|Covid-19|Giovanni Battista Zupi observes that the planet Mercury has orbital phases.
December 4 (November 24 in Julian calendar) – English astronomers Jeremiah Horrocks and William Crabtree are the first and only scientific observers of a transit of Venus, predicted by Horrocks.
The Casiquiare canal, a river forming a natural canal between the Amazon River and Orinoco River basins, is first encountered by Europeans
Girard Desargues introduces the concept of infinity into geometry.
April 12 – Martin Lister, English naturalist and physician (died 1712)
December 18 – Gottfried Kirch, German astronomer (died 1710)
approx. date – Daniel Greysolon, Sieur du Lhut, French explorer (died 1710)
June 6 – Peter Crüger, German polymath (born 1580)
August 7 – Martin van den Hove, Dutch astronomer (born 1605)
Mutio Oddi, Italian mathematician (born 1569)
1639 in science Wikipedia
The year 1639 in science and technology involved some significant events.