Vacation spots in the us for In his study of how many naked-eye cometary apparitions there would ordinarily be each century, Licht calculated that there would be an average of Ramsey and Licht wrote about the situation in the first century BC To take the irst century B.C. as an example, Hasegawa lists naked-eye comets seen during those hundred years, out of which were seen by only the Romans and/or Greeks, by only the Chinese and/or Koreans, and by observers both in the Mediterranean and in the Far East. However, based upon the statistics in Hasegawa’s catalogue for recent centuries, for which our records are fullest, there should have been as many as naked-eye comets visible during the first century B.C. According to the analysis of Hughes, the rate of naked-eye-observed long-period comets has been rather consistent over the past , years at approximately ? per century. For the period BC to AD we have surviving records of at most one-third of all visible comets. Vacation spots in the us 2016.