Well, that same question was asked and pondered over for some time in the period following the Napoleonic Wars.
In fact Professor Friedrich Max Willen of the Royal Theosophical Society spent several years work on the answer to that question. Through painstaking research and the application of numerical methods, he calculated those odds to be -
A Million To One
Professor Friedrich Max Willen
of the Royal Theosophical Society.
First scholar to calculate the odds of anything
coming from Mars, using modern rational methods.
... well, we all know how those odds turned out !