Scientists zero in on location of a probable meteorite fall
February 20, 2008, 5 pm

 
 

Scientists including Dick Pugh and Alex Ruzicka at the Cascadia Meteorite Laboratory (CML) at Portland State University are sorting through dozens of phone calls and emails sent in to the laboratory to determine whether the bright meteor (fireball) seen over a large region of the Pacific Northwest yesterday (February 19) at around 5:30 AM Pacific Time produced any meteorites and if so, where they might be found.  Based on eyewitness and seismic data, it appears that the meteor probably did produce meteorites (rocks on the ground) northeast of Pendleton in Oregon.  Eyewitnesses from Oregon,Washington, British Columbia, Idaho, Montana, and California saw a fireball moving generally northwest to southeast.  This trajectory is generally consistent with video of the fireball taken from Portland, Oregon and elsewhere.  Sonic booms sufficiently loud to rattle windows and startle people awake were reported in Hermiston and Pendleton in Oregon; at these locations the fireball was bright enough to turn night into day for a few seconds.  Less intense sonic booms were reported in Union, Oregon.  At least one and possibly two major break-ups of the meteor occurred shortly before it hit the ground, producing dozens of tracks with three major ones apparently corresponding to large pieces of material.  Some eyewitnesses said the natural display reminded them of a “Roman Candle” firework.  Based on the observations, it appears that the meteor experienced a “terminal airburst”, fragmenting into various pieces that likely would have dropped meteorites northeast of the Pendleton area.  The explosive airburst was evidently recorded by seismometers of the Pacific Northwest Seismic Network (PNSW).  Preliminary models of the seismic data indicate an airburst northeast of Pendleton and southeast of Walla Walla, Washington.  Meteorites would likely be found just downrange (to the southeast) of the airburst location suggested by the seismic network.  Reports of the fireball and of possible meteorites it produced should be sent to the Cascadia Meteorite Laboratory (503-287-6733 for Dick Pugh; or by email to Alex Ruzicka at ruzickaa@pdx.edu ). Dick Pugh will be visiting Hermiston and Pendleton in the first week of March to give meteorite lectures, and members of the public are welcome to bring suspected meteorites to those events.
 

 

Information provided by Alex Ruzicka, Assistant Professor of Geology, Portland State University