Παρασκευή 15 Φεβρουαρίου 2013

Russian Fireball Not Linked to Asteroid Flyby



02.15.13
 
Map showing the meteorite impact areaA fireball seen flying over Russia on Feb. 15 at 3:20: 26 UTC impacted Chelyabinsk. Preliminary information is that this object was unrelated to asteroid 2012 DA14, which made a safe pass by Earth today. Image credit: Google Earth, NASA/JPL-Caltech › Larger view
Preliminary information indicates that a fireball in Chelyabinsk, Russia, is not related to asteroid 2012 DA14, which is flying by Earth safely today.
The Russian fireball is the largest reported since 1908, when a fireball hit Tunguska, Siberia. The fireball entered the atmosphere at about 40,000 mph (18 kilometers per second). The impact time was 7:20:26 p.m. PST, or 10:20:26 p.m. EST on Feb. 14 (3:20:26 UTC on Feb. 15), and the energy released by the impact was in the hundreds of kilotons.
Based on the duration of the event, it was a very shallow entry. It was larger than the fireball over Indonesia on Oct. 8, 2009. Measurements are still coming in, and a more precise measure of the energy may be available later. The size of the object before hitting the atmosphere was about 49 feet (15 meters) and had a mass of about 7,000 tons.
The fireball, which was about one-third the diameter of asteroid 2012 DA14, was brighter than the sun. Its trail was visible for about 30 seconds, so it was a grazing impact through the atmosphere.
It is important to note that this estimate is preliminary, and may be revised as more data is obtained.
 
 
DC Agle  818-393-9011
Jet Propulsion Laboratory, Pasadena, Calif.
agle@jpl.nasa.gov

2013-061

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