News Releases - Air Force Technical Applications Center [AFTAC]
News Releases
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.
- USAF 94-004 (November 8, 1994)
- USAF 94-005 (December 23, 1994)
- USAF 95-006 (January 23, 1995)
- USAF 95-008 (March 9, 1995)
- USAF 95-014 (August 8, 1995)
- USAF 95-015 (December 22, 1995)
- USAF 96-001 (February 6, 1996)
- USAF 96-002 (April 24, 1996)
- USAF 97-001 (May 5, 1997)
- USAF 97-002 (July 21, 1997)
- DOD 97-001 (October 21, 1997)
- DOD 98-001 (April 22, 1998)
- USAF 98-001 (June 8, 1998)
- USAF 98-002 (June 8, 1998)
- USAF 98-003 (June 8, 1998)
- DOD 99-001 (July 18, 1999)
- DOD 20-001 (January 19, 2000)
- DOD 20-002 (March 16, 2000)
- DOD 20-003 (October 30, 2000)
- DOD 21-001 (May 22, 2001)
- DOD 21-002 (July 26, 2001)
- USAF 21-001 (July 27, 2001)
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
http://www.fas.org/irp/agency/aftac/news/
Created by John Pike
Maintained by Steven Aftergood
Updated August 6, 2002
