The Catriona Catastrophe:
"Someone had Blundered" ( Tennyson ).    

The next line reads "Theirs was not to reason why" but with your permission, I wouild like to do a little reasoning, unlike Tennyson's heroes.

The expected track of Catrionas's shadow on February 14 was based on careful calculations by experts in Belgium and the US, using the latest available precise data on the position of Menkalinan and the orbit of Catriona.  As February 14 approached, the United States Naval Observatory obtained updated orbital data and this enabled the shadow track to be defined as a line passing through Gobabis and Gansbaai, with the usual uncertainties of a hundred or more kilometres.  Three days before the event, final measurements and computations at the University of Basel moved the line about 150 Km further West,  causing it to miss the Peninsula area.  Now these corrections were of the order of 0.1 arc seconds.  This corresponds to the diameter of a R1 coin seen at a distance of 40 kilometres.  Errors as small as this are unavoidable.  It is a miracle of astrometry that the errors are so small.  An amateur told me that his computer showed Catriona not near Menkalinan but in another constellation.  This would have meant an error of at least 8 degrees, 288 000 times larger than the kind of error we are talking about.  Some people think a gross mistake was made:  A friend listened attentively ( I thought )  to one of the talks where I explained that the probability of being in the right place to see the event was small.  Afterwards he reported that, to his great disappointment, he had not seen Menkalinan disappear and that he was quite put out.

"Danie"  he asked kindly  "Was there a miscalculation?"

Yes there was.  My blunder was in not making allowance for mankind's irrational optimism when it comes to statistical probabilities.  Casino operators know all about this trait and use it to make their fortunes.  In the meantime a few dedicate observers throughout Southern Africa continue to watch for planetary occultations.  These heroes' expectations are not high but they keep trying like Bruce's spider,  to end on a different historical note.

Danie Overbeek