Did a Comet strike the Earth in 540 A.D. ?

By Craig: Fireballs and asteroids have received a lot of attention over the last ten days or so. First there was the Siberian meteor, and then the near miss of Asteroid da14 on Friday last. Although my knowledge of fireballs, comets, and meteors is primarily on the historical side, I do know a little bit about the statistics that relate to these otherworldly cosmic bodies. For instance, some of the news reports have erroneously stated that the 2013 Siberian fireball was the largest meteor to enter the earth's atmosphere since the Tunguska blast of 1908. This is wrong. First, there is no concrete evidence that the Tunguska event was the result of a meteor impact. Second, another Siberian fireball, the Sikhote-Alin meteor of 1947 was estimated to have been in the neighborhood of 70 tonnes. As of now estimates regarding the 2013 Siberian meteor range from 10 tonnes to 10,000 tonnes (which I find kind of hard to believe.)

       I have previously written on this blog, and on my website www.fireballhistory.com about historical encounters with fireballs. I have seen a few wild ones in my many years of looking up at the night sky. On the evening of January 24, 2007 at approximately 1950 hours I observed a large bright green bolide in the north-eastern sky. I had a clear view of the meteor and watched it for a good eight seconds or so before it completely disappeared, as if someone had turned off a light switch. I estimate that it's apparent magnitude was about -11 or -12 which is about as bright as the full moon. Other people reported the bolide, and the newspapers soon got hold of it. It found it's way to the Drudge Report, and even the late night talk show Coast-to-Coast. It was the brightest meteor that I had ever seen, and I have seen a few bright ones over the years.

      As spectacular as this bolide was back in 2007, it was nothing compared to what a lot of Russians observed last week in the Ural mountains of Siberia. However, this latest Siberian impact event can not even compare to what this planet has encountered in the past. Even the Tunguska event which has been estimated to be a blast 1000 times more powerful than the atomic bomb dropped on Hiroshima would be considered a chump relative to what could one day strike the earth. In fact, "COULD" is not being really accurate. One day in the future a random fragment from space "WILL" careen into our planet destroying civilization as we now know it. When this event will occur is not known. Comet's routinely enter the inner solar system, and the historical, and archaeological records show (even in recorded history) that cometary debris has struck the earth. The year 540 A.D. (or possibly 541) seems to be a good candidate for a possible encounter with a comet. The chronicler Roger of Wendover records that "there appeared a comet in Gaul, so vast that the whole sky seemed on fire." It is also recorded that "blood fell from the heavens, and a great mortality ensued." Irish chroniclers also took note of the dreadful mortality that took place at around this time. The author and Dendrochronologist Mike Baillie who is the author of the book, Exodus to Arthur: Catastrophic Encounters With Comets has made note of growth reduction in the tree rings of European oaks and North American bristlecone pines suggesting that some widespread global event took place around this time. Did the earth have a close interaction with a comet? The jury is still deliberating on this one.