August 31

1797 - Astronomer James Ferguson is born. He discovered the first previously unknown asteroid to be detected, from North America at the US Naval Observatory. (This asteroid is now known as "31 Euphrosyne".)
1916 - Astronomer Robert Hanbury Brown is born. Known for his work in radar and observational astronomy, Brown developed radar for uses in aerial combat during and after WWII, later applying the same to radio astronomy.
1939 - Nazi Germany mounts a "false flag" attack on the Gleiwitz radio station, creating an excuse to attack Poland the following day, thus starting World War II in Europe.
1955 - The first solar-powered car was publicly demonstrated at General Motors' "Powerama" exhibit in Chicago.