An alternative theory, first suggested in 1882 by Ignatius L. Donnelly in Ragnarok: The Age of Fire and Gravel, is that the fire was caused by a meteor shower. This was described as a "fringe theory" concerning Biela's Comet. At a 2004 conference of the Aerospace Corporation and the American Institute of Aeronautics and Astronautics, engineer and physicist Robert Wood suggested that the fire began when a fragment of Biela's Comet impacted the Midwest. Biela's Comet had broken apart in 1845 and had not been observed since. Wood argued that four large fires took place, all on the same day, all on the shores of Lake Michigan (see related events), suggesting a common root cause. Eyewitnesses reported sighting spontaneous ignitions, lack of smoke, "balls of fire" falling from the sky, and blue flames. According to Wood, these accounts suggest that the fires were caused by the methane that is commonly found in comets.
An alternative theory, first suggested in 1882 by Ignatius L. Donnelly in Ragnarok: The Age of Fire and Gravel, is that the fire was caused by a meteor shower. This was described as a "fringe theory" concerning Biela's Comet. At a 2004 conference of the Aerospace Corporation and the American Institute of Aeronautics and Astronautics, engineer and physicist Robert Wood suggested that the fire began when a fragment of Biela's Comet impacted the Midwest. Biela's Comet had broken apart in 1845 and had not been observed since. Wood argued that four large fires took place, all on the same day, all on the shores of Lake Michigan (see related events), suggesting a common root cause. Eyewitnesses reported sighting spontaneous ignitions, lack of smoke, "balls of fire" falling from the sky and blue flames. According to Wood, these accounts suggest that the fires were, caused by the methane that is commonly found in comets.