News Releases - Air Force Technical Applications Center [AFTAC]

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Fireballs are normally millimeter-sized meteoroids that have entered the atmosphere. There is a very good possibility that fireballs greater than -20 in magnitude in brightness [produced by much larger meteoroids of the order of one meter in diameter] will be detected by US Government satellites. Their bright flash arises from energy released upon explosive disintegration due to action of aerodynamic forces. Usually meteoroids disintegrate at altitudes of 30 to 45 km above the Earth’s surface, but some penetrate the atmosphere to altitudes of about 20 km.

There are two kinds of satellite detectors, visible and infrared, which are sensitive only to very bright events (magnitude about -20 and brighter). They operate on a global scale and are able to monitor impacts of meter-sized and larger bodies. Since the mid-1970's more than 250 fireball events have been detected from orbit by infrared sensors on the Defense Support Program spacecraft. The average number of meteoroid fireballs detected by infrared radiation sensors is currently about 30 per year. Approximately 20% of this total have also been detected by optical sensors of the Nuclear Detection System on NAVSTAR satellites. These visible radiation sensors have recorded light curves for some of these events. While these meteoroid fireballs exhibit many features of a nuclear detonations with the same yield, there are specific differences.

The following are press releases/announcements from the Air Force Technical Applications Centre (AFTAC) Office of Public Affairs and elsewhere. These releases relate to satellite observations of fireballs detected in the atmosphere by optical and infrared sensors aboard DoD satellites.


Sources

  • Peter G. Brown's Archive of DoD Press Releases

  • Historical Evidence of Recent Impacts on the Earth, Ivan V. Nemtchinov, I.B. Kosarev, O.P. Popova, V.V. Shuvalov, V.V. Svettsov, R.E. Spalding, C. Jacobs, J. Shavez, E. Tagliaferri (PDF 2.3M) Planetary Defense Workshop Proceedings Lawrence Livermore National Laboratory Livermore, California May 22-26, 1995
  • SATELLITE OBSERVATIONS OF A METEORITE PRODUCING FIREBALL: THE ST. ROBERT EVENT Peter Brown , Alan R. Hildebrand, Daniel W. E. Green, Denis Page, Cliff Jacobs, Doug Revelle, Edward Tagliaferri, John Wacker and Bob Wetmiller INTERNATIONAL WORKSHOP TUNGUSKA96 July 14-17, 1996


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    Updated August 6, 2002