Moreover, it is silly to say the dark ages started then in some grand cataclysm. The dark ages began much earlier and were not a grand cataclysm but a slow historical process. The causes of which were not written on the sky, but in perfectly understandable and perfectly boneheaded practices of the governors of the Roman empire, in lost wars, etc. Whether the article writers like it or not, grand historical events of entirely human making are far too common to need explanation by such distant and esoteric causes.
Then there are particular claims like multi-megaton impacts every 50 years. This seems incredibly unlikely, given that all of one has ever been even remotely documented in all of recorded history, a little less than 100 years ago. By hypothesis, there were 7 others since the time of Galileo. Where are they? Where is any observation of their effects? Not even one in any location where anybody would see any aftermath?
Then there is the idea that it must be associated with comets. Um, how? A full straight on hit by an entire comet would indeed be spectacular enough, and on geological timescales (millions and hundreds of millions of years) is believeable enough. But cometary debris? Give me a break. It is more rarified than snow, and the same composition. Tossing it in seems entirely an appeal to ridiculous astrological beliefs of the distant past, which were based on entirely false ideas of what they were in the first place, let alone what they caused.
The hard realities of the matter are that sure, stuff from space can and does hit the earth, but also recorded history is but the flies of summer compared to the time scales involved in such solar system phenomena. A few thousands years is nothing, and that is all there is any real record of. As for 1159 BC and 1628 BC, the idea that anybody knows anything truly reliable about them is pretty silly, let alone shifting dates of civilizational events clear around the globe by 70 years arbitrarily. Let alone the idea that civilizational changes need any such esoteric and remote causes, when we know perfectly well that e.g. Dorians arriving can make a Greek "dark age", and Germans arriving a western European one, and Mongols arriving can revamp China, etc. There are about 100 times too many big civilizational shifts to map all of them to impacts from space.
Moreover, such explanations have a long and entirely dubious history. Sunspots and a solar minimum are suppose to explain the crisis of the early 17th century, for example. Little things like the Reformation or the 30 years war depopulating central Europe are supposed to be mere aftershocks. Yeah right. And Gustavus Adolphus was fated by a meteor, and born under the sign of whatever, too. Praetorian guards selling the empire to the highest bidder, dozens of civil wars, whole nations invading the empire, ridiculous economic practices, systematic slavery, declining population induced by all of the above and by changes in morals, are all supposed to not matter at all. Which is rather like Kim Il Sung blaming 7 years of famine in North Korea on the weather.