2014 AA was a small
Apollo
Apollo, grc, Ἀπόλλωνος, Apóllōnos, label=genitive , ; , grc-dor, Ἀπέλλων, Apéllōn, ; grc, Ἀπείλων, Apeílōn, label=Arcadocypriot Greek, ; grc-aeo, Ἄπλουν, Áploun, la, Apollō, la, Apollinis, label= ...
near-Earth asteroid
A near-Earth object (NEO) is any small Solar System body whose orbit brings it into proximity with Earth. By convention, a Solar System body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical units (AU). ...
roughly 2–4 meters in diameter that
struck Earth on 2 January 2014.
It was discovered on 1 January 2014 by
Richard Kowalski
Richard A. Kowalski (born 1963) is an American astronomer who has discovered numerous asteroids and comets, among them, many near-Earth objects.
Kowalski has had a lifelong interest in astronomy with an emphasis on planetary science. As an am ...
at the
Mount Lemmon Survey
Mount Lemmon Survey (MLS) is a part of the Catalina Sky Survey with List of observatory codes, observatory code List of observatory codes#G96, G96. MLS uses a cassegrain reflector telescope (with 10560x10560-pixel camera at the f/1.6 prime focu ...
at an
apparent magnitude
Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's li ...
of 19 using a
reflecting telescope
A reflecting telescope (also called a reflector) is a telescope that uses a single or a combination of curved mirrors that reflect light and form an image. The reflecting telescope was invented in the 17th century by Isaac Newton as an alternati ...
at
Mount Lemmon Observatory
Mount Lemmon Observatory (MLO), also known as the Mount Lemmon Infrared Observatory, is an astronomical observatory located on Mount Lemmon in the Santa Catalina Mountains approximately northeast of Tucson, Arizona (US). The site in the Coronad ...
.
2014 AA was only observed over a short observation arc of about 70 minutes,
and entered Earth's atmosphere about 21 hours after discovery.
Nonetheless it remains one of only a few asteroids observed before impact (see
Asteroid impact prediction
Asteroid impact prediction is the prediction of the dates and times of asteroids impacting Earth, along with the locations and severities of the impacts.
The process of impact prediction follows three major steps:
# Discovery of an asteroid and ...
).
Entry
![2014aa imploc](https://upload.wikimedia.org/wikipedia/commons/8/8d/2014aa_imploc.png)
Using a
poorly determined orbit, the
JPL Small-Body Database
The JPL Small-Body Database (SBDB) is an astronomy database about small Solar System bodies. It is maintained by Jet Propulsion Laboratory (JPL) and NASA and provides data for all known asteroids and several comets, including orbital parameters and ...
listed a
3-sigma solution with impact occurring around 2 January 2014 02:33
UT ± 1 hour and 5 minutes.
[ The ]Minor Planet Center
The Minor Planet Center (MPC) is the official body for observing and reporting on minor planets under the auspices of the International Astronomical Union (IAU). Founded in 1947, it operates at the Smithsonian Astrophysical Observatory.
Function
...
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
The Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center in the City of La Cañada Flintridge, California, United States.
Founded in the 1930s by Caltech researchers, JPL is owned by NASA an ...
verified that impact was virtually certain. It entered the atmosphere going about 11.7 km/s with respect to
Dependent and independent variables are variables in mathematical modeling, statistical modeling and experimental sciences. Dependent variables receive this name because, in an experiment, their values are studied under the supposition or demand ...
Earth.
The impactor would have been roughly the size of , which exploded above the Nubian Desert
The Nubian Desert ( ar, صحراء النوبة, ''Şaḩrā’ an Nūbyah'') is in the eastern region of the Sahara Desert, spanning approximately 400,000 km2 of northeastern Sudan and northern Eritrea, between the Nile and the Red Sea. Th ...
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
Nominal may refer to:
Linguistics and grammar
* Nominal (linguistics), one of the parts of speech
* Nominal, the adjectival form of "noun", as in "nominal agreement" (= "noun agreement")
* Nominal sentence, a sentence without a finite verb
* Nou ...
orbit show that 2014 AA entered Earth's shadow cone approximately 40 minutes before entering the atmosphere.
Infrasound
Infrasound, sometimes referred to as low status sound, describes sound waves with a frequency below the lower limit of human audibility (generally 20 Hz). Hearing becomes gradually less sensitive as frequency decreases, so for humans to perce ...
was detected by three stations of the Comprehensive Nuclear-Test-Ban Treaty Organization
The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) is an international organization that will be established upon the entry into force of the Comprehensive Nuclear-Test-Ban Treaty, a Convention that outlaws nuclear test explosions. It ...
. Peter Brown and Petrus Jenniskens located weak signals from infrasound stations in Bolivia, Brazil and Bermuda. 2014 AA entered Earth's atmosphere around 03:06 ± 5 min UT, 3,000 km from Caracas
Caracas (, ), officially Santiago de León de Caracas, abbreviated as CCS, is the capital and largest city of Venezuela, and the center of the Metropolitan Region of Caracas (or Greater Caracas). Caracas is located along the Guaire River in the ...
, Venezuela, far from any landmass. No ships or planes reported witnessing the event. A recalculation of the impact parameters of this meteor based on infrasound recordings puts it in the Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...
about 1900 km (1030 nautical miles) east of Port of Spain
Port of Spain (Spanish: ''Puerto España''), officially the City of Port of Spain (also stylized Port-of-Spain), is the capital of Trinidad and Tobago and the third largest municipality, after Chaguanas and San Fernando. The city has a municip ...
in Trinidad
Trinidad is the larger and more populous of the two major islands of Trinidad and Tobago. The island lies off the northeastern coast of Venezuela and sits on the continental shelf of South America. It is often referred to as the southernmos ...
, at a longitude of impact of nearly 44º west and a latitude of 11º north, the impact time being 2456659.618 JD UTC. Extensive numerical simulations indicate that, prior to impact, 2014 AA was subjected to a number of secular resonances and it may have followed a path similar to those of the NEOs , , , and ; NEOs in this transient group experience close encounters with the Earth-Moon system at perihelion and Mars at aphelion and could be a dynamical family.
Other discoveries
Kowalski previously discovered , the first asteroid discovered before Earth impact, using the same telescope in October 2008. There are about a billion
Billion is a word for a large number, and it has two distinct definitions:
*1,000,000,000, i.e. one thousand million, or (ten to the ninth power), as defined on the short scale. This is its only current meaning in English.
* 1,000,000,000,000, i.e ...
near-Earth objects in the size range of 2014 AA, and impacts of comparably-sized objects occur several times each year.
Several years later, 2018 LA
2018 LA, also known as ZLAF9B2, was a small Apollo asteroid, Apollo near-Earth asteroid in mean diameter that impacted the atmosphere with small fragments reaching the Earth at roughly 16:44 UTC (18:44 local time) on 2 June 2018 near the border o ...
was also discovered by the Mount Lemmon Survey, and ended up impacting Earth in southern Botswana
Botswana (, ), officially the Republic of Botswana ( tn, Lefatshe la Botswana, label=Setswana, ), is a landlocked country in Southern Africa. Botswana is topographically flat, with approximately 70 percent of its territory being the Kalahar ...
in June 2018.
See also
* Asteroid impact prediction
Asteroid impact prediction is the prediction of the dates and times of asteroids impacting Earth, along with the locations and severities of the impacts.
The process of impact prediction follows three major steps:
# Discovery of an asteroid and ...
*
* WT1190F
WT1190F (9U01FF6, UDA34A3, or UW8551D) was a small temporary satellite of Earth that impacted Earth on 13 November 2015 at 06:18:21.7 (± 0.1 seconds) UTC. It is thought to have been space debris from the trans-lunar injection stage of the ...
* 2018 LA
2018 LA, also known as ZLAF9B2, was a small Apollo asteroid, Apollo near-Earth asteroid in mean diameter that impacted the atmosphere with small fragments reaching the Earth at roughly 16:44 UTC (18:44 local time) on 2 June 2018 near the border o ...
* 2019 MO
*
*
References
External links
The atmospheric impact trajectory of asteroid 2014 AA
arXiv
arXiv (pronounced "archive"—the X represents the Greek letter chi ⟨χ⟩) is an open-access repository of electronic preprints and postprints (known as e-prints) approved for posting after moderation, but not peer review. It consists of ...
13 January 2016
Two maps of the possible impact region
(Yahoo groups / Project Pluto)
2014 AA – New Year’s Earth impactor
( Carl W. Hergenrother)
*
*
{{DEFAULTSORT:2014 AA
#
Minor planet object articles (unnumbered)
Discoveries by Richard Kowalski
January 2014 events
Predicted impact events
20140102
20140101
2014 in space