I recall this, too, that such events traditionally signal a shift in the heaven’s sanction of the current dynasty. Comets and other events, I guess including earthquakes, often heralded a dynastic change, the previous dynasty losing popular support upon the appearance of such phenomenons. It was not lost on some, either, that the 1976 quake occurred about the time of Mao’s death. I’m wondering if the leaders in Beijing are thinking about this.