1972 Great Daylight Fireball

Atmospheric phenomenon November 2025 The Great Fireball streaks through the daylight sky, as seen from Grand Teton National Park. 1972 08 10 United States, Canada right Earthgrazer:The Great Daylight Fireball of 1972(Credit & Copyright: Antarctic search for meteorites program, Case Western Reserve University, James M. Baker)http://www.phys.ncku.edu.tw/~astrolab/mirrors/apod_e/ap090302.html Astronomy Picture of the Day 2009 March 2. https://web.archive.org/web/20161019155203/http://www.phys.ncku.edu.tw/~astrolab/mirrors/apod_e/ap090302.html 2016-10-19 Grand Teton Meteor Near Miss! The Great Daylight Fireball (also known as the Grand Teton Meteor) was an Earth-grazing fireball that passed within 57 km mi ft of Earth's surface at 20:29 UTC on August 10, 1972. It entered Earth's atmosphere at a speed of 15 km/s km/h mph 0 on in daylight over Utah, United States (14:30 local time) and passed northwards leaving the atmosphere over Alberta, Canada. It was seen by many people and recorded on film and by space-borne sensors.http://www.astrosociety.org/pubs/mercury/9806/impact.html Observation of Meteoroid Impacts by Space-Based Sensors https://web.archive.org/web/20071020025037/http://www.astrosociety.org/pubs/mercury/9806/impact.html 2007-10-20 Astronomical Society of the Pacific Edward Tagliaferri 2003 It was first detected by satellite at an altitude of about 73 km, tracked as it descended to about 53 km, and then tracked as it climbed back out of the atmosphere', 'object is still in an Earth-crossing orbit around the Sun and passed close to the Earth again in August 1997' An eyewitness to the event, located in Missoula, Montana, saw the bolide pass directly overhead and heard a double sonic boom. The smoke trail lingered in the atmosphere for several minutes. The atmospheric pass modified the object's mass and orbit around the Sun. A 1994 study found that it is probably still in an Earth-crossing orbit and predicted that it would pass close to Earth again in August 1997. Ceplecha Z. 1994 Earth-grazing daylight fireball of August 10, 1972 Astronomy and Astrophysics 283 287 https://adsabs.harvard.edu/pdf/1994A%26A...283..287C However, the object has not been observed again and so its post-encounter orbit remains unknown.https://neo.ssa.esa.int/web/guest/neo-chronology NEO Chronology – NEO neo.ssa.esa.int 2025-08-20 Description thumb|right|312px|Map of the object's trajectory from Z. Ceplecha (1994). The red icon marks atmospheric entry over Utah, the black icon marks perigee over Idaho, and the yellow icon marks exit over Alberta. Analysis of its appearance and trajectory showed the object was about 3 to 14 m ft 0 off us in diameter, depending on whether it was a comet made of ice or a stony and therefore denser asteroid.gsna maa Other sources identified it as an Apollo asteroid in an Earth-crossing orbit that would make a subsequent close approach to Earth in August 1997.a In 1994, Czech astronomer Zdeněk Ceplecha reanalysed the data and suggested the passage would have reduced the asteroid's mass to about a third or half of its original mass, reducing its diameter to 2 to 10 m ft 0 off us.http://www.maa.agleia.de/Comet/Other/1972.html Daylight Fireball of August 10, 1972 C. Kronberg Munich Astro Archive archived summary by Gary W. Kronk of early analysis and of Zdeněk Ceplecha's paper for Astronomy and Astrophysics in 1994, '3 meters, if a carbonaceous chondrite, or as large as 14 meters, if composed of cometary materials', 'post-encounter ... 2 or 10 meters' https://web.archive.org/web/20050120051405/http://www.maa.agleia.de/Comet/Other/1972.html 2005-01-20 The object was tracked by military surveillance systems and sufficient data obtained to determine its orbit both before and after its 100-second passage through Earth's atmosphere. Its velocity was reduced by about 0.8 km/s km/h mph 0 on and the encounter significantly changed its orbital inclination from 15 degrees to 7 degrees.http://www.fis.unipr.it/~albino/ITASN/GSNA/US19720810/US19720810.html US19720810 (Daylight Earth grazer) Global Superbolic Network Archive 2000 Size: 5 to 10 m https://web.archive.org/web/20040307122520/http://www.fis.unipr.it/~albino/ITASN/GSNA/US19720810/US19720810.html 2004-03-07 If it had not entered at such a grazing angle, this meteoroid would have lost all its velocity in the upper atmosphere, possibly ending in an airburst, and any remnant would have fallen at terminal velocity.Collins Gareth S. Melosh H. Jay Marcus Robert A. June 2005 Earth Impact Effects Program: A Web-based computer program for calculating the regional environmental consequences of a meteoroid impact on Earth https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1945-5100.2005.tb00157.x Meteoritics & Planetary Science 40 6 817–840 10.1111/j.1945-5100.2005.tb00157.x 10044/1/11554 free subscription See also List of asteroid close approaches to Earth References Further reading Abe1 Abe S. Borovicka J. Spurny P. Koten P. Ceplecha Z. Tamagawa T abstract Earth-grazing fireball on March 29, 2006 European Planetary Science Congress 2006 Berlin 18–22 September 2006 486 2006epsc.conf..486A the first and second Earth-grazing fireballs observed on August 10, 1972 (Jacchia, 1974; Ceplecha, 1979) and on October 13, 1990 (Borovicka and Ceplecha, 1992) Abe2 Abe Shinsuke etal 2006 http://sonotaco.jp/forum/download.php?id=5723 Earth-grazing fireball on March 29, 2006 European Planetary Science Congress 2006 486 full details: orbit, charts, spectra, composition 2008-07-07 2006epsc.conf..486A External links US19720810 (Daylight Earth grazer) orbital characteristics from Global Superbolide Network Archive, 2000 Fireball, meteorite, bolide, meteor, video and photo https://web.archive.org/web/20081204203940/http://fireball.meteorite.free.fr/index_en.html December 4, 2008 link to photos and cine film by Linda Baker Earthgrazer: The Great Daylight Fireball of 1972 overview of the event including photo by NASA's Astronomy Picture of the Day Astronomical Society of the Pacific: Observation of Meteoroid Impacts by Space-Based Sensors – one of several similar events; includes ground track * Category:Meteoroids Great Daylight Fireball 19720810 Category:20th-century Earth impact events Category:Earth-grazing fireballs Great Daylight Fireball Great Daylight Fireball Category:20th-century astronomical events