1609 in science

The year 1609 in science and technology involved some significant events.

Astronomy

 * July 26 – English scientist Thomas Harriot becomes the first to draw an astronomical object after viewing it through a telescope: he draws a map of the Moon, preceding Galileo by several months.
 * Johannes Kepler publishes Astronomia nova, containing his first two laws of planetary motion.

Biology

 * Charles Butler publishes The Feminine Monarchie, or, A Treatise Concerning Bees.

Exploration

 * April 4 – Henry Hudson sets out from Amsterdam in the Halve Maen.
 * August 28 – Hudson finds Delaware Bay.
 * September 11–12 – Hudson sails into Upper New York Bay and begins a journey up the Hudson River.

Medicine

 * Louise Bourgeois Boursier publishes Diverse Observations on Sterility; Loss of the Ovum after Fecundation, Fecundity and Childbirth; Diseases of Women and of Newborn Infants in Paris, the first book on obstetrics written by a woman.
 * Jacques Guillemeau publishes De l'heureux accouchement des femmes in which he describes a method of assisted breech delivery.

Technology

 * Cornelius Drebbel invents the thermostat.

Births

 * June 29 – Pierre Paul Riquet, French engineer and canal builder (died 1680)
 * October 8 – John Clarke, English physician (died 1676)

Deaths

 * March 26 – John Dee, English alchemist, astrologer and mathematician (born 1527)
 * April 4 – Carolus Clusius, Flemish botanist (born 1525)
 * August 4 - Joseph Duchesne, French physician and alchemist (born c.1544).
 * August 16 : André du Laurens, French physician and gerontologist (born 1558).
 * December – Oswald Croll, German iatrochemist (born c. 1563)