In the early hours of Monday morning, a huge fireball was seen streaking across the sky of the American Midwest before exploding with a sonic boom that shook residential homes in the Green Bay area of Wisconsin. The blue-green fireball was reported to the American Meteor Society (AMS) by scores of witnesses, who subsequently wrote on its website:
“The fireball was seen primarily from Illinois and Wisconsin, but witnesses from Michigan, Indiana, Ohio, Iowa, New York, Kentucky, Minnesota and Ontario (Canada) also reported the event.”
One of the people witnessing the extraordinary event was Officer Patrick Murphy of the Chillicothe Police Department, who was out patrolling in his squad car when he spotted the bright fireball shooting past a set of traffic light. The incident was captured on his dashcam, and after heading to the northeast part of town where it appeared to have fallen, Murphy said that there were no signs of any flames.
“It definitely caught me off guard a little bit. Obviously, I was not expecting to see that. I figured it was probably a meteor because I don’t know what else it could possibly be,” explained Officer Murphy.
Given its subsequent explosion, the AMS said that the fireball was most likely a bolide, which is a brighter-than-usual meteor of between 1 and 100 meters in length that usually enter Earth’s atmosphere with enough force to explode. In 2013, for instance, a 20-meter superbolide exploded over the city of Chelyabinsk in Russia, with its large shock wave damaging 7,200 buildings and resulting in injures to around 1,500 people. Also in Russia, the Tunguska event of 1908 is thought to have been caused by a superbolide somewhere between 60 and 190 metres long, which was so powerful that it demolished 80 million trees over a 2,150 square kilometres area.
Fortunately, the fireball seen traveling southwest to northeast across several American Midwestern states was less than the size of a car, or less than 5 meters in length. It was also about 10 miles overhead when it eventually is believed to have exploded over Lake Michigan, with the meteors fragments subsequently scattering over the waters of the Great Lake. Commenting on the incident, Mike Hankey, operations manager for the AMS, said that it was most likely a block of icy rock that had been flung into our atmosphere, adding:
“It was a really big bolide, a fragment from an asteroid. It showed up on Doppler weather radar over Lake Michigan. Very big return, sad we can’t go meteorite hunting.”