Learn about the history of science by reading about the significant scientific events that took place on this day in history.
1971 - Mariner 9 spacecraft becomes first to orbit another planet.
NASA's Mariner 9 spacecraft entered orbit around Mars to become the first spacecraft to orbit another planet. Mariner 9 was designed to study the Martian atmosphere and send back mapping images of the surface. By the time it was shut down, it returned 7329 photographs showing massive extinct volcanoes, a 3000 mile long canyon and channels that suggest water used to flow on the surface.
1946 - First artificial snow is produced.Vincent Schaefer produced the first artificial snow in the Berkshire Mountains of New England by the his method of cloud seeding. He spread dry ice, solid carbon dioxide, using an airplane over natural clouds to produce the snow.
1893 - Edward Adelbert Doisy was born.
Doisy was an American biochemist who was awarded half the 1943 Nobel Prize in Medicine for the discovery of the chemistry of vitamin K. Vitamin K was discovered by Henrik Dam, who received the other half the the Nobel Prize, and Doisy isolated two different forms of the vitamin, determined their structures and synthesized them. Vitamin K is used in surgery and medicine to promote blood clotting. Doisy also isolated the sex hormones estrone, estriol, and estradiol.