Title: The Innisfree meteorite and the Canadian camera network Authors: Halliday, I., Blackwell, A. T., & Griffin, A. A.
The events which led to the establishment of the camera network known as the Meteorite Observation and Recovery Project (MORP) are described. The network consists of 12 small observatories, each equipped with five cameras, a meteor detector, and exposure control systems. A bright fireball was observed from the ground and from an aircraft above clouds. Two MORP stations photographed the event, from which a predicted impact point was calculated, leading to the recovery of a 2-kg meteorite near Innisfree, Alberta. Five smaller pieces were located after the disappearance of snow. Measurements of the weak radioactivity produced by cosmic-ray activity were made on the main piece shortly after recovery. The results are of special interest because the meteor photographs provide a reliable orbit for the object before impact. Innisfree is only the third meteorite for which such a well-defined orbit is available. The low-inclination direct orbit appears normal for asteroidal fragments which collide with earth.
Name: INNISFREE Place of fall: 13 km NE of Innisfree, Alberta, Canada. 53°24'54"N., 111°20'15"W. Date of fall: February 5, 1977. Class and type: Stone. Olivine-hypersthene chondrite (L4-5). Number of individual specimens: 6, and fragments. Total weight: 3.79 kg Circumstances of find: The main mass, of 2.07 kg, was found on snow on February 17, 1977, at the site predicted from calculations based on fireball photographs. Other stones were found on April 10th and 11th. A further fragment was found on April 21st. All stones were found within a 400 m X 500 m area. Centre of `ellipse of fall' was 300 m from point predicted from calculations assuming a 4 kg mass. Specimens now in National Meteorite Collection, Geological Survey of Canada, Ottawa and in the University of Alberta, Edmonton, Canada. Source