1972 Great Daylight Fireball

1972 Great Daylight Fireball
DateAugust 10, 1972 (1972-08-10)
LocationNorthern America
External media
Images
image icon Earthgrazer:
The Great Daylight Fireball of 1972
(Credit & Copyright: Antarctic search for meteorites program, Case Western Reserve University, James M. Baker)[1]
Video
video icon 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 kilometres (35 mi; 187,000 ft) of Earth's surface at 20:29 UTC on August 10, 1972. It entered Earth's atmosphere at a speed of 15 kilometres per second (9.3 mi/s)[2] 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.[3] An eyewitness to the event, located in Missoula, Montana, saw the object 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.[3][4] However, the object has not been observed again and so its post-encounter orbit remains unknown.[5]

  1. ^ Astronomy Picture of the Day Archived 2016-10-19 at the Wayback Machine. 2009 March 2.
  2. ^ Cite error: The named reference gsna was invoked but never defined (see the help page).
  3. ^ a b Observation of Meteoroid Impacts by Space-Based Sensors Archived 2007-10-20 at the Wayback Machine 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'
  4. ^ Ceplecha, Z. (1994). "Earth-grazing daylight fireball of August 10, 1972". Astronomy and Astrophysics. 283: 287.
  5. ^ "NEO Chronology – NEO".