By: Timothy Kays
The jet setters tend to refer to this area of the nation as boring, fly-over country. What flew over the area on the evening of January 16 was anything but boring, though. From as far west as Iowa, to as far east as Pennsylvania, and as far north as southern Ontario, Canada, a significant fireball lit the night skies, and amazed a multitude of witnesses to its celestial splendor.
A fireball is a meteor that is significantly brighter than the usual ‘shooting star’. The International Astronomical Union defines a fireball as, “…a meteor brighter than any of the planets,” and carries an apparent magnitude of -4 or greater. Magnitude numbers are measured the opposite of other scales of intensity, with negative numbers being brighter than positive. The brightest star in the night sky, Sirius, carries a magnitude of -1.46. A fireball that reaches a magnitude of -14 is classified as a bolide, and a fireball reaching -17 or brighter is referred to as a superbolide.
These have a tendency to explode in the lower atmosphere, wreaking havoc in the process. One of the most famous low atmospheric explosions that coincided with a meteor or fireball was the Russian Tunguska Event of 1908. Although it has been speculated that the event was due to an unseen comet striking the earth, there is no speculation as to the outcome.
The explosion, between three and six miles above ground level, released the energy equivalent of 185 Hiroshima-scale atomic bombs, while flattening 770 square miles of forestland. While the event of January 16 was far less dramatic, it was still a sight to see. According to their detailed logs, beginning shortly after 8:00 p.m., the American Meteor Society (AMS) received a total of 665 reports of the fireball, which was entered into the record books under the title ‘AMS Event 168-2018’.
Of these reports, 93 stated that there was a concurrent sound associated with the fireball, and 180 reported a delayed sound. 62 observers reported seeing some form of fragmentation as the fireball passed. Most of the apparent magnitude reports place the fireball in the superbolide category, with some stating numbers as low as -27. Although most observers said that the event lasted from 1 to 3.5 seconds, there were some that said that the display lasted much longer.
This might have been attributed to air ionization, a glowing trail of ionized particles often left in the wake of a meteor. The greatest concentration of observers was found from the Chicago to Milwaukee area, then across southern Michigan. The majority of reports fix the time of the event at or around 8:10 p.m.
The fireball added another dimension of wonderment to its passage. At 8:10 p.m. the United States Geological Survey noted an earthquake in southeastern Michigan, which they associated with the appearance of the fireball. With a magnitude of only 2.0 on the open-ended Richter Scale, the temblor epicenter was located north of Walled Lake, Michigan, near the intersection of Maple Road and Pontiac Trail. Although the USGS listed it as a ‘meteorite’ event, no evidence has been found indicating an impact site, indicating that the ‘earthquake’ was actually a sonic boom.
The night skies quieted for a while, but just prior to midnight, a second fireball was reported. Not as bright as the first, this fireball, carrying the title AMS Event 206-2018, was seen from Winona, Minnesota, to just north of Greenville, South Carolina. A total of 108 reports of the event were fielded by the AMS, with the greatest concentration from Chicago to Cincinnati.
The earth is under constant bombardment by space debris, most of which is the size of grains of sand. Once they come into contact with the atmosphere, they burn up overhead, leaving a streak of light as they pass. Sometimes, the little rocks are not so little, and they create quite the show as they pass through the atmosphere. They can be bright enough to light up the night with the intensity of sunlight.
They can hiss and pop as they pass, and yes…sometimes they can explode. Although the area was spared the worst case scenario, the five second event of January 16 will provide a lifetime of memories for those fortunate enough to have seen it.
Timothy can be reached at firstname.lastname@example.org