleakala Observatory on 17 September 2020. It was initially suspected to be an artificial object due to its low velocity relative to Earth and later on the noticeable effects of solar radiation pressure on its orbit. Spectroscopic observations by NASA's Infrared Telescope Facility in December 2020 found that the object's spectrum is similar to that of stainless steel, confirming the object's artificial nature.^[8] Following the object's confirmation as space debris, the object was removed from the Minor Planet Center's database on 19 February 2021.^[9]

^ ^a ^b Cite error: The named reference MPEC-2020-S78 was invoked but never defined (see the help page).
^ ^a ^b ^c ^d Cite error: The named reference MPC-object was invoked but never defined (see the help page).
^ Cite error: The named reference NEO-Exchange was invoked but never defined (see the help page).
^ ^a ^b ^c Cite error: The named reference jpldata was invoked but never defined (see the help page).
^ Cite error: The named reference CNEOS was invoked but never defined (see the help page).
^ Peter Birtwhistle (Great Shefford Observatory). "Light curve".
^ Cite error: The named reference NEODy20201201 was invoked but never defined (see the help page).
^ Cite error: The named reference NASA-20201202 was invoked but never defined (see the help page).
^ Cite error: The named reference MPEC-2021-D62 was invoked but never defined (see the help page).

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[MPEC-2020-S78-1] Cite error: The named reference MPEC-2020-S78 was invoked but never defined (see the help page).

[MPC-object-2] Cite error: The named reference MPC-object was invoked but never defined (see the help page).

[NEO-Exchange-3] Cite error: The named reference NEO-Exchange was invoked but never defined (see the help page).

[jpldata-4] Cite error: The named reference jpldata was invoked but never defined (see the help page).

[CNEOS-5] Cite error: The named reference CNEOS was invoked but never defined (see the help page).

[Birtwhistle-6] Peter Birtwhistle (Great Shefford Observatory). "Light curve".

[NEODy20201201-7] Cite error: The named reference NEODy20201201 was invoked but never defined (see the help page).

[NASA-20201202-9] Cite error: The named reference NASA-20201202 was invoked but never defined (see the help page).

[MPEC-2021-D62-10] Cite error: The named reference MPEC-2021-D62 was invoked but never defined (see the help page).

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