(517103) 2013 EM20

(517103) 2013 EM20
Discovery[1][2]
Discovered byMt. Lemmon Survey
Discovery date12 January 2008
Designations
Designation
(517103) 2013 EM20
2008 AO112
Orbital characteristics[2]
Epoch 9 June 2026 (JD 2461200.5)
Uncertainty parameter 0
Aphelion1.8072 AU (Q)
Perihelion0.93531 AU (q)
1.3713 AU (a)
Eccentricity0.31793
1.6058 yr (586.53 d)
165.45° (M)
Inclination8.3634°
73.879°
350.17°
Earth MOID0.04314 AU
TJupiter4.758
Physical characteristics
Dimensions~310 meters (1,020 ft)[3]
Mass4.1×1010 kg (assumed)[3]
19.9[2]

(517103) 2013 EM20 (also designated 2008 AO112) is an Apollo near-Earth asteroid and potentially hazardous object.[2] It was discovered on 12 January 2008 by the Mount Lemmon Survey at an apparent magnitude of 21 using a 1.5-meter (59 in) reflecting telescope.[1] The asteroid was quickly lost and had an estimated diameter of 310 meters (1,020 ft).[3] On 25 June 2009, with an observation arc of only 1 day in January 2008, the asteroid had a 1 in 4 million chance of impacting Earth on that very day.[3] The virtual impactor had not been eliminated from the Sentry Risk Table by the day of the potential impact.

The asteroid was recovered on 5 March 2013 as 2013 EM20.[4] Precovery images from 7 April 1997 at Kitt Peak National Observatory were located.[2] It was removed from the Sentry Risk Table on 30 March 2013.[5] It is now known that on 25 June 2009 the asteroid was 1.45 AU from Earth.[6]

References

  1. 1 2 "MPEC 2008-D33". IAU Minor Planet Center. 25 February 2008. Retrieved 28 August 2013. (K08AB2O)
  2. 1 2 3 4 5 6 "JPL Small-Body Database Browser: (2013 EM20 = 2008 AO112)" (last observation: 2026-05-08; arc: 29.08 years). Jet Propulsion Laboratory. Retrieved 7 July 2026.
  3. 1 2 3 4 "Earth Impact Risk Summary: 2008 AO112". Wayback Machine: NASA/JPL Near-Earth Object Program Office. 25 June 2009. Archived from the original on 25 June 2009. Retrieved 28 August 2013. (2.5e-07 = 1 in 4,000,000 chance)
  4. ↑ "MPEC 2013-E32 : 2013 EM20". IAU Minor Planet Center. 8 March 2013. Retrieved 28 August 2013. (K13E20M)
  5. ↑ "Date/Time Removed". NASA/JPL Near-Earth Object Program Office. Archived from the original on 2 June 2002. Retrieved 28 August 2013.
  6. ↑ Horizons output. "Horizon Online Ephemeris System". Retrieved 28 August 2013. (Geocentric Solution)