October 12, 2015

Ephemeris for the real Columbus Day for once, Monday, October 12th.  The Sun will rise at 7:54.  It’ll be up for 11 hours and 9 minutes, setting at 7:03.  The Moon is new today, and won’t be visible.

On Columbus’ 4th voyage to the Caribbean he was stranded on Jamaica.  For a while the natives of the island fed Columbus and his men.  However due to the thievery of some of his crew, these people no longer trusted Columbus any refused them any more supplies.  Columbus consulted a table of eclipses and found that a lunar eclipse was to occur on February 29th that year (1504), and that at his location the moon would rise in eclipse.  He went to the leader of the people and said that they had displeased their god by refusing his crew food, and that the god would turn the Moon red in anger.  It worked.  As Arthur C. Clarke once wrote: “Any sufficiently advanced technology is indistinguishable from magic.”

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.


February 29, 1504 Lunar Eclipse

The moon rising from Jamaica February 29, 1504 as shown by Stellarium with some additional shadow darkening by myself.

Tomorrow I’ll look at what Columbus got wrong… Beside being lost.

I note for the record that Stellarium calendar dating includes what I call the Gregorian discontinuity.  It drops the 10 days between October 4, 1582 and October 15th, which was the adjustment the Gregorian calendar makes to move ahead the actual vernal equinox from March 11 to the 21st.  Christian churches always  use the tabular value of March 21 as the vernal equinox for the calculation of the date of Easter.  The old Julian calendar let that slip back about 3/4 of a day every century.

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