Probable impact location of near-Earth asteroid 2014 AA based on infrasound data from the Comprehensive Nuclear-Test-Ban Treaty Organization.
|Discovered by||Richard Kowalski
Mount Lemmon Survey (G96)
|Discovery date||1 January 2014|
|MPC designation||2014 AA|
|Observation arc||~70 minutes|
|Aphelion||1.41 AU (Q)|
|Perihelion||0.91 AU (q)|
|1.16 AU (a)|
|Dimensions||~3 meters (10 ft)|
|Mass||~4×104 kg (assumed)|
2014 AA was a small near-Earth asteroid roughly 2–4 meters in diameter that struck Earth on 2 January 2014. 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. 2014 AA was only observed over a short observation arc of about 70 minutes, and entered Earth's atmosphere about 21 hours after discovery.
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. The Minor Planet Center listed impact as occurring around 2 January 2014 05:00 UT ± 10 hours. Independent calculations by Bill Gray, the Minor Planet Center and Steve Chesley at the Jet Propulsion Laboratory have verified that impact was virtually certain.
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. Calculations by Pasquale Tricarico using the nominal orbit show that 2014 AA entered Earth's shadow cone approximately 40 minutes before entering the atmosphere.
Infrasound was detected by three stations of the Comprehensive Nuclear-Test-Ban Treaty Organization. Peter Brown and Petrus Jenniskens located weak signals from infrasound stations in Bolivia, Brazil and Bermuda. 2014 AA entered Earth's atmosphere around 04:02 UT 3,000 km from Caracas, Venezuela, far from any landmass. No ships or planes have reported witnessing the event.
Kowalski previously discovered 2008 TC3, the first asteroid discovered before Earth impact, using the same telescope in October 2008. 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.
- "The First Discovered Asteroid of 2014 Collides With The Earth - An Update". NASA/JPL. 3 January 2014. Retrieved 4 January 2014.
- "MPEC 2014-A02 : 2014 AA". IAU Minor Planet Center. 2 January 2014. Retrieved 2 January 2014. (K14A00A)
- "JPL Small-Body Database Browser: (2014 AA)" (last observation: 1 January 2014; arc: 1 day). Jet Propulsion Laboratory. Retrieved 2 January 2014.
- "JPL Close-Approach Data: (2014 AA)" (last observation: 1 January 2014; arc: 1 day). Retrieved 2 January 2014.
- Guido, Ernesto (2 January 2014). "Small asteroid 2014 AA hit the Earth's atmosphere". Associazione Friulana di Astronomia e Meteorologia. Retrieved 2 January 2014.
- Beatty, Kelly (2 January 2014). "Small Asteroid 2014 AA Hits Earth". Sky & Telescope. Retrieved 3 January 2014.
- Orbital simulation from JPL (Java) / Ephemeris
- 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)