1609 – Galileo Galilei demonstrates his first telescope to Venetian lawmakers.
1894 – Shibasaburo Kitasato discovers the infectious agent of the bubonic plague and publishes his findings in The Lancet.
1981 – Voyager 2 spacecraft makes its closest approach to Saturn
1989 – Voyager 2 spacecraft makes its closest approach to Neptune, at the time the outermost planet in the Solar System.
1561 – Philippe van Lansberge, Dutch astronomer
1841 – Emil Theodor Kocher, Swiss medical researcher; Nobel Prize laureate
1900 – Hans Adolf Krebs, German physician and biochemist; Nobel Prize laureate
1903 – Árpád Élő, Hungarian physicist
1916 – Frederick Chapman Robbins, American pediatrician and virologist; Nobel Prize laureate
1928 – Herbert Kroemer, German-born physicist, Nobel Prize laureate
1822 – William Herschel, German-born astronomer
1867 – Michael Faraday, English scientist
1908 – Henri Becquerel, French physicist, Nobel laureate
1956 – Alfred Kinsey, American zoologist and sexologist