Direct records of sunspots and the solar cycle have been maintained in astronomical observatories for about 1610 AD, while indirect records derived from 14 C analysis of ice cores go back to about 900 AD. Minima in the sunspot cycle present conditions conducive to the entry or activation of new pathogens and also for mutations of already circulating bacteria and viruses. Three grand minima of solar activity on record-the Sporer minimum (1450-1550 AD), Maunder minimum (1650-1700 AD) and the Dalton minimum (1800-1830) have all been marked by a preponderance of pandemics-Small Pox, English Sweats, Plague and Cholera. The sunspot numbers recorded for the present period 2002-2017 include the deepest sunspot minimum (Cycle 23-24) since records began, and a trend to declining numbers throughout the cycle. The same period has seen the resurgence of several pandemics-SARS, MERS, Zika, Ebola, Influenza A. We consider it prudent to take note of these facts whilst planning future strategies for pandemic surveillance and control.

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The extended period of mass extinctions around the K/T boundary correlating with extraterrestrial amino acids in the sediment record constitutes strong evidence of a cometary cause. The input of extraterrestrial matter over lo5 yr supports the hypothesis of a giant comet, fragmented into subcomets on close encounter