1972 Great Daylight Fireball
| Date | August 10, 1972 |
|---|---|
| Location | Northern America |
| External media | |
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| Images | |
| Earthgrazer: The Great Daylight Fireball of 1972 (Credit & Copyright: Antarctic search for meteorites program, Case Western Reserve University, James M. Baker) | |
| Video | |
| 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) 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. 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. However, the object has not been observed again and so its post-encounter orbit remains unknown.