2014 AA
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Probable impact location of near-Earth asteroid 2014 AA based on infrasound data from the Comprehensive Nuclear-Test-Ban Treaty Organization.[1]
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Discovery[2] | |
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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] | |
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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]
Contents
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
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External links
- Orbital simulation from JPL (Java) / Ephemeris
- The atmospheric impact trajectory of asteroid 2014 AA – arXiv 13 Jan 2016
- Two maps of the possible impact region (Yahoo groups / Project Pluto)
- 2014 AA – New Year’s Earth impactor (Carl W. Hergenrother)
- ScienceCasts: New Year's Asteroid Strike (ScienceAtNASA on YouTube)
- 2014 AA at the JPL Small-Body Database
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