Today marks the 51st anniversary of manned space travel, and if you happen to be in a former Soviet country, you may be celebrating Cosmonautics Day. On April 12, 1961, 27-year-old Russian cosmonaut Yuri Gagarin was the first human in space, orbiting the Earth for nearly two hours. The USSR beat the US in the space race by just three weeks, and two years later, Russia would send the first woman to space. Flickr user (and new father, congrats!) AlphaTangoBravo snapped this picture of a Russian Cosmonauts poster he picked up in Moscow. You can celebrate the anniversary of space travel, or Yuri’s Night, at parties around the world.