A small asteroid discovered in the early hours of January 1, 2013 hit the Earth's atmosphere about 21 hours later and burned up harmlessly. NASA' Jet Propulsion Laboratory (JPL) announced today that the 6 to 9 foot asteroid, named Asteroid 2014 AA, impacted the Earth's atmosphere over the Atlantic Ocean off the western coast of Africa. The asteroid had been spotted by the Catalina Sky Survey near Tuscon, Ariz. The astronomers were able make follow-up observations on the asteroid.
NASA's Near-Earth Object Program Office at JPL was able to use the precise observations made by the Catalina Sky Survey to determine possible impact zones. Steve Chesley of JPL produced a plot of impact zones for Asteroid 2014 AA crossing the Atlatic and cutting across Sub-Saharan Africa.
Chesley's plot helped Peter Brown of the University of Western Ontario, and Petrus Jenniskens of the SETI Institute, Mountain View, Calif., to search the data from low-frequency infrasound observation sites of the Comprehensive Nuclear-Test-Ban Treaty Organization. They found weak signals from stations in Bolivia, Brazil and Bermuda that indicated that the likely impact location was indeed positioned within the predicted area.
Infrasound stations monitor ultra-low frequency sounds to determine the location of atmospheric explosions. The stations often pick up airbursts from the impact of small asteroids called fireballs or bolides. There are estimated to be approximately one billion objects the size of Asteroid 2014 AA and several impact the Earth's atmosphere each year.
The asteroid that entered the Earth's atmosphere above Russia on February 15, 2013 was between 17 and 20 meters in size, much larger than Asteroid 2014 AA. A non-profit group called the B612 foundation has plans to launch a private space telescope to locate undiscovered near-Earth asteroids (see video).