July – Danish astronomerLongomontanus arrives in Prague, where he works with the Moon orbital theory; he brings the rest of Tycho's astronomical instruments with him.
First recorded use of the word Naturalist in its modern English sense, in Christopher Sutton's Disce Mori.
Earth sciences
February 19 – The PeruvianvolcanoHuaynaputina erupts catastrophically. This is the largest known volcanic explosion in South America and triggers severe global climatic events including the Russian famine of 1601–1603.