The full Moon has an especially close companion tonight: Spica, the brightest star of Virgo. From the eastern half of the country, they’ll appear to almost touch each other as night falls. They’ll be a bit farther apart for those in the west, but still close.

A dozen American astronauts walked on the Moon, with the final steps coming half a century ago. Their missions are among those commemorated today – the International Day of Human Spaceflight. The day was established by the United Nations, in 2011, to “celebrate the beginning of the space era for all mankind.”

That era began on this date in 1961, when the Soviet Union launched the first human into space. Yuri Gagarin made one orbit around Earth aboard Vostok 1, then parachuted to the ground after re-entering the atmosphere. Exactly 20 years later, the United States launched the first space shuttle. The U.N. General Assembly named those missions, along with the first Moon landing, as motivation for the Day of Human Spaceflight.

The first celebration of the date came in 2001. A private group created “Yuri’s Night,” which continues today. It combines science and engineering with music, art, and other activities.

Space centers, museums, planetariums, and other venues host events to celebrate the date. If you can’t make it, though, celebrate on your own by watching the Moon – the site of the first human steps beyond our own planet.

Script by Damond Benningfield