The subject of today's post isn't anything new; it was just new to me, and, I suspect, will be to a good many of my readers, as well. I found out about it from a long-time loyal reader of Skeptophilia, who sent me a link about it with a note saying, "Okay, this is interesting. What think you?"
The link was to a 2008 article that appeared in Phys.org entitled, "Cuneiform Clay Tablet Translated for the First Time." The tablet in question is called the "Sumerian planisphere," and was discovered in the ruins of Nineveh by a British archaeologist named Henry Layard in the middle of the nineteenth century. From where it was found, it was dated to around 700 B.C.E., and although it was recognized that part of what it contained was maps of constellations, no one was quite sure what it was about.
The researchers were puzzled by the fact that the arrangements of the stars in the constellations were close to, but not exactly the same as, the configurations they would have had at the time it was made, but then they concluded that those would have been their positions 2,400 years earlier -- and they claimed the text and maps didn't just show the stars on any old night, but on a sequence of nights chronicling the approach of a comet or asteroid.
Which, ultimately, hit the Earth.
They claim the collision site was near Köfels, Austria, and triggered a five-kilometer-wide fireball. Why no huge crater, then? The answer, they say, is that the steep side of the mountain gave way because of the impact, and a landslide ensued. Organic matter trapped in the debris flow gave an approximate date, but once deciphered, the Sumerian planisphere's detailed sky maps (including the position of the Sun, the timing of sunrise, and so on) supposedly pinpointed the exact day of the impact: the 29th of June, 3123 B.C.E.
Between the planisphere and the geometry of the collision site, the researchers claimed that the comet came in at a very shallow angle -- their estimate is about six degrees -- clipped the nearby peak of Gamskogel, and exploded, creating a five-kilometer-wide moving fireball that finally slammed into Kófels head-on.
You may be wondering why Sumerian astronomers had any particular interest about an impact that occurred almost four thousand kilometers away. They have an answer for that, too; the shallow impact angle created a sheet of superheated debris that arced away from the impact site, and right toward what is now the Middle East. A 2014 paper by Joachim Seifert and Frank Lemke concluded that the greatest amount of damage didn't occur right at the collision site, but where all that flaming debris eventually landed -- in Mesopotamia."The back plume from the explosion (the mushroom cloud) would be bent over the Mediterranean Sea re-entering the atmosphere over the Levant, Sinai, and Northern Egypt," said Mark Hempsell of the University of Bristol, who is the chief proponent of the Köfels collision hypothesis. "The ground heating though very short would be enough to ignite any flammable material - including human hair and clothes. It is probable more people died under the plume than in the Alps due to the impact blast."