In late February and early March of 1524 there occurred in Aquarius-Pisces an impressive massing of all five planets normally visible to the naked eye. This was the densest such gathering in centuries. In both China and the West such phenomena had long loomed large because of their astrological association with world-changing events on the grandest scale. Events in 1524 in China and Europe in response to the phenomenon provide insight into the widely divergent Chinese and Western responses to such “millennial” events. The following discussion contrasts the astrological background and contemporary impact of this signal event in late Ming China and Reformation Europe.