Researchers seek insight from January’s Michigan meteor

Posted at 5:56 PM, Aug 27, 2018
and last updated 2018-08-27 17:56:12-04

DETROIT (AP) — Michigan seismologists are studying a meteor that exploded in the atmosphere over the state in January with the help of scientists at the Scripps Institution of Oceanography in San Diego.

The University of Michigan seismologists and the California scientists will publish their combined data on Michigan’s celestial event in a research paper, the Detroit Free Press reported . It’s slated for publication later this month.

The findings could help researchers understand how often bolides, the name for meteors that explode in the atmosphere, occur outside the view of witnesses.

The Jan. 17 meteor showered small fragments down toward Earth near Livingston County’s Hamburg Township west of Detroit. Witnesses watched the spectacular meteor flash across southern Michigan skies. People in Illinois, Indiana, Pennsylvania, Ohio, Missouri and Ontario, Canada, also reported seeing the meteor.

It’s rare for such large meteor events to occur in a heavily populated area within the recording capability of several scientific instruments.

“This event kind of fell into our laps; we were studying something else,” said Michael Hedlin, head of the Laboratory for Atmospheric Acoustics at Scripps.

Hedlin’s team was researching atmospheric gravity waves using infrasound sensors across the eastern and central U.S., which constantly record low-frequency sound. When the meteor made its sonic boom, Hedlin knew he had plenty of infrasound data related to it.

Seismologist Jeroen Ritsema at the University of Michigan’s Department of Earth and Environmental Sciences also didn’t expect to study the event. But he knew that he could review constantly recorded seismic data from the region to find the meteor’s burst.

Seismometers are sensitive and record the smallest ground movements, Ritsema said. He was able to track the recording of the meteor’s blast at seven seismometer stations in Michigan, Ohio and Ontario.

Hedlin contacted Ritsema to combine their separate disciplines into a research project.

“We could locate it (seismically) at exactly the same location where the infrasound was placing it,” Ritsema said.

The two research teams together confirmed the location the bolide came into the atmosphere over Michigan and the time of the blast.

Buried in the collected data could be more new knowledge about bolide meteorite events, said Hedlin.

“They probably have a lot of secrets we haven’t found yet,” he said. “I want to find out.”