Astronomy:1994 WR12

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1994 WR12
Discovery[1][2]
Discovered byC. S. Shoemaker
Discovery sitePalomar Obs.
Discovery date28 November 1994
Designations
1994 WR12
Minor planet categoryNEO · Aten[1][3]
Orbital characteristics[3]
Epoch 2022-Jan-21 (JD 2459600.5)
Uncertainty parameter 0
Observation arc27.01 yr (9,864 d)
|{{{apsis}}}|helion}}1.0577 astronomical unit|AU (158.23 million km)
|{{{apsis}}}|helion}}0.4562 AU (68.25 million km)
0.7570 AU (113.25 million km)
Eccentricity0.39735
Orbital period240.6 days (0.659 yr)
Mean anomaly217.06°
Mean motion1° 29m 45.96s / day
Inclination6.8515°
Longitude of ascending node62.608°
206.03°
Earth MOID0.0018 AU (0.70 LD)
Physical characteristics
Mean diameter130 m (est.)[4]
92 – 210 m (CNEOS)
Mass2.9×109 kg (est.)[4]
Absolute magnitude (H)22.3[3]


1994 WR12 is an asteroid and near-Earth object approximately 130 meters (430 feet) in diameter.[3][4] As a member of the Aten group almost all of its orbit is closer to the Sun than Earth is. On 24 November 1994 it passed about 374100 km from the Moon.[3] First imaged at Kitami Observatory on 26 November 1994,[1] it was discovered two nights later by American astronomer Carolyn S. Shoemaker at Palomar Observatory on 28 November 1994.[2] The asteroid then went unobserved from 1994 until it was recovered by Mauna Kea in March 2016.[1] It was removed from the Sentry Risk Table on 2 April 2016.[5]

Close approaches[3]
Date JPL SBDB
nominal geocentric
distance 		uncertainty
region
(3-sigma)
2021-11-29 6152189 km ± 34 km[6]
2046-11-25 1633719 km ± 4133 km
2190-11-23 135000000 km ± 815 million km[7]

Description

1994 WR12 orbits the Sun at a distance of 0.5–1.1 AU once every 8 months (240 days). Its orbit has an eccentricity of 0.40 and an inclination of 7° with respect to the ecliptic.[3]

It has an Earth minimum orbital intersection distance of 0.0018 AU (269,000 km), which translates into 0.7 lunar distances.[3] On 25 November 2046, it will pass 1633719 km from Earth with an uncertainty of ±4133 km.[3] While listed on the Sentry Risk Table the range for the 2046 close approach distance varied from 0.001 AU (150,000 km) to 0.039 AU (5,800,000 km) from Earth.[8]

While listed on the Sentry Risk Table,[9] virtual clones of the asteroid that fit the uncertainty in the known trajectory showed 116 potential impacts between 2054 and 2109.[4] It had about a cumulative 1 in 9090 chance of impacting the Earth.[4] The formerly poorly known trajectory of this asteroid was further complicated by close approaches to Venus and Mercury.[3] It was recovered by Mauna Kea in March 2016,[1] which extended the observation arc from 34 days to 21 years.

It is estimated that an impact would produce the equivalent of 77 megatons of TNT,[4] roughly 1.5 times that of most powerful nuclear weapon ever detonated (Tsar Bomba).

See also

  • Lost asteroids

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 "1994 WR12". Minor Planet Center. https://www.minorplanetcenter.net/db_search/show_object?object_id=1994+WR12. 
  2. ↑ 2.0 2.1 "MPEC 1994-Y05 : 1994 WR12". IAU Minor Planet Center. 1994-12-21. http://www.minorplanetcenter.net/mpec/J94/J94Y05.html.  (J94W12R)
  3. ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 "JPL Small-Body Database Browser: (1994 WR12)". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=3005969&view=OPC. 
  4. ↑ 4.0 4.1 4.2 4.3 4.4 4.5 "Archive: Earth Impact Risk Summary: 1994 WR12". NASA/JPL Near-Earth Object Program Office. 26 March 2016. http://neo.jpl.nasa.gov/risk/1994wr12.html. 
  5. ↑ "Removed Objects". NASA/JPL Near-Earth Object Program Office. https://cneos.jpl.nasa.gov/sentry/removed.html. 
  6. ↑ "Horizons Batch for 2021-Nov-29 06:05 UT". JPL Horizons. https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%271994+WR12%27&START_TIME=%272021-Nov-29%2006:05%27&STOP_TIME=%272021-Nov-30%27&STEP_SIZE=%271+day%27&QUANTITIES=%2720,39%27. Retrieved 2021-11-28. 
  7. ↑ "Horizons Batch for 2190-Nov-23 22:27 UT". JPL Horizons. https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%271994+WR12%27&START_TIME=%272190-Nov-23%2022:27%27&STOP_TIME=%272190-Nov-24%27&STEP_SIZE=%271+day%27&QUANTITIES=%2720,39%27. Retrieved 2021-11-29. 
  8. ↑ "JPL Close-Approach Data: (1994 WR12)". https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=1994WR12&view=OPC. 
    "(1994 WR12)". http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=1994WR12;cad=1%23cad.  (last observation: 1994-12-31; arc: 35 days; Uncertainty: 8)
  9. ↑ "Archive: Sentry Risk Table". NASA/JPL Near-Earth Object Program Office. 2013-05-29. http://neo.jpl.nasa.gov/risk/. 

External links



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