2014 AA

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2014 AA
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Discovery[2]
Discovered by Richard Kowalski
Mount Lemmon Survey (G96)
Discovery date 1 January 2014
Designations
MPC designation 2014 AA
Apollo, NEO[3]
Orbital characteristics[3]
Epoch 1 January 2014 (JD 2456658.5)
Uncertainty parameter 9
Observation arc ~70 minutes[2]
Aphelion 1.4066 AU (210.42 Gm) (Q)
Perihelion 0.91659 AU (137.120 Gm) (q)
1.1616 AU (173.77 Gm) (a)
Eccentricity 0.21090 (e)
1.25 yr (457.26 d)
324.01° (M)
Inclination 1.4109° (i)
101.61° (Ω)
52.316° (ω)
Earth MOID 4.54412×10−7 AU (67.9791 km)
Jupiter MOID 3.58092 AU (535.698 Gm)
Physical characteristics
Dimensions ~3 meters (10 ft)
Mass ~4×104 kg (assumed)
30.9[3]

2014 AA was a small Apollo near-Earth asteroid roughly 2–4 meters in diameter that struck Earth on 2 January 2014.[2] It was discovered on 1 January 2014 by Richard Kowalski at the Mount Lemmon Survey at an apparent magnitude of 19 using a 1.52-meter (60 in) reflecting telescope at Mount Lemmon Observatory.[2] 2014 AA was only observed over a short observation arc of about 70 minutes,[2] and entered Earth's atmosphere about 21 hours after discovery.[1]

Entry

Using a poorly determined orbit, the JPL Small-Body Database listed a 3-sigma solution with impact occurring around 2 January 2014 02:33 UT ± 1 hour and 5 minutes.[4] The Minor Planet Center listed impact as occurring around 2 January 2014 05:00 UT ± 10 hours.[2] Independent calculations by Bill Gray, the Minor Planet Center and Steve Chesley at the Jet Propulsion Laboratory have verified that impact was virtually certain.[2]

The impactor would have been roughly the size of 2008 TC3, which exploded above the Nubian Desert in Sudan on 7 October 2008. Calculations by Chesley suggest the impactor fell somewhere on an arc extending from Central America to East Africa, with a best-fit location just off the coast of West Africa.[2] Calculations by Pasquale Tricarico using the nominal orbit show that 2014 AA entered Earth's shadow cone approximately 40 minutes before entering the atmosphere.[5]

Infrasound was detected by three stations of the Comprehensive Nuclear-Test-Ban Treaty Organization.[6] Peter Brown and Petrus Jenniskens located weak signals from infrasound stations in Bolivia, Brazil and Bermuda.[1] 2014 AA entered Earth's atmosphere around 04:02 UT[1] 3,000 km from Caracas, Venezuela, far from any landmass.[6] No ships or planes have reported witnessing the event.[6]

Kowalski previously discovered 2008 TC3, the first asteroid discovered before Earth impact, using the same telescope in October 2008.[6] There are about a billion near-Earth objects in the size range of 2014 AA, and impacts of comparably-sized objects occur several times each year.[1]

See also

References

  1. 1.0 1.1 1.2 1.3 1.4 "The First Discovered Asteroid of 2014 Collides With The Earth - An Update". NASA/JPL. 3 January 2014. Retrieved 4 January 2014.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 "MPEC 2014-A02 : 2014 AA". IAU Minor Planet Center. 2 January 2014. Retrieved 2 January 2014.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles> (K14A00A)
  3. 3.0 3.1 3.2 "JPL Small-Body Database Browser: (2014 AA)" (last observation: 1 January 2014; arc: 1 day). Jet Propulsion Laboratory. Retrieved 4 April 2016.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  4. "JPL Close-Approach Data: (2014 AA)" (last observation: 1 January 2014; arc: 1 day). Retrieved 2 January 2014.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  5. Guido, Ernesto (2 January 2014). "Small asteroid 2014 AA hit the Earth's atmosphere". Associazione Friulana di Astronomia e Meteorologia. Retrieved 2 January 2014.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  6. 6.0 6.1 6.2 6.3 Beatty, Kelly (2 January 2014). "Small Asteroid 2014 AA Hits Earth". Sky & Telescope. Retrieved 3 January 2014.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>

External links