On 12 April 1961 at 9:07 AM Moscow time, the USSR launched Vostok 1 on a single orbit flight with cosmonaut Yuri Gagarin aboard, the first human in space. The fiftieth anniversary of the event is being celebrated at hundreds of parties around the world, see http://yurisnight.net for more information.

See also http://L5Development.com/i_resource/history/DayInHistory.php?d=0412