Ivars Peterson

Columbus had observed a lunar eclipse on an earlier voyage and had noticed discrepancies between the predictions made by Zacuto and those contained in the Ephemerides. Moreover, he had no reliable way of determining the correct local time of this particular projected eclipse. The times provided by Regiomontanus for its start and end were for Nuremberg, Germany.

Despite these uncertainties, Columbus was desperate enough to take a chance. On the day before the predicted eclipse, he summoned the leaders of the native inhabitants and warned them through an interpreter that if they did not cooperate with him, the moon would disappear from the sky on the following night.

The natives for the most part were unimpressed; some even laughed. Columbus nervously awaited the outcome of his gamble. Could he rely on tables that had been compiled several decades earlier and that predicted the positions of celestial bodies only for the years between 1475 and 1506? How large were the errors?

Amazingly, the prediction proved correct. As the full moon rose in the east on the appointed night, Earth's shadow was already biting into its face. As the moon rose higher, the shadow became larger and more distinct until it completely obscured the moon, leaving nothing but a faint red disk in the sky.

The natives were sufficiently frightened by this unexpected occurrence and by Columbus's uncanny prediction to beg forgiveness and appeal to him to restore their moon to the sky. Columbus responded that he wished to consult with his deity. He retired to his quarters, using a half-hour sandglass to time how long the eclipse would last. Some time later, when the eclipse had reached totality, he emerged to announce that the moon, in answer to his prayers, would gradually return to its normal brightness.